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Träfflista för sökning "WFRF:(Andersson Sören 1957 ) "

Sökning: WFRF:(Andersson Sören 1957 )

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1.
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2.
  • af Edholm, Karolina, et al. (författare)
  • Clinical Reasoning : Leg weakness and stiffness at the emergency room
  • 2019
  • Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 92:6, s. E622-E625
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • A 48-year-old woman from the Maghreb came to the emergency department with insidious gait difficulties, urgency, and constipation starting 6 months prior to the visit. The patient's complaints consisted of weakness, stiffness, and pain in her legs. Her medical history consisted of Hashimoto thyroiditis and breast cancer, with the latter having motivated surgery 4 months prior to admission. Histopathologic examination had demonstrated ductal cancer sensitive to estrogen and mapping with sentinel node biopsy ruled out metastasis. For that reason, the patient was treated with local radiation given weekly over 1 month and treatment with tamoxifen was started. Physical examination upon admission demonstrated weakness and spasticity in both legs. Reflexes were brisk; bilateral nonsustained foot clonus and Babinski sign were also present. Bilateral dorsal flexion was reduced, but vibration and sensation to touch and pinprick were normal. Sphincter tonus was reduced; systemic manifestations such as myalgias, fever, skin rashes, uveitis, sicca, and arthritic joints were absent.
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3.
  • Andersson, Sören, 1957-, et al. (författare)
  • CHIMERIC MOMP ANTIGEN
  • 2015
  • Patent (populärvet., debatt m.m.)
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4.
  • Andersson, Sören, 1957-, et al. (författare)
  • Chimeric MOMP antigen
  • 2014
  • Patent (populärvet., debatt m.m.)abstract
    • The present invention regards polypeptides capable of eliciting an immunological response that is protective against Chlamydia trachomatis. The polypeptide comprises a first amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 1 and a second amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 2. Furthermore, production of these polypeptides and pharmaceutical compositions comprising them are also provided.
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5.
  • Asghar, Naveed, 1983-, et al. (författare)
  • Transient Expression of Flavivirus Structural Proteins in Nicotiana benthamiana 
  • 2022
  • Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:10
  • Tidskriftsartikel (refereegranskat)abstract
    • Flaviviruses are a threat to public health and can cause major disease outbreaks. Tick-borne encephalitis (TBE) is caused by a flavivirus, and it is one of the most important causes of viral encephalitis in Europe and is on the rise in Sweden. As there is no antiviral treatment availa-ble, vaccination remains the best protective measure against TBE. Currently available TBE vaccines are based on formalin-inactivated virus produced in cell culture. These vaccines must be delivered by intramuscular injection, have a burdensome immunization schedule, and may exhibit vaccine failure in certain populations. This project aimed to develop an edible TBE vaccine to trigger a stronger immune response through oral delivery of viral antigens to mucosal surfaces. We demonstrated successful expression and post-translational processing of flavivirus structural pro-teins which then self-assembled to form virus-like particles in Nicotiana benthamiana. We performed oral toxicity tests in mice using various plant species as potential bioreactors and evaluated the immunogenicity of the resulting edible vaccine candidate. Mice immunized with the edible vaccine candidate did not survive challenge with TBE virus. Interestingly, immunization of female mice with a commercial TBE vaccine can protect their offspring against TBE virus infection. 
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6.
  • Bringsén, Åsa, 1970-, et al. (författare)
  • Success factors for visual artists functioning as health promoters at a workplace : results from a Swedish case study
  • 2009
  • Konferensbidrag (refereegranskat)abstract
    • IntroductionThe interest in relations between arts and workplace related health has increased. The focus has mostly been on the work of arts and health from a disease perspective and to the best of our knowledge the research focusing on relation between the artists and workplace related health from a salutogenic perspective is rare. In 2007 a project called the Contemporary Artists in Contemporary Society (CACS) Scania project was implemented and evaluated. The project consisted of twelve visual artists being positioned at eight workplaces on half time for a period of six months. The idea of the project was that unprejudiced meetings between the artists and the staff could result in workplace related health promoting processes. This study will try to unravel some of the mystery of how artists’ presence can result in workplace related promotion of health.  AimThe aim was to identify success factors for visual artists functioning as health promoters at a workplace. ProcedureThe search for success criterion started with going through the project descriptions and the evaluation reports from the CACS Scania project. This exposition led to the selection of one project that was considered a particularly successful case. Two artists had been placed at the office for management of regional development in Scania. The employees consisted mainly of civil servants and administrators. The evaluation material belonging to this particular project was studied, searching for possible explanations to the success of the project. The material consisted of digital recordings from a focus group interview with five of the participating staff, an interview with the manager, an interview with the two artists as well as stories written by the two artists throughout the project and finally the project description as well as the folder that the two artists produced as a summary of the project. The analysis of the material was influenced by qualitative content analysis and three categories of success factors were found. ResultsThe experience of the participating staffThe result showed that the staff mainly had had positive project related experiences. The staffs’ experiences could be linked to the salutogenic factors comprehensibility, manageability and meaningfulness. The various project related activities were found to be meaningful and the different activities were considered a pleasant reflective break from an everyday routine based and hectic practice. Some of the staff reported having problems managing the openness and indistinctiveness of the project, but the frequent communication with the artists, as well as support from the manager made the indistinctiveness manageable. The presence of the artists and the different project related activities were often found to be amusing, with adherent facilitation of wellbeing among the staff. At other occasions the presence of the artists could be considered disturbing. The artists brought new perspectives into the workplace that sometimes challenged the staffs’ customary way of thinking and acting, opening up possibilities for creativity and reflective processes of work related learning. It seemed as if the positive health related experiences of the staff relied on communication and mutual construction of intellectual fellowship and project related meaning (intersubjectivity). A framework for the work of the artistsFour criteria were considered a useful framework for a description of the artists successful work at the workplace. 1. Presence - The artists were often present at the workplace. 2. Inspiration – The artists were inspired by the workplace. 3. Activity - The artists were constantly presenting things and activated the staff through out the project 4. Communication – The artists communicated with the staff during the development, implementation and completion process of the project. Organisational climateIt seemed as if the organisational climate was suitable for using artists as health promoters. The staff and the manager were for instance describing them as willing to try new and innovative strategies for the development of their work in general and their work related health in particular. ConclusionTo conclude there is a health promoting potential when involving artists as health promoters at a workplace. For this potential to be realised we found three categories of success factors. The experience of the participating staff were considered important since positive experiences, with adherent positive feelings, form the base for psychological and biological processes that generally have a positive impact on health. These experiences are on the other hand dependent on other facilitating factors, that here can be linked to for instance the artists as well as the organisational climate. 
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7.
  • Du, Juan, et al. (författare)
  • Prevalence of Oral Human Papillomavirus Infection among Youth, Sweden
  • 2012
  • Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention. - 1080-6040 .- 1080-6059. ; 18:9, s. 1468-1471
  • Tidskriftsartikel (refereegranskat)abstract
    • Human papillomavirus (HPV) causes cervical, head, and neck cancers. We studied 483 patients at a youth clinic in Stockholm, Sweden, and found oral HPV prevalence was 9.3% and significantly higher for female youth with than without cervical HPV infection (p = 0.043). Most oral HPV types matched the co-occurring cervical types.
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8.
  • Ejaz, Muslima, et al. (författare)
  • Anal human papillomavirus infection among men who have sex with men and transgender women living with and without HIV in Pakistan : findings from a cross-sectional study
  • 2021
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 11:11
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: The aim of this study was to determine the prevalence of infection, genotypes and risk factors for human papillomavirus (HPV) among men who have sex with men (MSM) and transgender women living with and without HIV in Pakistan. Anal infection with HPV is very common worldwide among MSM, particularly among MSM living with HIV. The high prevalence of HIV among MSM and male-to-female transgendered individuals in Pakistan is a significant health concern since access to screening and health-seeking is often delayed in this stigmatised key population.DESIGN: This cross-sectional study was conducted between March 2016 and November 2017.PARTICIPANTS, SETTING AND DATA COLLECTION: This study recruited MSM and transgender-women who self-reported to have had anal sex in the last 6 months, and were at least 18 years of age, from the sexual health and antiretroviral therapy centres. Structured questionnaires were administered, and blood samples were obtained to confirm HIV status. Anal swabs were collected for HPV-DNA detection and typing.MAIN OUTCOME MEASURES: The primary outcome was the prevalence of 'HPV-DNA infection'. The prevalence ratios (PR) were calculated using Cox proportional hazard model algorithms to analyse the association between exposure variables and HPV-infection.RESULTS: Complete data were available for 298 MSM and transgender women (HIV +n=131; HIV-n=167). The overall HPV-DNA prevalence was 65.1% and was higher in participants living with HIV as compared with HIV-negative (87% vs 48%; χ2p≤0.001). Likewise, 28.9% of participants living with HIV were infected with two or more than two types of HPV as compared with 18.8% participants without HIV(χ2 p≤0.001). The most frequent HPV type was HPV6/11 (46.9%), followed by HPV16 (35.1%), HPV18 (23.2%) and HPV35 (21.1%). HIV status (PR 2.81, 95% CI 2.16 to 3.82) and never condom use (PR 3.08, 95% CI 1.69 to 5.60)) were independently associated with prevalence of 'anal-HPV16 infection' when adjusting for confounding for age, other sexual and behavioural factors, for example, smoking and alcohol consumption.CONCLUSION: High prevalence of HPV indicates a substantial future risk of anal cancer in Pakistani MSM and transgender women, and particularly in those living with HIV. Current findings support anal Pap-smear HPV screening for this particular group and vaccination efforts for future generations.
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9.
  • Ejaz, Muslima, et al. (författare)
  • Human papillomavirus-associated anal squamous intraepithelial lesions in men who have sex with men and transgender women living with and without HIV in Karachi Pakistan : implications for screening and prevention
  • 2021
  • Ingår i: BMC Infectious Diseases. - : BioMed Central. - 1471-2334. ; 21:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Anal squamous intraepithelial lesions (ASIL), strongly related to human papilloma virus (HPV) infection, is more prevalent among men who have sex with men (MSM). However, no such data are available for Pakistan yet, and neither HPV vaccination nor anal-cytology screening is implemented in Pakistan. The purpose of this first ever study was to assess the prevalence of HPV-related anal cytological abnormalities among MSM and transgender women living with and without HIV infection in Pakistan.METHODS: We conducted a cross-sectional study from March 2016 to November 2017 at sexual health centers run by the Perwaaz Trust and the National AIDS Control Program in Karachi. The study enrolled MSM and transgender women aged greater-than-and-equal-to-18-years who reported anal sex in the preceding 6 months. We collected two anal samples for liquid-based cytology and HPV type testing by PCR, and socio-demographic and behavioral data were collected through face-to face interviews. ASIL and its associations with biological and behavioral risk factors were analyzed through Cox regression for prevalence ratios (PR) and corresponding 95% confidence intervals (CIs).RESULTS: Out of 271 qualifying participants, 79% were MSM and 21% transgender women. The mean age was 28.8 (± 8) years. Almost 35% (93/271) of the study population had ASIL detected, ASIL was significantly more common among participants living with HIV than in HIV negative ((50/118) 42.4%; vs. (43/153) 28.1%) (p ≤ 0.001). Among ASIL, 66% (61/93) had low-grade squamous intraepithelial lesions (LSIL), and 3.6% (3/93) had high-grade squamous intraepithelial lesions (HSIL). The overall, HPV16 positivity was 35.5% (33/93) among all abnormal anal lesions and all 3 HSIL were HPV16 positive, however, HPV16 positivity could show its association with ASIL detection in univariate model only (PRcrude: 2.11(1.39-3.18)). Moreover, any HR-HPV type (PR 3.04; 95% CI 1.75-5.26), concurrent sexually transmitted infection (STI) (2.13; (1.28-3.55)) and HIV + /HPV + coinfection (1.75; (1.07-2.88)) remained independently associated with ASIL in the multivariate model.CONCLUSIONS: Abnormal anal cytology among MSM and transgender is prevalent enough to consider optimal screening regimens. Further studies are required to see if periodic anal cytology can be made part of HIV care and treatment programs among MSM in Pakistan.
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10.
  • Eliasson, Henrik, et al. (författare)
  • Kinetics of the immune response associated with tularemia : comparison of an enzyme-linked immunosorbent assay, a tube agglutination test, and a novel whole-blood lymphocyte stimulation test
  • 2008
  • Ingår i: Clinical and Vaccine Immunology. - 1556-6811 .- 1556-679X. ; 15:8, s. 1238-1243
  • Tidskriftsartikel (refereegranskat)abstract
    • We have developed and evaluated a novel and simplified whole-blood lymphocyte stimulation assay that focuses on the measurement of gamma interferon after 24 h of stimulation with whole-cell tularemia antigen and a tularemia enzyme-linked immunosorbent assay (ELISA) based on highly purified lipopolysaccharide antigen. Comparison of the kinetics of the two assays and those of the traditional tube agglutination test shows that the cellular immune response can be detected earlier by the lymphocyte stimulation assay. This test already shows a high proportion of positive results during the first week after the onset of the disease, may be applicable in everyday laboratory practice, and has the potential of changing routine diagnostics for tularemia. The new ELISA has a high sensitivity and becomes positive to a high degree during the second week of disease. 
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11.
  • Esbjörnsson, Joakim, et al. (författare)
  • Long-term follow-up of HIV-2-related AIDS and mortality in Guinea-Bissau : a prospective open cohort study
  • 2019
  • Ingår i: The Lancet HIV. - : The Lancet Publishing Group. - 2405-4704 .- 2352-3018. ; 6:1, s. E25-E31
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: HIV type 2 (HIV-2) is considered more benign and has fewer pathogenic consequences than HIV type 1 (HIV-1) for most infected individuals. However, reliable estimates of time to AIDS and mortality among those with HIV-2 infection are absent. We therefore aimed to compare the time to AIDS and mortality, and the CD4 T-cell dynamics between those infected with HIV-1 and HIV-2.METHODS: We did a prospective open cohort study. We included all police officers with regular employment from police stations in both urban and rural areas of Guinea-Bissau since Feb 6, 1990. We continued to include participants until Sept 28, 2009, and follow-up of HIV-1-positive and HIV-2-positive individuals continued until Sept 28, 2013. We collected blood samples at enrolment and at scheduled annual follow-up visits at police stations. We analysed longitudinal data from individuals infected with HIV-1 and HIV-2 according to time to AIDS, time to death, and T-cell dynamics. Time of HIV infection was estimated as the mid-timepoint between last HIV-seronegative and first HIV-seropositive sample. Data from an additional 2984 HIV-uninfected individuals from the same population were analysed to assess the effect of natural mortality on HIV-related mortality.FINDINGS: 872 participants tested HIV positive during the 23-year study period: 408 were infected with HIV-1 (183 infected before and 225 infected after enrolment) and 464 were infected with HIV-2 (377 before and 87 after enrolment). The median time from HIV infection to development of AIDS was 6·2 years (95% CI 5·4-7·1) for HIV-1 infection and 14·3 years (10·7-18·0) for HIV-2 infection (p<0·0001). The median survival time after HIV infection was 8·2 years (95% CI 7·5-8·9) for HIV-1 infection and 15·6 years (12·0-19·2) for HIV-2 infection (p<0·0001). Individuals who were infected with HIV-1 or HIV-2 before enrolment showed similar results. Comparison with uninfected individuals indicated limited confounding contribution from natural mortality. Mean CD4 percentages were higher in individuals with HIV-2 than in those with HIV-1 during early infection (28·0% [SE 1·3] vs 22·3% [1·7]; p=0·00094) and declined at a slower rate (0·4% [0·2] vs 0·9% [0·2] per year; p=0·028). HIV-2-infected individuals developed clinical AIDS at higher mean CD4 percentages (18·2%, IQR 7·2-25·4) than HIV-1-infected individuals (8·2%, 3·0-13·8; p<0·0001).INTERPRETATION: Our results show that both HIV-1-infected and HIV-2-infected individuals have a high probability of developing and dying from AIDS without antiretroviral treatment.
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12.
  • Hadad, Ronza, 1984-, et al. (författare)
  • Protection against genital tract Chlamydia trachomatis infection following intranasal immunization with a novel recombinant MOMP VS2/4 antigen
  • 2016
  • Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Hoboken, USA : Wiley-Blackwell. - 0903-4641 .- 1600-0463. ; 124, s. 1078-1086
  • Tidskriftsartikel (refereegranskat)abstract
    • The asymptomatic nature of most Chlamydia trachomatis infections and the lack of appropriate effects by current prevention and management call for vaccine development. We evaluated a recombinant subunit vaccine candidate based on the major outer membrane protein variable segments 2 and 4 (MOMP VS2/4). To achieve maximal immunogenicity and ease of production and purification, MOMP VS2/4 was constructed by using highly immunogenic sequences of MOMP only, thereby minimizing the presence of hydrophobic regions, and spacing the immunogenic epitopes with a flexible amino acid sequence. A purification tag was also added. The MOMP VS2/4 was given intranasally, with or without intravaginal boost, with cholera toxin (CT) adjuvant to C57BL/6 mice, which were screened for immunogenicity and protection against a live challenge infection with C. trachomatis serovar D. Bacterial shedding, cell-mediated responses, and antibody responses were monitored. Immunized mice exhibited significantly less bacterial shedding and were better protected against infertility as compared to unimmunized control mice. Immunizations stimulated both systemic and local specific antibody (IgG1, IgG2c, and IgA) responses, and primed T cells that produced interferon-c and interleukins 13 and 17 upon challenge with recall antigen. Thus, MOMP VS2/4, in combination with CT adjuvant, stimulated Th1, Th2, and Th17 effector cells, and generated protective immunity associated with less pathology. We regard MOMP VS2/4 as a promising candidate for further development into a mucosal chlamydial vaccine.
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13.
  • Hansson, Charlotta, et al. (författare)
  • Feeding transgenic plants that express a tolerogenic fusion protein effectively protects against arthritis
  • 2016
  • Ingår i: Plant Biotechnology Journal. - : Wiley-Blackwell. - 1467-7644 .- 1467-7652. ; 14:4, s. 1106-1115
  • Tidskriftsartikel (refereegranskat)abstract
    • Although much explored, oral tolerance for treatment of autoimmune diseases still awaits the establishment of novel and effective vectors. We investigated if the tolerogenic CTA1(R7K)-COL-DD fusion protein can be expressed in edible plants and in this way induce oral tolerance and protect against arthritis. The fusion protein was recombinantly expressed in Arabidopsis thaliana plants, which were fed to H-2q restricted DBA/1 mice to assess the preventive effect on collagen-induced arthritis (CIA). The treatment resulted in fewer mice exhibiting disease and arthritis scores were significantly reduced. Immune suppression was evident in treated mice and serum biomarkers for inflammation as well as anti-collagen IgG responses were reduced. In spleen draining and lymph nodes, CD4+ T cell responses were reduced. Concomitant with a reduced effector T cell activity with lower IFNg, IL-13 and IL-17A production we observed an increase in IL-10 production to recall antigen stimulation in vitro, suggesting reduced Th1, Th2 and Th17 activity subsequent to upregulated IL-10 and regulatory T cell (Treg) functions. The present study shows that edible plants expressing a tolerogen were effective at stimulating CD4 T cell tolerance and in protecting against CIA disease. Our study conveys optimism as to the potential of using edible plants for oral treatment of rheumatoid arthritis.
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14.
  • Holmbom, Martin, 1984-, et al. (författare)
  • Prehospital delay is an important risk factor for mortality in community-acquired bloodstream infection (CA-BSI) : a matched case–control study
  • 2021
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 11:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives The aim of this study was to identify prehospital and early hospital risk factors associated with 30-day mortality in patients with blood culture-confirmed community-acquired bloodstream infection (CA-BSI) in Sweden.Methods A retrospective case–control study of 1624 patients with CA-BSI (2015–2016), 195 non-survivors satisfying the inclusion criteria were matched 1:1 with 195 survivors for age, gender and microorganism. All forms of contact with a healthcare provider for symptoms of infection within 7 days prior CA-BSI episode were registered. Logistic regression was used to analyse risk factors for 30-day all-cause mortality.Results Of the 390 patients, 61% (115 non-survivors and 121 survivors) sought prehospital contact. The median time from first prehospital contact till hospital admission was 13 hours (6–52) for non-survivors and 7 hours (3–24) for survivors (p&lt;0.01). Several risk factors for 30-day all-cause mortality were identified: prehospital delay OR=1.26 (95% CI: 1.07 to 1.47), p&lt;0.01; severity of illness (Sequential Organ Failure Assessment score) OR=1.60 (95% CI: 1.40 to 1.83), p&lt;0.01; comorbidity score (updated Charlson Index) OR=1.13 (95% CI: 1.05 to 1.22), p&lt;0.01 and inadequate empirical antimicrobial therapy OR=3.92 (95% CI: 1.64 to 9.33), p&lt;0.01. In a multivariable model, prehospital delay &gt;24 hours from first contact remained an important risk factor for 30-day all-cause mortality due to CA-BSI OR=6.17 (95% CI: 2.19 to 17.38), p&lt;0.01.Conclusion Prehospital delay and inappropriate empirical antibiotic therapy were found to be important risk factors for 30-day all-cause mortality associated with CA-BSI. Increased awareness and earlier detection of BSI in prehospital and early hospital care is critical for rapid initiation of adequate management and antibiotic treatment.All data relevant to the study are included in the article or uploaded as supplemental information.
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15.
  • Kalbina, Irina, 1961-, et al. (författare)
  • Arabidopsis thaliana plants expressing Rift Valley fever virus antigens : Mice exhibit systemic immune responses as the result of oraladministration of the transgenic plants
  • 2016
  • Ingår i: Protein Expression and Purification. - San Diego, USA : Elsevier. - 1046-5928 .- 1096-0279. ; 127, s. 61-67
  • Tidskriftsartikel (refereegranskat)abstract
    • The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula.The economic impact of this pathogen due to livestock losses, as well as its relevance to public health,underscores the importance of developing effective and easily distributed vaccines. Vaccines that can bedelivered orally are of particular interest.Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virusantigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein.Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Westernblotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicityin mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportionof the mice elicited specific IgG antibody responses, as compared to the control animals that were fedwild-type plants and of which none sero-converted.Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virusproteins, and that the plants are immunogenic when given orally to mice. These are promising findingsand provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus.
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16.
  • Kalbina, Irina, 1961-, et al. (författare)
  • Expression of chimeric Chlamydia trachomatis MOMP protein antigen in Arabidopsis thaliana and Daucus carota
  • 2011
  • Ingår i: Molecular farming. - Bryssel : COST. ; , s. 38-38
  • Konferensbidrag (refereegranskat)abstract
    • Urogenital chlamydial infection, caused by Chlamydia trachomatis, is the main sexually transmitted infection in Sweden. Despite active programmes for detection and case finding, nearly 37 000 cases were reported in 2010. Serovar E strains are considered to cause approximately 40-50% of these cases. A vaccine would be highly valuable in order to control the epidemic.The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in transgenic plants failed. A chimeric gene construct of Chlamydia trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP.The designed construct was successfully expressed in Arabidopsis thaliana, and in Daucus carota. A chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in the transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP– up to 3% of TSP.
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17.
  • Kumakech, Edward, 1977-, et al. (författare)
  • Cervical cancer risk perceptions, sexual risk behaviors and sexually transmitted infections among Bivalent Human Papillomavirus vaccinated and non-vaccinated young women in Uganda-5 year follow up study
  • 2017
  • Ingår i: BMC Women's Health. - : BioMed Central. - 1472-6874. ; 17
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Previous studies were conflicting regarding the associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors and STIs. This study compared the HPV-vaccinated and non-vaccinated young women in Uganda regarding cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections 5 years after vaccine implementation.Methods: This was a population-based comparative cross-sectional survey conducted in Uganda. The 438 participants were sexually active young women aged 15-24 years and mean age was 18.6 (SD 1.4). The majority (53.0%) were HPV-vaccinated in 2008 without assessment of sexual activity prior to HPV vaccination. Upon verbal assessment of sexual activity at the time of follow-up, data were collected using a questionnaire and laboratory testing of blood samples for syphilis and HIV infections.Results: There were no significant differences between the HPV-vaccinated and non-vaccinated groups regarding the prevalence of high-risk sexual behaviors, syphilis and HIV infections. Cervical cancer risk perceptions and age at sexual debut were nonetheless significantly lower among the vaccinated group compared to their non-vaccinated counterparts. However, HPV vaccination was not significantly associated to cervical cancer risk perceptions and early age at sexual debut in multivariate logistic regression analysis.Conclusions: We found no associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections among young women in Uganda 5 years after vaccine implementation. Young girls in the study population were found to be sexually active at a young age, affirming the importance of targeting girls of younger age for HPV vaccination.
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18.
  • Kumakech, Edward, 1977-, et al. (författare)
  • Integration of HIV and cervical cancer screening perceptions of healthcare providers and policy makers in Uganda
  • 2014
  • Ingår i: BMC Public Health. - : BioMed Central. - 1471-2458. ; 14
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: HIV-positive women have an increased risk of developing cervical cancer (CC) compared to the HIV-negative women. Despite this, HIV and CC screening programs in many developing countries have remained disintegrated. Therefore, the objective of the study was to explore perceptions of healthcare providers (HCP) and policy makers (PM) about integration of HIV and CC screening services in Uganda.Methods: This was a qualitative study conducted among 16 participants comprising of 12 healthcare providers and 4 policy makers in Uganda. Data were collected through individual interviews. Participants were purposively selected from different level of health facilities with clinics for HIV and CC screening services. Content analysis method was used to analyze the data.Results: Three themes emerged from the data, namely appreciating benefits of integration, worrying about the limited health system capacity and potential consequences of integration and feeling optimistic about integration under improved health system conditions. The benefits embraced the women - particularly the HIV-positive women- but also men, healthcare providers and the health system or the government. There were worries that HIV stigma and shortage of healthcare workers would affect the effective delivery of the integrated program.Conclusion: Integration of HIV and CC screening can offer manifold benefits to all stakeholders in the health system, more so to the women. However, its feasibility in developing countries such as Uganda will most likely be hampered by weak and inefficient health systems. Therefore, when considering HIV and CC screening integration, it is important not to only recognize the benefits but also take into account resources requirements for addressing the existing weaknesses and inefficiencies in the health systems such as limited infrastructure, insufficient drugs and supplies, inadequate and poorly motivated healthcare workers.
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19.
  • Kumakech, Edward, 1977-, et al. (författare)
  • Significantly reduced genoprevalence of vaccine-type HPV-16/18 infections among vaccinated compared to non-vaccinated young women 5.5 years after a bivalent HPV-16/18 vaccine (Cervarix®) pilot project in Uganda
  • 2016
  • Ingår i: PLoS ONE. - San Francisco, USA : Public Library of Science (PLoS). - 1932-6203. ; 11:8
  • Tidskriftsartikel (refereegranskat)abstract
    • The objective of this study was to determine the prevalence and some predictors for vaccine and non-vaccine types of HPV infections among bivalent HPV vaccinated and non-vaccinated young women in Uganda. This was a comparative cross sectional study 5.5 years after a bivalent HPV 16/18 vaccination (Cervarix®, GlaxoSmithKline, Belgium) pilot project in western Uganda. Cervical swabs were collected between July 2014-August 2014 and analyzed with a HPV genotyping test, CLART® HPV2 assay (Genomica, Madrid Spain) which is based on PCR followed by microarray for determination of genotype. Blood samples were also tested for HIV and syphilis infections as well as CD4 and CD8 lymphocyte levels. The age range of the participants was 15-24 years and mean age was 18.6(SD 1.4). Vaccine-type HPV-16/18 strains were significantly less prevalent among vaccinated women compared to non-vaccinated women (0.5% vs 5.6%, p 0.006, OR 95% CI 0.08 (0.01-0.64). At type-specific level, significant difference was observed for HPV16 only. Other STIs (HIV/syphilis) were important risk factors for HPV infections including both vaccine types and non-vaccine types. In addition, for non-vaccine HPV types, living in an urban area, having a low BMI, low CD4 count and having had a high number of life time sexual partners were also significant risk factors. Our data concurs with the existing literature from other parts of the world regarding the effectiveness of bivalent HPV-16/18 vaccine in reducing the prevalence of HPV infections particularly vaccine HPV- 16/18 strains among vaccinated women. This study reinforces the recommendation to vaccinate young girls before sexual debut and integrate other STI particularly HIV and syphilis interventions into HPV vaccination packages.
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20.
  • Lillsunde-Larsson, Gabriella, 1971-, et al. (författare)
  • Human Papillomavirus (HPV) and HPV 16-Variant Distribution in Vulvar Squamous Cell Carcinoma in Sweden
  • 2012
  • Ingår i: International Journal of Gynecological Cancer. - 1048-891X .- 1525-1438. ; 22:8, s. 1413-1419
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: To investigate the human papillomavirus (HPV) and HPV type 16-variant distribution in a series of vulvar squamous cell carcinomas (VSCC) and to evaluate the impact of HPV and HPV 16-variant on prognosis.Methods: A series of 133 patients who had a diagnosis of VSCC (1983-2008) was selected for the study. Detection of 11 high-risk HPV types (16, 18, 31, 33, 39, 45, 51, 52, 56, 58, and 59) and 2 low-risk HPV types (6 and 11) was performed with real-time polymerase chain reaction. Samples positive for HPV 16 were further analyzed for variant determination of 7 positions in the E6 gene with polymerase chain reaction and pyrosequencing.Results: Forty (30.8%) of 130 tumors were found to be HPV positive. Human papillomavirus type 16 was found in 31 cases, HPV 18 was found in 2 cases, HPV 33 was found in 5 cases, and HPV 56 and HPV 59 were found in one case each. All but one tumor harboring HPV 16 were of European linage, and the 3 most common variants were E-p (n = 13), E-G350 (n = 7), and E-G131 (n = 5). HPV positivity was associated with the basaloid tumor type and occurred in significantly younger patients. Overall and recurrence-free survival rates were better in HPV-positive cases, but after correction for age and tumor size, HPV status was no longer an independent and significant prognostic factor. The survival rates of the various HPV 16 variants were not significantly different, but there was a trend of worse outcome for the E-G131-variant group.Conclusions: Human papillomavirus positivity of 30.8% is similar to other reports on VSCC. To our knowledge, this first variant determination of HPV 16 in vulvar carcinoma in a Swedish cohort indicated that the variant E-G131 may have an increased oncogenic potential in patients with VSCC.
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21.
  • Lillsunde-Larsson, Gabriella, 1971-, et al. (författare)
  • Prognostic impact of human papilloma virus (HPV) genotyping and HPV-16 subtyping in vaginal carcinoma
  • 2013
  • Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 129:2, s. 406-411
  • Tidskriftsartikel (refereegranskat)abstract
    • ObjectiveThe objectives of this study are to investigate the human papilloma virus (HPV) distribution in vaginal cancer and to evaluate HPV-genotype as well as HPV16-variant impact on prognosis.MethodsSixty-nine patients diagnosed with primary vaginal carcinoma (1975-2002) were included in the study. Detection of twelve high-risk HPV (hr HPV) and two low-risk HPV (lr HPV) was performed with realtime-PCR. Samples positive for HPV-16 were analyzed for variants in the E6-gene with PCR and pyrosequencing.Results53.6% (37/69) of the tumors were found to be HPV-positive, mostly for HPV-16 (N=26). Other HPV-types were HPV-18 (N=2), HPV-31 (N=2), HPV-33 (N=2), HPV-45 (N=1), HPV-52 (N=2), HPV-56 (N=1) and HPV-58 (N=1). Only European subtypes of HPV-16 were represented and the two most common HPV-16-variants were E-p (N=13) and E-G350 (N=11). Patients with HPV-positive tumors (N=37) had a significantly (log-rank test=3341; p = 0.0008) superior 5-year overall survival rate as well as cancer-specific survival rate and progression-free survival rate (p = 0.0002; p = 0.0004), compared with patients with HPV-negative tumors (N=32). Interestingly, patients with HPV-16-positive tumors had a superior overall survival compared with patients with tumors containing other HPV-genotypes. In a Cox proportional multivariate analysis age, tumor size, and HPV-status were independent and significant prognostic factors with regard to overall survival rate.ConclusionsHPV-status is of prognostic importance in vaginal carcinoma and varies with viral genotype. In this era of HPV-vaccination, genotypes other than those included in the vaccination program could still lead to vaginal carcinoma with unfavorable prognosis.
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22.
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23.
  • Lindh, Ingrid, 1982-, et al. (författare)
  • Oral delivery of plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to high doses
  • 2014
  • Ingår i: Vaccine. - : Elsevier. - 0264-410X .- 1873-2518. ; 32:20, s. 2288-2293
  • Tidskriftsartikel (refereegranskat)abstract
    • During early infection with human immunodeficiency virus type 1 (HIV-1), there is a rapid depletion of CD4+ T-cells in the gut-associated lymphoid tissue (GALT) in the gastrointestinal tract. Therefore, immediate protection at these surfaces is of high priority for the development of an HIV-1 vaccine. Thus, transgenic plants expressing HIV-1 antigens, which are exposed to immune competent cells in the GALT during oral administration, can be interesting as potential vaccine candidates. In the present study, we used two HIV-1 p24 antigen-expressing transgenic plant systems, Arabidopsis thaliana and Daucus carota, in oral immunization experiments. Both transgenic plant systems showed a priming effect in mice and induced humoral immune responses, which could be detected as anti-p24-specific IgG in sera after an intramuscular p24 protein boost. Dose-dependent antigen analyses using transgenic Arabidopsis thaliana indicated that low p24 antigen doses were superior to high p24 antigen doses
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24.
  • Lindh, Ingrid, 1982-, et al. (författare)
  • Oral delivery of transgenic plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to higher doses
  • 2012
  • Ingår i: Retrovirology. - : BioMed Central (BMC). - 1742-4690. ; 9:Suppl. 2
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundThe gut associated lymphoid tissue (GALT) includes around two thirds of the total lymphoid system. CD4+ T-cells in the GALT are a main target for HIV during primary infection. Thus, immunization targetting GALT is likely to be of importance for an effective vaccine strategy. Transgenic plants expressing HIV antigens can reach GALT conveniently. This system allows multiple boosts, has simple logistics (no cold chain, no injections) and large production capacity.MethodsThree groups of mice were given extract from plant lines expressing HIV-1 p24 at (A) low level (20 ng/feeding); (B) high level (460 ng/feeding); (C) control (wild type, 0 ng). No adjuvant was included. The extracts were administered by gastric tube day 0, 14 and 28. On day 55 all mice were given an intramuscular (i.m.) boost with 10 micrograms of purified p24 antigen. Immune responses were determined by measurement of p24-antibodies in serum by ELISA.ResultsThe mice immunized by the low dose plant line (A) showed a higher systemic immune response after i.m. boost compared to the high dose group (B). The w.t. controls (C) had undetectable p24-responses. The responses in group A were 3 to 10 times higher (ELISA OD values) than in group B. Pre-boost antibody responses were at background levels in all groups. Preliminary analyses indicate a predomninant Th1-type response (antigen-specific IgG2a higher than IgG1).ConclusionSimple and inexpensive means of vaccination are important in order to reach large numbers of people with effective vaccine regimens. The HIV-1 p24 low dose transgenic plant extracts given orally showed a superior priming effect in mice compared to the p24 high dose extracts. This could be an immunization method and route worth exploring further.
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25.
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26.
  • Malm, Kerstin, 1960-, et al. (författare)
  • Analytical evaluation of nine serological assays for diagnosis of syphilis
  • 2015
  • Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley-Blackwell. - 0926-9959 .- 1468-3083. ; 29:12, s. 2369-2376
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: The diagnosis of syphilis is most frequently dependent on antibody detection with serological assays. Assays for both treponemal and non-treponemal antibodies are needed to provide a sensitive and specific diagnosis. For decades, a first screening has been done with non-treponemal assays, followed by treponemal. However, in recent years, following laboratory automation, the reverse sequence screening algorithms have been developed, using a treponemal assay as the initial screening test.Objective: To evaluate serological assays for treponemal and non-treponemal antibodies, to use in reverse algorithm screening of syphilis.Material and methods: Six treponemal assays (one IgM-specific assay), two non-treponemal assays and one novel dual point-of-care (POC) assay for serological diagnosis of syphilis were evaluated. Serum samples from Guinea-Bissau and Sweden were examined, as well as two performance panels and samples from blood donors. Sensitivity and specificity were calculated for each assay, using different assays as gold standard test.Results: The Macro-Vue RPR Card test was the most sensitive non-treponemal test and the TrepSure Anti-Treponema EIA Screen and the SeroDia TP-PA were the most sensitive and specific treponemal assays. Among the automated assays, both the Liaison Treponema Screen and Architect Syphilis TP showed high sensitivity, however, the former had clearly higher specificity.Conclusions: In resourced settings, where the reverse sequence algorithm is preferred for screening, an automated treponemal immunoassay for initial screening subsequently followed by the TrepSure test or TP-PA assay as a second treponemal assay appear highly effective. Finally, a quantitative highly sensitive non-treponemal assay, e.g. the Macro-Vue RPR Card test, could then be used as a supplementary test to evaluate activity of the syphilis infection.
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27.
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28.
  • Malm, Kerstin, 1960-, et al. (författare)
  • Evaluation of the Veris MDx (TM) system for quantification of Hepatitis B DNA and Hepatitis C and HIV-1 RNA in a medium sized University Hospital
  • 2016
  • Ingår i: Journal of Clinical Virology. - : Elsevier. - 1386-6532 .- 1873-5967. ; 82, s. S27-S27
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: In the diagnosis and treatment of Hepatitis B (HBV), Hepatitis C (HCV) and HIV, it is crucial to detect and quantify viral nucleic acid. Patients on therapy are monitored continuously to out-rule relapses or reinfections (HCV) while for patients with HIV these tests are important to early on detect potential break-throughs due to resistance development. Quantification methods are today more standardized and fast but still with no opportunity to analyze the samples with full random access. Recently the VERIS MDxTMplatform from Beckman Coulter with this possibility was launched.Objectives: To evaluate a new, random access laboratory instrument for the simultaneous detection and quantification of HBV, HCV and HIV-1.Methods: WHO standards for HBV-DNA, HCV-RNA and HIV-1-RNA provided from the National Institute for Biological Standards and Control (NIBSC) were diluted down to the designated lowest level of detection and analyzed in triplicates on the Veris MDxTM(Beckman Coulter Inc. 250 S. Kraemer Blvd. Brea, CA U.S.A.) instrument. Plasma samples from routine laboratory testing were analyzed and compared to the routine methods used at our hospital or the referral hospital, for HBV; COBAS®AmpliPrep/COBAS® TaqMan®HBV Test, v2.0 (Roche Molecular Diagnostics, 4300 Hacienda Drive, Pleasanton, CA, USA) (Karolinska University Hospital Huddinge), for HCV; COBAS® TaqMan®HCV Test v2.0 for use with the High Pure System (Roche) (Örebro) and for HIV; Aptima HIV-1 Quant Dx Assay (Hologic Inc. 250 Campus Drive Marlborough, MA, USA) (Örebro). 55 samples for HBV, 120 samples for HCV and 60 samples for HIV have been analyzed so far. The absolute majority of samples for HCV and HIV analysis were from patients on treatment. All viral load data were analyzed as log10-transformed values.Results: The Veris MDxTMshowed good compatibility to the designated quantities of the WHO standards (except for HIV-1 where a slight over-quantification could be observed for dilutions in the higher range, i.e. >1000 copies/mL). The limits of detection assigned by the manufacturer could be confirmed. In clinical samples the Veris MDxTM showed similar results to the comparators with a correlation for quantifiable samples of 0.94 (HBV), 0.98 (HCV) and 0.98 (HIV). The Veris MDxTMshowed a slightly higher sensitivity though as DNA/RNA was detected in 4 samples for HBV, 8 for HCV and 7 for HIV when the comparator method did not. The opposite was seen in 0, 0 and 6 samples respectively.Conclusion: The Veris MDxTMfor quantitative analysis of HBV, HCV and HIV nucleic acids showed good correlation to the comparator methods used in this study with a tendency of higher sensitivity for the detection of HBV and HCV. The Instrument provides an easy, fast and flexible method for quantification of RNA and DNA in plasma samples.
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29.
  • Manjate, Alice, 1971-, et al. (författare)
  • Laboratory-based evaluation of the 4th-generation AlereTM HIV Combo rapid point-of-care test
  • 2024
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:2
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Mozambique is a high-prevalence country for HIV and early detection of new HIV infections is crucial for control of the epidemic. We aimed to evaluate the accuracy of the 4th-generation rapid diagnostic test (RDT) AlereTM HIV Combo in detecting acute and seroconverted HIV-infection, among sexually-active women attending three clinical health centers in Maputo, Mozambique.METHODS: Women aged 14-55 years (n = 920) seeking care at the Mavalane Health Area, Maputo (February 2018-January 2019) were included, and blood specimens sampled. Sociodemographic and sexual behavior data were collected. Point-of-care HIV testing was performed using Alere DetermineTM HIV-1/2 and Uni-GoldTM HIV-1/2. All samples were also tested using Enzygnost® HIV Integral 4 and Innotest® HIV Antigen mAb in laboratory. The 4th-generation RDT AlereTM HIV Combo was evaluated on serum samples in the laboratory. Finally, Innotest® HIV Antigen mAb, Enzygnost® HIV Integral 4 (Ag/Ab), and HIV RNA quantification acted as gold standard assays in the evaluation of AlereTM HIV Combo test for HIV antigen detection (in clinical samples and in three HIV-1 seroconversion panels).RESULTS: The antibody component of the 4th generation AlereTM HIV Combo RDT demonstrated a sensitivity and specificity of 100% examining clinical samples. However, the test did not detect HIV p24 antigen in any clinical samples, while Innotest® HIV Antigen mAb, verified by Enzygnost® HIV Integral 4 (Ag/Ab) and/or HIV RNA quantification, detected HIV antigen in six clinical samples. Furthermore, the AlereTM HIV Combo RDT had a low sensitivity in the detection of HIV p24 antigen in seroconversion panels. The HIV prevalence among the examined women was 17.8%.CONCLUSIONS: The 4th-generation RDT AlereTM HIV Combo showed similar sensitivity to the 3rd-generation RDTs to detect seroconverted HIV-infections. However, the sensitivity for detection of HIV p24 antigen and diagnosing acute HIV infections, before seroconversion, was low. There is an urgent need to develop and evaluate simple and affordable POC tests with high sensitivity and specificity for diagnosing individuals with acute HIV infection in resource-limited settings with high HIV prevalence.
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30.
  • Maueia, Cremildo, et al. (författare)
  • Identification of the Human Papillomavirus Genotypes, According to the Human Immunodeficiency Virus Status in a Cohort of Women from Maputo, Mozambique
  • 2021
  • Ingår i: Viruses. - : MDPI. - 1999-4915. ; 14:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Human papillomavirus (HPV) infection is now a well-established cause of cervical cancer and other anogenital cancers. An association between human immunodeficiency virus (HIV) infection and higher HPV incidence and prevalence are commonly reported. This study was conducted to demonstrate HPV prevalence, genotypes and its characteristics, according to the HIV status in women from Maputo in Mozambique.METHODS: A total of 233 participants with ages ranging from fourteen to forty-five were included. Cervical samples were collected, DNA extracted, and HPV genotyping was performed using the HPV Direct Flow CHIP Kit.RESULTS: In total, 177 HIV-negative and 56 HIV-positive women were included in the analysis. The overall HPV prevalence was 63% and was significantly higher among HIV-positive women (79% versus 58% among HIV-negative women; p = 0.005). The prevalence of multiple HPV type infections was 32%. High-risk HPV types 52, 68, 35, 18 and 16 were the most frequent. A higher proportion of HIV-positive women had multiple HPV types compared with HIV-negative women.CONCLUSIONS: This study demonstrated a high prevalence of HPV in the study cohort. HIV-positive women were identified as having the highest HPV prevalence and infection with multiple HPV types across all ages. High-risk genotypes were the most commonly found.
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31.
  • Msafiri, Frank, et al. (författare)
  • Vaccine-Induced Seroreactivity Impacts the Accuracy of HIV Testing Algorithms in Sub-Saharan Africa : An Exploratory Study
  • 2022
  • Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:7
  • Tidskriftsartikel (refereegranskat)abstract
    • The detection of vaccine-induced HIV antibody responses by rapid diagnostic tests (RDTs) may confound the interpretation of HIV testing results. We assessed the impact of vaccine-induced seroreactivity (VISR) on the diagnosis of HIV in sub-Saharan Africa. Samples collected from healthy participants of HIVIS and TaMoVac HIV vaccine trials after the final vaccination were analyzed for VISR using HIV testing algorithms used in Mozambique and Tanzania that employ two sequential RDTs. The samples were also tested for VISR using Enzygnost HIV Integral 4 ELISA and HIV western blot assays. Antibody titers to subtype C gp140 were determined using an in-house enzyme-linked immunosorbent assay (ELISA). The frequency of VISR was 93.4% (128/137) by Enzygnost HIV Integral 4 ELISA, and 66.4% (91/137) by western blot assay (WHO interpretation). The proportion of vaccine recipients that would have been misdiagnosed as HIV-positive in Mozambique was half of that in Tanzania: 26.3% (36/137) and 54.0% (74/137), respectively, p < 0.0001. In conclusion, the HIV RDTs and algorithms assessed here will potentially misclassify a large proportion of the HIV vaccine recipients if no other test is used. Increased efforts are needed to develop differential serological or molecular tools for use at the point of care.
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32.
  • Ninyio, Nathaniel, 1985-, et al. (författare)
  • Development and analysis of prospective anti-HIV probiotic vaccines
  • 2022
  • Ingår i: 19th Smögen Summer Symposium on Virology. - : Virus- och Pandemifonden – Swedish Society for Virology. ; , s. 40-40
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Major improvements have been made in the treatment and prevention of HIV/AIDS. However, a prophylactic vaccine is still unavailable, and several vaccine-candidate trials yielded less than favourable results. Given that the HIV pandemic has not slowed down significantly, there is an urgent need for the development of an effective vaccine. The HIV-1 Gag protein, a key player in HIV particle assembly, is a suitable antigen for use in HIV vaccine development since antibodies targeting HIV-1 Gag will interfere with the replication of the virus. In our vaccine development strategy, it was important for us to develop a candidate for mucosal administration. This is because the mucosal route is the major site for HIV transmission and early viral replication, which is associated with extensive and rapid depletion of CD4+ T-cells in the Gut-Associated Lymphoid Tissue (GALT). Here, we transformed probiotic strains of Lactobacillus plantarum and Lactobacillus fermentum with the recombinant plasmid vectors pSIP409 and pSIP411 harbouring the HIV-1 GagM gene. Following electroporation, HIV-1 GagM expression was induced in the probiotics using peptide pheromone. Via PCR and sequencing, the presence of GagM was confirmed in the L. plantarum+ pSIP409-GagM and L. fermentum+ pSIP411-GagM clones. Protein expression was induced with peptide pheromone. Then, protein expression was confirmed by western blotting with goat anti-HIV p24 primary antibody and anti-goat secondary antibody. ELISA was also performed to confirm the antigenicity of the HIV-1 Gag antigen and to also quantify the antigen in the two Lactobacilli clones. Our results show that 1.5×109 CFU of L. plantarum+ pSIP409-GagM expressed 125μg of HIV-1 Gag and 1.9×109 CFU of L. fermentum+ pSIP411-GagM clones expressed 125μg of HIV-1 Gag respectively. In vitro digestion with pepsin, pancreatin and bile salts suggested that partial digestion of the probiotic vaccine candidates may occur when administered orally. Taken together, our probiotic HIV-1 vaccine candidates showed good prospects for further immunological analysis via animal trial.
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33.
  • Ninyio, Nathaniel, 1985-, et al. (författare)
  • Stable expression of HIV-1 MPER extended epitope on the surface of the recombinant probiotic bacteria Escherichia Coli Nissle 1917 using CRISPR/Cas9
  • 2024
  • Ingår i: Microbial Cell Factories. - : BioMed Central (BMC). - 1475-2859. ; 23:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Mucosal vaccines have the potential to induce protective immune responses at the sites of infection. Applying CRISPR/Cas9 editing, we aimed to develop a probiotic-based vaccine candidate expressing the HIV-1 envelope membrane-proximal external region (MPER) on the surface of E. coli Nissle 1917.RESULTS: The HIV-1 MPER epitope was successfully introduced in the porin OmpF of the E. coli Nissle 1917 (EcN-MPER) and the modification was stable over 30 passages of the recombinant bacteria on the DNA and protein level. Furthermore, the introduced epitope was recognized by a human anti-HIV-1 gp41 (2F5) antibody using both live and heat-killed EcN-MPER, and this antigenicity was also retained over 30 passages. Whole-cell dot blot suggested a stronger binding of anti-HIV-1 gp41 (2F5) to heat-killed EcN-MPER than their live counterpart. An outer membrane vesicle (OMV) - rich extract from EcN-MPER culture supernatant was equally antigenic to anti-HIV-1 gp41 antibody which suggests that the MPER antigen could be harboured in EcN-MPER OMVs. Using quantitative ELISA, we determined the amount of MPER produced by the modified EcN to be 14.3 µg/108 cfu.CONCLUSIONS: The CRISPR/Cas9 technology was an effective method for establishment of recombinant EcN-MPER bacteria that was stable over many passages. The developed EcN-MPER clone was devoid of extraneous plasmids and antibiotic resistance genes which eliminates the risk of plasmid transfer to animal hosts, should this clone be used as a vaccine. Also, the EcN-MPER clone was recognised by anti-HIV-1 gp41 (2F5) both as live and heat-killed bacteria making it suitable for pre-clinical evaluation. Expression of OmpF on bacterial surfaces and released OMVs identifies it as a compelling candidate for recombinant epitope modification, enabling surface epitope presentation on both bacteria and OMVs. By applying the methods described in this study, we present a potential platform for cost-effective and rational vaccine antigen expression and administration, offering promising prospects for further research in the field of vaccine development.
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34.
  • Olsen, Birgitta, 1952-, et al. (författare)
  • Phenotypic and genetic characterisation of bacterial sexually transmitted infections in Bissau, Guinea-Bissau, West Africa : a prospective cohort study
  • 2012
  • Ingår i: BMJ Open. - London, United Kingdom : BMJ Publishing Group Ltd. - 2044-6055. ; 20:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Knowledge regarding characteristics and transmission of Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium and antibiotic resistance in N gonorrhoeae in Guinea-Bissau, West Africa, is entirely lacking.Objectives: To characterise N gonorrhoeae, C trachomatis and M genitalium samples from Guinea-Bissau and to define bacterial populations, possible transmission chains and for N gonorrhoeae spread of antibiotic-resistant isolates.Design: Prospective cohort study.Setting: Two sexual health and family planning clinics, Bissau, Guinea-Bissau.Participants: Positive samples from 711 women and 27 men.Material and methods: Positive samples for N gonorrhoeae (n=31), C trachomatis (n=60) and M genitalium (n=30) were examined. The gonococcal isolates were characterised with antibiograms, serovar determination and N gonorrhoeae multiantigen sequence typing (NG-MAST). The C trachomatis ompA gene and the M genitalium mgpB gene were sequenced, and phylogenetic analyses were performed.Results: For N gonorrhoeae, the levels of resistance (intermediate susceptibility) to ciprofloxacin, erythromycin, rifampicin, ampicillin, tetracycline, penicillin G and cefuroxime were 10% (0%), 6% (10%), 13% (10%), 68% (0%), 74% (0%), 68% (16%) and 0% (84%), respectively. All isolates were susceptible to cefixime, ceftriaxone, spectinomycin and azithromycin, and the minimum inhibitory concentrations of kanamycin (range: 8-32 mg/l) and gentamicin (range: 0.75-6 mg/l) were low (no resistance breakpoints exist for these antimicrobials). 19 NG-MAST sequence types (STs) (84% novel STs) were identified. Phylogenetic analysis of the C trachomatis ompA gene revealed genovar G as most prevalent (37%), followed by genovar D (19%). 23 mgpB STs were found among the M genitalium isolates, and 67% of isolates had unique STs.Conclusions: The diversity among the sexually transmitted infection (STI) pathogens may be associated with suboptimal diagnostics, contact tracing, case reporting and epidemiological surveillance. In Guinea-Bissau, additional STI studies are vital to estimate the STI burden and form the basis for a national sexual health strategy for prevention, diagnosis and surveillance of STIs.
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35.
  • Scherbak, Nikolai, 1967-, et al. (författare)
  • Production of anti-viral vaccines using probiotic bacteria
  • 2022
  • Ingår i: 19th Smögen Symposium on Virology: Abstracts. - : Virus- och Pandemifonden – Swedish Society for Virology. ; , s. 16-16
  • Konferensbidrag (refereegranskat)abstract
    • The mucosal surfaces throughout the body are constantly exposed to microorganisms. The mucosal surfaces accommodate a large part of the body’s immune system. For effective vaccination, it is believed that direct immunization on mucosal surfaces will be more effective than the more conventional systemic immunization. Certain probiotic bacteria provide significant adjuvant effects that may be utilized for the desired immune response. Virus-like particles (VLPs) are complexes of viral proteins that without being infectious are efficient in mimicking the natural viral structures. While presenting the patterns of viral antigens, the VLPs have been shown to efficiently interact with dendritic cells and be effective in triggering the B and T-cell immunity. HIV-1 Gag is one of the most highly conserved structural antigens and contains several immunodominant T- and B-cell epitopes. Mosaic Gag protein matches 74% of 9-amino-acid potential epitopes in global Gag sequences thus maximizing the coverage of potential T-cell epitopes for a viral population.The current study aimed to develop probiotic strains of Lactobacillus plantarum NC8 and E. coli Nissle 1917 that produced recombinant mosaic HIV-1 Gag protein as VLPs.For the transient expression of the mosaic HIV-1 Gag protein (GagM), the gene-carrying expression vectors were transformed into the L. plantarum and in probiotic E.coli Nissle 1917. Protein expression of the GagM was shown to lead to the formation of the VLPs of the recombinant HIV-1 Gag proteins. This was confirmed through immunoblotting and transmission electron microscopy (TEM).Our study shows that probiotic lactobacteria can be developed to express HIV-1 Gag VLPs, which may be used for VLP production and potentially for vaccine delivery. Further evaluation of the concept is merited.
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36.
  • Strid, Åke, 1960-, et al. (författare)
  • HIV, Chlamydia trachomatis and Helicobacter pylori vaccine antigen and proteinaceous adjuvant production in arabidopsis and carrot
  • 2010
  • Ingår i: Molecular farming. - Bryssel : COST. ; , s. 17-17
  • Konferensbidrag (refereegranskat)abstract
    • In our project, we use plants for synthesis of vaccine antigens and adjuvant proteins. Among targeted diseases are HIV, Chlamydia trachomatis (CT) and Helicobacter pylori (HP) infections. Novel genetic constructs have been designed for production of optimized antigen proteins and several transformation techniques and intracellular protein production sites are being examined for yield optimization. Both Arabidopsis thaliana (HIV, CT, HP) and carrot (HIV, CT) have been successfully used as production hosts and plant-produced antigens against HIV (primarily the p24 protein), CT (own designed chimera of the MOMP protein) and HP (different versions of the TonB protein). For HIV and CT these antigens have been used in immunization trials in laboratory mice, giving rise to systemic immune responses. For this purpose both consumption of plant tissue and distribution of purified antigens have been used. For CT, the administration of the recombinant protein has also been shown to protect against the disease in mice. Moreover, to further increase the effect of vaccine antigens, we also use plants to produce protein-based adjuvants for inclusion in vaccine formulations. These adjuvants are based either on the bacterial flagellin protein or are cholera toxin-derived chimeric proteins.
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37.
  • Tembe, Nelson, et al. (författare)
  • Reference Values for Clinical Laboratory Parameters in Young Adults in Maputo, Mozambique
  • 2014
  • Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Clinical laboratory reference values from North American and European populations are currently used in most Africans countries due to the absence of locally derived reference ranges, despite previous studies reporting significant differences between populations. Our aim was to define reference ranges for both genders in 18 to 24 year-old Mozambicans in preparation for clinical vaccine trials.Methods: A cross-sectional study including 257 volunteers (102 males and 155 females) between 18 and 24 years was performedat a youth clinic in Maputo, Mozambique. All volunteers were clinically healthy and human immunodeficiency virus, Hepatitis B virus and syphilis negative. Median and 95% reference ranges were calculated for immunological, hematological and chemistry parameters. Ranges were compared with those reported based on populations in other African countries and the US. The impact of applying US NIH Division of AIDS (DAIDS) toxicity tables was assessed.Results: The immunology ranges were comparable to those reported for the US and western Kenya. There were significant gender differences in CD4(+) T cell values 713 cells/mu L in males versus 824 cells/mu L in females (p < 0.0001). Hematologic values differed from the US values but were similar to reports of populations in western Kenya and Uganda. The lower and upper limits of the ranges for hemoglobin, hematocrit, red blood cells, white blood cells and lymphocytes were somewhat lower than those from these African countries. The chemistry values were comparable to US values, with few exceptions. The upper limits for ALT, AST, bilirubin, cholesterol and triglycerides were higher than those from the US. DAIDStables for adverse events predicted 297 adverse events and 159 (62%) of the volunteers would have been excluded.Conclusion: This study is the first to determine normal laboratory parameters in Mozambique. Our results underscore the necessity of establishing region-specific clinical reference ranges for proper patient management and safe conduct of clinical trials.
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38.
  • Thulin Hedberg, Sara, 1980-, et al. (författare)
  • Droplet digital PCR for absolute quantification of proviral load of human T-cell lymphotropic virus (HTLV) types 1 and 2
  • 2018
  • Ingår i: Journal of Virological Methods. - : Elsevier. - 0166-0934 .- 1879-0984. ; 260, s. 70-74
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Human T-lymphotrophic virus (HTLV) types 1 and 2 cause lifelong infection whereby most infected individuals are asymptomatic whilst a minority develop infection-related disease. These latter patients invariably have been found to have high proviral load (PVL). Therefore, infected patients are monitored by determining the proportion of lymphocytes that are infected with HTLV-1/2. An increase in PVL has been shown to represent an increasing risk of developing HTLV-associated diseases. Monitoring of PVL requires a reliable and sensitive method. In this study assays based on droplet digital PCR (ddPCR) were established and evaluated for detection and quantification of HTLV-1/2.OBJECTIVES: To develop two parallel assays to detect the tax genes and determine the PVL of HTLV-1 and -2.STUDY DESIGN: Sixty-seven clinical samples from patients infected with HTLV-1 or HTLV-2 were analysed. The samples had previously been analysed with a qPCR and a comparison between ddPCR and qPCR was performed. The specificity of the assays were determined by analyzing samples from 20 healthy blood donors.RESULTS: The ddPCR was a stable and sensitive method for detection and quantification of HTLV-1 and -2. When comparing the qPCR and ddPCR the correlation was high (Pearsons correlation coefficient 0.96). The variability of the ddPCR was very low with intra-assay coefficient of variation (CV) of 0.97-3.3% (HTLV-1) and 1.7-8.2% (HTLV-2) and inter-assay CV of 1.8-6.1% (HTLV-1) and 1.2-12.9% (HTLV-2).CONCLUSIONS: The ddPCR reliably quantified HTLV DNA in clinical samples and could be a useful tool for monitoring of PVLs in HTLV-infected individuals.
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39.
  • Tran, Pham Tue Hung, 1991- (författare)
  • Characterizing important flavivirus-host interactions : Replication, assembly, restriction factors and vaccine development
  • 2022
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The genus Flavivirus (family Flaviviridae) consists of important zoonotic viruses that cause morbidity and mortality worldwide. These viruses are enveloped and have a positive-sense single-stranded RNA genome encoding a polyprotein. Cleavages of the polyprotein by host and viral proteases result in individual viral proteins, including the structural capsid (C), pre-membrane (prM), envelope (E) proteins, and seven nonstructural proteins. Removal of the C-prM-E genes in the flavivirus genome results in replicons that can replicate in transfected cells but do not generate infectious virus particles. The replicon can be co-expressed with the C-prM-E genes in trans, resulting in packaging of the replicon and generation of replicon virus-like particles (RVPs).During cellular infection, various host proteins are employed, supporting multiple stages of the virus life cycle. In this thesis, we identified and characterized functions of the host lunapark protein and two members of the Endosomal Sorting Complexes Required for Transport Machinery – ALIX and CHMP4A. We also revealed how the host proteins were recruited by virus proteins during infection.To counteract the virus infection, virus-infected cells can express antiviral proteins. We demonstrated the antiviral mechanism of interferonstimulated gene (ISG) 15 and the E3 ligase for ISG15 conjugation HERC5, which degrades ALIX and CHMP4A, indirectly targets virus infection. Furthermore, using proteomic screening, we identified tripartite motif-containing proteins (TRIM) – TRIM21 and TRIM14 – as restriction factors to Langat virus and Zika virus.We also established and characterized an RVP production system based on the West Nile virus (WNV) Kunjin strain. The system was used as a vector to express antigens from Ebola virus (EBOV), which can potentially be developed as a vaccine platform against WNV and EBOV.
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40.
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41.
  • Viegas, Edna Omar, et al. (författare)
  • Human papillomavirus prevalence and genotype distribution among young women and men in Maputo city, Mozambique
  • 2017
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 7:7
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: Human papillomavirus (HPV) is a well-known cause of cervical cancer, the second most frequent cancer in female African populations. This study aimed at determining the prevalence of HPV infections and the genotype distribution in young adults aged 18-24, in Maputo city, Mozambique, and to assess the suitability of commercially available HPV vaccines.METHODS: This cross-sectional study was conducted between 2009 and 2011 at a youth clinic in Maputo Central Hospital. Cervical and urethral samples were obtained from 236 women and 176 men, respectively. Demographic and behavioural data were collected using structured questionnaires. HPV genotyping was performed for 35 different high, probably or possibly high-risk and low-risk HPV types using the CLART Human Papillomavirus 2.RESULTS: HPV prevalence was 168/412 (40.8%; 95% CI 36.0 to 45.5) and was significantly higher in women than in men (63.6%vs10.2%). HPV52 was the most frequent type found in women, followed by HPV35, -16,-53, -58,-6 and -51. In men, HPV51 ranked the highest, followed by HPV6, -11,-52, -59 and -70. HIV infection and sexual debut before 18 years of age were associated with multiple HPV infections (OR 3.03; 95% CI 1.49 to 6.25 and OR 6.03; 95% CI 1.73 to 21.02, respectively). Women had a significantly higher HPV infection prevalence than men (p<0.001). The 9-valent HPV vaccine would cover 36.8% of the high-risk genotypes circulating in women in this study, compared with 26.3% and 15.8% coverage by the bivalent and quadrivalent vaccines, respectively.CONCLUSION: This study confirmed the high burden of HPV infections in young women in Maputo city, Mozambique. The HPV prevalence was associated with high-risk sexual behaviour. Sex education and sexually transmitted infection prevention interventions should be intensified in Mozambique. Only a proportion of the high-risk HPV genotypes (37%) were covered by currently available vaccines.
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42.
  • Viegas, Edna Omar, et al. (författare)
  • Incidence of HIV and the Prevalence of HIV, Hepatitis B and Syphilis among Youths in Maputo, Mozambique : A Cohort Study
  • 2015
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Prevalence of HIV in Mozambique among individuals aged 15-49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25-29 years and 35-39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.Methods: The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18-24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.Results: The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: +/-1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97-6.31), 12.2% (95% CI 10.5%-14.0%), and 0.36% (95% CI 0.15%-0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67-1.92). Retention rates were stable throughout the study being 85.1% at the last visit.Conclusion: Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country.
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43.
  • Viegas, Edna Omar, et al. (författare)
  • Intradermal HIV-1 DNA immunization using needle-free ZetajetTM injection followed by HIV-modified vaccinia virus Ankara vaccination is safe and immunogenic in Mozambican young adults : a phase I randomized controlled trial
  • 2018
  • Ingår i: AIDS Research and Human Retroviruses. - : Mary Ann Liebert. - 0889-2229 .- 1931-8405. ; 34:2, s. 193-205
  • Tidskriftsartikel (refereegranskat)abstract
    • We assessed safety and immunogenicity of HIV-DNA priming using ZetajetTM, a needle-free device intradermally followed by intramuscular HIV-MVA boosts, in 24 healthy Mozambicans. Volunteers were randomized to receive three immunizations of 600 µg (n = 10; 2 x 0.1mL) or 1200 µg (n = 10; 2 x 0.2mL) of HIV-DNA (3 mg/mL), followed by two boosts of 108pfu HIV-MVA. Four subjects received placebo saline injections. Vaccines and injections were safe and well tolerated with no difference between the two priming groups. After three HIV-DNA immunizations, IFN-γ ELISpot responses to Gag were detected in 9/17 (53%) vaccinees, while none responded to Env. After the first HIV-MVA, the overall response rate to Gag and/or Env increased to 14/15 (93%); 14/15 (93%) to Gag and 13/15 (87%) to Env. There were no significant differences between the immunization groups in frequency of response to Gag and Env or magnitude of Gag responses. Env responses were significantly higher in the higher-dose group (median 420 vs 157.5 SFC/million PBMC, p=0.014). HIV-specific antibodies to subtype C gp140 and subtype B gp160 were elicited in all vaccinees after the second HIV-MVA, without differences in titers between the groups. Neutralizing antibody responses were not detected. Two (13%) of 16 vaccinees, one in each of the priming groups, exhibited antibodies mediating antibody-dependent cellular cytotoxicity to CRF01_AE. In conclusion, HIV-DNA vaccine delivered intradermally in volumes of 0.1-0.2 mL using ZetajetTM was safe and well tolerated. Priming with the 1200 µg dose of HIV-DNA generated higher magnitudes of ELISpot responses to Env.
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44.
  • Wallenhammar, Amélie, 1986-, et al. (författare)
  • Developing a novel strategy to determine new Tick-borne encephalitis foci
  • 2018
  • Ingår i: 15th Smögen Summer Symposium on Virology, Smögen, Sweden, August 23-25, 2018..
  • Konferensbidrag (refereegranskat)abstract
    • TBEV is the most important viral tick-borne zoonosis in Europe, and infection may lead to severeCNS disease, including encephalitis and myelitis. Climate changes have increased the tickdistribution in Sweden, increasing the risk areas of Tick-borne encephalitis (TBE) at severalregions including the Örebro county. The TBE virus (TBEV) is usually transmitted to humans viatick bites, however oral transmission through consumption of non-pasteurized dairy products havealso been described. Both TBEV and antibodies against the viral proteins have been detected inmilk of goats, sheep and cattle. Since the prevalence of TBEV in the tick population is low there is a need for new and robust surveillance techniques identifying novel risk areas of TBEV at earlystages.In this study we have developed a strategy for identifying new TBEV foci. We have collected raw milk and colostrum samples from sheep and goats in the Örebro region. The milk samples were analyzed for the presence of TBEV antibodies by ELISA. In addition, the ELISA results were further verified by an in-house Western Blot assay where milk samples were used asprimary antibody to detect the Envelope-protein of TBEV. This method has so far revealed two novel TBEV foci within the Örebro county. Questing ticks and ticks feeding on sheep have been collected at areas of TBEV positive milk. The ticks are currently being analyzed for TBEV by PCR. The specific Örebro strains will be isolated from TBEV positive ticks and the viral genomeswill be further characterized using established next-generation sequencing technique.
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45.
  • Wallenhammar, Amélie, 1986-, et al. (författare)
  • Revealing new tick-borne encephalitis foci by screening antibodies in sheep milk
  • 2019
  • Ingår i: 16th Smögen Symposium on Virology, August 22-24, 2019.
  • Konferensbidrag (refereegranskat)abstract
    • Climate changes have increased the tick-distribution in Sweden, and the prevalence of ticks has been predicted to increase towards the northern parts of the country, increasing the risk of tick-borne zoonosis in new regions. Tick-borne encephalitis (TBE) is the most important viral tick-borne zoonosis in Sweden as well as in Europe. TBE virus (TBEV) infection often leads to severe CNS disease, including encephalitis and severe myelitis, which may lead to paralysis and respiratory failure in humans. TBEV and antibodies against TBEV are excreted in milk of goats, sheep and cattle and the virus can be ingested orally by consumption of non-pasteurized dairy products. Since the prevalence of TBEV in the tick population is low there is a need for new and robust surveillance techniques identifying new risk areas of TBEV at early stages.In this study we have developed a novel strategy for identifying new TBEV foci. We have collected raw milk and colostrum samples from sheep and goats in Örebro County, Sweden. The milk samples were analyzed for the presence of TBEV antibodies by ELISA, and validated by an in-house Western Blot assay where milk samples were used as primary antibody to detect purified TBEV E-protein. By monitoring TBEV antibodies in milk we have found three novel foci in the Örebro County which also overlap with the plausible place of infection of registered human TBE cases reported during 2009-2018. Furthermore, the stability of TBEV in milk and raw milk was studied at different temperatures. Our data indicates that keeping unpasteurized milk at 4 ˚C will preserve the infectivity of TBEV for several days. Ticks have also been collected from areas with TBEV positive milk. We aim to extract total RNA from the sampled ticks, followed by TBEV detection by nested-PCR and next-generation sequencing.Here we present a novel technique to reveal risk areas of TBE in Sweden, which is robust, reliable, and non-invasive and can accordingly be used to map TBEV “hotspots”. In the TBE foci, more than 50 % of the tested animals were antibody positive, and TBEV infectivity in refrigerated milk was preserved, stressing the importance of pasteurization before consumption.
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46.
  • Wallenhammar, Amélie, 1986-, et al. (författare)
  • Revealing new tick-borne encephalitis virus foci by screening antibodies in sheep milk
  • 2020
  • Ingår i: Parasites & Vectors. - : BioMed Central. - 1756-3305. ; 13:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Tick distribution in Sweden has increased in recent years, with the prevalence of ticks predicted to spread towards the northern parts of the country, thus increasing the risk of tick-borne zoonoses in new regions. Tick-borne encephalitis (TBE) is the most significant viral tick-borne zoonotic disease in Europe. The disease is caused by TBE virus (TBEV) infection which often leads to severe encephalitis and myelitis in humans. TBEV is usually transmitted to humans via tick bites; however, the virus can also be excreted in the milk of goats, sheep and cattle and infection may then occur via consumption of unpasteurised dairy products. Virus prevalence in questing ticks is an unreliable indicator of TBE infection risk as viral RNA is rarely detected even in large sample sizes collected at TBE-endemic areas. Hence, there is a need for robust surveillance techniques to identify emerging TBEV risk areas at early stages.METHODS: Milk and colostrum samples were collected from sheep and goats in Örebro County, Sweden. The milk samples were analysed for the presence of TBEV antibodies by ELISA and validated by western blot in which milk samples were used to detect over-expressed TBEV E-protein in crude cell extracts. Neutralising titers were determined by focus reduction neutralisation test (FRNT). The stability of TBEV in milk and colostrum was studied at different temperatures.RESULTS: In this study we have developed a novel strategy to identify new TBEV foci. By monitoring TBEV antibodies in milk, we have identified three previously unknown foci in Örebro County which also overlap with areas of TBE infection reported during 2009-2018. In addition, our data indicates that keeping unpasteurised milk at 4 °C will preserve the infectivity of TBEV for several days.CONCLUSIONS: Altogether, we report a non-invasive surveillance technique for revealing risk areas for TBE in Sweden, by detecting TBEV antibodies in sheep milk. This approach is robust and reliable and can accordingly be used to map TBEV "hotspots". TBEV infectivity in refrigerated milk was preserved, emphasising the importance of pasteurisation (i.e. 72 °C for 15 s) prior to consumption.
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