| 1. |
- Åberg, Anna, et al.
(författare)
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Helicobacter pylori adapts to chronic infection and gastric disease via ph-responsive baba-mediated adherence
- 2017
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Ingår i: Cell Host and Microbe. - : Elsevier BV. - 1931-3128 .- 1934-6069. ; 21:3, s. 376-389
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Tidskriftsartikel (refereegranskat)abstract
- The BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease.
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| 2. |
- Lan, P. T., et al.
(författare)
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Reproductive tract infections including sexually transmitted infections : a population-based study of women of reproductive age in a rural district of Vietnam.
- 2008
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Ingår i: Sexually Transmitted Infections. - London : BMJ Publishing Group. - 1368-4973 .- 1472-3263. ; 84:2, s. 126-132
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the prevalences of reproductive tract infections (RTI)/sexually transmitted infections (STI) among married women in a rural district of Vietnam, and analyse the influence of socioeconomic, sociodemographic, and other determinants possibly related to RTI/STI. Methods: A community-based cross-sectional study. Married women aged 18–49 years (n = 1012) were interviewed and underwent a gynaecological examination. Specimens were collected for laboratory diagnosis of chlamydia, gonorrhoea, trichomonas, bacterial vaginosis (BV), candidiasis, hepatitis B, HIV, and syphilis. Results: In total, 37% of the women were clinically diagnosed with an RTI/STI. Aetiologically confirmed RTI/STI was identified in 39% of the women (including 6% with STI). Endogenous infections were most prevalent (candidiasis 26%, BV 11%) followed by hepatitis B 8.3%, Chlamydia trachomatis 4.3%, Trichomonas vaginalis 1%, Neisseria gonorrhoeae 0.7%, genital warts 0.2%, and HIV and syphilis 0%. Fifty per cent of the STI cases were asymptomatic. Younger age and intrauterine devices were significantly associated with an increased risk of BV. Determinants of candidiasis were vaginal douching, high education level and low economic status, whereas a determinant of chlamydia was high economic status. Outmigration of the husband was associated with an increased risk of hepatitis B surface antigen seroposivity among women. Conclusions: RTI/STI were prevalent among married women in a rural population of Vietnam. Syndromic algorithms should be consistently supplemented by risk assessment in order to reduce under and overtreatment. Microscopic diagnosis could be applied in primary care settings to achieve more accurate diagnoses. The promotion of health education aimed at reducing RTI/STI prevalences is an important tool in STI/HIV control programmes. Vaccination to prevent hepatitis B for migrants should be considered.
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| 3. |
- Lundbäck, David, et al.
(författare)
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Molecular epidemiology of Neisseria gonorrhoeae- identification of the first presumed Swedish transmission chain of an azithromycin-resistant strain
- 2006
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 114:1, s. 67-71
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, 10 azithromycin-resistant Neisseria gonorrhoeae isolates from 6 Swedish male patients in 2004, 3 sporadic Swedish azithromycin-resistant N. gonorrhoeae isolates from recent years and one Swedish N. gonorrhoeae isolate from 2003 that was susceptible to azithromycin but assigned the same serological variant (serovar), i.e. IB-37, as the isolates from 2004 were included. The isolates were characterized phenotypically using antibiograms and serovar determination and genetically with pulsed-field gel electrophoresis (PFGE), entire porB gene sequencing and N. gonorrhoeae multiantigen sequence typing (NG-MAST). The epidemiological information and the results of the thorough phenotypic characterisation and genetic characterisation identified the first presumed domestic transmission of one azithromycin-resistant N. gonorrhoeae strain in Sweden in 2004. This stresses the need for continuous surveillance of the antibiotic susceptibility of N. gonorrhoeae in order to identify emergence of new resistance, monitor the changing patterns of the susceptibility, and be able to update treatment recommendations on a regular basis.
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| 4. |
- Shipitsyna, Elena, et al.
(författare)
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Composition of the Vaginal Microbiota in Women of Reproductive Age - Sensitive and Specific Molecular Diagnosis of Bacterial Vaginosis Is Possible?
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:4, s. e60670-
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objective: Bacterial vaginosis (BV) is the most common vaginal disorder, characterized by depletion of the normal lactobacillus-dominant microbiota and overgrowth of commensal anaerobic bacteria. This study aimed to investigate the composition of the vaginal microbiota in women of reproductive age (healthy women and women with BV), with the view of developing molecular criteria for BV diagnosis. Materials and Methods: Vaginal samples from 163 women (79 control, 73 BV and 11 intermediate (Lactobacillary grade II flora) cases) were analyzed using 454 pyrosequencing of the hypervariable regions V3-V4 of the 16S rRNA gene and 16 quantitative bacterial species/genus-specific real-time PCR assays. Sensitivities and specificities of potential BV markers were computed using the Amsel criteria as reference standard for BV. The use of quantitative thresholds for prediction of BV, determined for both relative abundance measured with 454 pyrosequencing and bacterial load measured with qPCR, was evaluated. Results: Relative to the healthy women, the BV patients had in their vaginal microbiota significantly higher prevalence, loads and relative abundances of the majority of BV associated bacteria. However, only Gardnerella vaginalis, Atopobium vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 detected at or above optimal thresholds were highly predictable for BV, with the best diagnostic accuracy shown for A. vaginae. The depletion of Lactobacillus species combined with the presence of either G. vaginalis or A. vaginae at diagnostic levels was a highly accurate BV predictor. Conclusions: Quantitative determination of the presence of G. vaginalis, A. vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 as well as the depletion of Lactobacillus was highly accurate for BV diagnosis. Measurements of abundance of normal and BV microbiota relative to total bacteria in vaginal fluid may provide more accurate BV diagnosis, and be used for test-of-cure, rather than qualitative detection or absolute counts of BV related microorganisms.
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| 5. |
- Hadad, Ronza, 1984-, et al.
(författare)
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First National Genomic Epidemiological Study of Neisseria gonorrhoeae Strains Spreading Across Sweden in 2016
- 2022
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The increasing transmission and antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a global health concern with worrying trends of decreasing susceptibility to also the last-line extended-spectrum cephalosporin (ESC) ceftriaxone. A dramatic increase of reported gonorrhea cases has been observed in Sweden from 2016 and onward. The aim of the present study was to comprehensively investigate the genomic epidemiology of all cultured N. gonorrhoeae isolates in Sweden during 2016, in conjunction with phenotypic AMR and clinical and epidemiological data of patients. In total, 1279 isolates were examined. Etest and whole-genome sequencing (WGS) were performed, and epidemiological data obtained from the Public Health Agency of Sweden. Overall, 51.1%, 1.7%, and 1.3% resistance to ciprofloxacin, cefixime, and azithromycin, respectively, was found. No isolates were resistant to ceftriaxone, however, 9.3% of isolates showed a decreased susceptibility to ceftriaxone and 10.5% to cefixime. In total, 44 penA alleles were found of which six were mosaic (n = 92). Using the typing schemes of MLST, NG-MAST, and NG-STAR; 133, 422, and 280 sequence types, respectively, and 93 NG-STAR clonal complexes were found. The phylogenomic analysis revealed two main lineages (A and B) with lineage A divided into two main sublineages (A1 and A2). Resistance and decreased susceptibility to ESCs and azithromycin and associated AMR determinants, such as mosaic penA and mosaic mtrD, were predominantly found in sublineage A2. Resistance to cefixime and azithromycin was more prevalent among heterosexuals and MSM, respectively, and both were predominantly spread through domestic transmission. Continuous surveillance of the spread and evolution of N. gonorrhoeae, including phenotypic AMR testing and WGS, is essential for enhanced knowledge regarding the dynamic evolution of N. gonorrhoeae and gonorrhea epidemiology.
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| 6. |
- Parihar, Vishal Singh, et al.
(författare)
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Characterization of human invasive isolates of Listeria monocytogenes in Sweden 1986-2007
- 2008
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Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 5:6, s. 755-761
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Tidskriftsartikel (refereegranskat)abstract
- Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.
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| 7. |
- Ivarsson, Lovisa, et al.
(författare)
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Changes in testing and incidence of Chlamydia trachomatis and Neisseria gonorrhoeae : the possible impact of the COVID-19 pandemic in the three Scandinavian countries
- 2022
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 52:9, s. 623-631
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study aimed to investigate what impact the COVID-19 pandemic and its associated restrictions had on Chlamydia trachomatis and Neisseria gonorrhoeae infections in Sweden, Denmark and Norway, countries with very different governmental strategies for handling this pandemic.Methods: Retrospective analysis of data collected via requests to Swedish regions and to health authorities in Denmark and Norway. The data were collected for the years 2018-2020 and the data from Sweden were more detailed.Results: When the pandemic restrictions were installed in 2020, the number of reported chlamydia cases decreased. The decline was most pronounced in Norway 10.8% (2019: n = 28,446; 2020: n = 25,444) while it was only 3.1% in Denmark (2019: n = 35,688; 2020: n = 34,689) and 4.3% in Sweden (2019: n = 34,726; 2020: n = 33,339). Nucleic acid amplifications tests for chlamydia decreased in Sweden (10%) and Norway (18%) in 2020 compared to 2019, while in Denmark a 21% decrease was noted in April 2020 but thereafter increased to a higher level than 2019. The number of reported gonorrhoea cases decreased in Sweden (17%) and in Norway (39%) in 2020 compared to 2019, while a 21% increase was noted in Denmark.Conclusions: Pandemic restrictions had an impact on the number of reported chlamydia infections in all three countries, but only temporarily and did not seem to be correlated to the restriction levels. The number of reported gonorrhoea infections in Sweden and Norway significantly decreased but not in Denmark. Pandemic restrictions appear to have had a limited effect on the spread of chlamydia and gonorrhoea.
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| 8. |
- Aspholm, Marina, et al.
(författare)
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Helicobacter pylori adhesion to carbohydrates
- 2006
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Ingår i: Methods in Enzymology. - 0076-6879 .- 1557-7988. ; 417, s. 293-339
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Tidskriftsartikel (refereegranskat)abstract
- Adherence of bacterial pathogens to host tissues contributes to colonization and virulence and typically involves specific interactions between bacterial proteins called adhesins and cognate oligosaccharide (glycan) or protein motifs in the host that are used as receptors. A given pathogen may have multiple adhesins, each specific for a different set of receptors and, potentially, with different roles in infection and disease. This chapter provides strategies for identifying and analyzing host glycan receptors and the bacterial adhesins that exploit them as receptors, with particular reference to adherence of the gastric pathogen Helicobacter pylori.
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| 9. |
- Olsen, Birgitta, 1952-, et al.
(författare)
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Phenotypic and genetic characterisation of bacterial sexually transmitted infections in Bissau, Guinea-Bissau, West Africa : a prospective cohort study
- 2012
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Ingår i: BMJ Open. - London, United Kingdom : BMJ Publishing Group Ltd. - 2044-6055. ; 20:2
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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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| 10. |
- Golparian, Daniel, 1984-, et al.
(författare)
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Multidrug-resistant Neisseria gonorrhoeae isolate SE690 : mosaic penA-60.001 gene causing ceftriaxone resistance internationally has spread to the more antimicrobial- susceptible genomic lineage, Sweden, September 2022
- 2023
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Ingår i: Eurosurveillance. - : European Centre for Disease Prevention and Control. - 1025-496X .- 1560-7917. ; 28:10
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Tidskriftsartikel (refereegranskat)abstract
- We report a ceftriaxone-resistant, multidrug-resist-ant urogenital Neisseria gonorrhoeae in a female sex worker in Sweden, September 2022, who was treated with ceftriaxone i g, but did not return for test-of-cure. Whole genome sequencing of isolate SE690 identified MLST ST8i30, NG-STAR CCi885 (new NG-STAR ST4859) and mosaic penA-6o.oo1. The latter, causing ceftriax-one resistance in the internationally spreading FC428 clone, has now also spread to the more antimicrobial -susceptible genomic lineage B, showing that strains across the gonococcal phylogeny can develop ceftri-axone resistance.
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