1.
Hadad, Ronza, 1984-, et al.
(författare)
Novel meningococcal 4CMenB vaccine antigens : prevalence and polymorphisms of the encoding genes in Neisseria gonorrhoeae
2012
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley-Blackwell. - 0903-4641 .- 1600-0463. ; 120:9, s. 750-760
Tidskriftsartikel (refereegranskat) abstract
The first cross-protective Neisseria meningitidis vaccine (focus on serogroup B), the protein-based 4 component meningococcus serogroup B (4CMenB), includes the New Zealand outer membrane vesicle and three main genome-derived neisserial antigens (GNAs). These GNAs are fHbp (fused to GNA2091), NHBA (fused to GNA1030) and NadA. In this study, the prevalence and polymorphisms of the nucleotide and amino acid sequences of the 4CMenB antigens in a temporally and geographically diverse collection of N. gonorrhoeae isolates (n similar to=similar to 111) were investigated. All the examined GNA genes, except the nadA gene, were present in all gonococcal isolates. However, 25 isolates contained premature stop codons in the fHbp gene and/or the nhba gene, resulting in truncated proteins. Compared with the 4CMenB antigen sequences in reference strain MC58, the gonococcal strains displayed 67.095.4% and 60.994.9% identity in nucleotide sequence and amino acid sequence, respectively, in the equivalent GNA antigens. The absence of NadA, lack of universal expression of fHbp and NHBA and the uncertainty regarding the surface exposure of fHbp as well as the function of NHBA in N. gonorrhoeae will likely limit the use of the identical 4CMenB antigens in a gonococcal vaccine. However, possible cross-immunity of 4CMenB with gonococci and expression and function of the equivalent gonococcal GNAs, as well as of more appropriate GNAs for a gonococcal vaccine, need to be further examined.
2.
Golparian, Daniel, 1984-, et al.
(författare)
Analytical specificity and sensitivity of the novel dual-target GeneProof Neisseria gonorrhoeae PCR kit for detection of N-gonorrhoeae
2015
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley-Blackwell. - 0903-4641 .- 1600-0463. ; 123:11, s. 955-958
Tidskriftsartikel (refereegranskat) abstract
Detection of Neisseria gonorrhoeae relies increasingly on nucleic acid amplification tests (NAATs). The specificity of many gonococcal NAATs has been suboptimal and supplementary testing remains recommended in Europe and several additional countries. The novel dual-target GeneProofNeisseria gonorrhoeae PCR kit, targeting porA pseudogene and 16S rRNA gene, showed a high specificity and sensitivity when isolates of non-gonococcal Neisseria and related species (n=144), and gonococci (n=104) were tested. However, rare gonococcal porA mutants were only detected in the 16S rRNA gene target and two non-gonococcal isolates showed a low-level cross-reactivity in the 16S rRNA gene target. The detection limit for both targets was 1.5 copies per reaction.
3.
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.
4.
Unemo, Magnus, 1970-, et al.
(författare)
Genetic homogeneity/heterogeneity of Propionibacterium acnes isolated from patients during cardiothoracic reoperation
2007
Ingår i: Anaerobe. - London : Academic Press. - 1075-9964 .- 1095-8274. ; 13:3-4, s. 121-126
Tidskriftsartikel (refereegranskat) abstract
Following cardiothoracic surgery, deep sternal wound infection (SWI) remains one of the most severe complications. Recently, Propionibacterium acnes has been suspected as an etiological agent of deep SWI. However, this bacterium constitutes part of the resident micro-flora of the human skin. Consequently, findings of P. acnes in invasive samples are difficult to value. The aims of this study were to develop and optimize a pulsed-field gel electrophoresis (PFGE) protocol for P. acnes, in order to investigate the genetic homogeneity/heterogeneity of P. acnes isolates from multiple tissue samples (predominantly biopsies), collected at different locations, from 12 patients during cardiothoracic reoperation. There were 24 distinguishable PFGE fingerprints identified among the P. acnes isolates (n=54). Five (42%) of the patients carried only isolates that were interpreted as presumably clonally related. From the remaining seven patients, two or three different P. acnes clones were cultured, however, from six of them, the clones were identified in multiple samples. P. acnes may be a relatively frequent etiological agent of postoperative cardiothoracic infections. Existence of several clonally related P. acnes isolates derived from multiple samples from patients suffering from deep SWI after cardiothoracic surgery has not previously been shown.
5.
6.
Boiko, Iryna, et al.
(författare)
Antimicrobial susceptibility of Neisseria gonorrhoeae isolates and treatment of gonorrhoea patients in Ternopil and Dnipropetrovsk regions of Ukraine, 2013-2018
2019
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : John Wiley & Sons. - 0903-4641 .- 1600-0463. ; 127:7, s. 503-509
Tidskriftsartikel (refereegranskat) abstract
Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a major public health concern globally. However, recent gonococcal AMR data from Eastern Europe are extremely limited and no AMR data for strains spreading in Ukraine have ever been internationally published. We investigated the AMR of N. gonorrhoeae isolates in two regions of Ukraine (Ternopil 2013-2018, Dnipropetrovsk 2013-2014), and, where information was available, the treatment administered to the corresponding gonorrhoea patients. Determination of minimum inhibitory concentration (MIC) of eight antimicrobials was performed using Etest and resistance breakpoints from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) were applied. Overall, 9.3% of the examined 150 isolates were resistant to ciprofloxacin, 6.0% to tetracycline, 2.0% to azithromycin, and 0.7% to benzylpenicillin. No isolates were resistant to ceftriaxone, cefixime, spectinomycin, or gentamicin. However, one (0.7%) isolate showed a MIC value of 0.125 mg/L for both ceftriaxone and cefixime, i.e., bordering resistance. Eighty-eight (67.2%) of 131 patients were administered dual therapy (ceftriaxone 1 g plus doxycycline/clarithromycin/azithromycin/ofloxacin) and 22 (16.8%) ceftriaxone 1 g monotherapy. Worryingly, 21 (16.0%) patients received monotherapy with clarithromycin/doxycycline/azithromycin/ofloxacin/benzylpenicillin. In conclusion, the antimicrobial susceptibility of gonococcal strains spreading in Ternopil and Dnipropetrovsk, Ukraine during 2013-2018 was high. Low levels of resistance to ciprofloxacin, tetracycline, azithromycin, and benzylpenicillin were found, but no resistance to the internationally recommended ceftriaxone, cefixime, or spectinomycin. Ceftriaxone 1 g should remain as empiric first-line treatment, in dual therapy with azithromycin or doxycycline or in monotherapy. Continued and expanded gonococcal AMR surveillance in Ukraine is essential to monitor the susceptibility to particularly extended-spectrum cephalosporins, azithromycin and doxycycline.
7.
Hadad, Ronza, 1984-, et al.
(författare)
Macrolide and fluoroquinolone resistance in Mycoplasma genitalium in two Swedish counties, 2011-2015
2018
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Hoboken, NJ, USA : Wiley-Blackwell Publishing Inc.. - 0903-4641 .- 1600-0463. ; 126:2, s. 123-127
Tidskriftsartikel (refereegranskat) abstract
Mycoplasma genitalium, causing non-gonococcal non-chlamydial urethritis and associated with cervicitis, has developed antimicrobial resistance (AMR) to both the macrolide azithromycin (first-line treatment) and the fluoroquinolone moxifloxacin (second-line treatment). Our aim was to estimate the prevalence of resistance, based on genetic AMR determinants, to these antimicrobials in the M. genitalium population in two Swedish counties, Örebro and Halland, 2011-2015. In total, 672 M. genitalium positive urogenital samples were sequenced for 23S rRNA and parC gene mutations associated with macrolide and fluoroquinolone resistance, respectively. Of the samples, 18.6% and 3.2% in Örebro and 15.2% and 2.7% in Halland contained mutations associated with macrolide and fluoroquinolone resistance, respectively. The predominating resistance-associated mutations in the 23S rRNA gene was A2059G (n = 39) in Örebro and A2058G (n = 13) and A2059G (n = 13) in Halland. The most prevalent possible resistance-associated ParC amino acid alterations were S83I (n = 4) in Örebro and S83N (n = 2) in Halland. Resistance-associated mutations to both macrolides and fluoroquinolones were found in 0.7% of samples. Our findings emphasize the need for routine AMR testing, at a minimum for macrolide resistance, of all M. genitalium-positive samples and regular national and international surveillance of AMR in M. genitalium, to ensure effective patient management and rational antimicrobial use.
8.
Jacobsson, Susanne, 1974-, et al.
(författare)
WHO laboratory validation of Xpert((R)) CT/NG and Xpert((R)) TV on the GeneXpert system verifies high performances
2018
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : John Wiley & Sons. - 0903-4641 .- 1600-0463. ; 126:12, s. 907-912
Tidskriftsartikel (refereegranskat) abstract
Effective tests for diagnosis of sexually transmitted infections (STIs), used point of care to inform treatment and management decisions, are urgently needed. We evaluated the analytical sensitivity and specificity of the Xpert((R)) CT/NG and Xpert((R)) TV tests, examining 339 samples spiked with phenotypically and/or genetically diverse strains of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis, and other related species that may cross-react. The APTIMA Combo 2 test and APTIMA TV test were used as reference tests. The analytical sensitivity for all three agents in the Xpert((R)) CT/NG and Xpert((R)) TV tests was <= 10(2) genome equivalents/reaction. The analytical specificity of both tests was high. False-positive results were identified in the Xpert((R)) TV test when challenging with high concentrations of Trichomonas tenax, Trichomonas gallinae, Trichomonas stableri, and Trichomonas aotus. However, the clinical relevance of these cross-reactions can likely be neglected, because these species have not been identified in urogenital samples from humans. In conclusion, the analytical sensitivity and specificity of the user-friendly Xpert((R)) CT/NG and Xpert((R)) TV tests on the GeneXpert system were high. The results support the use of specimens from also extra-genital sites, for example, pharynx and rectum. However, appropriate clinical validations are additionally required.
9.
Jensen, Jørgen Skov, et al.
(författare)
In vitro activity of the first-in-class triazaacenaphthylene gepotidacin alone and in combination with doxycycline against drug-resistant and -susceptible Mycoplasma genitalium
2020
Ingår i: Emerging Microbes & Infections. - : Taylor & Francis. - 2222-1751. ; 9:1, s. 1388-1392
Tidskriftsartikel (refereegranskat) abstract
Mycoplasma genitalium has developed resistance to first-line azithromycin and second-line moxifloxacin. Third-line pristinamycin is only 75% effective. Gepotidacin, a novel triazaacenaphthylene topoisomerase II inhibitor, blocks bacterial DNA replication. We determined thein vitroactivity of gepotidacin alone and in combination with doxycycline against a diverse collection of Mycoplasma genitalium isolates (n = 54).Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by a Vero-cell culture method. Macrolide resistance was present in 31 (57%) isolates, fluoroquinolone resistance in 18 (33%) isolates, and 17 (31%) had dual resistance. Synergy testing was performed for gepotidacin and doxycycline by checkerboard analysis for two macrolide- and two dual-resistant isolates.Gepotidacin was active against all 54 M. genitalium isolates with median and modal MICs of 0.125 mg/L and MIC(90)of 0.25 mg/L (range <= 0.016-0.5 mg/L). No difference in gepotidacin MIC between macrolide-resistant and -susceptible isolates (p = 0.24) or between fluoroquinolone-, dual-resistant and -susceptible isolates (p = 0.2) was demonstrated. Gepotidacin MBCs were available for 44 M. genitalium isolates with median MIC of 0.064 mg/L and median MBC of 0.125 mg/L. All isolates had <= 4-fold difference between MIC and MBC, suggesting bactericidal effect for gepotidacin. Checkerboard analysis indicated synergistic effect for gepotidacin in combination with doxycycline [fractional inhibitory concentration index (sigma FICI) of 0.5] for two isolates and additive/indifference (sigma FICI at 0.62 and 0.75) for two isolates.Gepotidacin warrants further evaluation in clinical treatment trials for M. genitalium. Combination therapy with doxycycline should be clinically studied to assess effect and potential protection against development and/or spread of gepotidacin resistance.
10.
Khairullin, Rafil, et al.
(författare)
Syphilis epidemiology in 1994-2013, molecular epidemiological strain typing and determination of macrolide resistance in Treponema pallidum in 2013-2014 in Tuva Republic, Russia
2016
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Hoboken, USA : Wiley-Blackwell. - 0903-4641 .- 1600-0463. ; 124:7, s. 595-602
Tidskriftsartikel (refereegranskat) abstract
The incidence of syphilis in the Tuva Republic (geographical centre of Asia), Russia has been exceedingly high historically. No detailed examinations and no molecular investigations of Treponema pallidum strains transmitted in the Tuva Republic, or in general, in Russia, were published internationally. We examined the syphilis epidemiology in 1994-2013, and the molecular epidemiology and macrolide resistance in T. pallidum strains in 2013-2014 in the Tuva Republic. Among 95 mainly primary or secondary syphilis patients, the arp, tpr, tp0548 and 23S rRNA genes in 85 polA gene-positive genital ulcer specimens were characterized. The syphilis incidence in Tuva Republic peaked in 1998 (1562), however declined to 177 in 2013. Among the 70 (82%) completely genotyped specimens, six molecular strain types were found. Strain type 14d/f accounted for 91%, but also 14c/f, 14d/g, 14b/f, 14i/f, 9d/f, and 4d/f were identified. Two (2.4%) specimens contained the 23S rRNA A2058G macrolide resistance mutation. This is the first internationally published typing study regarding T. pallidum in Russia, performed in the Tuva Republic with the highest syphilis incidence in Russia. The two molecular strain types 4d/f and 9d/f have previously been described only in Eastern and Northern China and for the first time, macrolide-resistant syphilis was described in Russia.
