The 2008 WHO N. gonorrhoeae reference strain panel was extensively characterized, which is crucial for the expansion of gonococcal AMR surveillance nationally and internationally. The panel is available through WHO sources for quality assurance and quality control aspects of current phenotypic testing protocols, to allow valid comparison of AMR data derived by divergent methods, and also for the control of present and future molecular assays for AMR detection. Additional WHO reference strains can be included as required by the emergence of additional resistant phenotypes and/or genotypes.
The recent emergence and transmission of Neisseria gonorrhoeae isolates with reduced susceptibility to expanded-spectrum cephalosporins such as cefixime and ceftriaxone have been reported. The aim of this study was to determine the correlation of different polymorphisms in the penA, mtrR, porB1b (penB), and ponA genes of N. gonorrhoeae with reduced susceptibility to cefixime and ceftriaxone. Eighteen gonococcal isolates with reduced cefixime and ceftriaxone susceptibility (Cef i ) and two susceptible isolates were characterized using serovar determination, antibiograms, N. gonorrhoeae multiantigen sequence typing (NG-MAST), and sequencing of penA, mtrR, porB1b, and ponA alleles. For the Cef i isolates (n ؍ 18), the MICs of cefixime and ceftriaxone ranged between 0.032 to 0.38 g/ml and 0.064 to 0.125 g/ml, respectively. These isolates were assigned five different serovars and six divergent NG-MAST sequence types. Eleven isolates (61%) with higher MICs of cefixime and ceftriaxone contained a nearly identical penA mosaic allele and previously described polymorphisms in mtrR (a single nucleotide [A] deletion in the promoter), penB (mutations in porB1b encoding loop 3 of PorB1b), and ponA (ponA1 polymorphism). The remaining seven Cef i isolates (39%), which had somewhat lower MICs of cefixime and ceftriaxone, contained an aspartic acid insertion (Asp-345a) in PBP 2 in conjunction with alterations of 4 to 10 amino acid residues in the C-terminal region of the transpeptidase domain of penA. In conclusion, an unambiguous association between penA mosaic alleles, in conjunction with genetic polymorphisms in mtrR, porB1b, and ponA, and greater reduced susceptibility to cefixime and ceftriaxone was identified.
Objectives: To study the prevalence, symptoms, and signs of Mycoplasma genitalium and Chlamydia trachomatis infections in women attending a Swedish STD clinic, accessible for both sexes, and in a group of young women called in the cervical cancer screening programme. Methods: A cross sectional study among female STD clinic attendees in Ö rebro and a study among women called for Papanicolaou smear screening. Attendees were examined for urethritis and cervicitis. First void urine and endocervical samples were tested for M genitalium and C trachomatis. Results: The prevalence of C trachomatis and M genitalium in the STD clinic population was 10% (45/465) and 6% (26/461), respectively. Dual infection was diagnosed in four women. In the cancer screening group of women the corresponding prevalence was 2% (1/59) and 0%, respectively. Among the STD clinic attendees there were no significant differences in symptoms (32% v 23%, RR 1.4, 95% CI 0.6 to 3.4) or signs (71% v 50%, RR 1.4, 95% CI 0.9 to 2.3) between C trachomatis and M genitalium infections. Microscopic signs of cervicitis were significantly more common among M genitalium and C trachomatis infected women than in the cancer screening group of women. 56% (15/27) of male partners of M genitalium infected women were infected with M genitalium compared to 59% of male partners of C trachomatis infected women who were infected with C trachomatis (p = 0.80). Conclusions: M genitalium is a common infection associated with cervicitis and with a high prevalence of infected sexual partners supporting its role as a cause of sexually transmitted infection. M ycoplasma genitalium was isolated originally from the urethra of two men with non-gonococcal urethritis (NGU) in 1980.1 2 Isolation of this bacterium is very difficult, but the use of polymerase chain reaction (PCR) technology has consistently shown M genitalium to be a major cause of non-chlamydial non-gonococcal urethritis (NCNGU) among men. [2][3][4][5][6][7][8] There is also increasing evidence that M genitalium causes mucopurulent cervicitis in women 9 and that it may cause endometritis 10 11 and possibly tubal infection with sequelae in the form of ectopic pregnancy or tubal infertility.12 Only one published study has failed to show an association between urogenital tract disease and the presence of M genitalium in the female genital tract. 13 However, no asymptomatic patients were included in that study and surprisingly, as many as 38% of the women were positive compared with a C trachomatis prevalence of 8%, raising concern about the specificity of the M genitalium assay. Most M genitalium studies in STD clinic outpatients have focused on symptomatic patients with urethritis and have used nonsymptomatic patients as controls. These studies demonstrate that M genitalium, C trachomatis, and Neisseria gonorrhoeae are significantly more frequently detected among symptomatic patients than among asymptomatic controls, thus indicating that these bacteria are pathogens of the genital tract. This is emphasised by the fact t...
Background and ObjectiveBacterial 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 MethodsVaginal 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.ResultsRelative 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.ConclusionsQuantitative 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.
A method for detection and genotyping of genital Chlamydia trachomatis infections based on omp1 gene amplification and sequencing was developed. DNA was extracted from urogenital or urine samples using a Chelex-based method, and an approximately 1,100-bp-long fragment from the omp1 gene was directly amplified and sequenced. Genotyping was performed by BLAST similarity search, and phylogenetic tree analysis was used to illustrate the evolutionary relationships between clinical isolates and reference strains. The method was used to determine the genotypes of C. trachomatis in 237 positive urogenital and/or urine specimens collected at a Swedish sexually transmitted disease clinic during 1 year. The most common genotypes corresponded to serotypes E (47%) and F (17%). The omp1 gene was highly conserved for genotype E (106 of 112 samples without any mutation) and F (41 of 42 samples without any mutation) strains but appear slightly less conserved for genotypes G (n ؍ 6) and H (n ؍ 6), where the sequences displayed one to four nucleotide substitutions relative to the reference sequence. Genotyping of samples collected at the follow-up visit indicated that two patients had become reinfected, while three other patients suffered treatment failure or reinfection. One woman appeared to have a mixed infection with two different C. trachomatis strains. This omp1 genotyping method had a high reproducibility and could be used for epidemiological characterization of sexually transmitted Chlamydia infections.
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