Mycoplasma genitalium causes male nonchlamydial, nongonococcal urethritis and is associated with cervicitis and pelvic inflammatory disease in women. Epidemiological studies indicate that M. genitalium is sexually transmitted, and the aim of the present study was to further substantiate this by means of a DNA typing system. A typing assay based on a diagnostic mgpB gene PCR was developed, evaluated, and applied directly to urogenital specimens. The assay had a low limit of detection and hence a high typeability. Sequences of isolates from 52 unrelated patients were divided into 29 different sequence types, giving a discriminatory index of 0.95. Two to six M. genitalium-positive specimens were collected from each of 44 patients over a median interval of 56 days (range, 11 to 1,395). Forty had the same sequence type in consecutive specimens. Specimens collected from two men were repeatedly positive at intervals of 472 and 1,395 days, respectively, but the sequence types had changed. A new strain was introduced in one sexual dyad, and the sequence types changed subsequently. Seventy-nine M. genitalium-positive specimens from 19 couples were investigated, and all partners initially had concordant sequence types, but one couple had discordant types at one time point before a newly introduced strain took over. The present typing system is simple and reproducible and has an excellent discriminatory capacity which might prove useful in studies of sexual networks and for evaluation of treatment failures. In the laboratory, this system may document the uniqueness of newly isolated M. genitalium strains.
Three cohorts of Danish male military recruits (n = 1069) were studied for pharyngeal meningococcal carriage during 3 months at different seasons: 39-47% of entrants were meningococcal carriers and the carriage rate remained constant over time and season. However, individual changes in the carrier state occurred frequently, and after 3 months 34% had changed carrier state on one or more occasions. Initially, a loss of carriage predominated; on the other hand almost 20% of non-carriers had acquisition of meningococci within the first month. The serological phenotypes of the 670 carrier strains were compared with those of 261 invasive strains recovered concurrently from patients with meningococcal disease country-wide. Both carrier strains and invasive strains were phenotypically heterogeneous. Almost 60% of the invasive strains belonged to three phenotypes: B:15:P1.7, 16, C:2a:P1.2, 5 and C:2b:P1.2, 5. In contrast, these phenotypes only amounted to 3.2% of the carrier strains, among which no phenotype was found with a prevalence above 4.9%. However, 30% of the carrier strains had serological phenotypes identical to those of 80% of the invasive strains. Our results indicated that the transmission rate of potential pathogenic carrier strains did not differ from that of other carrier strains.
The incidence rate (IR) and case-fatality rate (CFR) of meningococcal disease increased during the late 1980s and early 1990s in North Jutland County, Denmark. We examined the hypothesis that phenotypic markers of Neisseria meningitidis are predictors of septicaemia with or without meningitis, rapid disease progress and fatal outcome of meningococcal disease and we studied whether changes in IR and CFR over time might be related to emergence or spread of certain phenotypes. This follow-up study was based on a complete registration of 413 cases of meningococcal disease in North Jutland County during 1980-99. Phenotypic markers included serogroup, serotype and serosubtype. A complete phenotype was available for 315 cases (76 %); 100 (32 %) strains were phenotype B : 15 : P1.7,16 and 31 (10 %) were C : 2a : P1.2,5. Septicaemia without meningitis was less common in cases with B : 15 : P1.7,16 and C : 2a : P1.2,5 strains. No association was found between phenotype and rapid disease progress. The overall CFR was 12 %. An increased CFR was associated with phenotypes B : 15 : P1.7,16 [odds ratio (OR) 2·8, 95 % confidence interval (CI) 1·2-18·5] and C : 2a : P1.2,5 (OR 5·2, 95 % CI 1·6-16·4) when compared with other phenotypes. The prevalence of B : 15 : P1.7,16 strains increased gradually during the study period and the CFR increased from 8 % during 1980-89 to 19 % during 1990-99, although the CFR for other phenotypes also increased. The CFR for C : 2a : P1.2,5 remained high ($20 %), but the contribution of this phenotype to the overall CFR decreased during the study period. In conclusion, phenotypes B : 15 : P1.7,16 and C : 2a : P1.2,5 were predictors of an increased CFR. The high prevalence of phenotype B : 15 : P1.7,16 contributed to increased overall IR and CFR during 1990-99.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.