Treponema pallidum Subspecies Pallidum Intrapatient Homogeneity at Various Body Locations in Men with Infectious Syphilis.

Syphilis, caused by Treponema pallidum subspecies pallidum (TP), is a complex multistage infectious disease. Systematic dissemination occurs within a few hours of transmission. We determined the molecular variation of TP at various body locations and peripheral blood within patients in different stages of syphilis to assess the distribution of TP strains at these locations. We included 162 men who have sex with men (MSM) with syphilis visiting the Sexual Health Center in Amsterdam between 2018 to 2019, who had TP DNA detected in at least one sample type (anal swab, urine sample, peripheral blood, pharyngeal swab, and/or ulcer swab). TP DNA was detected in 287 samples using a qPCR targeting the polA gene. With multilocus sequence typing (TP-MLST) based on partial sequence analysis of three genetic regions (tp0136, tp0548, tp0705), we characterized all TP DNA positive samples. Samples could be typed (119/287) from at least one anatomical location or peripheral blood from 93/162 (57%) patients in the following stages: 48 (52%) primary, 35 (38%) secondary, and 10 (11%) early latent stage syphilis. The TP-MLST type was identical within each of the 12 patients with typed samples at ≥2 different body locations. The most prevalent TP strains were 1.3.1 (39/93, 42%) and 1.1.1 (17/93, 18%) belonging to the SS14 lineage; 80% (74/93) of the patients carried a SS14 lineage TP strain and 20% (19/93) Nichols lineage. The distribution of TP-MLST types did not differ between patients by syphilis stage. We found intrapatient TP strain homogeneity and no TP strain variation between anatomical location or syphilis stages. More early latent samples should be typed and added in future studies to investigate this in more detail. IMPORTANCE Syphilis, caused by Treponema pallidum subspecies pallidum, is a complex multistage infectious disease. Systematic dissemination is known to occur within a few hours of transmission. Despite the effective antibiotic penicillin, syphilis remains prevalent worldwide. Men who have sex with men are disproportionally affected in high income countries like the Netherlands where 96% of the syphilis cases in 2020 were among this population. The inability to in vitro culture T. pallidum directly from patient samples limits whole-genome sequencing efforts. Fortunately, in 2018 a multilocus sequence typing technique was developed for T. pallidum allowing the monitoring of circulating strains. The significance of our research is in the investigation of T. pallidum molecular variation at various body locations and blood within patients in different stages of syphilis in order to assess the distribution of strains at these locations.

Multilocus sequence typing of Trichomonas vaginalis clinical samples from Amsterdam, the Netherlands.

OBJECTIVES: In this cross-sectional epidemiological study we aimed to identify molecular profiles for Trichomonas vaginalis and to determine how these molecular profiles were related to patient demographic and clinical characteristics. SETTING: Molecular typing methods previously identified two genetically distinct subpopulations for T. vaginalis; however, few molecular epidemiological studies have been performed. We now increased the sensitivity of a previously described multilocus sequence typing (MLST) tool for T. vaginalis by using nested PCR. This enabled the typing of direct patient samples. PARTICIPANTS: From January to December 2014, we collected all T. vaginalis positive samples as detected by routine laboratory testing. Samples from patients either came from general practitioners offices or from the sexually transmitted infections (STI) clinic in Amsterdam. Epidemiological data for the STI clinic patients were retrieved from electronic patient files. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the success rate of genotyping direct T. vaginalis positive samples. The secondary outcome was the relation between T. vaginalis genotypes and risk factors for STI. RESULTS: All 7 MLST loci were successfully typed for 71/87 clinical samples. The 71 typed samples came from 69 patients, the majority of whom were women (n=62; 90%) and half (n=34; 49%) were STI clinic patients. Samples segregated into a two population structure for T. vaginalis representing genotypes I and II. Genotype I was most common (n=40; 59.7%). STI clinic patients infected with genotype II reported more sexual partners in the preceding 6 months than patients infected with genotype I (p=0.028). No other associations for gender, age, ethnicity, urogenital discharge or co-occurring STIs with T. vaginalis genotype were found. CONCLUSIONS: MLST with nested PCR is a sensitive typing method that allows typing of direct (uncultured) patient material. Genotype II is possibly more prevalent in high-risk sexual networks.

Trichomonas vaginalis and Mycoplasma genitalium: age-specific prevalence and disease burden in men attending a sexually transmitted infections clinic in Amsterdam, the Netherlands.

BACKGROUND: Men are not routinely tested for Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) in the Netherlands and, therefore, very few studies have looked into their prevalence and/or role in urogenital complaints in the Dutch male population. OBJECTIVE: To describe the age-specific prevalence and disease burden of TV and MG, and their co-occurrence with Chlamydia trachomatis (CT), in men attending the sexually transmitted infections (STI) clinic in Amsterdam, the Netherlands. METHODS: Urine samples and clinical data were collected from 526 men who have sex with women (MSW) and 678 men who have sex with men (MSM) attending the STI clinic. To investigate age as a risk factor, we oversampled older men. Urine samples were tested for TV and MG using molecular tests. RESULTS: The overall prevalence was 0.5% (6/1204) for TV and 3.1% (37/1204) for MG. Four out of the six TV cases were older than 40 years and all TV cases were MSW. No age trend was observed for MG, nor did MG prevalence differ between MSW and MSM. Co-infections between TV or MG and CT were rare. TV infection did not associate with urogenital symptoms, whereas 5.9% of men reporting urogenital symptoms were infected with MG. CONCLUSIONS: TV infection was rare in men, asymptomatic and was limited to the heterosexual network. MG infection was relatively common and equally prevalent among MSW and MSM of all ages. Most MG infections remained asymptomatic, however, our results suggest that up to 6% of urogenital complaints could be explained by MG infection.