MLVA Subtyping of Genovar E Chlamydia trachomatis Individualizes the Swedish Variant and Anorectal Isolates from Men who Have Sex with Men

This study describes a new multilocus variable number tandem-repeat (VNTR) analysis (MLVA) typing system for the discrimination of Chlamydia trachomatis genovar D to K isolates or specimens. We focused our MLVA scheme on genovar E which predominates in most populations worldwide. This system does not require culture and therefore can be performed directly on DNA extracted from positive clinical specimens. Our method was based on GeneScan analysis of five VNTR loci labelled with fluorescent dyes by multiplex PCR and capillary electrophoresis. This MLVA, called MLVA-5, was applied to a collection of 220 genovar E and 94 non-E genovar C. trachomatis isolates and specimens obtained from 251 patients and resulted in 38 MLVA-5 types. The genetic stability of the MLVA-5 scheme was assessed for results obtained both in vitro by serial passage culturing and in vivo using concomitant and sequential isolates and specimens. All anorectal genovar E isolates from men who have sex with men exhibited the same MLVA-5 type, suggesting clonal spread. In the same way, we confirmed the clonal origin of the Swedish new variant of C. trachomatis. The MLVA-5 assay was compared to three other molecular typing methods, ompA gene sequencing, multilocus sequence typing (MLST) and a previous MLVA method called MLVA-3, on 43 genovar E isolates. The discriminatory index was 0.913 for MLVA-5, 0.860 for MLST and 0.622 for MLVA-3. Among all of these genotyping methods, MLVA-5 displayed the highest discriminatory power and does not require a time-consuming sequencing step. The results indicate that MLVA-5 enables high-resolution molecular epidemiological characterisation of C. trachomatis genovars D to K infections directly from specimens

Active Trachoma and Ocular Chlamydia trachomatis Infection in Two Gambian Regions: On Course for Elimination by 2020?

Trachoma is the leading infectious cause of blindness worldwide, and is mainly found in tropical and poor countries. It is caused by infection of the eyes with the bacterium Chlamydia trachomatis. However, sometimes the clinical signs of disease can be present without infection being detected. Control efforts involve surgery, antibiotic treatment, face washing, and environmental improvement for better hygiene. Surveys of trachoma help countries to know whether and where they should implement control interventions. The Gambia is found in West Africa and has suffered from trachoma for decades. We conducted a survey of two Gambian regions to look at how much trachoma disease and C. trachomatis infection there is in the eyes. We found that although there was enough disease (≥10%) to warrant antibiotic treatment for everyone in the regions, there was nearly no infection (0.3%). This means that using clinical signs alone to make treatment decisions in low prevalence settings like The Gambia can lead to the waste of scarce resources. Our results also suggest that since less than 1% of children are infected with C. trachomatis, The Gambia is on course to achieve the World Health Organization's aim of eliminating blinding trachoma by the year 2020

Diagnostic Accuracy of a Prototype Point-of-Care Test for Ocular Chlamydia trachomatis under Field Conditions in The Gambia and Senegal

Trachoma, caused by infection of the eye with the bacterium Chlamydia trachomatis, is the leading infectious cause of blindness and is associated with poverty. Antibiotic treatment of all community members is one of the recommended control strategies for trachoma. However, in places where the prevalence of clinical signs is low, C. trachomatis eye infection is often absent. Laboratory testing for C. trachomatis infection by polymerase chain reaction (PCR) is highly sensitive but expensive and requires well-trained staff. A simple point-of-care (POC) test that can be used in trachoma-affected communities could help trachoma control efforts. We evaluated a POC test for C. trachomatis eye infection. Children under 10 years of age were screened for clinical signs of trachoma and C. trachomatis eye infection. The POC test result was compared with laboratory PCR test results. The POC test detected just over half of PCR test positives correctly. However, the POC test tended to give false-positive results in hot and dry conditions, which is the typical environment of trachoma. The POC test requires high specificity since it would be used to make treatment decisions at the community level. Therefore, its present format requires improvement before it can be utilized in trachoma control

Mycoplasma genitalium: An Emerging Cause of Sexually Transmitted Disease in Women

Mycoplasma genitalium is an emerging sexually transmitted pathogen implicated in urethritis in men and several inflammatory reproductive tract syndromes in women including cervicitis, pelvic inflammatory disease (PID), and infertility. This comprehensive review critically examines epidemiologic studies of M. genitalium infections in women with the goal of assessing the associations with reproductive tract disease and enhancing awareness of this emerging pathogen. Over 27,000 women from 48 published reports have been screened for M. genitalium urogenital infection in high- or low-risk populations worldwide with an overall prevalence of 7.3% and 2.0%, respectively. M. genitalium was present in the general population at rates between those of Chlamydia trachomatis and Neisseria gonorrhoeae. Considering more than 20 studies of lower tract inflammation, M. genitalium has been positively associated with urethritis, vaginal discharge, and microscopic signs of cervicitis and/or mucopurulent cervical discharge in seven of 14 studies. A consistent case definition of cervicitis is lacking and will be required for comprehensive understanding of these associations. Importantly, evidence for M. genitalium PID and infertility are quite convincing and indicate that a significant proportion of upper tract inflammation may be attributed to this elusive pathogen. Collectively, M. genitalium is highly prevalent in high- and low-risk populations, and should be considered an etiologic agent of select reproductive tract disease syndromes in women

A case of sylvatic dermatophytosis due to Trichophyton mentagrophytes in a cat

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