Transcontinental Dissemination of the L2b/D-Da Recombinant Chlamydia trachomatis Lymphogranuloma venereum (LGV) Strain: Need of Broad Multi-Country Molecular Surveillance.

Previously, we identified a Chlamydia trachomatis lymphogranuloma venereum (LGV) recombinant strain possessing a non-LGV ompA genotype. Here, culture-independent genome sequencing confirms its circulation in Europe, Middle East, and North America, and unveils emergence of antibiotic resistance. Broad surveillance is needed.

High-resolution multilocus sequence typing for Chlamydia trachomatis: improved results for clinical samples with low amounts of C. trachomatis DNA.

BACKGROUND: Several Multilocus Sequence Typing (MLST) schemes have been developed for Chlamydia trachomatis. Bom's MLST scheme for MLST is based on nested PCR amplification and sequencing of five hypervariable genes and ompA. In contrast to other Chlamydia MLST schemes, Bom's MLST scheme gives higher resolution and phylogenetic trees that are comparable to those from whole genome sequencing. However, poor results have been obtained with Bom's MLST scheme in clinical samples with low concentrations of Chlamydia DNA. RESULTS: In this work, we present an improved version of the scheme that is based on the same genes and MLST database as Bom's MLST scheme, but with newly designed primers for nested-1 and nested-2 steps under stringent conditions. Furthermore, we introduce a third primer set for the sequencing step, which considerably improves the performance of the assay. The improved primers were tested in-silico using a dataset of 141 Whole Genome Sequences (WGS) and in a comparative analysis of 32 clinical samples. Based on cycle threshold and melting curve analysis values obtained during Real-Time PCR of nested-1 & 2 steps, we developed a simple scoring scheme and flow chart that allow identification of reaction inhibitors as well as to predict with high accuracy amplification success. The improved MLST version was used to obtain a genovars distribution in patients attending an STI clinic in Tel Aviv. CONCLUSIONS: The newly developed MLST version showed great improvement of assay results for samples with very low concentrations of Chlamydia DNA. A similar concept could be applicable to other MLST schemes.

Delayed diagnosis of colorectal sexually transmitted diseases due to their resemblance to inflammatory bowel diseases.

OBJECTIVE: Sexually transmitted diseases (STDs), mainly lymphogranuloma venereum (LGV), induce colorectal symptoms that may be misdiagnosed as inflammatory bowel disease (IBD). This study describes patients who presented with STDs masquerading as IBD in order to improve understanding of missed diagnosis of colorectal STDs and their association with LGV in Israel. METHODS: This retrospective, descriptive study characterized the clinical, endoscopic, and pathological findings of 16 patients who were diagnosed with a colorectal STD after erroneously being diagnosed with IBD. Molecular genotyping was used to characterize some of the Chlamydia trachomatis isolates. RESULTS: All patients were men who have sex with men (MSM), mostly HIV-1-positive, and had clinical and endoscopic findings compatible with IBD. The STD was diagnosed 1-36 months after the initial diagnosis: 14 were positive for Chlamydia trachomatis, of which three were of the LGV2b (ST58) serotype and one was ST 108 serotype. Five were positive for gonorrhea and four were positive for syphilis. Several pathogens were diagnosed in six episodes. CONCLUSIONS: Colorectal STDs may resemble IBD and therefore their diagnosis may be delayed. IBD symptoms in MSM who engage in non-protected anal sex should prompt at least syphilis and anal PCR for STD testing. If C. trachomatis is diagnosed but LGV subtyping cannot be done, doxycycline 100mg twice daily for 21days should be recommended.

Microbial Source Tracking in Adjacent Karst Springs.

Modern man-made environments, including urban, agricultural, and industrial environments, have complex ecological interactions among themselves and with the natural surroundings. Microbial source tracking (MST) offers advanced tools to resolve the host source of fecal contamination beyond indicator monitoring. This study was intended to assess karst spring susceptibilities to different fecal sources using MST quantitative PCR (qPCR) assays targeting human, bovine, and swine markers. It involved a dual-time monitoring frame: (i) monthly throughout the calendar year and (ii) daily during a rainfall event. Data integration was taken from both monthly and daily MST profile monitoring and improved identification of spring susceptibility to host fecal contamination; three springs located in close geographic proximity revealed different MST profiles. The Giach spring showed moderate fluctuations of MST marker quantities amid wet and dry samplings, while the Zuf spring had the highest rise of the GenBac3 marker during the wet event, which was mirrored in other markers as well. The revelation of human fecal contamination during the dry season not connected to incidents of raining leachates suggests a continuous and direct exposure to septic systems. Pigpens were identified in the watersheds of Zuf, Shefa, and Giach springs and on the border of the Gaaton spring watershed. Their impact was correlated with partial detection of the Pig-2-Bac marker in Gaaton spring, which was lower than detection levels in all three of the other springs. Ruminant and swine markers were detected intermittently, and their contamination potential during the wet samplings was exposed. These results emphasized the importance of sampling design to utilize the MST approach to delineate subtleties of fecal contamination in the environment.