Direct high-resolution genotyping of Chlamydia trachomatis positive swabs from women in Southampton using ompA and three variable-number tandem repeats

Abstract number: O103

Wang Y., Skilton R., Andrews E., Clarke I., Marsh P.

Objectives: Genital chlamydial infection is the commonest diagnosed sexually transmitted infection in the UK. Chlamydia trachomatis infections are caused by strains which fall into two pathovars: 'serovars' of lymphogranuloma venereum (LGV) and the genitourinary 'serovars' D-K. Although these serovars can be discriminated by outer membrane protein gene (ompA) sequencing (genotyping) or multi-locus sequence typing (MLST), neither affords the high-resolution genetic typing required for local epidemiology and accurate contact-tracing. Therefore our objectives were to develop and apply a new high resolution genetic typing technique to studying the molecular epidemiology of C. trachomatis in positive swabs from our local genitourinary medicine (GUM) clinic.

Methods: 162 endocervical swabs were taken at the Southampton GUM clinic and tested by routine diagnostic PCR for the presence of C. trachomatis. Positive samples were genotyped by use of a variable number tandem repeat (VNTR)-ompA sequencing technique. Isolates were cultured from the positives where possible.

Results: Of the 162 samples, 86 were fully typed by VNTR-ompA. Only one mixed infection (E & F) in one sample was confirmed. The commonest genotypes were D, E & F, comprising 20%, 45% and 15% of the genotyped positives respectively. Within each of these genovars there were multiple VNTR sub-types. 69 of the swabs yielded culturable isolates able to passage multiple times.

Conclusions: This is the first comprehensive fine molecular epidemiology genetic typing survey of C. trachomatis in the UK. Amongst the common genotypes, there are a significant number of defined sub-types, which may reflect backgrounds of particular demographics relating to age group, geography, high-risk sexual behaviour, and sexual networks.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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