Highly diverse MLVA-ompA genotypes of rectal Chlamydia trachomatis among men who have sex with men in Brighton, UK and evidence for an HIV-related sexual network.
In this prospective study, we aimed to determine the distribution of genotypes by multilocus variable number tandem repeat (VNTR) analysis plus analysis of the ompA gene (MLVA-ompA) of rectal Chlamydia trachomatis among men who have sex with men (MSM) attending Brighton Genitourinary Medicine (GUM) Clinic and to examine any correlations with clinical variables, including HIV status, and to isolate rectal C. trachomatis cultures maximising the possibility of obtaining complete genotyping data.



Samples were assigned genotypes by PCR and sequencing of the markers of the MLVA-ompA genotyping system. Rectal C. trachomatis was isolated in cell culture using McCoy cells. Data regarding demographics, HIV status, rectal symptoms and history of sexually transmitted infections, including C. trachomatis, were collected.



1809 MSM attending the clinic between October 2011 and January 2013 took part in the study, 112 (6.2%) of whom had rectal samples that tested positive for C. trachomatis. 85/112 (75.9%) C. trachomatis-positive rectal samples were assigned 66 different genotypes. Two distinct genotype subclusters were identified: subcluster 1 consisted of more HIV-negative men than subcluster 2 (p=0.025), and the MLVA-ompA genotypes in these subclusters reflected this. Isolates were successfully cultured from 37 of the 112 specimens, from which 27 otherwise unobtainable (from direct PCR) MLVA-ompA genotypes were gained.



The most prevalent genotypes were G, E and D representing some overlap with the heterosexual distribution in UK. Subcluster 1 consisted of more 'heterosexual genotypes' and significantly more HIV-negative men than subcluster 2, associated with 'MSM genotypes'. There was a higher diversity of C. trachomatis strains among MSM in Brighton than observed in other cities.
Department of Molecular Microbiology, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Clare
C
Labiran
Public Health England, Public Health Laboratory Southampton, Southampton General Hospital, Southampton, UK.
Peter
P
Marsh
Claude Nicol Clinic, Royal Sussex County Hospital, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK.
Judith
J
Zhou
Claude Nicol Clinic, Royal Sussex County Hospital, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK.
Alan
A
Bannister
Department of Molecular Microbiology, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Ian Nicholas
IN
Clarke
Clinical Investigation Research Unit, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK.
Stephanie
S
Goubet
Claude Nicol Clinic, Royal Sussex County Hospital, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK.
Suneeta
S
Soni
D000328:Adult; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control; D002692:Chlamydia trachomatis / Q000235:genetics* / Q000302:isolation & purification*; D005838:Genotype; D018023:HIV Seronegativity; D006679:HIV Seropositivity; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D015995:Prevalence; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D012725:Sexual Behavior; D006113:United Kingdom / Q000453:epidemiology
D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins
CHLAMYDIA TRACHOMATIS; GAY MEN; HIV; MOLECULAR EPIDEMIOLOGY; SEXUAL BEHAVIOUR