title: No indication for tissue tropism in urogenital and anorectal Chlamydia trachomatis infections using high-resolution multilocus sequence typing.
abstract: BACKGROUND
  Previous studies showed that C. trachomatis strains found in MSM are different from those in heterosexuals. This study investigates whether the differences in strain distribution between MSM and heterosexuals are due to tissue tropism.
  
  
  METHODS
  C. trachomatis positive samples were collected from MSM (anorectal) and women (anorectal, cervical, vaginal, pharyngeal) visiting the STI outpatient clinic of Amsterdam between 2008 and 2013. All samples were typed using multilocus sequence typing (MLST). Epidemiological data were derived from electronic patient records.
  
  
  RESULTS
  We obtained full MLST data for C. trachomatis from 207 MSM and 185 women, all with anorectal infections. Six large clusters were identified of which 3 consisted predominantly of samples from women (89%-100%), whereas the other 3 consisted predominantly of samples from MSM (97%-100%). Furthermore, we obtained full MLST data from 434 samples of 206 women with concurrent infections at multiple anatomical locations. No association was observed between C. trachomatis cluster and the anatomical location of infection.
  
  
  CONCLUSIONS
  We found no indication for tissue tropism in urogenital, pharyngeal and anorectal C. trachomatis infections. Combined with results from previously conducted studies, we hypothesize that MSM and heterosexuals have different distributions of C. trachomatis strains due to their separate sexual networks.
authors.forename: Bart
authors.initials: B
authors.lastname: Versteeg
authors.forename: Martijn S
authors.initials: MS
authors.lastname: van Rooijen
authors.forename: Maarten F
authors.initials: MF
authors.lastname: Schim van der Loeff
authors.forename: Henry J C
authors.initials: HJ
authors.lastname: de Vries
authors.affiliation: Public Health Laboratory, Cluster Infectious Diseases, Public Health Service Amsterdam, Amsterdam, The Netherlands. sbruisten@ggd.amsterdam.nl.
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Bruisten
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques; D002584:Cervix Uteri / Q000382:microbiology; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D002692:Chlamydia trachomatis / Q000145:classification / Q000235:genetics*; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D058885:Multilocus Sequence Typing / Q000379:methods*; D010614:Pharynx / Q000382:microbiology; D012007:Rectum / Q000382:microbiology; D012189:Retrospective Studies; D012309:Risk-Taking; D012725:Sexual Behavior; D014621:Vagina / Q000382:microbiology; D055815:Young Adult