title: The pig-tailed macaque rectal model: microflora and chlamydial infection.
abstract: BACKGROUND
  A topical microbicide should protect against acquisition of sexually transmitted infection during both vaginal and rectal intercourse. The rectal microflora of the Macaca nemestrina (pig-tailed macaque) and humans were examined, as well as the histopathology of rectal tissues. In a subset of macaques, a human rectal isolate of Chlamydia trachomatis was inoculated into the rectum to establish rectal chlamydial infection.
  
  
  OBJECTIVE
  To evaluate the comparability of the pig-tailed macaque rectal model with humans.
  
  
  METHODS
  Rectal swabs were collected for microbiologic analysis to characterize normal microflora in pig-tailed macaques and humans. Subsequently, 10 macaques received a rectal inoculation with C trachomatis, serovar D, prepared from a clinical rectal isolate.
  
  
  RESULTS
  The rectal microflora of pig-tailed macaques (n = 80) were found to be comparable with the rectal flora of humans (n = 40). The prevalence of Lactobacillus in the rectum was higher in the macaques than in humans. Coliform and Enterococcus were decreased in the macaques, as compared with those of humans. In 9 of 10 macaques, rectal chlamydial infection was confirmed by culture or ligase chain reaction on days 2, 7, and 14 after inoculation. The test results were positive for rectal chlamydial infection by ligase chain reaction only for the remaining animal on day 14 after inoculation.
  
  
  CONCLUSIONS
  The findings demonstrate that the rectal environment of the pig-tailed macaque is a useful model for further evaluation of newly developed topical microbicides for rectal use. Furthermore, such products can be evaluated for protection against rectal chlamydial infection in this model.
authors.affiliation: Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington 98195-6460, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Patton
authors.forename: Y T
authors.initials: YT
authors.lastname: Cosgrove-Sweeney
authors.forename: L K
authors.initials: LK
authors.lastname: Rabe
authors.forename: S L
authors.initials: SL
authors.lastname: Hillier
mesh_terms: D000285:Administration, Rectal; D000293:Adolescent; D000328:Adult; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D001706:Biopsy; D002690:Chlamydia Infections / Q000382:microbiology* / Q000517:prevention & control*; D002692:Chlamydia trachomatis / Q000145:classification / Q000502:physiology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D016983:Enterococcus / Q000502:physiology; D005260:Female; D006801:Humans; D007778:Lactobacillus / Q000502:physiology; D008254:Macaca nemestrina; D008297:Male; D012002:Rectal Diseases / Q000382:microbiology* / Q000517:prevention & control*; D012007:Rectum / Q000382:microbiology* / Q000648:ultrastructure; D012703:Serotyping
chemical_list: D000891:Anti-Infective Agents, Local