title: Effect of antibiotics on Oxalobacter formigenes colonization of human gastrointestinal tract.
abstract: OBJECTIVE
  Oxalobacter formigenes is a bacterium residing in the human gastrointestinal tract that degrades oxalate and reduces its availability for absorption. This bacterium is assumed to be antibiotic sensitive, and repeated antibiotic therapies could eradicate it. The aim of the present study was to determine the differences in the colonization by O. formigenes of individuals who had been on antibiotics for at least 5 days at the time of sample collection and individuals who had not taken antibiotics for at least 3 months.
  
  
  METHODS
  Stool samples were collected from 80 individuals without stone disease (35 with and 45 without antibiotic consumption) and 100 patients with stone disease (20 with and 80 without antibiotic consumption). Oxalobacter formigenes was detected by a polymerase chain reaction-based method, and the presence/absence of O. formigenes was correlated with urinary oxalate concentrations.
  
  
  RESULTS
  Lower percentages of individuals without stone disease and with stone disease who were consuming antibiotics had O. formigenes colonization than individuals without antibiotic consumption. Urinary oxalate concentrations were higher in the individuals without O. formigenes than in colonized individuals.
  
  
  CONCLUSIONS
  Our observations confirm a direct association between antibiotic consumption and absence of O. formigenes. Absence of intestinal O. formigenes could represent a pathogenic factor in calcium oxalate urolithiasis when antibiotics are prescribed generously.
authors.affiliation: Department of Urology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India. ramamittal@yahoo.com
authors.forename: R D
authors.initials: RD
authors.lastname: Mittal
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: H K
authors.initials: HK
authors.lastname: Bid
authors.forename: B
authors.initials: B
authors.lastname: Mittal
mesh_terms: D000042:Absorption / Q000187:drug effects; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015139:Blotting, Southern; D002129:Calcium Oxalate / Q000378:metabolism; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry / Q000209:etiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D020624:Oxalobacter formigenes / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D016133:Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D002129:Calcium Oxalate