152One year impact of clindamycin and ciprofloxacin administration on the human normal microflora

Background. The purpose of this study is to assess the effect of clindamycin (150 mg qid for 10 days) and ciprofloxacin (500 mg bd for 10 days) on the skin, nasal, saliva and intestinal microflora of healthy humans for a period of one year In addition, the consequences of the emergence and persistence of clindamycin and ciprofloxacin resistant bacteria in the normal microflora were studied. Methods. Thirty healthy subjects (15 males and 15 females) were randomly assigned in 3 groups and clindamycin, ciprofloxacin and placebo were given for 10 days period. Skin, nasal, saliva, faeces samples were collected at day -1, day 11, 1 month, 2 months, 4 months and 12 months. Agar plates were incubated in anaerobic and aerobic condition. Clindamycin and ciprofloxacin plates were also used. Bio assay was used to detect antibiotic concentration. MIC was done by the agar dilution method against 5 antibiotics. Results. In the clindamycin group, minor effects on Coagulase-negative staphylococci (CoNS) observed on the skin microflora and normalized after 2-4 months. Nasal microflora normalized after 4-12 months. Saliva microflora normalized after 1 to 4 months. There were minor effects on the Enterococci, Bifidobacteria, Lactobacilli and Bacteroides that normalized after 2-12 months. Clindamycin was detected in faeces on day 11. In the ciprofloxacin group, minor effect on CoNS observed and normalized after 4 months. Nasal microflora there were minor effects on CoNS and P. acnes that normalized after 2 months. In the saliva microflora there were minor effects on alphahemolytic Streptococci, Fusobacteria that normalized after 4 to 12 months. Initially there was no effect on the Enterococci but after 4 months there was an increase that normalized after 1 year. There were major effects on E. coliand on Bifidobacteria that normalized after 2 months. There were minor effects on Lactobacilli and Bacteroides. Ciprofloxacin was detected in faeces on day 11. Conclusion. The interval of the normal microflora to be normalized after clindamycin or ciprofloxacin treatment is different for different bacterial species at different body sites. It takes 1-12 months to normalize the human microflora after treatment. No Clostridium difficile was detected in any of the samples. Disclosures. M. U. Rashid, European Union: received funding A. Weintraub, European Union: received funding C. E. Nord, European Union: received funding.