In this study we aimed to determine the microorganisms found in perianal fistulas in Crohn's disease and whether treatment with ciprofloxacin affects these microorganisms. Thirteen patients (males/females, 7/6; median age, 34 years; range, 18-61 years) with fistulas were treated with infliximab, 5 mg/kg intravenously, at weeks 6, 8, and 12 and randomized to double-blind treatment with ciprofloxacin, 500 mg bd (n = 6), or placebo (n = 7) for 12 weeks. Samples were taken at baseline and at weeks 6 and 18. In the ciprofloxacin group 10 different genera of microorganisms were identified, while 13 genera could be identified in the placebo group. Gram-negative enteric floras were present in a small minority. The genera found in patients with perianal fistulas were predominantly gram-positive microorganisms. Therefore, antimicrobial treatment should be directed toward these microorganisms.

Antibiotics, Crohn's disease, Perianal fistulas
dx.doi.org/10.1007/s10620-005-2769-4, hdl.handle.net/1765/62145
Digestive Diseases and Sciences
Department of Medical Microbiology and Infectious Diseases

West, R.L, van der Woude, C.J, Endtz, H.P, Hansen, B.E, Ouwedijk, M, Boelens, H.A.M, … Kuipers, E.J. (2005). Perianal fistulas in Crohn's disease are predominantly colonized by skin flora: Implications for antibiotic treatment?. Digestive Diseases and Sciences, 50(7), 1260–1263. doi:10.1007/s10620-005-2769-4