The influence of endoscopic procedures upon the contamination of Helicobacter pylori cultures

Abstract

BACKGROUND: Among the various diagnostic methods for the detection of Helicobacter pylori infection, histological examination and microbiological processing of gastric biopsy samples are assumed to be the gold standard techniques. AIMS: Since H. pylori culture can be affected by the presence of non-H. pylori bacteria, we evaluated the efficacy of endoscope disinfection and the influence of endoscopic procedures on culture contamination. PATIENTS AND METHODS: The procedures used during the first two routine endoscopies were evaluated during 28 consecutive days. Endoscopy room, forceps and endoscopic channel were analyzed before and after the beginning of normal procedures. After disinfection, a biopsy simulation was performed to verify the gastric bacteria. RESULTS: Endoscope disinfection removed all organisms from forceps and endoscopic channel with 100% efficacy. The most frequent non-H. pylori bacteria detected were Streptococcus bovis, Enterobacter hormaechei, and Staphylococcus aureus. The sensibility of the H. pylori culture was affected by the presence of non-H. pylori bacteria. CONCLUSION:The risk of transmission of microorganisms was not detectable when sterilized biopsy forceps and stringent disinfection standards were employed. Whilst S. bovis and E. hormaechei may be common in gastric microbial flora, the presence of P. aeruginosa and S. aureus indicated that the manipulation of biopsies could be responsible for culture contamination with these bacteria.