| Abstract: | Background: Inflammation of the colon is often found during colonoscopy. In order to confirm the pathogenesis of the lesion, bacterial cultures are applied. Biopsied tissue specimens are used for bacterial culture, and fluid culture after colonoscopic washing also has been used for bacterial identification. In the latter method, sterile saline solution is sprayed over the area and then is collected with the fluid. The two methods have not been compared with each other. Methods: The subjects comprised 89 cases with inflammatory lesions detected during colonoscopy. Samples were collected by both methods at the inflammatory site. The bacterial load was semiquantitatively evaluated as 1+, 2+, and 3+. Results: Pathological bacteria were found in nine cases. Vibrio parahaemolyticus was detected in one case only by tissue culture. In the other eight cases, bacteria cultures were positive by both methods. A total of 36 kinds of bacteria constituting the intestinal flora were identified. The detection rate was 83.9% by fluid culture and 70.9% by tissue culture. It was significantly larger by fluid culture than by tissue culture. Bacteria were isolated at a rate of 3.61 species per sample by fluid culture and 3.05 species per sample by tissue culture. The bacterial load per species was a median of 2.00+ by fluid culture and 1.27+ by tissue culture. The number of detected bacterial species and the bacterial load per species were significantly larger by fluid culture than by tissue culture. Conclusion: Fluid culture after colonoscopic washing is recommended to identify intestinal bacteria by culture. |
