A study of the efficacy of bacterial biofilm cleanout for gastrointestinal endoscopes

AIM:To compare the influence and clearance effect of enzymatic and non-enzymatic detergents against Escherichia coli (E. coli) biofilm on the inner surface of gastroscopes.METHODS:Teflon tubes were incubated in a mixture of different detergents and E. coli culture (106 CFU/mL) for 72 h at 15℃,and biofilms on the inner surface of the teflon tubes were analyzed by bacterial count and scanning electron microscopy. To evaluate the clear-ance effect of detergents,after biofilms were formed on the inner surface of Teflon tubes by 72 h lavage with E. coli culture,tubes were lavaged by enzymatic and non-enzymatic detergents at a speed of 250 mL/min,then biofilms on the inner surface were analyzed by bacterial count and scanning electron microscopy.RESULTS:Non-enzymatic detergent had a better inhi-bition function on biofilm formation than enzymatic de-tergent as it reduced bacterial burden by 2.4 log compared with the control samples (P = 0.00). Inhibition function of enzymatic detergent was not significantly different to that of control samples and reduced bac-terial burden by 0.2 log on average (P > 0.05). After lavaging at 250 mL/min for 3 min,no living bacteria were left in the tubes. Scanning electron microscopy observation showed biofi lms became very loose by the high shear force effect. CONCLUSION:Non-enzymatic detergent has a better inhibition effect on biofilm formation at room temperature. High speed pre-lavage and detergents are very important in temporal formed biofilm elimination.

Double-balloon enteroscopy for obscure gastrointestinal bleeding: A single center experience in China

AIM: To evaluate the diagnostic value of double-balloon enteroscopy (DBE) for obscure gastrointestinal bleeding (OGIB). METHODS: The data about 75 OGIB patients who underwent DBE in January 2007-June 2009 in our hospital were retrospectively analyzed. RESULTS: DBE was successfully performed in all 75 patients without complication. Of the 75 patients, 44 (58.7%) had positive DBE findings, 22 had negative DBE findings but had potential bleeding at surgery and capsule endoscopy, etc . These 66 patients were finally diagnosed as OGIB which was most commonly caused by small bowel tumor (28.0%), angiodysplasia (18.7%) and Crohn’s disease (10.7%). Lesions occurred more frequently in proximal small bowel than in distal small bowel (49.3% vs 33.3%, P = 0.047). CONCLUSION: DBE is a safe, effective and accurate procedure for the diagnosis of OGIB.