English

Abstract

BACKGROUND: Microorganisms growing in multilayered cell clusters embedded in a matrix of extracellular polysaccharide (slime) which facilitates the adherence of these microorganisms to biomedical surfaces and protect them from host immune system and antimicrobial therapy. There are various methods to detect biofilm production like Tissue Culture Plate (TCP) ,Tube method (TM) ,Modified Congo Red Agar Method (MCRA),bio luminescent assay ,piezoelectric sensors and fluorescent microscopic examination. OBJECTIVES : This study was conducted to compare three methods for the detection of biofilms and compare with antibiotic sensitivity pattern, in uropathogenic Escherichia coli. METHOD: This study was carried out at the Department of Microbiology Dr. B. R. Ambedkar Medical College from Dec 2011 to June 2012. Total number of 107 clinical Escherichia coli isolates were randomly selected from all age groups were subjected to biofilm detection methods and their antibiotic resistance pattern was compared. Isolates were identified by standard phenotypic methods. Biofilm detection was tested by TCP, TM and MCRA methods . Antibiotic susceptibility test of uropathogenic E coli was performed using Kirby –Bauer disc diffusion method according to CLSI guidelines. RESULTS: From the total of 107 clinical isolate 74 (69.1 %) isolates showed biofilm formation by all the TCP, TM, CRP methods. Biofilm forming isolates from catheter associated UTI showed drug resistance to more than 6 drugs. Only 2(13.3%) isolates from Asymptomatic UTI showed biofilm by TM & MCRA methods & were sensitive all drugs. Biofilm forming isolates from symptomatic UTI showed mixed drug resistance pattern. CONCLUSION: We conclude from our study that biofilm formation is more common in catheterized patients. TCP method is more quantitative and reliable method for the detection of biofilm forming micro-organisms as compared to TM and MCRA methods. So TCP method can be recommended for screening of biofilm as virulence marker in drug resistant E coli isolates.