OnLine Journal of Biological Sciences

Correlation Between in vitro Biofilm Formation and Virulence Properties of Extra-Intestinal Pathogenic Escherichia Coli (Expec)

Md. Fakruddin, Khanjada Shahnewaj Bin Mannan and Reaz Mohammad Mazumdar

DOI : 10.3844/ojbsci.2014.261.270

OnLine Journal of Biological Sciences

Volume 14, Issue 4

Pages 261-270


About 65 Escherichia coli strains isolated from extra-intestinal sites were included in this study to determine their biofilm formation capability and virulence properties. About 87% ExPEC isolates were motile and 12.3% were found to be non-motile. Only 12.30% isolates were strong biofilm former (SBF >1.5) whereas 18.46% isolates were non biofilm former. About 71% isolates were capable to express curli but curli expression is lower in isolates from pus and peritoneal fluid. About 41.53% isolates have moderate capability (CSH value 21-50%) to adhere to hydrocarbons whereas 20% didn’t show any hydrocarbon adherence capability. Most of the isolates showed moderate cell aggregation (60-80%) potential with S. maltophila but 15.4% isolates were found to be non-aggregative. Forty-one (63.07%) strains were resistant to 2 or more of the most commonly clinically used antibiotics. 44.6% isolates were haemolytic, 35.3% showed colicin activity, 47.7% were MRHA positive, 49.2% had SAT value ≤2.0 M and 9.2% were protease producer. About 77% (50 out of 65) of the isolates harbor type 1 gene. csgA gene was found in 61.5% (40) isolate, papC was found in 64.6% (42), afa and sfa genes were found in 67.7% (44) each. Biofilm formation may contribute to the pathogenic potential of ExPEC.


© 2014 Md. Fakruddin, Khanjada Shahnewaj Bin Mannan and Reaz Mohammad Mazumdar. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.