Assessment of Escherichia coli isolates for In vitro biofilm production

A total of 14 Escherichia coli isolates were assessed for their ability to produce biofilm in-vitro by slime production on Congo red agar medium (CRA) and microtitre plate assay. Out of 14 isolates tested, 12 were slime producing on CRA as indicated by black colonies. The isolates of E.coli varied in their ability to produce biofilm on the surface of microtitre plate ranging from 0.101 to 0.543 ODm. Out of 14 isolates tested, 10 were positive for biofilm production employing criterion of blank corrected ODs9s > 0.1. Two of slime negative isolated were also negative for biofilm production where as the two slime positive isolates were found to be negative for biofilm production