Evaluation of biofilm formation by three different methods and its antibiogram with special reference to indwelling medical devices from a tertiary care hospital

Abstract

Biofilms are produced by both Gram-positive and Gramnegative bacteria. Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus viridans, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa are commonly associated with the production of biofilms. [4] The expression of biofilms in these bacteria is mainly determined by operons. Operons are the clusters of coregulated genes with related functions. The series of genes in an operon are transcribed as a single mRNA and consists of an upstream promoter and a downstream terminator. [5] The biofilm production in Staphylococcus spp is regulated by the expression of polysaccharide intracellular adhesion (PIA) which is the gene product of

Detecting of biofilm formation in the clinical isolates of Pseudomonas aeruginosa and Escherichia coli: an evaluation of different screening methods

“…Siddhiqui et al reported that the CRA method is not appropriate for biofilm detection. Out of 112 clinical isolates, CRA detected only 14.25% as biofilm producers as compared to TM which detected 29.46% as biofilmforming bacteria [1]. The tube method also detected 38% isolates as biofilm producers.…”

“…Test organisms were cultured on the CRA medium and incubated aerobically for 24 -48 h at 37 °C. Black colonies with a dry crystalline consistency indicated biofilm production [1].…”