Abstract: To elucidate the correlation between biofilm-forming ability and virulence factors, improved crystal violet semi-quantitative method and common PCR were used for biofilm-forming ability quantitative analysis and phase variation antigen 43 detection in 180 pet-brone E.coli respectively; the results revealed that 30.1%(55/180) of the strains detected agn43 and 96.4%(53/55)of the agn43 positive strains performed biofilm-forming ability, showing significant difference from non-biofilm forming group(P<0.01).

Key words: E.coli; biofilm; virulence factor; agn43