Comparative Analysis of Virulence Factors of Escherichia coli from Non-enteric Infections

Abstract

There is correlation between cert ain properties of E. coli strains and capacity of the strain to cause non-enteric infections. The aim of this study was to compare Escherichia coli strains isolated from non-enteric infection with those from faeces of normal healthy individuals, for their possession of haemolysin, mannoseresistanthaemagglutinin, colicin, protease, cell surface hydrophobicity and antibiotic susceptibility. Source wise distribution of the haemolytic strains were 60% from urine, 41.7% from blood, 33.3% from peritoneal fluid, 50% from pus and 26.7% from stool. Colicinogeny was found to be a common property of both clinical and faecal E. coli and only a few of the urine and blood isolates (52 and 41.7%, respectively) exhibited colicin V activity. Mannose Resistant Haemagglutinin (MRHA) test showed positive (MRHA) reaction for 47.7% of the clinical E. coli isolates, while this value was only 26.7% for the controls. A significant association between haemolysin production and MRHA of human type O erythrocytes was found, as 75.86% of the Hly E. coli strains were also MRHA. The data obtained in this study suggested that haemolysin production, MRHA of human type O erythrocytes and hydrophobic cell surface might be important for E. coli strains to initiate and sustain infection at non-enteri c sites. Received: June 12, 2012; Accepted: June 21, 2012; Published: August 11, 201