A contribution on Coliforms causing mastitis in cows with reference to serotypes and virulence factors of E. coli isolates

Abstract

How to cite this article:Eighteen E. coli isolates were serotyped to nine different serogroups; O111:H4 (3), O127:H6 (3), O26 (2), O126 (2), O119:H6(1), O114:H21 (1), O55:H7 (1), O44:H18 (1), O124 (1) and (3) untyped. Virulence tests were performed on the 18 isolated E.coli, it was found that 15 isolates (83.3%) were serum resistant, 13 isolates (72.2%) had Congo Red binding activity, 6 isolates (33.3%) were invasive and one isolate (5.6%) had haemolytic activity. PCR was applied to detect the presence of Shiga like toxin producing E. coli (stx1 and stx2 genes) on the nine different strains (one strain for each serogroup), where stx1 and stx2were found in 8 (88.9%) and 4 (44.4%) of the nine examined strains, respectively. While stx1 and stx2 genes were found together in 3 strains (33.3%). Conclusions: E. coli isolates usually posses one or more virulence factors that may help in establishment at the infection site and subsequently causing clinical bovine mastitis. Keywords:Coliforms, E. coli, Serotypes, Virulence Factors, Stx1, Stx 2. Sayed, S. M.Sayed, S.M., Egypt-Animal Health Research Institute (Assiut Regional Lab., Bacteriology Dept.)ABSTRACT AJMI: http://escipub.com/american-journal-of-microbiology-and-immunology/ 0010