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

Escherichia coli [E. coli] is the predominant coliform species causing intramammary infections. Where in the present study, E. coll isolates were 1.8 strains [17.82%] followed by Enterobacter aerogenes 3 strains [2.97%] and Klebsiella pneumoniae one strain [0.99%] from 101 clinical mastitic milk samples of cows. 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. coll, 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. coll [stxl and stx2 genes] on the nine different strains[one strain for each serogroup], where stxl and stx2 were found in 8 [88.9%] and 4 [44.4%] of the nine examined strains, respectively. While stxl 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

Some antibiotic resistant bacteria of public health hazard isolated from raw milk sold in some Assiut City markets

A total of 50 raw milk samples were collected in this study from some Assiut City markets, Egypt, and examined for isolation of some human hazard pathogens. The percentages of the isolated pathogens were 46, 76, 78, 4 and 24% for Staph. aureus. Enterococcus faecalis, E. coli, Citrobacter freundii and Yersinia enterocolitica respectively. In vitro Antibiogram was carried out on all isolates against [8] different antimicrobial agents; moreover, ail of these isolates showed multi-drug resistance against tow or more of the tested antibiotics. The public heath hazards of the isolated pathogens were alsfrtliscussed