Prevalence, antimicrobial resistance and substantial virulence-associated genes of escherichia coli isolated from colibacillosis in neonatal calves in Egypt

Anotace: Pathogenic Escherichia coli (E. coli) consider the most common bacterial agent causes calf diarrhea, particularly in newborn calves. Therefore, this study highlights prevalence, serotyping, antibiogram pattern of E. coli recovered from diarrheic calves in Egypt. In addition to the investigation of six virulence encoding genes (iss, fimH, tsh, iutA, stx2 and eaeA) using polymerase chain reaction (PCR). One hundred and twenty calves were examined for E. coli existence. A total of 16 (40%) E. coli strains were isolated from 40 diarrheic calves samples. Seven E. coli serotypes (O26, O157, O78, O125, O146, O44, and O18) were recovered, and O26 and O157 were the most common. The tested strains exhibit high susceptibility to ciprofloxacin, enrofloxacin and polymixin and amoxicillin/clavulanic acid, while a high resistance to streptomycin, gentamycin, tetracycline, sulfamethoxazole/trimethoprim, chloramphenicol, and neomycin was recorded. The iss and fimH genes were the most frequently identified virulence genes in all tested strains (100%), followed by eaeA (31.25%) and stx2 (6.25%), whereas tsh and iutA were not detected at all. Our findings emphasize the existence of multi-an¬timicrobial resistance strain as well as virulence genes, which is crucial for developing novel methods to control of colibacillosis in calves.