Calf Diarrhoea in Sharkia Province, Egypt: Diagnosis; Prevalence, Virulence Profiles and Zoonotic Potential of the Causal Bacterial Agents

A total of 240 samples (80 faecal, 160 blood) from diarrhoeic dairy cow calves (1 day-3 months old) and 20 blood samples from control group (apparently healthy calves) were collected from 2 dairy farms located in Sharkia Province, Egypt. Also, thirty-five hand swab samples were collected from calves' handlers at these farms. Diagnosis of diarrhea was based on clinical signs and hemato-biochemical examinations of blood samples where significant alterations were observed in diarrheic calves compared to controls. Faecal and hand swab samples were examined bacteriologically for the presence of E.coli and Salmonella spp. The results showed an overall prevalence rate of 35% for E. coli in diarrhoeic calves and 28.57% in handlers. Salmonella spp. were detected in diarrhoeic calves and handlers with percentages of 16.25, 8.57%, respectively. PCR results verified that stx2, eaeA and ast A genes were amplified in 10.71,14.28,14.28% of E. coli isolates from calves, respectively compared to 20% for stx2 and (10%, each) for eaeA and astA in handlers. Of 13 Salmonella isolates from diarrhoeic calves, 30.77 and 15.38% of the isolates were harboring spvC and stn genes, respectively. In contrast neither spvC nor stn gene was detected in isolates from handlers. This study proved that acute phase proteins (AAPs) as C-reactive protein (CRP) and Haptoglobin (HP) are valuable prognostic factors for diarrhoeal disease in calves. Virulent E. coli and Salmonellae are potentially zoonotic pathogens play a contributing role in calf diarrhoea in Sharkia Province, Egypt.