Longitudinal Study of Some Bacterial, Parasitic, and Viral Enteric Pathogens isolated from Diarrheic Calves from Dairy Herd in Egypt

Neonatal calf diarrhea remains one of the most important problems faced by livestock, causing great economic losses. Fecal samples were collected from 100 diarrheic calves in Al-Fayoum governorate, Egypt during 2021, and 2022, to investigate the prevalence of Enterotoxigenic Escherichia coli (ETEC), Salmonella typhimurium, Klebsiella pneumonia, Clostridium perfringens, bovine rotavirus, bovine coronavirus, and Cryptosporidium parvum which are the major enteropathogens associated with neonatal calf diarrhea, the prevalence of enteropathogens were 58%, 29%, 34%, 14%, 35%, 8%, and 65% respectively. Molecular characterization was performed to confirm the E. coli, Klebsiella pneumonia, Salmonella typhimurium, Clostridium perfringens, and Cryptosporidium isolates and to detect some virulent genes associated with their pathogenicity. All the bacterial isolates gave a clear band with 16S rRNA. In E. coli, virulent genes (K99, F41, phoA) were detected, also; Salmonella strains were found positive for the invA and sopB gene, while all Clostridium perfringens strains were tested positive for Alpha and Beta toxin but negative for Epsilon toxin. On the other hand, all Klebsiella pneumoniae isolates were tested positive with iutA and fimH genes. Also, the in-vitro antibiotic sensitivity testing of bacterial isolates was applied. Statistical analysis was carried out to determine the potential influence of age factor on the reported prevalences of concurrent infections, which revealed that the animals age significantly affected the infection prevalence in all pathogens inversely excepts those infected by Klebsiella was affected by age directly, and those infected by E. Coli, or Cryptosporidium, were not affected by age at all. Good hygienic management and good vaccination program are very important to overcome acute diarrhea in neonate calves and the misuse of antibiotic revealed the presence of multidrug resistance isolates of some enteropathogenic bacteria.