Phenotypic characterization of bacterial isolates from the genital tract of dairy cows with endometritis

The present study aimed to investigate the prevalence and phenotypic characteristics of uterine pathogens in 110 pluriparous cows (75 cows with repeat breeding associated with subclinical endometritis and 35 cows with clinical endometritis) from various veterinary clinics in Qalyubia Governorate, Egypt, during the period from September 2021 to February 2025. Uterine swab samples were collected and subjected to bacteriological culture and phenotypic characterization and antimicrobial resistance profiles. The bacteriological examination revealed that bacterial pathogens were isolated from 97 of the positive uterine swabs (88.2%), with 26 (26.8%) being single pure cultures and 71 (73.2%) mixed cultures. Among these, 64 out of 75 samples (85.3%) and 33 out of 35 samples (94.3%) were positive for bacterial pathogens from subclinical and clinical endometritis swabs, respectively. Antimicrobial resistance profiles showed that Staphylococcus aureus was resistant to oxacillin, tetracycline, ampicillin, and streptomycin, but sensitive to norfloxacin, gentamicin, ciprofloxacin, amoxicillin/clavulanic acid, cephapirin, and cefotaxime. Escherichia coli was resistant to oxacillin, ampicillin, tetracycline, cefotaxime, cephapirin, and streptomycin, but sensitive to norfloxacin, gentamicin, ciprofloxacin, and co-trimoxazole. Trueperella pyogenes was resistant to tetracycline, oxacillin, ampicillin, streptomycin, co-trimoxazole, and doxycycline, but sensitive to gentamicin, cephapirin, ciprofloxacin, norfloxacin, amoxicillin/clavulanic acid, and cefotaxime. In conclusion, S. aureus, E. coli, and T. pyogenes, were the predominant Multidrug-resistance (MDR), pathogens associated with subclinical and clinical endometritis in dairy cows.