Isolation, identification, and antibiogram profiles of bacteria from dairy cows with postpartum uterine infection in southern Ethiopia

Background: Uterine infections pose a significant problem for dairy farmers worldwide, leading to poor reproductive performance and economic losses. These infections, caused primarily by bacterial pathogens, can negatively affect cow fertility, milk production, and overall welfare. This study was conducted between December 2020 and December 2021 to gain insights into the incidence risk of uterine infections in postpartum dairy cows, isolate and identify bacterial causes and determine the antimicrobial susceptibility profile of the isolated bacteria. A total of 236 cows from 74 dairy farms were monitored from calving to 90 days postpartum, and aseptic uterine swab samples were collected from 40 cows with uterine infections. The samples were cultured, and the isolated bacteria were tested for antimicrobial susceptibility using the disk diffusion method. Results: Out of 236 cows monitored during the postpartum phase, 45 (19.1%) were found to have contracted uterine infection, which could be either metritis or clinical endometritis. The incidence risk of metritis was 11.4% (n=27), while the incidence risk of endometritis was 7.6% (n=18). Of the 40 cultured swab samples, 29 (72.5%) had one or more bacteria isolated. The most commonly isolated bacteria were Escherichia coli (45%), coagulase-positive staphylococci (30%), and Klebsiella spp. (22.5%). Other bacteria, including Arcanobacterium pyogenes . (12.5%), Fusobacterium spp. (12.5%), Enterobacter aerogenes (12.5%), coagulase-negative staphylococci (12.5%), Streptococcus spp. (7.5%) Salmonella spp, (5%) Proteus spp (5%) and Pasteurella spp (2.5%) were also isolated. All of the isolated bacteria demonstrated resistance to at least one of the antimicrobials tested. Multidrug resistance was observed in E. coli , Klebsiella spp., A. pyogenes , and Fusobacterium spp. Gentamicin was found to be the most effective antimicrobial against all bacteria tested, while tetracycline was the least effective of all. Conclusion: The study found that a significant proportion of cows in the population were affected by uterine infections and the isolated bacteria developed resistance to several antimicrobials. The study emphasizes the need for responsible use of antimicrobials to prevent the emergence of antimicrobial resistance. It also highlights the importance of raising awareness among dairy farmers to avoid the indiscriminate use of antibiotics and its consequences.