Infectious endometritis in Arabian mares: an updated clinical investigation of uterine microbial isolates, antimicrobial sensitivities and fertility in Egypt

The present study aimed to survey the prevalence of microbial isolates in the uterus of sub-fertile Arabian mares and to identify their existing antimicrobial sensitivities. In addition, to evaluate the efficacy of antimicrobial therapy based on the fertility outcomes determined by sonographic pregnancy diagnosis. Double guarded uterine swabs were collected from (barren) Arabian mares during mid-estrus. Based on the laboratory findings of microbial culture and antimicrobial sensitivity, mares were treated, inseminated and tested for pregnancy two weeks after ovulation. The predominant microbial isolates were Beta-hemolytic streptococci (BHS) (38.9%), Escherichia coli (E. coli) (33.3%), Staphylococcus aureus (S. aureus) (20.4%) and Candida albicans (C. albicans) (7.4%). Moreover, the sensitivity of BHS and E. coli isolates to cefepime was significantly higher (P< 0.05) than the rest of the antimicrobials (57.14% and 55.56%, respectively). However, S. aureus isolates did not display a significant difference regarding their antimicrobial sensitivities, its sensitivity to amoxicillin-clavulanic acid was the highest (36.37%). On the other hand, fluconazole was the favored antifungal in this study (100 % sensitivity). The pregnancy outcomes were variable depending on the type of microbial isolate and antimicrobial treatment; for instance, cefepime resulted in the highest pregnancy rates in BHS and S. aureus mare groups (66.67% and 100%, respectively). Interestingly, amikacin achieved the highest pregnancy rate in the E. coli group (66.67%). In conclusion, BHS is the dominant uterine isolate in Arabian sub-fertile mares. For most cases of bacterial endometritis, cefepime may be the antibiotic of choice and fluconazole may be the effective therapy in the case of C. albicans infection. However, standard diagnostic and treatment procedures should be used to minimize the emergence of antimicrobial resistance.