Bacteriological And Cytological Findings In Postpartum Dairy Cows With Subclinical Endometritis

Abstract

Subclinical endometritis is a condition that produces negative effects on lactation yield and fertility of dairy cows during the puerperal period. The objective of the research consisted in the characterization of the uterine microbiota of dairy cows and the identification of pathogens associated with infertility. Differential selective media for aerobic and anaerobic bacteria were used for the isolation and identification of bacteria. To establish the diagnosis of subclinical endometritis, 54 animals were evaluated at ≥ 60 days postpartum; cytologically healthy cows (n = 32), cows with subclinical endometritis (n = 22). The microbiological examination was performed using samples of cervico-vaginal secretions collected from the same animals by vaginoscopy, namely 4 cows with endometritis and 4 healthy cows. Cervicovaginal secretions were examined microbiologically and the isolates identified included Gram-positive bacteria in percentage of 62.5% and 37.5% Gram-negative bacteria. The highest incidence was reported for Escherichia coli (16.66%), vancomycin-resistant Enterococcus spp. (16.66%), Staphylococcus spp (14.58%) and Streptococcus agalactiae (12.5%). The prevalence of subclinical endometritis, 40.7% (22/54) was established on the basis of cell ratios (≥ 5% polymorphonuclear cells) assessed following examination of endometrial smears. Antimicrobial susceptibility profile determination revealed high susceptibility to florfenicol (93.75%), enrofloxacin (91.66%), marbofloxacin (91.66%) followed by amoxicillin/clavulanic acid (83.33%) and cefquinome (70.83%). Antimicrobial resistance to tetracycline (100%), streptomycin (89.58%), colistin (72.91%) and penicillin (68.75%) was reported. In conclusion, the results of this study confirm that the combination of endometrial cytology with the microbiological examination of uterine discharges seems to be a good method for the diagnosis of subclinical endometritis, and provides an update of information about the microbiota present in the uterus of dairy cows after parturition, the state of its resistance to antibiotics and the effect on reproductive performance.