IDENTIFICATION, MOLECULAR CONFIRMATION AND ANTIBIOTIC SENSITIVITY OF BACTERIA ISOLATED FROM REPEAT BREEDER COWS IN RANGPUR DIVISION

Abstract

Recently repeat breeding syndrome becomes a significant challenge for dairy producer due to large economic loss in Bangladesh. The present study was conducted from January to June 2023 to observe the prevalence of repeat breeding syndrome, to isolate and identify the bacteria with their molecular confirmation and antibiotic sensitivity causing repeat breeding syndrome in cows in the northern region of Bangladesh. By using a questionnaire and history-taking techniques (more than 10 years old, one calf in life, three subsequent Artificial Insemination (AI) failures to conceive, having no perceptible anomalies of reproductive tract) to interview dairy owners, repeat breeding syndrome was identified. Bacteria were isolated and identified from the cervical mucus of affected cows. For confirmation of the detected bacteria, PCR was used. The agar disc diffusion method was utilized to investigate the antibiotic sensitivity of the detected isolates against widely used antibiotics in vitro. The prevalence of repeat breeding syndrome was 41.33%. The prevalence of E. coli was 40%, Styphylococcus aureus 40% and Klebsiella spp. 10%. Molecular detection of E. coli and Staphylococcus aureus was confirmed by using Eco 223 (F), Eco 455 (R), Sau 234(F) and Sau 1501(R) primers. The target genes were 16S and 23S rRNA and the size of the product amplified at 232 bp and 1267 bp respectively. According to the antibiogram profile, E. coli was resistant to ciprofloxacin, penicillin, tetracycline, amoxicillin, and erythromycin, but sensitive to ceftriaxone and gentamicin. While Staphylococcus aureus was resistant to ampicillin and erythromycin, it was sensitive to ciprofloxacin, ceftriaxone, and levofloxacin. It was also intermediately resistant to vancomycin and amoxicillin. Klebsiella spp. showed resistance to ceftriaxone, penicillin, and amoxicillin, while remaining sensitive to ciprofloxacin, tetracycline, and intermediate resistance to erythromycin and gentamicin. It should be concluded that E. coli, Styphylococcus aureus and Klebsiella spp. are the most common bacteria causing repeat breeding syndrome in cows. Treatment for repeat breeding syndrome should be done after performing antibiotic sensitivity test.