Department of Veterinary Medicine, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Vet Res Commun. 2024 Jun;48(3):1497-1510. doi: 10.1007/s11259-024-10322-2. Epub 2024 Feb 12.
Multidrug-resistant bacteria have become the predominant etiology in bovine female reproductive tract infections and thus require effective treatment approaches. The main goal of this study was the molecular detection of mecA, blaZ, tetK, and aacA-aphD genes in Staphylococcus aureus (S. aureus) responsible for methicillin, beta-lactam, tetracycline, and aminoglycoside resistance respectively. Phylogenetic analysis was conducted to check the homology of staphylococcal genes with NCBI sequences. The in-vitro efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) in combination therapies against MDR S. aureus was evaluated using well diffusion assay and checkerboard method. Vaginal swab samples (n = 384) collected from bovines suffering from endometritis, pyometra, and retained placenta were tested for S. aureus. Results showed a 17.96% overall prevalence. Both phenotypic and genotypic resistance was observed among S. aureus isolates with 50.72% and 37.68% isolates being confirmed as methicillin-resistant (MRSA), 36.23% and 18.84% isolates exhibiting beta-lactam, 40.58%, and 27.54% isolates showing tetracycline, and 33.33% and 36.23% isolates showing aminoglycosides resistance based on disc diffusion and gene confirmation, respectively. Phylogenetic analysis indicated homology with previously reported Pakistani isolates suggesting the possibility of MDR S. aureus transmission within and between animals. Synergy testing indicated that combinations of ceftriaxone-ketoprofen (153.77%), ceftriaxone-meloxicam (149.55%), amoxiclav-flunixin meglumine (106.06%), and oxytetracycline-flunixin meglumine (104.47%) showed synergy on well diffusion assay. Based on the fractional inhibitory concentration index by checkerboard method, oxytetracycline-meloxicam and gentamicin-ketoprofen combinations exhibited synergistic interaction. In conclusion, MDR S. aureus resistance was mitigated in-vitro through the combination of antibiotics (oxytetracycline, gentamicin) with NSAIDs (meloxicam, ketoprofen) that could be used to create therapeutic strategies for bovine reproductive issues.
耐多药细菌已成为牛雌性生殖道感染的主要病因，因此需要有效的治疗方法。本研究的主要目的是检测耐甲氧西林金黄色葡萄球菌（MRSA）中负责甲氧西林、β-内酰胺类、四环素和氨基糖苷类耐药的 mecA、blaZ、tetK 和 aacA-aphD 基因的分子检测。进行系统发育分析以检查葡萄球菌基因与 NCBI 序列的同源性。采用琼脂扩散法和棋盘法评估非甾体抗炎药（NSAIDs）联合治疗耐多药金黄色葡萄球菌的体外疗效。从患有子宫内膜炎、子宫积脓和胎衣滞留的牛中采集阴道拭子样本（n=384），检测金黄色葡萄球菌。结果显示总流行率为 17.96%。金黄色葡萄球菌分离株表现出表型和基因型耐药，其中 50.72%和 37.68%的分离株被确认为耐甲氧西林金黄色葡萄球菌（MRSA），36.23%和 18.84%的分离株对β-内酰胺类药物耐药，40.58%和 27.54%的分离株对四环素类药物耐药，33.33%和 36.23%的分离株对氨基糖苷类药物耐药基于圆盘扩散和基因确认。系统发育分析表明与先前报道的巴基斯坦分离株具有同源性，表明耐多药金黄色葡萄球菌在动物体内和动物之间传播的可能性。协同试验表明，头孢曲松-酮洛芬（153.77%）、头孢曲松-美洛昔康（149.55%）、阿莫西林-氟尼辛葡甲胺（106.06%）和土霉素-氟尼辛葡甲胺（104.47%）组合在琼脂扩散试验中显示协同作用。根据棋盘法的部分抑菌浓度指数，土霉素-美洛昔康和庆大霉素-酮洛芬组合表现出协同相互作用。总之，通过将抗生素（土霉素、庆大霉素）与 NSAIDs（美洛昔康、酮洛芬）联合使用，可在体外减轻耐多药金黄色葡萄球菌的耐药性，这可为牛的生殖问题创造治疗策略。
