Liu Junjun, Wang Xin, Bi Chongliang, Mehmood Khalid, Ali Farah, Qin Jianhua, Han Zhaoqing
College of Veterinary Medicine/Traditional Chinese Veterinary Medicine, Hebei Agriculture University, Baoding, China.
College of Agriculture and Forestry, Linyi University, Linyi City, China.
Front Vet Sci. 2022 Aug 22;9:966533. doi: 10.3389/fvets.2022.966533. eCollection 2022.
Mastitis is an economically important disease in the dairy industry, which is caused by various infectious pathogens. There is limited information known about the situation of drug resistance and virulence factors of () in mastitis bovine milk in Anhui. Therefore, a total of 125 fresh milk samples from clinically mastitis-positive bovine animals were collected. The bacteria pathogens were identified bacterial culture, Gram staining, biochemical analysis, DNA extraction, 16s rRNA amplification, and phylogenetic analysis. Drug resistance analyses were performed through drug-resistant genes and virulence genes amplification. Results showed that a total of 24.8% (31/125) bacterial isolates were isolated and identified as by Gram straining, biochemical reactions, and 16 s rRNA genes blasting. Multiple sequence alignment analysis found that the current isolates were highly similar (96.9-100.0%) to previous isolates. Phylogenetic analysis demonstrated that was similar with MK809241.1 isolated from food in China and wCP030426.1 isolated from a person in the United States. The bacterial isolates were detected resistant to 11 antibiotics, such as Penicillin G, SXT, Ciprofloxacin, Norfloxacin, Polymyxin B, Levofloxacin, Chloramphenicol, Clindamycin, Clarithromycin, Erythromycin, and Spectinomycin. Drug-resistant genes of blaZ, ermC, rpoB, and ant (4')-la were successfully amplified. Virulence genes of hla, nuc, clfa, and eta were found in bacteria. The current study isolated from milk samples and revealed its drug-resistant situation, drug-resistant genes, and virulence genes. Hence, regular monitoring of in milk samples from dairy cows may contribute to the prevention and treatment of public health concerns causing bacteria in this region.
乳腺炎是乳制品行业中一种具有重要经济影响的疾病，由多种传染性病原体引起。关于安徽患乳腺炎奶牛乳汁中（）的耐药性和毒力因子情况，已知信息有限。因此，共采集了125份临床乳腺炎阳性奶牛的新鲜乳汁样本。通过细菌培养、革兰氏染色、生化分析、DNA提取、16s rRNA扩增和系统发育分析来鉴定细菌病原体。通过耐药基因和毒力基因扩增进行耐药性分析。结果显示，通过革兰氏染色、生化反应和16s rRNA基因比对，共分离并鉴定出24.8%（31/125）的细菌分离株。多序列比对分析发现，当前分离株与先前分离株高度相似（96.9 - 100.0%）。系统发育分析表明，这些细菌分离株与从中国食品中分离出的MK809241.1以及从美国一个人身上分离出的wCP030426.1相似。检测到这些细菌分离株对11种抗生素耐药，如青霉素G、复方新诺明、环丙沙星、诺氟沙星、多粘菌素B、左氧氟沙星、氯霉素、克林霉素、克拉霉素、红霉素和壮观霉素。成功扩增出blaZ、ermC、rpoB和ant(4')-la的耐药基因。在（）细菌中发现了hla、nuc、clfa和eta的毒力基因。本研究从乳汁样本中分离出（），并揭示了其耐药情况、耐药基因和毒力基因。因此，定期监测奶牛乳汁样本中的（）可能有助于预防和治疗该地区引起公共卫生问题的细菌。
