本研究调查了两个季节(春季和秋季)以及包括中国11个省在内的四个地区的奶牛场中从原料奶中分离出的金黄色葡萄球菌的发生和耐药率。总的来说,从405个奶牛场收集了750个原料奶样品。通过圆盘扩散测试测试了15种抗菌剂的耐药性,并进行PCR检测以鉴定金黄色葡萄球菌分离株的耐药基因。在750个样本中,276(36.8%)金黄色葡萄球菌阳性,春季有150人(41.1%)为阳性,秋季有126人(32.7%)为阳性。中国东北地区金黄色葡萄球菌的发生率(45%)高于中国西部(33%)和中国南部(31.9%),分别,并且该比率与中国西部和中国南部的比率显着不同(p<0.05)。在276个分离株中,261株(94.6%)对1种以上抗菌药物耐药,多药耐药菌株193株(69.9%)。BlaZ(46.3%),dfrG(35.5%),和tetM(27.2%)基因在金黄色葡萄球菌菌株中以高频率检测到。我们的数据显示,不同地区和两个季节的阻力模式存在差异(p<0.05)。从奶牛场获得的原料奶中分离出的金黄色葡萄球菌的发生和耐药率可能在中国仍然引起严重的问题。
This study investigated the occurrence and resistance rates of Staphylococcus aureus strains isolated from raw milk in the dairy farms over two seasons (spring and autumn) and across four regions that included 11 provinces in
China. In total, 750 raw milk samples from the 405 dairy farms were collected. Fifteen antimicrobial agents were tested for antimicrobial resistance via disk diffusion tests, and PCR tests were performed to identify drug resistance genes of S. aureus isolates. Out of 750 samples, 276 (36.8%) were positive for S. aureus, with 150 (41.1%) being positive in spring and 126 (32.7%) being positive in autumn. The occurrence rate of S. aureus in northeastern
China (45%) was higher than that in western
China (33%) and southern
China (31.9%), respectively, and the rate significantly (p < 0.05) differed from those of western
China and southern
China. Of 276 isolates, 261 (94.6%) strains were resistant to more than 1 antimicrobial drug, and 193 (69.9%) strains were multidrug resistant. The blaZ (46.3%), dfrG (35.5%), and tetM (27.2%) genes were detected at a high frequency in the S. aureus strains. Our data revealed a variation (p < 0.05) in the resistance patterns in the different regions and across the two seasons. The occurrence and drug resistance rates of S. aureus isolated from raw milk obtained from dairy farms may still cause severe problems in
China.