Abdi Reta D, Gillespie Barbara E, Ivey Susan, Pighetti Gina M, Almeida Raul A, Kerro Dego Oudessa
Department of Animal Science, Hebert College of Agriculture, The University of Tennessee, Knoxville, TN 37996, USA.
Department of Biomedical Sciences, College of Veterinary Medicine, Long Island University Post, Roth Hall, Brookville, NY 11548, USA.
Animals (Basel). 2021 Jan 8;11(1):131. doi: 10.3390/ani11010131.
Mastitis is the most prevalent and economically important disease caused by different etiological agents, which leads to increased somatic cell count (SCC) and low milk quality. Treating mastitis cases with antimicrobials is essential to reduce SCC and improve milk quality. Non-prudent use of antimicrobials in dairy farms increased the development of antimicrobial resistant bacteria. This study's objectives were (1) to isolate and identify etiological agents of mastitis and (2) to determine antimicrobial resistance profiles of bacterial isolates. A total of 174 quarter milk samples from 151 cows with high SCC and clinical mastitis from 34 dairy farms in Tennessee, Kentucky, and Mississippi were collected. Bacterial causative agents were determined by bacteriological and biochemical tests. The antimicrobial resistance of bacterial isolates against 10 commonly used antimicrobials was tested. A total of 193 bacteria consisting of six bacterial species, which include , , , , and were isolated. was the predominant isolate followed by spp., , and spp. Results of this study showed that Gram-negatives ( and spp.) were more resistant than Gram-positives ( and spp.). Continuous antimicrobial resistance testing and identification of reservoirs of resistance traits in dairy farms are essential to implement proper mitigation measures.
乳腺炎是由不同病原体引起的最普遍且在经济上最重要的疾病，它会导致体细胞数（SCC）增加以及牛奶质量下降。使用抗菌药物治疗乳腺炎病例对于降低体细胞数和提高牛奶质量至关重要。奶牛场中不谨慎使用抗菌药物增加了抗菌药物耐药菌的产生。本研究的目的是（1）分离和鉴定乳腺炎的病原体，以及（2）确定细菌分离株的抗菌药物耐药谱。从田纳西州、肯塔基州和密西西比州的34个奶牛场的151头体细胞数高且患有临床乳腺炎的奶牛中总共采集了174份乳区牛奶样本。通过细菌学和生化试验确定细菌病原体。测试了细菌分离株对10种常用抗菌药物的耐药性。总共分离出193株细菌，包括六种细菌，分别是 、 、 、 、 和 。 是主要的分离株，其次是 属、 和 属。本研究结果表明，革兰氏阴性菌（ 和 属）比革兰氏阳性菌（ 和 属）更具耐药性。持续进行抗菌药物耐药性测试并识别奶牛场耐药性状的储存库对于实施适当的缓解措施至关重要。
