Freitas C H, Mendes J F, Villarreal P V, Santos P R, Gonçalves C L, Gonzales H L, Nascente P S
Laboratório de Micologia e Bioprospecção, Programa de Pós-Graduação em Parasitologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas - UFPel, Av. Eliseu Maciel, CEP 96160-000, Capão do Leão, RS, Brazil.
Programa de Pós-Graduação em Veterinária, Departamento de Veterinária Preventiva, Faculdade de Veterinária, Universidade Federal de Pelotas - UFPel, Av. Eliseu Maciel, CEP 96160-000, Capão do Leão, RS, Brazil.
Braz J Biol. 2018 Nov;78(4):661-666. doi: 10.1590/1519-6984.170727. Epub 2018 Jan 8.
Mastitis is an inflammatory process of the udder tissue caused mainly by the bacteria Staphylococcus aureus. The indiscriminate use of antibiotics fosters conditions that favor the selection of resistant microorganisms, suppressing at the same time susceptible forms, causing a serious problem in dairy cattle. Given the importance in performing an antibiogram to select the most adequate antimicrobial therapy, the aim of this study was to identify bacteria isolated from cow's milk with mastitis, in dairy farms situated in the city of Pelotas, Rio Grande do Sul, and to determinate the susceptibility profile of these isolates against the antibiotics used to treat this illness. A total of 30 isolates of Staphylococcus spp., were selected from milk samples from the udder quarters with subclinical mastitis whose species were identified through the Vitek system. The susceptibility profile was performed by the disk diffusion assay, against: ampicillin, amoxicillin, bacitracin, cephalexin, ceftiofur, enrofloxacin, gentamicin, neomycin, norfloxacin, penicillin G, tetracycline and trimethoprim. In the antibiogram, 100.0% of the isolates were resistant to trimethoprim and 96.7% to tetracycline and neomycin, three strains of Staphylococcus spp., (10.0%) presented resistance to the 12 antibiotics tested and 24 (80.0%) to at least eight. These results showed the difficulty in treating mastitis, due to the pathogens' resistance.
乳腺炎是一种主要由金黄色葡萄球菌引起的乳腺组织炎症过程。抗生素的滥用营造了有利于耐药微生物选择的条件，同时抑制了敏感菌，给奶牛养殖业带来了严重问题。鉴于进行药敏试验以选择最适当抗菌治疗的重要性，本研究的目的是鉴定从南里奥格兰德州佩洛塔斯市奶牛场患有乳腺炎的奶牛乳汁中分离出的细菌，并确定这些分离株对用于治疗该疾病的抗生素的敏感性谱。从患有亚临床乳腺炎的乳腺象限的乳汁样本中总共选择了30株葡萄球菌属分离株，其菌种通过Vitek系统进行鉴定。通过纸片扩散法对以下抗生素进行敏感性分析：氨苄青霉素、阿莫西林、杆菌肽、头孢氨苄、头孢噻呋、恩诺沙星、庆大霉素、新霉素、诺氟沙星、青霉素G、四环素和甲氧苄啶。在药敏试验中，100.0%的分离株对甲氧苄啶耐药，96.7%对四环素和新霉素耐药，3株葡萄球菌属（10.0%）对所测试的12种抗生素均耐药，24株（80.0%）对至少8种抗生素耐药。这些结果表明，由于病原体的耐药性，乳腺炎的治疗存在困难。
