Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Recife, PE, Brasil.
Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
Braz J Microbiol. 2022 Dec;53(4):2215-2222. doi: 10.1007/s42770-022-00822-1. Epub 2022 Sep 8.
This research aimed to identify the diversity of bacterial species of the genus Staphylococcus spp. in subclinical mastitis in dairy herds in the state of Piauí, Northeastern Brazil, and to evaluate the phenotypic and genotypic resistance profile. Samples were obtained from a total of 17 dairy farms, amounting to 321 positive samples in the California Mastitis Test. Staphylococcus spp. were identified by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy. Subsequently, an antibiogram was performed, and a polymerase chain reaction was carried out to screen for resistance genes in the isolates. Among all the isolates, 59.45% (110/185) belonged to the Staphylococcus genus. Moreover, the following Staphylococcus spp. were identified Staphylococcus aureus, 68.1% (75/110); Staphylococcus chromogenes, 12.7% (14/110); Staphylococcus epidermidis, 5.4% (6/110); Staphylococcus sciuri, 4.5% (5/110); Staphylococcus warneri, 2.7% (3/110); Staphylococcus haemolyticus, 1.8% (2/110); Staphylococcus hominis, 1.8% (2/110); Staphylococcus arlettae, 0.9% (1/110); Staphylococcus capitis, 0.9% (1/110); and Staphylococcus gallinarum, 0.9% (1/110). The antibiogram showed a high frequency of resistance to penicillin and ampicillin, 70.0% (77/110) and 61.8% (68/110), respectively, and a low frequency of resistance to gentamicin and vancomycin, 10.9% (12/110) and 11.8% (13/110), respectively. In the genotypic tests for the different species of Staphylococcus spp., the occurrence of the blaZ gene was observed in 60.9% (67/110) of the isolates, followed by tetL and tetM, both with 20.0% (22/110) each, and the mecA and vanB genes were detected in 0.9% (1/110) of the samples. The identification of all Staphylococcus species isolated from subclinical mastitis cases and the phenotypic and genotypic resistance characterization in these isolates is of great importance for dairy farming in the state of Piauí, as well as for public health.
本研究旨在鉴定巴西皮奥伊州奶牛亚临床乳腺炎中葡萄球菌属细菌的多样性，并评估其表型和基因型耐药谱。从 17 个奶牛场共获得了 321 个加利福尼亚乳房炎测试阳性样本。使用基质辅助激光解吸电离飞行时间质谱法鉴定葡萄球菌属。随后，进行药敏试验，并对分离株进行聚合酶链反应以筛选耐药基因。在所有分离株中，59.45%（110/185）属于葡萄球菌属。此外，还鉴定出以下葡萄球菌属：金黄色葡萄球菌，68.1%（75/110）；变色葡萄球菌，12.7%（14/110）；表皮葡萄球菌，5.4%（6/110）；松鼠葡萄球菌，4.5%（5/110）；沃氏葡萄球菌，2.7%（3/110）；溶血葡萄球菌，1.8%（2/110）；人葡萄球菌，1.8%（2/110）；阿莱塔葡萄球菌，0.9%（1/110）；头状葡萄球菌，0.9%（1/110）；和鸡葡萄球菌，0.9%（1/110）。药敏试验显示青霉素和氨苄西林的耐药率较高，分别为 70.0%（77/110）和 61.8%（68/110），而庆大霉素和万古霉素的耐药率较低，分别为 10.9%（12/110）和 11.8%（13/110）。在不同葡萄球菌属的基因检测中，60.9%（67/110）的分离株中存在 blaZ 基因，其次是 tetL 和 tetM，分别为 20.0%（22/110），mecA 和 vanB 基因的检出率为 0.9%（1/110）。鉴定从亚临床乳腺炎病例中分离出的所有葡萄球菌属和这些分离株的表型和基因型耐药特征，对皮奥伊州的奶牛养殖业以及公共卫生具有重要意义。
