Departamento de Microbiologia Geral, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, CCS, Bloco I, Cidade Universitária, 21941-590 Rio de Janeiro, RJ, Brazil.
Res Microbiol. 2009 Oct;160(8):592-9. doi: 10.1016/j.resmic.2009.07.007. Epub 2009 Jul 25.
In the present study, 257 Staphylococcus spp. strains were isolated from bovine mastitis cases in 56 different Brazilian dairy herds located in the southeast region of the country and tested for antimicrobial substance (AMS) production. Forty-six strains (17.9%) exhibited AMS production and their identification as Staphylococcus aureus was based on the presence of Gram-positive cocci and on positive results in tests for the ability to coagulate rabbit plasma, to ferment mannitol, and to produce acetoin. The AMS were characterized as bacteriocins (Bac) by their sensitivity to proteolytic enzymes. The Bac(+) strains were tested for resistance to 14 antimicrobial agents showing different profiles. Eighteen strains (39.0%) expressed a multiple antibiotic resistance phenotype. Forty-five strains exhibited at least one plasmid DNA. Cross-immunity analysis against strain S. aureus A70, which produces aureocin A70, amplification of the aurABCD operon (which encodes aureocin A70) or detection of this same operon by DNA/DNA hybridization revealed that 34 strains produce bacteriocins either identical or similar to aureocin A70. The remaining 12 Bac(+) strains produce antimicrobial peptides that seem to be distinct from the best characterized staphylococcal bacteriocins described thus far. The bacteriocin produced by strain 4185 may possess potential practical applications, since it was able to inhibit important pathogens such as Bacillus cereus, Listeria monocytogenes, and Staphylococcus spp. isolated from nosocomial infections.
在本研究中，从巴西东南部 56 个不同的奶牛场的奶牛乳腺炎病例中分离出 257 株葡萄球菌属菌株，并对其抗菌物质（AMS）产生进行检测。46 株（17.9%）表现出 AMS 产生，其鉴定为金黄色葡萄球菌是基于革兰氏阳性球菌的存在以及对兔血浆凝固、甘露醇发酵和乙酰醇产生阳性结果。AMS 被蛋白酶敏感所特征化为细菌素（Bac）。Bac(+) 菌株对 14 种抗菌药物的耐药性进行了测试，表现出不同的耐药谱。18 株（39.0%）表现出多药耐药表型。45 株菌株显示至少有一种质粒 DNA。对金黄色葡萄球菌 A70 株产生的 aureocin A70 的交叉免疫分析、aurABCD 操纵子（编码 aureocin A70）的扩增或通过 DNA/DNA 杂交检测到该相同操纵子，揭示了 34 株菌株产生的细菌素与 aureocin A70 相同或相似。其余 12 株 Bac(+) 菌株产生的抗菌肽似乎与迄今为止描述的最具特征的葡萄球菌细菌素不同。菌株 4185 产生的细菌素可能具有潜在的实际应用价值，因为它能够抑制重要的病原体，如蜡状芽孢杆菌、单核细胞增生李斯特菌和从医院感染中分离出的葡萄球菌属。
