Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany.
Clin Microbiol Infect. 2012 Aug;18(8):745-55. doi: 10.1111/j.1469-0691.2012.03842.x. Epub 2012 Apr 17.
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates have been the subject of numerous studies during recent years. The characterization of such isolates has usually also included the determination of their resistance phenotypes and associated resistance genotypes. Analysis of the resistance genes present in LA-MRSA isolates has revealed a number of genes commonly found in S. aureus and coagulase-negative staphylococci of humans and animals. In addition, novel resistance genes and/or resistance genes that have been rarely detected in staphylococci so far have been encountered. These include the phenicol exporter gene fexA, the multiresistance gene cfr, the tetracycline resistance gene tet(L), the trimethoprim resistance gene dfrK, the macrolide-lincosamide-streptogramin B resistance gene erm(T), the lincosamide-streptogramin A-pleuromutilin resistance genes vga(C) and vga(E), and the apramycin resistance gene apmA. Most of these genes were located on multiresistance plasmids in LA-MRSA. The co-localization of these resistance genes with other resistance genes enables their co-selection and persistence. LA-MRSA can therefore act as a donor and a recipient of antimicrobial resistance genes within the Gram-positive gene pool.
近年来，已对与牲畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）分离株进行了大量研究。此类分离株的特征通常还包括其耐药表型和相关耐药基因型的测定。对 LA-MRSA 分离株中存在的耐药基因的分析揭示了许多常见于金黄色葡萄球菌和人类及动物中凝固酶阴性葡萄球菌的基因。此外，还发现了一些新型耐药基因和/或迄今为止在葡萄球菌中很少检测到的耐药基因。其中包括苯丙醇类外排基因 fexA、多耐药基因 cfr、四环素耐药基因 tet(L)、甲氧苄啶耐药基因 dfrK、大环内酯-林可酰胺-链阳菌素 B 耐药基因 erm(T)、林可酰胺-链阳菌素 A-截短侧耳素耐药基因 vga(C)和 vga(E)，以及安普霉素耐药基因 apmA。这些基因中的大多数位于 LA-MRSA 的多耐药质粒上。这些耐药基因与其他耐药基因的共定位使其能够共同选择和持续存在。因此，LA-MRSA 可以作为革兰氏阳性基因库中抗菌药物耐药基因的供体和受体。
