Phenotypic and molecular characteristics of methicillin-resistant and methicillin-susceptible Staphylococcus aureus isolated from pigs: implication for livestock-association markers and vaccine strategies.
Phenotypic and molecular characteristics of methicillin-resistant and methicillin-susceptible Staphylococcus aureus isolated from pigs: implication for livestock-association markers and vaccine strategies.
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DOI：
10.2147/idr.s173624
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发表时间：
2018
影响因子：
3.9
通讯作者：
Ye X
中科院分区：
文献类型：
--
作者：
Guo D;Liu Y;Han C;Chen Z;Ye X
常规的非治疗性抗菌药物使用和动物养殖中过度拥挤可能促进耐甲氧西林金黄色葡萄球菌（MRSA）的传播。本研究旨在研究猪源MRSA和甲氧西林敏感金黄色葡萄球菌的携带、流行和表型-基因型特征。收集了来自9个猪场和3个屠宰场的1458头猪的鼻拭子。所有菌株均进行了药敏、耐药基因和毒力基因检测，并进行了多位点序列分型。通过对应分析，探讨金黄色葡萄球菌分离株多种表型与分子特征之间的关系。在1458头猪中，金黄色葡萄球菌携带率为9.5%，MRSA携带率为3.3%，耐多药金黄色葡萄球菌携带率为9.3%。值得注意的是，97.1%的金黄色葡萄球菌耐多药，主要耐药模式是对克林霉素、四环素和红霉素不敏感。金黄色葡萄球菌和MRSA分离株的优势基因型为CC9 （ST9）。重要的是，所有金黄色葡萄球菌分离株均为scn基因阴性，并对四环素耐药。值得注意的是，9株利奈唑胺耐药菌株均为多重耐药菌株，其中1株表达cfr基因，6株表达optrA基因。对应分析表明克隆复合体与抗性模式或毒力基因有显著的相关性。例如，CC9与广泛耐药和共同携带chp、sak和hlb有关，CC1与多药耐药和共同携带sak和hlb有关。多种特征之间存在显著的对应关系，为疫苗策略的制定提供了启示，并为监测新的流行病学克隆提供了新思路。
Routine non-therapeutic antimicrobial use and overcrowding in animal farming may facilitate the propagation of methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to examine the carriage prevalence and phenotype–genotype characteristics of MRSA and methicillin-susceptible S. aureus isolated from pigs. Nasal swabs were collected from 1,458 pigs in 9 pig farms and 3 slaughterhouses. All strains were tested for antimicrobial susceptibility, resistance genes, and virulence genes, and characterized by multilocus sequence typing. The correspondence analysis was conducted to explore the relationships between multiple phenotypic and molecular characteristics of S. aureus isolates. In the 1,458 pigs, the carriage prevalence was 9.5% for S. aureus, 3.3% for MRSA, and 9.3% for multidrug-resistant S. aureus. Notably, 97.1% S. aureus isolates were multidrug resistant, and the predominant resistance pattern was non-susceptible to clindamycin, tetracycline, and erythromycin. The predominant genotype was CC9 (ST9) for S. aureus and MRSA isolates. Importantly, all S. aureus isolates were negative for the scn gene and resistant to tetracycline. Notably, all 9 linezolid-resistant isolates were classified as multidrug resistance, including 1 expressing the cfr gene and 6 expressing the optrA gene. The correspondence analysis showed a significant relationship between clonal complexes and resistance pattern or virulence genes. For example, CC9 was associated with extensive drug-resistance and co-carrying chp, sak, and hlb, and CC1 was associated with multidrug resistance and co-carrying sak and hlb. The significant correspondence relationship between multiple characteristics provides some implication for vaccine strategies and new ideas for monitoring new epidemiologic clones.