Rao Qing, Shang Weilong, Hu Xiaomei, Rao Xiancai
Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, PR China.
J Med Microbiol. 2015 Dec;64(12):1462-1473. doi: 10.1099/jmm.0.000185. Epub 2015 Oct 6.
Staphylococcus aureus is a leading cause of bacterial infections in hospitals and communities worldwide. With the development of typing methods, several pandemic clones have been well characterized, including the extensively spreading hospital-associated meticillin-resistant S. aureus (HA-MRSA) clone ST239 and the emerging hypervirulent community-associated (CA) MRSA clone USA300. The multilocus sequence typing method was set up based on seven housekeeping genes; S. aureus groups were defined by the sharing of alleles at ≥ 5 of the seven loci. In many cases, the predicted founder of a group would also be the most prevalent ST within the group. As a predicted founder of major S. aureus groups, approximately 90 % of ST121 strains was meticillin-susceptible S. aureus (MSSA). The majority of ST121 strains carry accessory gene regulator type IV, whereas staphylococcal protein A gene types for ST121 are exceptionally diverse. More than 90 % of S. aureus ST121 strains have Panton-Valentine leukocidin; other enterotoxins, haemolysins, leukocidins and exfoliative toxins also contribute to the high virulence of ST121 strains. Patients suffering from S. aureus ST121 infections often need longer hospitalization and prolonged antimicrobial therapy. In this review, we tried to summarize the epidemiology of the S. aureus clone ST121 and focused on the molecular types, toxin carriage and disease spectrum of this globally disseminated clone.
金黄色葡萄球菌是全球医院和社区细菌性感染的主要病因。随着分型方法的发展，已对多个大流行克隆株进行了充分表征，包括广泛传播的医院相关耐甲氧西林金黄色葡萄球菌（HA-MRSA）克隆株ST239和新兴的高毒力社区相关（CA）MRSA克隆株USA300。多位点序列分型方法基于7个管家基因建立；金黄色葡萄球菌菌群通过在7个位点中≥5个位点上等位基因的共享来定义。在许多情况下，一个菌群的预测创始株也将是该菌群中最常见的序列型（ST）。作为主要金黄色葡萄球菌菌群的预测创始株，约90%的ST121菌株为甲氧西林敏感金黄色葡萄球菌（MSSA）。大多数ST121菌株携带IV型辅助基因调节子，而ST121的葡萄球菌蛋白A基因类型异常多样。超过90%的金黄色葡萄球菌ST121菌株具有杀白细胞素；其他肠毒素、溶血素、杀白细胞素和剥脱毒素也导致ST121菌株的高毒力。患有金黄色葡萄球菌ST121感染的患者通常需要更长的住院时间和更长疗程的抗菌治疗。在本综述中，我们试图总结金黄色葡萄球菌克隆株ST121的流行病学，并重点关注这一全球传播克隆株的分子类型、毒素携带情况和疾病谱。
