Omuse Geoffrey, Van Zyl Kristien Nel, Hoek Kim, Abdulgader Shima, Kariuki Samuel, Whitelaw Andrew, Revathi Gunturu
Department of Pathology, Aga Khan University Hospital Nairobi, P.O. Box 30270-00100, Nairobi, Kenya.
Division of Medical Microbiology, Department of Pathology, Stellenbosch University, P. O. Box 19063, Western Cape, South Africa.
Ann Clin Microbiol Antimicrob. 2016 Sep 20;15(1):51. doi: 10.1186/s12941-016-0171-z.
Staphylococcus aureus (S. aureus) has established itself over the years as a major cause of morbidity and mortality both within the community and in healthcare settings. Methicillin resistant S. aureus (MRSA) in particular has been a major cause of nosocomial infections resulting in significant increase in healthcare costs. In Africa, the MRSA prevalence has been shown to vary across different countries. In order to better understand the epidemiology of MRSA in a setting, it is important to define its population structure using molecular tools as different clones have been found to predominate in certain geographical locations.
We carried out PFGE, MLST, SCCmec and spa typing of selected S. aureus isolates from a private and public referral hospital in Nairobi, Kenya.
A total of 93 S. aureus isolates were grouped into 19 PFGE clonal complexes (A-S) and 12 singletons. From these, 55 (32 MRSA and 23 MSSA) representative isolates from each PFGE clonal complex and all singletons were spa typed. There were 18 different MRSA spa types and 22 MSSA spa types. The predominant MRSA spa type was t037 comprising 40.6 % (13/32) of all MRSA. In contrast, the MSSA were quite heterogeneous, only 2 out of 23 MSSA shared the same spa type. Two new MRSA spa types (t13149 and t13150) and 3 new MSSA spa types (t13182, t13193 and t13194) were identified. The predominant clonal complex was CC 5 which included multi-locus sequence types 1, 8 and 241.
In contrast to previous studies published from Kenya, there's marked genetic diversity amongst clinical MRSA isolates in Nairobi including the presence of well-known epidemic MRSA clones. Given that these clones are resident within our referral hospitals, adherence to strict infection control measures needs to be ensured to reduce morbidity and mortality associated with hospital acquired MRSA infections.
多年来，金黄色葡萄球菌已成为社区和医疗机构发病和死亡的主要原因。特别是耐甲氧西林金黄色葡萄球菌（MRSA）一直是医院感染的主要原因，导致医疗成本大幅增加。在非洲，不同国家的MRSA流行率有所不同。为了更好地了解某一环境中MRSA的流行病学，使用分子工具定义其种群结构很重要，因为已发现不同的克隆在某些地理位置占主导地位。
我们对肯尼亚内罗毕一家私立和公立转诊医院中选定的金黄色葡萄球菌分离株进行了脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）、葡萄球菌染色体盒式甲氧西林抗性基因（SCCmec）分型和葡萄球菌蛋白A（spa）分型。
总共93株金黄色葡萄球菌分离株被分为19个PFGE克隆复合体（A - S）和12个单克隆。从中选取每个PFGE克隆复合体和所有单克隆的55株（32株MRSA和23株甲氧西林敏感金黄色葡萄球菌[MSSA]）代表性分离株进行spa分型。有18种不同的MRSA spa型和22种MSSA spa型。主要的MRSA spa型是t037，占所有MRSA的40.6%（13/32）。相比之下，MSSA非常异质，23株MSSA中只有2株共享相同的spa型。鉴定出2种新的MRSA spa型（t13149和t13150）和3种新的MSSA spa型（t13182、t13193和t13194）。主要的克隆复合体是CC 5，包括多位点序列类型1、8和241。
与肯尼亚此前发表的研究不同，内罗毕临床MRSA分离株之间存在显著的遗传多样性，包括存在著名的流行MRSA克隆。鉴于这些克隆存在于我们的转诊医院中，需要确保严格遵守感染控制措施，以降低与医院获得性MRSA感染相关的发病率和死亡率。
