Escobar-Pérez Javier Antonio, Castro Betsy Esperanza, Márquez-Ortiz Ricaurte Alejandro, Gaines Sebastián, Chavarro Bibiana, Moreno Jaime, Leal Aura Lucía, Vanegas Natasha
Laboratorio de Genética Molecular Bacteriana, Universidad El Bosque, Bogotá, D.C, Colombia.
Grupo de Microbiología, Dirección de Investigación en Salud Pública, Subdirección de Investigación Científica y Tecnológica, Instituto Nacional de Salud, Bogotá, D.C, Colombia.
Biomedica. 2014 Apr;34 Suppl 1:124-36. doi: 10.1590/S0120-41572014000500015.
USA300 is a genetic lineage found both in methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) isolates. In Colombia, hospital and community MRSA infections are caused by a USA300-related community genotype MRSA (CG-MRSA) clone. The genetic origin of this clone is unknown yet.
To identify and characterize methicillin-resistant (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates in order to improve the information about the origin of the CG-MRSA isolates in Colombia.
USA300-related MSSA isolates were detected and characterized from a study of 184 S. aureus isolates (90 MRSA and 94 MSSA) recovered from infections. The genetic relatedness of the isolates was established by means of pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and protein A gene typification ( spa typing).
Among 184 isolates, 27 (14.7%) showed molecular characteristics and genetic relationship with the USA300 clone, of which 18 were MRSA and nine were MSSA. All USA300-related MRSA harbored Staphylococcal cassette chromosome mec (SCC mec ) IVc (3.1.2). In the MSSA isolates, SCC mec remnants or att B duplicate sites were not detected.
In Colombia, the CG-MRSA isolates probably originated in the dissemination of an USA300-related MSSA clone which later acquired SCC mec IVc.
USA300是一种在耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）分离株中均能发现的基因谱系。在哥伦比亚，医院和社区的MRSA感染是由一种与USA300相关的社区基因型MRSA（CG-MRSA）克隆引起的。该克隆的基因起源尚不清楚。
鉴定和表征耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）分离株，以完善有关哥伦比亚CG-MRSA分离株起源的信息。
从一项对184株从感染中分离出的金黄色葡萄球菌（90株MRSA和94株MSSA）的研究中检测并表征与USA300相关的MSSA分离株。通过脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）和蛋白A基因分型（spa分型）确定分离株的遗传相关性。
在184株分离株中，27株（14.7%）显示出与USA300克隆的分子特征和遗传关系，其中18株为MRSA，9株为MSSA。所有与USA300相关的MRSA均携带葡萄球菌盒式染色体mec（SCC mec）IVc（3.1.2）。在MSSA分离株中，未检测到SCC mec残余物或att B重复位点。
在哥伦比亚，CG-MRSA分离株可能起源于一种与USA300相关的MSSA克隆的传播，该克隆后来获得了SCC mec IVc。
