Wongboot Warawan, Chomvarin Chariya, Engchanil Chulapan, Chaimanee Prajuab
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Southeast Asian J Trop Med Public Health. 2013 Jul 4;44(4):660-71.
The aims of this study were to develop multiplex PCR for simultaneous detection of five superantigenic toxin genes (sea, seb, sec, sed and tst-1) in Staphylococcus aureus isolated from 149 clinical samples and nasal swabs from 201 healthy subjects in Thailand, and to compare prevalence and expression of those genes between methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). The sensitivity of multiplex PCR was 10(3) CFU/ml (60 CFU/PCR reaction) for DNA templates extracted by both boiling and extraction methods. S. aureus strains from patients (65%) harbored more superantigenic toxin genes than healthy subjects (54%). MRSA (80%) isolated from patients harbored more superantigenic toxin genes than MSSA (52%). Sea was the most frequently found gene in S. aureus strains from patients and carriers. MRSAisolates harbored sea and produced SEA more frequently than MSSA isolates (p <0.05) and MRSA isolates (59%) from blood samples consisted of a higher number of superantigenic toxin producers than MSSA (9%) (p < 0.05). More S. aureus strains isolated from patients with severe septicemia contained superantigenic toxin genes (94%) and produced toxins (82%) than those from non-severe patients (64% and 57%, respectively). The multiplex PCR method described here offers a reliable tool for simultaneous detection of various staphylococcal toxin genes.
本研究的目的是开发多重聚合酶链反应（multiplex PCR），用于同时检测从泰国149份临床样本和201名健康受试者的鼻拭子中分离出的金黄色葡萄球菌中的5种超抗原毒素基因（sea、seb、sec、sed和tst-1），并比较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）中这些基因的流行率和表达情况。对于通过煮沸法和提取法提取的DNA模板，多重PCR的灵敏度为10(3) CFU/ml（60 CFU/PCR反应）。来自患者的金黄色葡萄球菌菌株（65%）携带的超抗原毒素基因比健康受试者（54%）更多。从患者中分离出的MRSA（80%）携带的超抗原毒素基因比MSSA（52%）更多。Sea是在患者和携带者的金黄色葡萄球菌菌株中最常发现的基因。MRSA分离株比MSSA分离株更频繁地携带sea并产生SEA（p <0.05），并且来自血液样本的MRSA分离株（59%）中产生超抗原毒素的菌株数量高于MSSA（9%）（p <0.05）。与非重症患者（分别为64%和57%）相比，从严重败血症患者中分离出的更多金黄色葡萄球菌菌株含有超抗原毒素基因（94%）并产生毒素（82%）。本文所述的多重PCR方法为同时检测各种葡萄球菌毒素基因提供了一种可靠的工具。
