da Cunha Maria de Lourdes R S, Calsolari Regina A O, Júnior João Pessoa Araújo
Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
Microbiol Immunol. 2007;51(4):381-90. doi: 10.1111/j.1348-0421.2007.tb03925.x.
The detection of staphylococcal enterotoxins is decisive for the confirmation of an outbreak and for the determination of the enterotoxigenicity of strains. Since the recognition of their antigenicity, a large number of serological methods for the detection of enterotoxins in food and culture media have been proposed. Since immunological methods require detectable amounts of toxin, molecular biology techniques represent important tools in the microbiology laboratory. In the present study, polymerase chain reaction (PCR) was used to identify genes responsible for the production of enterotoxins and toxic shock syndrome toxin 1 (TSST-1) in S. aureus and coagulase-negative staphylococci (CNS) isolated from patients and the results were compared with those obtained by the reverse passive latex agglutination (RPLA) assay. PCR detection of toxin genes revealed a higher percentage of toxigenic S. aureus strains (46.7%) than the RPLA method (38.3%). Analysis of the toxigenic profile of CNS strains showed that 26.7% of the isolates produced some type of toxin, and one or more toxin-specific genes were detected in 40% of the isolates. These results suggests the need for further studies in order to better characterize the pathogenic potential of CNS and indicate that attention should be paid to the toxigenic capacity of this group of microorganisms.
金黄色葡萄球菌肠毒素的检测对于确认疫情爆发以及确定菌株的产肠毒素能力至关重要。自认识到其抗原性以来，已提出了大量用于检测食品和培养基中肠毒素的血清学方法。由于免疫方法需要可检测量的毒素，分子生物学技术成为微生物学实验室的重要工具。在本研究中，采用聚合酶链反应（PCR）来鉴定从患者分离出的金黄色葡萄球菌和凝固酶阴性葡萄球菌（CNS）中负责产生肠毒素和毒性休克综合征毒素1（TSST-1）的基因，并将结果与通过反向被动乳胶凝集试验（RPLA）获得的结果进行比较。毒素基因的PCR检测显示，产毒素金黄色葡萄球菌菌株的比例（46.7%）高于RPLA方法（38.3%）。对CNS菌株的产毒谱分析表明，26.7%的分离株产生某种类型的毒素，40%的分离株检测到一个或多个毒素特异性基因。这些结果表明需要进一步研究以更好地表征CNS的致病潜力，并表明应关注这组微生物的产毒能力。
