Atshan Salman Sahab, Shamsudin Mariana Nor, Lung Leslie Than Thian, Sekawi Zamberi, Ghaznavi-Rad Ehsanollah, Pei Chong Pei
Department of Medical Microbiology and Parasitology, Universiti Putra Malaysia, Selangor, Serdang, Malaysia.
J Biomed Biotechnol. 2012;2012:417247. doi: 10.1155/2012/417247. Epub 2012 Mar 14.
The ability to adhere and produce biofilms is characteristic of enhanced virulence among isolates of methicillin-resistant Staphylococcus aureus (MRSA). The aim of the study is to find out whether these characteristics are consistently similar among isolates variations of MRSA. The study used 30 various isolates of MRSA belong to 13 spa types and 5 MLST types and determined the aggregation, the adherence, and the production of biofilms and slime for each isolate. The methods used to evaluate these characteristics were a modified Congo red agar assay (MCRA), a microtiter plate assay (MPA), high-magnification light microscopy, scanning electron microscopy (SEM), and PCR. The study found that isolates belonging to similar Spa, SCCmec, and ST types have similar abilities to produce biofilms; however, their ability to produce slime on CRA was found to be different. Moreover, isolates that have different Spa types showed high variation in their ability to produce biofilms. The results of light microscope revealed the isolates that produced strong and weak biofilms and formed similar aggregation on the glass surfaces. SEM results showed that all 30 MRSA isolates that were tested were 100% positive for biofilm formation, although to varying degrees. Further testing using PCR confirmed that 100% of the 30 isolates tested were positive for the presence of the icaADBC, fnbA, eno, ebps, clfA, and clfB genes. The prevalence of fib, cna, fnbB, and bbp in MRSA clones was 90, 93.33, 53.33, and 10%, respectively. This study indicate that differences in biofilm production capacities are caused by the differences in surface protein A (Spa) type and are not due to differences in MLST and SCCmec types.
黏附并产生生物膜的能力是耐甲氧西林金黄色葡萄球菌（MRSA）分离株毒力增强的特征。本研究的目的是确定这些特征在MRSA分离株变异中是否始终相似。该研究使用了30株不同的MRSA分离株，它们属于13种spa型和5种多位点序列分型（MLST）类型，并测定了每个分离株的聚集性、黏附性以及生物膜和黏液的产生情况。用于评估这些特征的方法有改良刚果红琼脂试验（MCRA）、微量滴定板试验（MPA）、高倍光学显微镜、扫描电子显微镜（SEM）和聚合酶链反应（PCR）。研究发现，属于相似spa、葡萄球菌染色体盒式甲氧西林酶（SCCmec）和ST型的分离株具有相似的生物膜产生能力；然而，发现它们在CRA上产生黏液的能力有所不同。此外，具有不同spa型的分离株在生物膜产生能力上表现出很大差异。光学显微镜结果显示，产生强生物膜和弱生物膜的分离株在玻璃表面形成了相似的聚集。SEM结果表明，所有测试的30株MRSA分离株生物膜形成均为100%阳性，尽管程度不同。使用PCR的进一步检测证实，30株测试分离株中有100%的icaADBC、fnbA、eno、ebps、clfA和clfB基因呈阳性。MRSA克隆中fib、cna、fnbB和bbp的流行率分别为90%、93.33%、53.33%和10%。本研究表明，生物膜产生能力的差异是由表面蛋白A（Spa）类型的差异引起的，而不是由于MLST和SCCmec类型的差异。
