College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
Foodborne Pathog Dis. 2013 Sep;10(9):757-63. doi: 10.1089/fpd.2012.1474. Epub 2013 Jun 20.
Staphylococcus aureus is a pathogenic bacterium capable of developing biofilms, leading to nosocomial infection and cross-contamination of foods. The current study was focused on the detection of adhesin genes, staphylococcal nuclease and hemolytic activities, and biofilm formation among the isolates of S. aureus from different sources. Fifteen adhesin genes (bap, bbp, clfA, clfB, cna, ebpS, fib, fnbA, fnbB, eno, icaAD, icaBC, sasG, sasC, pls) involved in S. aureus cell aggregation and biofilm accumulation were detected by polymerase chain reaction using specific primer. The activities of staphylococcal nuclease and hemolysis were analyzed by using toluidine blue-DNA agar and sheep blood agar for each strain. The ability of biofilm formation among different S. aureus strains was tested by using the glass tube method and microtiter-plate method. Our results showed the diversity of biofilm formation from different sources. Some isolates were strong biofilm producers; some were weak biofilm producers; and some were nonbiofilm producers. Staphylococcal nuclease and hemolysis seem to play a certain inhibitory role in biofilm formation. The adhesin genes varied among different S. aureus strains. The bap gene was not present in any strains. The bbp gene was only detected in one strain. The detection rates of other adhesin genes were as follows: clfB and sasG (100%); cna, eno, fib, and ebpS (93.75%); fnbA, icaAD, and icaBC (87.50%); fnbB (68.75%); sasC (31.25%); clfA (25%); and pls (12.50%), respectively. The variation between phenotypic and genotypic characterization may be due to the heterogeneity in the genetic origins. There was no direct correlation in distribution of adhesin genes and biofilm formation, which indicates that a single gene or subset of genes cannot be utilized as a biofilm indicator for morphology. Our results also indicated that biofilm formation might be affected by many factors, which brings new challenges to the prevention of this serious pathogen due to biofilm-related infection and contamination.
金黄色葡萄球菌是一种能够形成生物膜的致病菌，可导致医院感染和食物的交叉污染。本研究旨在检测不同来源的金黄色葡萄球菌分离株中的黏附素基因、葡萄球菌核酸酶和溶血活性以及生物膜形成。通过使用特异性引物的聚合酶链反应检测了 15 种与金黄色葡萄球菌细胞聚集和生物膜积累有关的黏附素基因（bap、bbp、clfA、clfB、cna、ebpS、fib、fnbA、fnbB、eno、icaAD、icaBC、sasG、sasC、pls）。用甲苯胺蓝-DNA 琼脂和绵羊血琼脂分析了每种菌株的葡萄球菌核酸酶和溶血活性。通过使用玻璃管法和微量滴定板法检测了不同金黄色葡萄球菌菌株的生物膜形成能力。我们的结果显示了不同来源的生物膜形成的多样性。一些分离株是强生物膜生产者；一些是弱生物膜生产者；还有一些是非生物膜生产者。葡萄球菌核酸酶和溶血似乎对生物膜形成有一定的抑制作用。黏附素基因在不同的金黄色葡萄球菌菌株中存在差异。bap 基因不存在于任何菌株中。bbp 基因仅在一株中检测到。其他黏附素基因的检出率如下：clfB 和 sasG（100%）；cna、eno、fib 和 ebpS（93.75%）；fnbA、icaAD 和 icaBC（87.50%）；fnbB（68.75%）；sasC（31.25%）；clfA（25%）和 pls（12.50%）。表型和基因型特征之间的差异可能是由于遗传起源的异质性所致。黏附素基因的分布与生物膜形成之间没有直接的相关性，这表明单个基因或基因子集不能用作形态学的生物膜指标。我们的结果还表明，生物膜形成可能受到许多因素的影响，这给预防这种严重病原体带来了新的挑战，因为生物膜相关的感染和污染。
