Dept. of Biomedical Science, Faculty of Medicine, Univ. of Malaya, Malaya, Kuala Lumpur, Malaysia.
Academic of Sciences Malaysia, Kuala Lumpur, Malaysia.
J Food Sci. 2018 Sep;83(9):2337-2342. doi: 10.1111/1750-3841.14300. Epub 2018 Aug 13.
Staphylococcus aureus is able to form multilayer biofilms embedded within a glycocalyx or slime layer. Biofilm formation poses food contamination risks and can subsequently increase the risk of food poisoning. Identification of food-related S. aureus strains will provide additional data on staphylococcal food poisoning involved in biofilm formation. A total of 52 S. aureus strains isolated from sushi and sashimi was investigated to study their ability for biofilm formation using crystal violet staining. The presence of accessory gene regulator (agr) groups and 15 adhesion genes was screened and their associations in biofilm formation were studied. All 52 S. aureus strains showed biofilm production on the tested hydrophobic surface with 44% (23/52) strains classified as strong, 33% (17/52) as moderate, and 23% (12/52) as weak biofilm producers. The frequency of agr-positive strains was 71% (agr group 1 = 21 strains; agr group 2 = 2 strains; agr group 3 = 12 strains; agr group 4 = 2 strains) whereas agr-negative strains were 29% (15/52). Twelve adhesion genes were detected and 98% of the S. aureus strains carried at least one adhesion gene. The ebps was significantly (p < .05) associated with strong biofilm producing strains. In addition, eno, clfA, icaAD, sasG, fnbB, cna, and sasC were significantly higher in the agr-positive group compared to the agr-negative group. The results of this study suggest that the presence of ebps, eno, clfA, icaAD, sasG, fnbB, cna, and sasC may play an important role in enhancing the stage of biofilm-related infections and warrants further investigation.
This work contributes to the knowledge on the biofilm formation and the distribution of agr groups in S. aureus strains as well as microbial surface components in recognizing adherence matrix molecules of organisms isolated from ready-to-eat sushi and sashimi. The findings provide valuable information to further study the roles of specific genes in causing biofilm-related infections.
金黄色葡萄球菌能够形成多层生物膜，嵌入糖萼或粘液层中。生物膜的形成会带来食品污染的风险，进而增加食物中毒的风险。鉴定与食品相关的金黄色葡萄球菌菌株将为涉及生物膜形成的葡萄球菌食物中毒提供更多数据。共研究了从寿司和刺身中分离的 52 株金黄色葡萄球菌，以使用结晶紫染色法研究其生物膜形成能力。筛选了辅助基因调节（agr）组和 15 个粘附基因的存在，并研究了它们在生物膜形成中的关联。所有 52 株金黄色葡萄球菌菌株在测试的疏水性表面上均显示出生物膜产生，其中 44%（23/52）菌株被分类为强，33%（17/52）为中度，23%（12/52）为弱生物膜产生者。agr 阳性菌株的频率为 71%（agr 组 1 = 21 株；agr 组 2 = 2 株；agr 组 3 = 12 株；agr 组 4 = 2 株），而 agr 阴性菌株为 29%（15/52）。检测到 12 个粘附基因，98%的金黄色葡萄球菌菌株至少携带一个粘附基因。ebps 与强生物膜产生菌株显著相关（p <.05）。此外，agr 阳性组中 eno、clfA、icaAD、sasG、fnbB、cna 和 sasC 的含量明显高于 agr 阴性组。本研究结果表明，ebps、eno、clfA、icaAD、sasG、fnbB、cna 和 sasC 的存在可能在增强与生物膜相关的感染阶段中发挥重要作用，值得进一步研究。
这项工作有助于了解金黄色葡萄球菌菌株中生物膜形成和 agr 组的分布情况，以及微生物表面成分识别与即食寿司和刺身分离的生物体粘附基质分子。研究结果为进一步研究特定基因在引起生物膜相关感染中的作用提供了有价值的信息。
