Szczuka Ewa, Krzymińska Sylwia, Bogucka Natalia, Kaznowski Adam
Department of Microbiology, Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, ul. Umultowska 89, 61-614, Poznań, Poland.
Antonie Van Leeuwenhoek. 2018 Jul;111(7):1259-1265. doi: 10.1007/s10482-017-1007-3. Epub 2017 Dec 20.
Staphylococcus hominis is a species of the coagulase-negative staphylococci. It has been designated as a potential pathogen but so far the pathogenic mechanisms of this bacterium have not been determined. We studied 30 clinical isolates of methicillin-resistant S. hominis, which were previously examined for biofilm forming properties. The results of this study revealed that all these S. hominis strains had the ability to adhere to HeLa cells. Over 40% of the S. hominis strains invaded epithelial cells. The invasion index ranged from 0 to 41.5%. All isolates exhibited the cytotoxic activity of extracellular factors, which caused the destruction of epithelial cells. More than 90% of these methicillin-resistant strains contained at least one aminoglycosides resistance gene. The ant(4')-I gene was found in 63% of the isolates, aac(6')/aph(2″) in 20% and aph(3')-IIIa in 47%. Two strains were assigned to SCCmec type VIII and three to SCCmec type III. The remaining isolates (83%) harboured a non-typeable SCCmec type. The mec complex A was predominant in this species. The results indicate that the pathogenicity of S. hominis may be multifactorial, involving adhesion, invasion and the activity of extracellular toxins, which cause damage to the host epithelium.
人葡萄球菌是凝固酶阴性葡萄球菌的一种。它已被认定为潜在病原体，但迄今为止该细菌的致病机制尚未明确。我们研究了30株耐甲氧西林人葡萄球菌临床分离株，这些菌株之前已检测过生物膜形成特性。本研究结果显示，所有这些人葡萄球菌菌株都有黏附HeLa细胞的能力。超过40%的人葡萄球菌菌株能侵袭上皮细胞。侵袭指数范围为0至41.5%。所有分离株均表现出细胞外因子的细胞毒活性，可导致上皮细胞破坏。超过90%的这些耐甲氧西林菌株至少含有一个氨基糖苷类耐药基因。63%的分离株中发现了ant(4')-I基因，20%中发现了aac(6')/aph(2″)基因，47%中发现了aph(3')-IIIa基因。两株菌株属于SCCmec VIII型，三株属于SCCmec III型。其余分离株（83%）携带不可分型的SCCmec类型。mec复合体A在该菌种中占主导地位。结果表明，人葡萄球菌的致病性可能是多因素的，涉及黏附、侵袭以及细胞外毒素的活性，这些因素会对宿主上皮造成损害。
