Department of Microbiology, Parasitology and Virology, Faculty of Midwives and Nursing, 'Carol Davila' University of Medicine and Pharmacy, Bucharest, Romania.
'Cantacuzino' National Medico-Military Research and Development Institute, Bucharest, Romania.
PLoS One. 2021 Feb 2;16(2):e0246478. doi: 10.1371/journal.pone.0246478. eCollection 2021.
Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients' quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and lecithinase (67%). Almost half of the strains produced a well-represented biofilm. The molecular characterization showed the presence of the genes cna, hlg, clfA, and clfB. Staphylococcal strains that produce difficult-to-treat skin and soft tissue infections seem to be characterized by an enhanced ability to produce different soluble virulence factors and to develop biofilms in vitro. Further studies need to be developed in other Staphylococcus spp. infections in order to confirm this hypothesis.
慢性感染对医疗保健系统构成了重大负担，并对患者的生活质量产生了重大影响。金黄色葡萄球菌虽然是共生菌，但也可能会成为致病菌，导致各种类型的感染。在这项研究中，我们旨在从表型和基因型两个方面描述参与治疗困难的皮肤和软组织感染的葡萄球菌株的毒力特征。通过培养依赖的测定评估了菌株分泌可溶性毒力因子的表型能力，并通过适应的结晶紫微量滴定法筛选了它们在惰性基质上形成生物膜的能力。我们还通过 PCR 测试了几种毒力基因的存在。研究中大多数菌株是从粉刺病变的脓性分泌物中分离出来的，经常分泌两种或三种可溶性毒力因子。最常分泌的可溶性毒力因子是酪蛋白酶（89%）、脂肪酶（71%）和卵磷脂酶（67%）。近一半的菌株产生了丰富的生物膜。分子特征表明存在 cna、hlg、clfA 和 clfB 基因。产生治疗困难的皮肤和软组织感染的葡萄球菌株似乎具有增强的产生不同可溶性毒力因子的能力，并能在体外形成生物膜。需要在其他金黄色葡萄球菌感染中进一步研究以验证这一假设。
