Rybak Bartosz, Werbowy Olesia, Debowski Karol, Plotka Magdalena, Kocot Aleksandra Maria
Department of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23A, 80-204 Gdansk, Poland.
Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
Int J Mol Sci. 2025 May 6;26(9):4424. doi: 10.3390/ijms26094424.
This study aimed to evaluate the virulence of 36 clinical isolates estimated as blood culture contaminants (BCCs). MALDI-TOF MS classified all isolates as coagulase-negative staphylococci (CoNS) with the highest percentage of S. epidermidis (77.78%). All tested strains formed biofilms with greater ability at room temperature than 37 °C. CoNS were sensitive to vancomycin (0% resistance) and had relatively low resistance to linezolid and rifampicin (8.33 and 22.22% resistance). The highest resistance was observed for penicillin (94.44%). Moreover, we observed the transfer of antibiotic resistance genes from the tested CoNS to and even to , although with lower efficiency. CoNS in planktonic form were completely combated by antiseptics after 10 and 60 s exposition, and activity against biofilms was time-dependent. The complete elimination of biofilms was observed after a 180 s exposure to Kodan and CITROclorex, and this exposure to Rivanol and Octenidyne showed still viable cells (>0.9 log CFU/mL). Our findings showed that a careful selection of antiseptics and extending the exposure time before blood collection can reduce the occurrence of blood culture contamination. However, our most important finding is the indication that CoNS naturally occurring on human skin and mucous membranes exhibit antibiotic resistance, and what is more, determinants of antibiotic resistance are transferred to both closely related Gram-positive bacteria and phylogenetically distant Gram-negative bacteria. Thus, our findings shed new light on CoNS-they indicate the necessity of their control due to the effective transfer of mobile genetic elements harboring antibiotic resistance genes, which may contribute to the spread of resistance genes and deepening the antibiotic crisis.
本研究旨在评估36株估计为血培养污染物（BCCs）的临床分离株的毒力。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）将所有分离株归类为凝固酶阴性葡萄球菌（CoNS），其中表皮葡萄球菌的比例最高（77.78%）。所有测试菌株均能形成生物膜，在室温下形成生物膜的能力强于37℃时。CoNS对万古霉素敏感（耐药率为0%），对利奈唑胺和利福平的耐药率相对较低（分别为8.33%和22.22%）。青霉素的耐药率最高（94.44%）。此外，我们观察到抗生素耐药基因从测试的CoNS转移到甚至，尽管效率较低。浮游形式的CoNS在接触防腐剂10秒和60秒后被完全杀灭，且对生物膜的活性呈时间依赖性。在接触柯达和西曲氯铵180秒后观察到生物膜被完全清除，而接触利凡诺和氯己定后仍有存活细胞（>0.9 log CFU/mL）。我们的研究结果表明，谨慎选择防腐剂并在采血前延长接触时间可减少血培养污染的发生。然而，我们最重要的发现是，人类皮肤和黏膜上自然存在的CoNS表现出抗生素耐药性，而且抗生素耐药性决定因素会转移到密切相关的革兰氏阳性菌和系统发育上较远的革兰氏阴性菌。因此，我们的研究结果为CoNS提供了新的认识——它们表明由于携带抗生素耐药基因的移动遗传元件的有效转移，有必要对其进行控制，这可能有助于耐药基因的传播并加剧抗生素危机。
