Department of Medical Microbiology, Gazi University Faculty of Medicine, Ankara, Turkey.
Department of Medical Microbiology Faculty of Medicine, Nigde Omer Halisdemir University, Nigde, Turkey.
BMC Microbiol. 2024 Nov 4;24(1):447. doi: 10.1186/s12866-024-03605-w.
Candida auris, a multidrug-resistant yeast, poses significant challenges in healthcare settings due to its ability to form biofilms and resistance to common disinfectants. Understanding its susceptibility to biocides used in hospital disinfection practices is crucial for infection control. We investigated the biocide sensitivity of eight clinical C. auris strains from different patients and one reference strain (CDC B11903) using the biocide activity tests.
Species identification was confirmed through MALDI-TOF MS, while clade differentiation and phylogenetic classification were determined via whole-genome sequencing. Biofilm formation was assessed using the MTT assay. Antifungal susceptibilities were tested according to CLSI standards. The effectiveness of biocides, including chlorine, chlorhexidine, and benzalkonium chloride, was evaluated through broth microdilution following CLSI standards and quantitative suspension and carrier tests, following EN standards.
All clinical strains were identified as clade 1, and the reference strain as clade 4, with all exhibiting biofilm formation. Clade 1 strains showed resistance to fluconazole, with MIC values ranging from 8 to 32 µg/ml, while being susceptible to other antifungals. Broth microdilution MIC assays for biocides demonstrated that all strains exhibited resistance to benzalkonium chloride. Chlorine and chlorhexidine showed variable efficacy, dependent on concentration and environmental cleanliness. Alcohol-based hand sanitizers demonstrated effectiveness against C. auris from the first minute of application.
The study highlights the variable susceptibility of C.auris to different biocides, underscoring the challenge in eradicating this pathogen from healthcare environments. Our findings advocate for the careful selection of disinfectants in hospital settings, emphasizing the need for high-concentration chlorine and chlorhexidine solutions to combat C. auris, even in especially clean environments.
由于耳念珠菌能够形成生物膜并对常见消毒剂具有耐药性，因此它是一种具有多重耐药性的酵母，在医疗保健环境中带来了巨大的挑战。了解其对医院消毒实践中使用的消毒剂的敏感性对于感染控制至关重要。我们使用消毒剂活性测试对来自不同患者的 8 株临床耳念珠菌菌株和 1 株参考菌株（CDC B11903）进行了消毒剂敏感性研究。
通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）确认物种鉴定，通过全基因组测序确定聚类分化和系统发育分类。使用 MTT 测定法评估生物膜形成。根据 CLSI 标准测试抗真菌药敏性。根据 CLSI 标准通过肉汤微量稀释法，以及根据 EN 标准通过定量悬液和载体测试评估消毒剂的有效性，包括氯、洗必泰、苯扎氯铵。
所有临床菌株均被鉴定为 1 聚类，参考菌株被鉴定为 4 聚类，所有菌株均表现出生物膜形成。1 聚类菌株对氟康唑表现出耐药性，MIC 值范围为 8 至 32 µg/ml，同时对其他抗真菌药物敏感。消毒剂肉汤微量稀释 MIC 测定表明，所有菌株均对苯扎氯铵表现出耐药性。氯和洗必泰的效果因浓度和环境清洁度而异。含酒精的洗手液在应用的第一分钟就显示出对耳念珠菌的有效性。
本研究强调了耳念珠菌对不同消毒剂的敏感性存在差异，这突显了从医疗保健环境中根除这种病原体的挑战。我们的研究结果主张在医院环境中谨慎选择消毒剂，强调即使在特别清洁的环境中，也需要使用高浓度的氯和洗必泰溶液来对抗耳念珠菌。
