Bivona Dalida, Nicitra Emanuele, Bonomo Carmelo, Calvo Maddalena, Migliorisi Giuseppe, Perez Marianna, Privitera Grete Francesca, Musso Nicolò, Stefani Stefania, Bongiorno Dafne
Department of Biomedical and Biotechnological Sciences, Medical Molecular Microbiology and Antibiotic Resistance Laboratory (MMARLab), University of Catania, 95123 Catania, Italy.
U.O.C. Laboratory Analysis Unit, A.O.U. 'Policlinico-San Marco', Via S. Sofia 78, 95123 Catania, Italy.
JAC Antimicrob Resist. 2024 Oct 5;6(5):dlae154. doi: 10.1093/jacamr/dlae154. eCollection 2024 Oct.
The recent emergence of fusidic acid (FA)-resistant has underscored the importance of active surveillance in isolating these strains. The molecular basis of fusidic acid resistance and the carriage of virulence factors in four borderline oxacillin-resistant (BORSA) clinical strains was assessed through phenotypical and genotypical methods.
All clinical strains were obtained from various hospital units in Sicily antibiotic susceptibility testing was conducted. WGS was performed using the Illumina MiSeq Platform, and data analysis was carried out to determine ST, resistome and virulome profiles.
Genotypic characterization revealed that the strains belong to four STs: ST630, ST8, ST15, and ST1. FA resistance was associated with mutations in the gene or and genes. Additionally, one case exhibited resistance to mupirocin, related to the presence of the gene. Borderline MIC values were observed for cefoxitin in three out of four cases, leading to their categorization as BORSA. Virulence gene content was complex and diversified, with one testing positive for the genes, coding for PVL toxin.
Resistance to FA is multifactorial, involving point mutations in chromosomal genes or association with mobile genetic elements. Monitoring the resistance to these antibiotics might help to manage and eradicate mupirocin- and FA-resistant strains, which are also known to be important carriers of virulence determinants.
耐夫西地酸(FA)菌株的近期出现凸显了积极监测以分离这些菌株的重要性。通过表型和基因型方法评估了四株临界耐苯唑西林金黄色葡萄球菌(BORSA)临床菌株中耐夫西地酸的分子基础及毒力因子携带情况。
所有临床菌株均取自西西里岛各医院科室并进行了抗生素敏感性测试。使用Illumina MiSeq平台进行全基因组测序(WGS),并开展数据分析以确定序列类型(ST)、耐药组和毒力组图谱。
基因型特征显示这些菌株属于四个序列类型:ST630、ST8、ST15和ST1。耐夫西地酸与fusA基因或fusA和rpoB基因中的突变相关。此外,1例表现出对莫匹罗星耐药,与mupA基因的存在有关。四例中有三例对头孢西丁观察到临界最低抑菌浓度(MIC)值,导致它们被归类为BORSA。毒力基因内容复杂且多样,其中1例对编码杀白细胞素(PVL)毒素的lukS-PV和lukF-PV基因检测呈阳性。
对夫西地酸的耐药是多因素的,涉及染色体基因中的点突变或与可移动遗传元件的关联。监测对这些抗生素的耐药情况可能有助于管理和根除耐莫匹罗星和耐夫西地酸的金黄色葡萄球菌菌株,这些菌株也是毒力决定因素的重要携带者。