Núñez Daniela, Jiménez Pablo, Cortez-San Martín Marcelo, Cortés Carolina, Cárdenas Matías, Michelson Sofia, Garay Tamara, Vecchiola Maggie, Céspedes Alejandra, Maldonado Jonathan E, Vásquez-Martínez Yesseny
Molecular Virology and Pathogen Control Laboratory, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile.
Laboratorio de Multiómica Vegetal y Bioinformática, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile.
Microorganisms. 2024 Jun 25;12(7):1284. doi: 10.3390/microorganisms12071284.
Antimicrobial resistance is a major global health problem, and, among Gram-positive bacteria, methicillin-resistant (MRSA) represents a serious threat. MRSA causes a wide range of infections, including bacteremia, which, due to the limited use of β-lactams, is difficult to treat. This study aimed to analyze 51 MRSA isolates collected in 2018 from samples of patients with bacteremia from two hospitals of the Metropolitan Health Service of Santiago, Chile, both in their resistance profile and in the identification of virulence factors. In addition, genomic characterization was carried out by the WGS of an isolate that was shown to be the one of greatest concern (N°. 42) due to its intermediate resistance to vancomycin, multiple virulence factors and being classified as ST8 PVL-positive. In our study, most of the isolates turned out to be multidrug-resistant, but there are still therapeutic options, such as tetracycline, rifampicin, chloramphenicol and vancomycin, which are currently used for MRSA infections; however, 18% were PVL positive, which suggests greater virulence of these isolates. It was determined that isolate N°42 is grouped within the USA300-LV strains (ST8, PVL+, COMER+); however, it has been suggested that, in Chile, a complete displacement of the PVL-negative ST5 clone has not occurred.
抗菌药物耐药性是一个重大的全球健康问题，在革兰氏阳性菌中，耐甲氧西林金黄色葡萄球菌（MRSA）构成严重威胁。MRSA可引发多种感染，包括菌血症，由于β-内酰胺类药物使用受限，菌血症难以治疗。本研究旨在分析2018年从智利圣地亚哥市立卫生服务中心两家医院的菌血症患者样本中收集的51株MRSA分离株，包括其耐药谱和毒力因子鉴定。此外，对一株因其对万古霉素中度耐药、具有多种毒力因子且被归类为ST8 PVL阳性而被证明是最受关注的分离株（编号42）进行了全基因组测序（WGS）以进行基因组特征分析。在我们的研究中，大多数分离株结果显示为多重耐药，但仍有治疗选择，如四环素、利福平、氯霉素和万古霉素，目前这些药物用于治疗MRSA感染；然而，18%的分离株PVL呈阳性，这表明这些分离株具有更强的毒力。已确定分离株编号42属于USA300-LV菌株组（ST8，PVL+，COMER+）；然而，有人认为，在智利，PVL阴性的ST5克隆尚未完全被取代。
