Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
Institute of Microbiology and Epizootics, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
Microb Drug Resist. 2021 Feb;27(2):145-153. doi: 10.1089/mdr.2020.0122. Epub 2020 May 22.
This study aimed at determining the mechanisms of linezolid resistance and the molecular characteristics of clinical ( = 2) and coagulase-negative staphylococci ( = 15) isolates obtained from four Spanish hospitals. The detection of linezolid resistance mechanisms (mutations and acquisition of resistance genes) was performed by PCR/sequencing. The antimicrobial resistance and virulence profile was determined, and the isolates were typed by different molecular techniques. Moreover, the genetic environment of the gene was determined by whole-genome sequencing. The gene was detected in one methicillin-resistant (MRSA) that also displayed the amino acid change Val118Ala in the ribosomal protein L4. The second isolate was methicillin susceptible and showed different alterations in the ribosomal protein L4. All remaining linezolid-resistant ( = 14) and isolates ( = 1) showed the mutation G2576T ( = 14) or C2534T ( = 1) in the 23S rRNA. Moreover, different amino acid changes were detected in the ribosomal proteins L3 and L4 in isolates. All isolates belonged to the multilocus sequence type ST2. Linezolid-resistant staphylococci (LRS) showed a multiresistance phenotype, including methicillin resistance that was detected in all isolates but one, and was mediated by the gene. The gene in the MRSA isolate was located together with the gene on a conjugative 38,864 bp plasmid. Linezolid- and methicillin-resistant ST2 showing mutations in the 23S rRNA and in the ribosomal proteins L3 and L4 are spread among Spanish hospitals, whereas LRS carrying acquired linezolid resistance genes are rarely detected.
本研究旨在确定利奈唑胺耐药机制以及从西班牙四家医院获得的临床（ = 2）和凝固酶阴性葡萄球菌（ = 15）分离株的分子特征。通过 PCR/测序检测利奈唑胺耐药机制（突变和耐药基因的获得）。测定了抗菌药物耐药性和毒力谱，并通过不同的分子技术对分离株进行分型。此外，通过全基因组测序确定了 基因的遗传环境。在一株耐甲氧西林金黄色葡萄球菌（MRSA）中检测到 基因，该菌还显示核糖体蛋白 L4 中的 Val118Ala 氨基酸改变。第二个分离株对甲氧西林敏感，核糖体蛋白 L4 有不同的改变。所有剩余的利奈唑胺耐药的 （ = 14）和 分离株（ = 1）均显示 23S rRNA 中的 G2576T（ = 14）或 C2534T（ = 1）突变。此外，在 分离株中还检测到核糖体蛋白 L3 和 L4 的不同氨基酸变化。所有 分离株均属于多位点序列型 ST2。利奈唑胺耐药葡萄球菌（LRS）表现出多药耐药表型，包括除一株外所有分离株均检测到的耐甲氧西林，由 基因介导。MRSA 分离株中的 基因与位于可移动 38,864 bp 质粒上的 基因一起。在西班牙的医院中，利奈唑胺和甲氧西林耐药的 ST2 表现出 23S rRNA 和核糖体蛋白 L3 和 L4 突变，而携带获得性利奈唑胺耐药基因的 LRS 则很少检测到。
