Youenou Benjamin, Martins Simoes Patricia, Tristan Anne, Farfour Eric, Beauruelle Clémence, Kolenda Camille, Ranc Anne-Gaëlle, Vandenesch François, Laurent Frédéric, Dupieux Céline
Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.
Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France.
J Antimicrob Chemother. 2023 Feb 1;78(2):445-449. doi: 10.1093/jac/dkac411.
To describe two linezolid-resistant MRSA strains carrying the cfr(B) gene detected in the French National Reference Centre for staphylococci.
Two linezolid-resistant MRSA strains isolated from cystic fibrosis patients in two different French hospitals in 2017 and 2019 were examined to explore the mechanisms of linezolid resistance. Antimicrobial susceptibility was tested using broth microdilution and gradient strips. The genetic determinants of linezolid resistance were assessed by a multiplex PCR targeting cfr/cfr(B), optrA and poxtA genes, by amplification and sequencing of individual 23S rRNA genes and by WGS using both Illumina and Nanopore technologies.
The two MRSA strains were resistant to linezolid but susceptible to tedizolid, and PCR-positive for cfr/cfr(B). The WGS analysis indicated that they belonged to two different STs (ST8-MRSA-IV and ST5382-MRSA-IV) and that they both harboured the cfr(B) gene on the same 9.7 kb Tn6218-like chromosomal transposon, a finding only previously reported in Enterococcus sp. and Clostridioides difficile.
To the best of our knowledge, this is the first description of the presence of cfr(B) in staphylococci, more specifically in linezolid-resistant MRSA strains. This finding illustrates the risk of horizontal intergenus transfer of oxazolidinone resistance genes in Staphylococcus aureus and highlights the need to monitor such emergence in this species.
描述在法国葡萄球菌国家参考中心检测到的两株携带cfr(B)基因的耐利奈唑胺金黄色葡萄球菌菌株。
对2017年和2019年从法国两家不同医院的囊性纤维化患者中分离出的两株耐利奈唑胺金黄色葡萄球菌菌株进行检测，以探究耐利奈唑胺的机制。采用肉汤微量稀释法和梯度纸条法检测抗菌药物敏感性。通过针对cfr/cfr(B)、optrA和poxtA基因的多重PCR、对单个23S rRNA基因进行扩增和测序以及使用Illumina和Nanopore技术进行全基因组测序来评估耐利奈唑胺的遗传决定因素。
这两株金黄色葡萄球菌菌株对利奈唑胺耐药，但对特地唑胺敏感，且cfr/cfr(B) PCR检测呈阳性。全基因组测序分析表明，它们属于两个不同的序列型（ST8-金黄色葡萄球菌-IV和ST5382-金黄色葡萄球菌-IV），并且它们在同一个9.7 kb的Tn6218样染色体转座子上都携带cfr(B)基因，这一发现此前仅在肠球菌属和艰难梭菌中报道过。
据我们所知，这是首次描述葡萄球菌中，更具体地说是在耐利奈唑胺金黄色葡萄球菌菌株中存在cfr(B)。这一发现说明了恶唑烷酮类耐药基因在金黄色葡萄球菌中水平跨属转移的风险，并强调了监测该物种中此类新出现情况的必要性。
