Iurescia Manuela, Diaconu Elena Lavinia, Alba Patricia, Feltrin Fabiola, Buccella Carmela, Onorati Roberta, Giacomi Angelo, Caprioli Andrea, Franco Alessia, Battisti Antonio, Carfora Virginia
National Reference Laboratory for Antimicrobial Resistance, Department of General Diagnostics, Istituto Zooprofilattico Sperimentale del Lazio e Della Toscana "M. Aleandri", 00178 Rome, Italy.
Antibiotics (Basel). 2023 Mar 7;12(3):530. doi: 10.3390/antibiotics12030530.
The genes encode for a 23S rRNA methyltransferase, conferring a multiresistance phenotype to phenicol, lincosamide, oxazolidinone, pleuromutilin, and streptogramin A antibiotics. These genes have been described in staphylococci, including methicillin-resistant (MRSA). In this study, we retrospectively performed an in-depth genomic characterisation of three -positive, multidrug-resistant (MDR) livestock-associated (LA) MRSA clonal complexes (CCs) 1 and 398 detected in different Italian pig holdings (2008-2011) during population studies on Italian livestock (2008-2014). We used a combined Illumina and Oxford Nanopore Technologies (ONT) whole genome sequencing (WGS) approach on two isolates (the 2008 CC1 and the 2010 CC398 isolates, but not the 2011 CC1 isolate). Interestingly, the three isolates presented different variants, with only one displaying a linezolid-resistant phenotype. In isolate 2008 CC1, the gene was identified within a Tn558 composite transposon-like structure flanked by IS elements located on a novel 44,826 bp plasmid. This represents the first report of CC1 LA-MRSA harbouring the gene in its functional variant. Differently, was chromosomally located in isolate 2010 CC398. Our findings have significant public health implications, confirm the need for the continuous genomic surveillance of -positive zoonotic LA-MRSA, and backdate presence in LA-MRSA from Italian pigs to at least 2008.
这些基因编码一种23S rRNA甲基转移酶，赋予对氯霉素、林可酰胺、恶唑烷酮、截短侧耳素和链阳菌素A类抗生素的多重耐药表型。这些基因已在葡萄球菌中被描述，包括耐甲氧西林金黄色葡萄球菌（MRSA）。在本研究中，我们回顾性地对在意大利牲畜群体研究（2008 - 2014年）期间，于不同意大利猪场（2008 - 2011年）检测到的三株阳性、多重耐药（MDR）家畜相关（LA）MRSA克隆复合体（CCs）1和398进行了深入的基因组特征分析。我们对两株分离株（2008年CC1和2010年CC398分离株，但未对2011年CC1分离株）采用了Illumina和牛津纳米孔技术（ONT）相结合的全基因组测序（WGS）方法。有趣的是，这三株分离株呈现出不同的变体，只有一株表现出对利奈唑胺耐药的表型。在2008年CC1分离株中，该基因在一个由位于一个新的44,826 bp质粒上的IS元件侧翼的Tn558复合转座子样结构中被鉴定出来。这代表了CC1 LA - MRSA在其功能变体中携带该基因的首次报道。不同的是，该基因位于2010年CC398分离株的染色体上。我们的发现具有重大的公共卫生意义，证实了对阳性人畜共患LA - MRSA进行持续基因组监测的必要性，并将LA - MRSA中该基因的存在追溯至至少2008年的意大利猪群。
