Vlad Mădălina-Alexandra, Lixandru Brîndușa-Elena, Muntean Andrei-Alexandru, Trandafir Irina, Luncă Cătălina, Tuchiluş Cristina
Department of Microbiology, Faculty of Medicine, "Grigore T. Popa" University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iași, Romania.
Medical Analysis Laboratory, "St. Spiridon" County Clinical Emergency Hospital Iași, 700111 Iași, Romania.
Microorganisms. 2024 Nov 29;12(12):2461. doi: 10.3390/microorganisms12122461.
Colistin resistance poses a significant clinical challenge, particularly in Gram-negative bacteria. This study investigates the occurrence of plasmid-mediated colistin resistance among isolates (, , and spp.) and non-fermentative rods ( and ). We analyzed 114 colistin-resistant isolates that were selected, based on resistance phenotypes, and isolated between 2019 and 2023. To achieve this, we used the rapid immunochromatographic test, NG-Test MCR-1; multiplex PCR for -1 to -8, and real-time PCR for -1 and -2. One isolate was identified as carrying the -1 gene, confirmed by NG-Test MCR-1, multiplex PCR and whole-genome sequencing. This strain, belonging to ST69, harbored four plasmids, harboring different antimicrobial resistance genes, with -1 being located on a 33,304 bp circular IncX4 plasmid. No -2 to -8-positive isolates were detected, prompting further investigation into alternative colistin resistance mechanisms. This is the first report of a -1-positive, colistin-resistant isolated from a human clinical sample in the North-East of Romania.
黏菌素耐药性带来了重大的临床挑战，尤其是在革兰氏阴性菌中。本研究调查了分离株（大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌属）和非发酵菌（鲍曼不动杆菌和铜绿假单胞菌）中质粒介导的黏菌素耐药性的发生情况。我们分析了114株基于耐药表型选择的、于2019年至2023年间分离出的黏菌素耐药分离株。为实现此目的，我们使用了快速免疫层析试验NG-Test MCR-1、针对mcr-1至mcr-8的多重PCR以及针对mcr-1和mcr-2的实时PCR。一株大肠埃希菌分离株经NG-Test MCR-1、多重PCR和全基因组测序确认携带mcr-1基因。该菌株属于ST69，携带四个质粒，含有不同的抗菌耐药基因，其中mcr-1位于一个33,304 bp的环状IncX4质粒上。未检测到mcr-2至mcr-8阳性分离株，这促使对其他黏菌素耐药机制进行进一步研究。这是罗马尼亚东北部从人类临床样本中分离出的mcr-1阳性、黏菌素耐药大肠埃希菌的首次报告。
