Rønning Torunn Gresdal, Enger Hege, Afset Jan Egil, Ås Christina Gabrielsen
The Norwegian MRSA Reference Laboratory, Department of Medical Microbiology, Clinic of Laboratory Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Front Microbiol. 2025 May 9;16:1564943. doi: 10.3389/fmicb.2025.1564943. eCollection 2025.
Infections caused by multidrug-resistant (MDR) bacteria are recognized as a critical One Health concern which poses a significant threat to public health, leading to increased morbidity and mortality across both high- and low-income countries. In this study, we investigated the epidemiology and molecular mechanisms of multidrug-resistant methicillin-resistant (MDR-MRSA) strains identified in Norway from 2008 to 2020, in order to gain a better understanding of the evolution and dissemination of multidrug resistance in . A total of 452 MDR-MRSA strains isolated from 429 individuals were analyzed from a dataset of 23,412 MRSA strains. Methods included epidemiological characterization, antimicrobial susceptibility testing (AST), and genetic analysis of a selection of strains using nanopore sequencing to identify antimicrobial resistance (AMR) genes and mutations, as well as their location on plasmids, SCC and other mobile genetic elements (MGEs). The study revealed an overall increasing trend in MDR-MRSA strains, with healthcare-associated strains being more prevalent among MDR-MRSA compared to the overall MRSA population. Significant heterogeneity in -types and clonal complexes exhibiting multidrug resistance was observed, with high resistance rates against multiple antibiotic groups, particularly erythromycin, ciprofloxacin/norfloxacin, tetracycline, gentamicin, and clindamycin in addition to cefoxitin. The predominant MDR-MRSA clones included t1476/CC8, t127/CC1, t189/CC188, and t030, t037/CC239. Among these, MRSA t1476/CC8 showed an upward trend toward the conclusion of the study period, indicating the emergence of a MDR-MRSA clone. A broad range of AMR genes and mutations were detected, linked to a wide variety of MGEs, highlighting the complex mechanisms of resistance development and dissemination within the MRSA population. This study highlights the rising challenge posed by MDR-MRSA strains, and reveals the multifactorial nature of AMR in , thus emphasizing the importance of continued surveillance, antibiotic stewardship and infection control measures, as well as global cooperation, in order to combat the spread of these multidrug-resistant pathogens.
耐多药（MDR）细菌引起的感染被认为是一个关键的“同一健康”问题，对公共卫生构成重大威胁，导致高收入和低收入国家的发病率和死亡率上升。在本研究中，我们调查了2008年至2020年在挪威鉴定出的耐多药耐甲氧西林金黄色葡萄球菌（MDR-MRSA）菌株的流行病学和分子机制，以便更好地了解耐多药在……中的演变和传播情况。从23412株金黄色葡萄球菌数据集中分析了从429名个体分离出的总共452株MDR-MRSA菌株。方法包括流行病学特征分析、抗菌药物敏感性测试（AST），以及使用纳米孔测序对部分菌株进行基因分析，以鉴定抗菌药物耐药性（AMR）基因和突变，以及它们在质粒、葡萄球菌染色体盒（SCC）和其他移动遗传元件（MGEs）上的位置。该研究揭示了MDR-MRSA菌株总体呈上升趋势，与总体金黄色葡萄球菌群体相比，医疗保健相关菌株在MDR-MRSA中更为普遍。观察到表现出耐多药的菌型和克隆复合体存在显著异质性，对多种抗生素组的耐药率较高，除头孢西丁外，尤其对红霉素、环丙沙星/诺氟沙星、四环素、庆大霉素和克林霉素耐药率高。主要的MDR-MRSA克隆包括t1476/CC8、t127/CC1、t189/CC188以及t030、t037/CC239。其中，MRSA t1476/CC8在研究期结束时呈上升趋势，表明出现了一种MDR-MRSA克隆。检测到广泛的AMR基因和突变，与多种MGEs相关，突出了金黄色葡萄球菌群体中耐药性产生和传播的复杂机制。本研究突出了MDR-MRSA菌株带来的日益严峻的挑战，并揭示了……中AMR的多因素性质，从而强调了持续监测、抗生素管理和感染控制措施以及全球合作以对抗这些耐多药病原体传播的重要性。
