Ghiglione Barbara, Rodriguez Ana Paula, Haim María Sol, Friedman Laura Esther, Lincopan Nilton, Ochiuzzi María Eugenia, Di Conza José Alejandro
Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires 1113, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires 1414, Argentina.
Antibiotics (Basel). 2025 May 29;14(6):557. doi: 10.3390/antibiotics14060557.
During the COVID-19 pandemic, the emergence of multidrug-resistant (MDR) pathogens, driven by heightened antibiotic usage and device-associated infections, has posed significant challenges to healthcare. This study reports an outbreak of producing NDM-5 and CTX-M-15 β-lactamases in a hospital in Buenos Aires, Argentina, from October 2020 to April 2021. To our knowledge, this represents the first documented outbreak of NDM-5-producing in the country. A total of 82 isolates were recovered from 40 patients, with 41.5% from blood cultures and 18.3% from respiratory and urinary samples, among others. Antimicrobial susceptibility testing, PCR-based methods, and MALDI-TOF MS cluster analysis were conducted. Whole genome sequencing (WGS) was performed to characterize the MLST, resistome and plasmid content. Biofilm formation assays and in vitro rifampicin susceptibility tests were also conducted. Most isolates exhibited resistance to carbapenems, cephalosporins, aminoglycosides, and fluoroquinolones, while retaining susceptibility to aztreonam. Genetic analysis confirmed the co-presence of the and genes. Clonal relationships was supported by PCR-based typing and MALDI-TOF MS cluster analysis. WGS revealed a resistome comprising 25 resistance genes, including and both β-lactamases, as well as the presence of an incomplete IncQ1 replicon associated with multiple resistance determinants. MLST classified this clone as belonging to ST135. Despite the biofilm-forming capacity observed across strains, rifampicin demonstrated potential for disrupting established biofilms at concentrations ≥32 µg/mL in vitro. The MDR profile of the outbreak strain significantly limited therapeutic options. This study highlights the growing threat of NDM-producing in Argentina. The absence of surveillance cultures from the index case limits insights into the outbreak's origin. These findings underscore the importance of integrating genomic surveillance into infection control protocols to mitigate the spread of MDR pathogens.
在新冠疫情期间，抗生素使用增加和设备相关感染导致多重耐药（MDR）病原体的出现，给医疗保健带来了重大挑战。本研究报告了2020年10月至2021年4月在阿根廷布宜诺斯艾利斯一家医院发生的产NDM-5和CTX-M-15β-内酰胺酶的疫情。据我们所知，这是该国首次有记录的产NDM-5疫情。共从40名患者中分离出82株菌株，其中41.5%来自血培养，18.3%来自呼吸道和尿液样本等。进行了药敏试验、基于PCR的方法和MALDI-TOF MS聚类分析。进行了全基因组测序（WGS）以表征MLST、耐药基因组和质粒含量。还进行了生物膜形成测定和体外利福平药敏试验。大多数分离株对碳青霉烯类、头孢菌素类、氨基糖苷类和氟喹诺酮类耐药，而对氨曲南敏感。基因分析证实了blaNDM-5和blaCTX-M-15基因的共存。基于PCR的分型和MALDI-TOF MS聚类分析支持克隆关系。WGS揭示了一个包含25个耐药基因的耐药基因组，包括blaNDM-5和两种β-内酰胺酶，以及与多个耐药决定因素相关的不完整IncQ1复制子的存在。MLST将该克隆分类为属于ST135。尽管观察到各菌株具有生物膜形成能力，但利福平在体外浓度≥32μg/mL时显示出破坏已形成生物膜的潜力。疫情菌株的MDR谱显著限制了治疗选择。本研究突出了阿根廷产NDM菌株日益增长的威胁。索引病例缺乏监测培养限制了对疫情起源的了解。这些发现强调了将基因组监测纳入感染控制方案以减轻MDR病原体传播的重要性。
