González-Espinosa Francisco, Maurizi Diego Marcelo, Pedersen Dina, Oriani Alejandra Soledad, Martinez Celeste, Martínez Lozano Jerson Andrés, Gutkind Gabriel, Radice Marcela, Cejas Daniela
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.
CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.
Microbiol Spectr. 2025 Aug 5;13(8):e0067225. doi: 10.1128/spectrum.00672-25. Epub 2025 Jun 23.
Here, we characterized the first isolates responsible for an outbreak in the intensive care units (ICUs) in a hospital in Argentina. Five isolates recovered from inpatients and sinks at the ICUs of one hospital in Bahia Blanca City were included. Identification and antimicrobial susceptibility tests were performed using an automated system (Phoenix). Besides, they were identified using two mass spectrometry systems (Bruker Daltonics and BioMérieux) and a multiplex-PCR for complex identification. Whole-genome sequencing (WGS) was conducted to confirm bacterial identification and to analyze their resistome and mobilome. Additionally, clonal and phylogenetic relationships were investigated among local and worldwide isolates. Based on the Phoenix system, all isolates were identified as and resistant to last-line antibiotics, consistent with a difficult-to-treat phenotype (DTR). All of them carried . The isolates were identified as by one of the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) systems and by multiplex-PCR. WGS confirmed all isolates as subsp. belonging to ST3029, an infrequent lineage among the genomes analyzed. They displayed fewer than six SNPs, which corresponded to a unique clone, and the phylogenetic analysis exhibited a close relationship with isolates recovered from an environmental source in Brazil.IMPORTANCE is an emerging pathogen in humans belonging to the complex. identification by classical biochemical methods is challenging, and it is often misidentified as has been isolated from diverse clinical samples such as blood, respiratory, and urinary tract infections, and in different environments. The present work describes for the first time isolates recovered in Argentina, which were resistant to the last line of antibiotics consistent with a difficult-to-treat phenotype and responsible for a hospital outbreak. In addition, the phylogenetic analysis exhibited a close relationship to environmental isolates from Brazil.
在此，我们对阿根廷一家医院重症监护病房（ICU）疫情中的首批分离株进行了特征分析。纳入了从布兰卡港市一家医院ICU的住院患者和水槽中分离出的5株菌株。使用自动化系统（Phoenix）进行鉴定和抗菌药敏试验。此外，还使用两种质谱系统（布鲁克道尔顿公司和生物梅里埃公司的产品）以及多重聚合酶链反应进行复杂鉴定。进行全基因组测序（WGS）以确认细菌鉴定结果，并分析其耐药基因组和可移动基因组。此外，还研究了本地和全球分离株之间的克隆和系统发育关系。基于Phoenix系统，所有分离株均被鉴定为[具体菌种]，并对最后一线抗生素耐药，这与难以治疗的表型（DTR）一致。所有菌株都携带[相关基因或特征]。这些分离株通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）系统之一和多重聚合酶链反应被鉴定为[具体菌种]。WGS确认所有分离株为[具体亚种]，属于ST3029，这是所分析基因组中罕见的谱系。它们显示出少于6个单核苷酸多态性（SNP），这对应于一个独特的克隆，系统发育分析表明它们与从巴西环境来源分离出的菌株关系密切。重要性[具体菌种]是属于[菌种复合体名称]的一种新兴人类病原体。通过经典生化方法进行[菌种]鉴定具有挑战性，并且它经常被误鉴定为[误鉴定的菌种]。[具体菌种]已从血液、呼吸道和尿路感染等多种临床样本以及不同环境中分离出来。本研究首次描述了在阿根廷分离出的[具体菌种]菌株，它们对最后一线抗生素耐药，具有难以治疗的表型，并导致了医院疫情。此外，系统发育分析表明它们与来自巴西的环境分离株关系密切。
