Salgueiro Vanessa, Manageiro Vera, Bandarra Narcisa M, Ferreira Eugénia, Clemente Lurdes, Caniça Manuela
National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal.
Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, University of Porto, Porto, Portugal.
Front Microbiol. 2023 Mar 8;14:1035547. doi: 10.3389/fmicb.2023.1035547. eCollection 2023.
ST398 can cause diseases in several different animals. In this study we analyzed ten ST398 previously collected in three different reservoirs in Portugal (humans, gilthead seabream from aquaculture and dolphin from a zoo). Strains tested against sixteen antibiotics, by disk diffusion or minimum inhibitory concentration, showed decreased susceptibility to benzylpenicillin (all strains from gilthead seabream and dolphin) and to erythromycin with an iMLS phenotype (nine strains), and susceptibility to cefoxitin (methicillin-susceptible , MSSA). All strains from aquaculture belonged to the same type, t2383, whereas strains from the dolphin and humans belonged to type t571. A more detailed analysis using single nucleotide polymorphisms (SNPs)-based tree and a heat map, showed that all strains from aquaculture origin were highly related with each other and the strains from dolphin and humans were more distinct, although they were very similar in ARG, VF and MGE content. Mutations F3I and A100V in gene and D278E and E291D in gene were identified in nine fosfomycin susceptible strains. The gene was also detected in six of the seven animal strains. The study of the genetic environment of -type (found in nine strains) allowed the identification of MGE (rep13-type plasmids and IS-type), presumably involved in the mobilization of this gene. All strains showed genes encoding efflux pumps from major facilitator superfamily (e.g., , -type and /-type), ATP-binding cassettes (ABC; ) and multidrug and toxic compound extrusion (MATE; /-type) families, all associated to decreased susceptibility to antibiotics/disinfectants. Moreover, genes related with tolerance to heavy metals (), and several VF (e.g., , , // and ) were also identified. Insertion sequences, prophages, and plasmids made up the mobilome, some of them associated with ARG, VF and genes related with tolerance to heavy metals. This study highlights that ST398 can be a reservoir of several ARG, heavy metals resistance genes and VF, which are essential in the adaption and survival of the bacterium in the different environments and an active agent in its dissemination. It makes an important contribution to understanding the extent of the spread of antimicrobial resistance, as well as the virulome, mobilome and resistome of this dangerous lineage.
ST398可在几种不同动物中引发疾病。在本研究中，我们分析了先前从葡萄牙三个不同宿主（人类、水产养殖的金头鲷和动物园的海豚）收集的10株ST398。通过纸片扩散法或最低抑菌浓度法对这些菌株进行了16种抗生素测试，结果显示它们对苄青霉素（所有来自金头鲷和海豚的菌株）和具有iMLS表型的红霉素（9株）敏感性降低，而对头孢西丁（甲氧西林敏感，MSSA）敏感。所有水产养殖来源的菌株属于同一类型，t2383，而来自海豚和人类的菌株属于t571类型。使用基于单核苷酸多态性（SNP）的树状图和热图进行更详细的分析表明，所有水产养殖来源的菌株彼此高度相关，而来自海豚和人类的菌株则更为不同，尽管它们在耐药基因（ARG）、毒力因子（VF）和移动遗传元件（MGE）含量方面非常相似。在9株对磷霉素敏感的菌株中鉴定出了基因中的F3I和A100V突变以及基因中的D278E和E291D突变。在7株动物菌株中的6株中也检测到了该基因。对9株菌株中发现的型遗传环境的研究使得能够鉴定出可能参与该基因移动的MGE（rep13型质粒和IS型）。所有菌株均显示出编码主要易化子超家族（例如型、型和/型）、ATP结合盒（ABC；型）和多药及有毒化合物外排（MATE；/型）家族的外排泵的基因，所有这些都与对抗生素/消毒剂敏感性降低有关。此外，还鉴定出了与重金属耐受性相关的基因（）以及几种VF（例如、、//和）。插入序列、原噬菌体和质粒构成了移动基因组，其中一些与ARG、VF以及与重金属耐受性相关的基因有关。本研究强调，ST398可能是多种ARG、重金属抗性基因和VF的储存库，这些对于细菌在不同环境中的适应和生存至关重要，并且是其传播的活性剂。它为理解抗菌药物耐药性的传播程度以及这一危险谱系的毒力组、移动基因组和耐药组做出了重要贡献。
