The increasing number of Chromobacterium haemolyticum human infection reports, especially in tropical regions and connected with environmental sources, resulted in an urge to better describe this species. This study aimed to characterize the C. haemolyticum resistome, virulence determinants and genetic platforms related with genome plasticity. A comparative genomic analysis was conducted between clinical C. haemolyticum genomes publicly available and the genome of an environmental isolate obtained in this study. The pangenome of C. haemolyticum was calculated and a total of 3378 core genes were predicted in its core genome, corresponding to 51.7% of the pangenome. Genetic determinants putatively encoding resistance to beta-lactams, fosfomycin, aminoglycosides and trimethoprim were predicted in all genomes, possibly constituting the intrinsic resistome of this species. In terms of resistance to beta-lactams, 4 genes were predicted encoding beta-lactamases of classes A, C and D. Moreover, the analysis of Chromobacterium genomes and C. haemolyticum environmental isolates reinforced the role of this genus as progenitor of the blaKPC gene. Putative virulence factors (VFs) were predicted in all genomes, related to adherence, toxins production, colonization and cell invasion. Secretion systems, including type III, were detected. A significant number of transposases and genomic islands were predicted in C. haemolyticum, in some cases above the average reported for Gram-negative bacterial genomes. We conclude that C. haemolyticum strains, including those of environmental origin, present a noteworthy collection of antibiotic resistance genes and VFs. Furthermore, sequences related to gene mobility and genome plasticity suggest high adaptability potential and a possible role as disseminator of antibiotic resistance.

中文翻译：

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溶血色杆菌的基因组分析：深入了解物种抗药性，毒力决定因素和基因组可塑性。

溶血性嗜铬杆菌人类感染的报告数量不断增加，特别是在热带地区且与环境有关的报告，促使人们对这种物种进行更好的描述。这项研究旨在表征溶血梭菌的抗药性，毒力决定因素和与基因组可塑性有关的遗传平台。在可公开获得的临床溶血梭状芽胞杆菌基因组与本研究中获得的环境分离基因组之间进行了比较基因组分析。计算溶血梭状芽孢杆菌的全基因组，并预测其核心基因组中共有3378个核心基因，相当于全基因组的51.7％。在所有基因组中都预测了可能编码对β-内酰胺，磷霉素，氨基糖苷和甲氧苄啶抗性的遗传决定子，可能构成了该物种的固有抵抗系统。就对β-内酰胺的抗性而言，预测有4个基因编码A，C和D类的β-内酰胺酶。此外，对色杆菌基因组和溶血梭状芽胞杆菌环境分离株的分析加强了该属作为blaKPC基因祖先的作用。 。在所有基因组中预测了假定的毒力因子（VFs），与粘附，毒素产生，定植和细胞侵袭有关。检测到包括III型在内的分泌系统。在溶血梭状芽孢杆菌中预测有大量的转座酶和基因组岛，在某些情况下高于革兰氏阴性细菌基因组报道的平均值。我们得出的结论是，溶血梭状芽孢杆菌菌株，包括那些来自环境的菌株，呈现出一系列值得注意的抗生素抗性基因和VFs。