Background

Pseudomonas aeruginosa is an important opportunistic pathogen especially in nosocomial infections due to its easy adaptation to different environments; this characteristic is due to the great genetic diversity that presents its genome. In addition, it is considered a pathogen of critical priority due to the high antimicrobial resistance.

Objectives

The aim of this study was to characterize the mobile genetic elements present in the chromosome of six Mexican P. aeruginosa strains isolated from adults with pneumonia and children with bacteremia.

Methods

The genomic DNA of six P. aeruginosa strains were isolated and sequenced using PacBio RS-II platform. They were annotated using Prokaryotic Genome Annotation Pipeline and manually curated and analyzed for the presence of mobile genetic elements, antibiotic resistances genes, efflux pumps and virulence factors using several bioinformatics programs and databases.

Results

The global analysis of the strains chromosomes showed a novel chromosomal rearrangement in two strains, possibly mediated by subsequent recombination and inversion events. They have a high content of mobile genetic elements: 21 genomic islands, four new islets, four different integrative conjugative elements, 28 different prophages, one CRISPR-Cas arrangements, and one class 1 integron. The acquisition of antimicrobials resistance genes into these elements are in concordance with their phenotype of multi-drug resistance.

Conclusion

The accessory genome increased the ability of the strains to adapt or survive to the hospital environment, promote genomic plasticity and chromosomal rearrangements, which may affect the expression or functionality of the gene and might influence the clinical outcome, having an impact on the treatment.

中文翻译：

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墨西哥铜绿假单胞菌副基因组组成的多样性

背景

铜绿假单胞菌容易适应不同的环境，是一种重要的机会性病原体，尤其是在医院感染中；这一特征是由于其基因组具有巨大的遗传多样性。此外，由于高抗菌素耐药性，它被认为是一种至关重要的病原体。

目标

本研究的目的是表征从患有肺炎的成人和患有菌血症的儿童中分离出来的六种墨西哥铜绿假单胞菌菌株染色体中存在的可移动遗传元件。

方法

使用 PacBio RS-II 平台分离和测序6株铜绿假单胞菌的基因组 DNA。使用原核基因组注释管道对它们进行注释，并使用多个生物信息学程序和数据库手动策划和分析移动遗传元件、抗生素抗性基因、外排泵和毒力因子的存在。

结果

菌株染色体的全局分析显示两个菌株中的新染色体重排，可能由随后的重组和倒位事件介导。它们具有高含量的可移动遗传元件：21 个基因组岛、4 个新胰岛、4 种不同的整合结合元件、28 种不同的前噬菌体、1 种 CRISPR-Cas 排列和 1 类整合子。在这些元件中获得抗菌素耐药基因与其多药耐药表型一致。

结论

辅助基因组增加了菌株对医院环境的适应或生存能力，促进基因组可塑性和染色体重排，可能影响基因的表达或功能，并可能影响临床结果，对治疗产生影响。