Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Department of Biology, West Virginia University, Morgantown, WV 26506, USA.
G3 (Bethesda). 2022 May 6;12(5). doi: 10.1093/g3journal/jkac073.
Pseudomonas aeruginosa is a Gram-negative nosocomial pathogen and one of the most prevalent organisms isolated from burn wounds worldwide. Pseudomonas aeruginosa strain M2 (O5 serotype, type B flagella) is utilized for examining the murine model associated with burns. Pseudomonas aeruginosa M2 is similar in lethality to common laboratory P. aeruginosa strains when infecting CD-1 mice. Conversely, we recently showed that, relative to these strains, P. aeruginosa M2-infected mice are more susceptible to sepsis and demonstrate a 6-log reduction in LD50 from subcutaneous infection at the infection site directly after 10% total body surface area burn. To better understand this striking phenotypic difference from other P. aeruginosa strains employed in burn models, we sequenced the P. aeruginosa M2 genome. A total of 4,136,641 read pairs were obtained, providing an average genome coverage of 97.5X; subsequent assembly yielded a draft genome with 187 contigs comprising 6,360,304 bp with a G + C content of 66.45%. Genome-based phylogeny estimation of 92 P. aeruginosa strains placed P. aeruginosa M2 with P. aeruginosa-12-4-4(59), a nonairway clinical strain isolated from the blood culture of a burn patient. Phylogenomic analyses identified genes shared between P. aeruginosa M2 and P. aeruginosa 14, another strain exhibiting increased lethality in thermal tissues, as well as P. aeruginosa M2 unique genes with diverse functions like degradation of toxic aromatic compounds, iron scavenging, swarming motility and biofilm formation, defense against invasive DNA, and host assault. Predicted lateral gene transfers illuminate proteins heretofore uncharacterized for roles in P. aeruginosa biology. Our work yields a rich resource for assessing P. aeruginosa genes required for increased lethality in burn tissue seroma.
铜绿假单胞菌是一种革兰氏阴性医院病原体，也是全球从烧伤伤口中分离出来的最常见的生物体之一。铜绿假单胞菌 M2 株（O5 血清型，B 型鞭毛）用于研究与烧伤相关的小鼠模型。当感染 CD-1 小鼠时，铜绿假单胞菌 M2 的致死率与常见的实验室铜绿假单胞菌菌株相似。然而，我们最近发现，与这些菌株相比，铜绿假单胞菌 M2 感染的小鼠更容易发生败血症，并且在 10%全身表面积烧伤后直接在感染部位的皮下感染中，LD50 降低了 6 个对数级。为了更好地理解这种与用于烧伤模型的其他铜绿假单胞菌菌株的显著表型差异，我们对铜绿假单胞菌 M2 基因组进行了测序。共获得 4,136,641 个读对，平均基因组覆盖率为 97.5X；随后的组装产生了一个由 187 个 contigs 组成的草案基因组，包含 6,360,304bp，G+C 含量为 66.45%。基于基因组的系统发育估计了 92 株铜绿假单胞菌菌株，将铜绿假单胞菌 M2 与铜绿假单胞菌-12-4-4(59)放在一起，这是一种从烧伤患者血液培养物中分离出来的非呼吸道临床菌株。系统基因组分析确定了铜绿假单胞菌 M2 与铜绿假单胞菌 14 之间共享的基因，铜绿假单胞菌 14 是另一种在热组织中具有更高致死率的菌株，以及铜绿假单胞菌 M2 独特的基因，具有多种功能，如降解有毒芳香化合物、铁掠夺、群集运动和生物膜形成、防御入侵 DNA 和宿主攻击。预测的水平基因转移阐明了迄今为止未被表征的铜绿假单胞菌生物学作用的蛋白质。我们的工作为评估铜绿假单胞菌在烧伤组织积血中增加致死率所需的基因提供了丰富的资源。
