Mathee Kalai, Narasimhan Giri, Valdes Camilo, Qiu Xiaoyun, Matewish Jody M, Koehrsen Michael, Rokas Antonis, Yandava Chandri N, Engels Reinhard, Zeng Erliang, Olavarietta Raquel, Doud Melissa, Smith Roger S, Montgomery Philip, White Jared R, Godfrey Paul A, Kodira Chinnappa, Birren Bruce, Galagan James E, Lory Stephen
Department of Molecular Microbiology and Immunology, College of Medicine, School of Computing and Information Sciences, College of Engineering, Florida International University, Miami, FL 33199, USA.
Proc Natl Acad Sci U S A. 2008 Feb 26;105(8):3100-5. doi: 10.1073/pnas.0711982105. Epub 2008 Feb 19.
One of the hallmarks of the Gram-negative bacterium Pseudomonas aeruginosa is its ability to thrive in diverse environments that includes humans with a variety of debilitating diseases or immune deficiencies. Here we report the complete sequence and comparative analysis of the genomes of two representative P. aeruginosa strains isolated from cystic fibrosis (CF) patients whose genetic disorder predisposes them to infections by this pathogen. The comparison of the genomes of the two CF strains with those of other P. aeruginosa presents a picture of a mosaic genome, consisting of a conserved core component, interrupted in each strain by combinations of specific blocks of genes. These strain-specific segments of the genome are found in limited chromosomal locations, referred to as regions of genomic plasticity. The ability of P. aeruginosa to shape its genomic composition to favor survival in the widest range of environmental reservoirs, with corresponding enhancement of its metabolic capacity is supported by the identification of a genomic island in one of the sequenced CF isolates, encoding enzymes capable of degrading terpenoids produced by trees. This work suggests that niche adaptation is a major evolutionary force influencing the composition of bacterial genomes. Unlike genome reduction seen in host-adapted bacterial pathogens, the genetic capacity of P. aeruginosa is determined by the ability of individual strains to acquire or discard genomic segments, giving rise to strains with customized genomic repertoires. Consequently, this organism can survive in a wide range of environmental reservoirs that can serve as sources of the infecting organisms.
革兰氏阴性菌铜绿假单胞菌的一个显著特征是它能够在多种环境中茁壮生长，这些环境包括患有各种衰弱性疾病或免疫缺陷的人类。在此，我们报告了从囊性纤维化（CF）患者中分离出的两株代表性铜绿假单胞菌菌株的基因组完整序列及比较分析，这些患者的遗传疾病使他们易受这种病原体感染。将这两株CF菌株的基因组与其他铜绿假单胞菌的基因组进行比较，呈现出一幅镶嵌基因组的图景，它由一个保守的核心成分组成，在每个菌株中被特定基因块的组合所打断。基因组的这些菌株特异性片段位于有限的染色体位置，称为基因组可塑性区域。在其中一株测序的CF分离株中鉴定出一个基因组岛，其编码能够降解树木产生的萜类化合物的酶，这支持了铜绿假单胞菌塑造其基因组组成以利于在最广泛的环境宿主中生存并相应增强其代谢能力的能力。这项工作表明生态位适应是影响细菌基因组组成的一种主要进化力量。与宿主适应型细菌病原体中所见的基因组缩减不同，铜绿假单胞菌的遗传能力取决于各个菌株获取或丢弃基因组片段的能力，从而产生具有定制基因组库的菌株。因此，这种生物体能够在广泛的环境宿主中生存，这些宿主可作为感染源。
