title: Genome dynamics and diversity of Shigella species, the etiologic agents of bacillary dysentery.
abstract: The Shigella bacteria cause bacillary dysentery, which remains a significant threat to public health. The genus status and species classification appear no longer valid, as compelling evidence indicates that Shigella, as well as enteroinvasive Escherichia coli, are derived from multiple origins of E.coli and form a single pathovar. Nevertheless, Shigella dysenteriae serotype 1 causes deadly epidemics but Shigella boydii is restricted to the Indian subcontinent, while Shigella flexneri and Shigella sonnei are prevalent in developing and developed countries respectively. To begin to explain these distinctive epidemiological and pathological features at the genome level, we have carried out comparative genomics on four representative strains. Each of the Shigella genomes includes a virulence plasmid that encodes conserved primary virulence determinants. The Shigella chromosomes share most of their genes with that of E.coli K12 strain MG1655, but each has over 200 pseudogenes, 300 approximately 700 copies of insertion sequence (IS) elements, and numerous deletions, insertions, translocations and inversions. There is extensive diversity of putative virulence genes, mostly acquired via bacteriophage-mediated lateral gene transfer. Hence, via convergent evolution involving gain and loss of functions, through bacteriophage-mediated gene acquisition, IS-mediated DNA rearrangements and formation of pseudogenes, the Shigella spp. became highly specific human pathogens with variable epidemiological and pathological features.
authors.affiliation: State Key Laboratory for Molecular Virology and Genetic Engineering, Chinese Ministry of Public Health, Beijing 100052, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zhang
authors.forename: Lihong
authors.initials: L
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Yan
authors.forename: Xudong
authors.initials: X
authors.lastname: Tang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Xiong
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
authors.forename: Ying
authors.initials: Y
authors.lastname: Xue
authors.forename: Yafang
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xingye
authors.initials: X
authors.lastname: Xu
authors.forename: Lilian
authors.initials: L
authors.lastname: Sun
authors.forename: Shuxia
authors.initials: S
authors.lastname: Chen
authors.forename: Huan
authors.initials: H
authors.lastname: Nie
authors.forename: Junping
authors.initials: J
authors.lastname: Peng
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Yuan
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wen
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Yao
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.forename: Boqin
authors.initials: B
authors.lastname: Qiang
authors.forename: Yunde
authors.initials: Y
authors.lastname: Hou
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.forename: Qi
authors.initials: Q
authors.lastname: Jin
mesh_terms: D004251:DNA Transposable Elements; D004405:Dysentery, Bacillary / Q000382:microbiology; D017353:Gene Deletion; D014644:Genetic Variation; D016680:Genome, Bacterial; D011544:Pseudogenes; D012760:Shigella / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements