title: Molecular characterization and analysis of high-level multidrug-resistance of Shigella flexneri serotype 4s strains from China.
abstract: To conduct the first comprehensive analysis of Shigella flexneri serotype 4s, a novel serotype found in 2010, we identified 24 serotype 4s isolates from 1973 shigellosis cases in China (2002-2014). The isolates were characterized by single nucleotide polymorphism (SNP) phylogenetic analysis, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) to determine their genetic relatedness, and analysed further for their antimicrobial susceptibilities and antimicrobial resistance determinants. The PFGE and SNP phylogenetic analyses suggest that S. flexneri serotype 4s strains are derived from multiple serotypes, including two predominant serotypes in China: serotype X variant and serotype II. Three new sequence types were identified by MLST. All isolates were resistant to ticarcillin, ampicillin and tetracycline, with high-level resistance to third-generation cephalosporins. Notably, all the isolates were multidrug resistant (MDR), with the highest levels of resistance observed for eight antimicrobials classes. Most isolates contain various antimicrobial resistance determinants. In conclusion, we found that serotype 4s isolates have multiple evolutionary sources, diverse biochemical characteristics and genomes, and highly prevalent multidrug resistance and antimicrobial-resistant determinants. With few clinical treatment options, continuous monitoring and timely intervention against this emerging MDR serotype is essential. The possibility that serotype 4s will become the next predominant serotype exists.
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Chaojie
authors.initials: C
authors.lastname: Yang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.affiliation: Beijing Chaoyang Hospital, Capital Medical University, Beijing 100043, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Qiuxia
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Xianyan
authors.initials: X
authors.lastname: Cui
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Fuli
authors.initials: F
authors.lastname: Wu
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Chunyu
authors.initials: C
authors.lastname: Sheng
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Xinying
authors.initials: X
authors.lastname: Du
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Qi
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Su
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Leili
authors.initials: L
authors.lastname: Jia
authors.affiliation: Shanghai Municipal Centre for Disease Control and Prevention, Shanghai 200336, China.
authors.forename: Xuebin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Henan Provincial Centre for Disease Control and Prevention, Zhengzhou 450016, China.
authors.forename: Jiayong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Henan Provincial Centre for Disease Control and Prevention, Zhengzhou 450016, China.
authors.forename: Shengli
authors.initials: S
authors.lastname: Xia
authors.affiliation: Health Bureau, Logistics Support Department of Central Military Commission, Chinese PLA, Beijing 100038, China.
authors.forename: Na
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Health Bureau, Logistics Support Department of Central Military Commission, Chinese PLA, Beijing 100038, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ma
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Shaofu
authors.initials: S
authors.lastname: Qiu
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Song
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D032023:Integrons / Q000235:genetics; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D065288:Serogroup; D012763:Shigella flexneri / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents