title: Plasmid-encoding extended-spectrum β-lactamase CTX-M-55 in a clinical Shigella sonnei strain, China.
abstract: OBJECTIVE
  To characterize a clinical Shigella sonnei strain harboring a conjugatable blaCTX-M-55-borne plasmid.
  
  
  METHODS
  S. sonnei strain #1081 was isolated from a dysentery patient in China. A CTX-M-55-encoding plasmid harbored in this strain was transformed to Escherichia coli, and then its complete nucleotide sequence was determined by next generation sequencing. The MIC values of bacterial strains were tested by using Vitec(®) 2 (Biomerieux, Marcy l'Etoile, France).
  
  
  RESULTS
  Strain #1081 conferred the resistance to multiple beta-lactam antibiotics. blaCTX-M-55 was the only known antibiotic resistance gene and located in a 3090-bp ISEcp1-blaCTX-M-55-orf477 transposition unit carried by a conjugatable plasmid p1081-CTXM in #1081. The ISEcp1-mediated transposition provided a sole promoter, which was located adjacently upstream of the inverted repeat right element of ISEcp1, to drive the expression of CTX-M-55.
  
  
  CONCLUSIONS
  Plasmid p1081-CTXM was a close variant of the IncI2-type plasmid pHN1122-1 that was harbored in a faecal E. coli strain recovered from a dog in China, indicating the potential transfer of CTX-M-55-encoding plasmids from faecal flora E. coli to human pathogen S. sonnei.
authors.affiliation: The 302nd Hospital of Chinese People's Liberation Army, Beijing, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Qu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Ying
authors.forename: Chuanling
authors.initials: C
authors.lastname: Zhang
authors.forename: Zhenhong
authors.initials: Z
authors.lastname: Chen
authors.forename: Suming
authors.initials: S
authors.lastname: Chen
authors.forename: Enbo
authors.initials: E
authors.lastname: Cui
authors.forename: Chunmei
authors.initials: C
authors.lastname: Bao
authors.forename: Huiying
authors.initials: H
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Changting
authors.initials: C
authors.lastname: Liu
authors.forename: Yuanli
authors.initials: Y
authors.lastname: Mao
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
mesh_terms: D002681:China; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004405:Dysentery, Bacillary / Q000382:microbiology; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids; D017422:Sequence Analysis, DNA; D012764:Shigella sonnei / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D014169:Transformation, Bacterial; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases
keywords: CTX-M-55; ISEcp1; Shigella sonnei; conjugatable plasmid