title: Characterization of plasmids encoding CTX-M β-lactamase and their addiction systems in Escherichia coli isolates from animals.
abstract: This study was focused on characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from chickens and CTX-M associated plasmid addiction systems (PASs) in E. coli from animals using molecular methods. In total, E. coli from nine (9.0%) of the 100 chicken samples examined produced CTX-M type ESBL namely CTX-M-14 (n=4), CTX-M-15 (n=4), and CTX-M-1 (n=1). All of them harbored an additional blaTEM-1 gene. Transfer of blaCTX-M gene was observed in eight out of the nine blaCTX-M-positive isolates by conjugation. Plasmid profiling of blaCTX-M-positive transconjugants revealed a high-molecular weight (95-165 kb) plasmid. Pulsed-field gel electrophoresis showed that most CTX-M-producing chicken isolates were genetically diverse. Furthermore, investigation of 92 conjugation-positive E. coli strains carrying blaCTX-M genes from pigs (n=76), chickens (n=8), and dogs (n=8) identified 230 PASs in the parental strains and 118 in their transconjugants. Among them, hok-sok, pemKI, and pndAC were the most frequently represented PASs in both the parental strains and the transconjugants. Moreover, the hok-sok and pemKI systems were strongly associated to IncF plasmids and the pndAC system to IncI1-Iγ plasmids. Our results suggest that the rapid spread of CTX-M genes in E. coli isolates among the animals could be attributed to the presence of multiple PASs in the CTX-M plasmids. To our knowledge, this is the first report of characterization of CTX-M associated PASs in E. coli isolates from pigs, chickens, and dogs. In addition, CTX-M-1 was detected for the first time in Korea.
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Migma Dorji
authors.initials: MD
authors.lastname: Tamang
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Mamata
authors.initials: M
authors.lastname: Gurung
authors.affiliation: Avian Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Kang
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Nam
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Moon
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Geum-Chan
authors.initials: GC
authors.lastname: Jang
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Suk-Chan
authors.initials: SC
authors.lastname: Jung
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Park
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, Anyang-ro 175, Anyang, Gyeonggi-do 430-757, Republic of Korea. Electronic address: imsk0049@korea.kr.
authors.forename: Suk-Kyung
authors.initials: SK
authors.lastname: Lim
mesh_terms: D000818:Animals; D002645:Chickens; D004283:Dog Diseases / Q000453:epidemiology / Q000382:microbiology*; D004285:Dogs; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology*; D056910:Republic of Korea / Q000453:epidemiology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; C456080:beta-lactamase CTX-M-14; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases
keywords: Addiction system; Animals; CTX-M ESBL; E. coli