title: Chromosome-encoded AmpC and CTX-M extended-spectrum β-lactamases in clinical isolates of Proteus mirabilis from Korea.
abstract: Among 222 Proteus mirabilis clinical isolates collected from 17 hospitals in Korea in 2008, 28 (12.6%) and 8 (3.6%) isolates exhibited extended-spectrum β-lactamase (ESBL) and AmpC phenotypes, respectively. The most common type of ESBL gene identified by PCR and sequencing experiments was bla(CTX-M-14a) (n = 12). The bla(CTX-M-90) (n = 4), bla(CTX-M-15) (n = 3), bla(CTX-M-12) (n = 3), bla(CTX-M-2) (n = 2), bla(CTX-M-14b) (n = 1), bla(TEM-52) (n = 5), and bla(SHV-12) (n = 1) genes were also detected. Eight isolates carried an AmpC β-lactamase gene, such as bla(CMY-2) (n = 6) or bla(DHA-1) (n = 2). All bla genes encoding CTX-M-1- and CTX-M-9-type enzymes and all bla(CMY-2) genes were preceded by ISEcp1-like elements. The bla(CTX-M-2) gene found in two isolates was located on a complex class 1 integron. The bla(DHA-1) gene was preceded by a transcriptional regulator gene and was followed by phage shock protein genes. The bla(CTX-M) genes were located on the chromosome in 21 isolates. A plasmid location for the bla(CTX-M) gene was found in only four isolates: the bla(CTX-M-14a) gene was located on ∼150-kbp IncA/C plasmids in three isolates and on a ∼50-kbp IncN plasmid in one isolate. The bla(TEM-52) gene was located on ∼50-kbp IncN plasmids in all five isolates. The AmpC β-lactamase genes were located on the chromosome in seven of eight isolates; one isolate carried the bla(CMY-2) gene on a ∼150-kbp IncA/C plasmid. Our results show that a chromosomal location of CTX-M ESBL and AmpC β-lactamase genes in P. mirabilis is no longer an unusual phenomenon in hospital environments.
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine Seoul, Republic of Korea.
authors.forename: Wonkeun
authors.initials: W
authors.lastname: Song
authors.forename: Juwon
authors.initials: J
authors.lastname: Kim
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Seo
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Shin
authors.forename: Sook Jin
authors.initials: SJ
authors.lastname: Jang
authors.forename: Young
authors.initials: Y
authors.lastname: Uh
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Shin
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Lee
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial / Q000235:genetics*; D019818:Clavulanic Acid / Q000494:pharmacology; D007723:Korea; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D019818:Clavulanic Acid; C048795:AmpC beta-lactamases; D001618:beta-Lactamases