Dissemination of transferable AmpC-type beta-lactamase (CMY-10) in a Korean hospital.
To determine dissemination and genotype of AmpC beta-lactamases and an extended-spectrum beta-lactamase among clinical isolates of Enterobacteriaceae, we performed antibiotic susceptibility testing, pI determination, induction test, plasmid profiles, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing. Among the 51 clinical isolates collected from a university hospital in Korea, six isolates were resistant to cephamycins. All six isolates produced a plasmid-encoded AmpC-type beta-lactamase, CMY-10. Five strains also produced one or more other beta-lactamases: SHV-12, an extended-spectrum beta-lactamase (five isolates); TEM-1, a class A beta-lactamase (two isolates); and a chromosomal AmpC beta-lactamase (one isolate, a strain of Enterobacter aerogenes, which produced all four of the beta-lactamases that were identified). One of six isolates produced only CMY-10. ERIC-PCR analysis revealed that dissemination of CMY-10 and SHV-12 was due to a clonal outbreak of a resistant strain and to the interspecies spread of resistance to cephamycins and broad-spectrum beta-lactams in Korea. CMY-10 beta-lactamase genes that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized from six clinical isolates. A sequence identical to the common regions in In6, In7, and a novel integron from pSAL-1 was found upstream from blaCMY-10 gene at nucleotides 1-71. A total of 15 nucleotides (I-15) or 18 nucleotides (I-18) between position 71 and 72 were inserted into the blaCMY-10 gene. The blaCMY-10 gene might be inserted into a sul1-type complex integron by I-15 or I-18.
Lee
Jung Hun
JH
Department of Biological Science, Myongji University, Kyunggido, Republic of Korea.
Jung
Ha Il
HI
Jung
Jun Ho
JH
Park
Jin Seo
JS
Ahn
Jun Bae
JB
Jeong
Seok Hoon
SH
Jeong
Byeong Chul
BC
Lee
Jung-Hyun
JH
Lee
Sang Hee
SH
D000595:Amino Acid Sequence; D001483:Base Sequence; D002513:Cephamycins / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000235:genetics* / Q000302:isolation & purification*; D005838:Genotype; D006785:Hospitals, University; D007723:Korea; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics*
D002513:Cephamycins; C491822:CMY-10 beta-lactamase; D001618:beta-Lactamases