TY - JOUR
T1 - Dissemination of transferable CTX-M-type extended-spectrum β-lactamase-producing Escherichia coli in Korea
AU - Jeong, S. H.
AU - Bae, I. K.
AU - Kwon, S. B.
AU - Lee, J. H.
AU - Song, J. S.
AU - Jung, H. I.
AU - Sung, K. H.
AU - Jang, S. J.
AU - Lee, Sang H.
PY - 2005
Y1 - 2005
N2 - Aims: Among 365 Escherichia coli isolated in 2003, 31 cefotaxime-resistant isolates were obtained from clinical specimens taken from adults hospitalized in Busan, Korea. Six extended-spectrum β-lactamase (ESBL)-producing isolates were investigated further to determine the mechanism of resistance. Methods and Results: These isolates were analysed by antibiotic susceptibility testing, pI determination, plasmid profiles, transconjugation test, PCR-restriction fragment length polymorphism (RFLP), enterobacterial repetitive consensus (ERIC)-PCR and DNA sequencing. All six of these isolates were found to contain the CTX-M-type ESBL genes. Five clinical isolates and their transconjugants produced CTX-M-3. One clinical isolate (K17391) and its transconjugant (trcK17391) produced CTX-M-15. Five clinical isolates also produced another TEM-1. One clinical isolate (K12776) also contained another TEM-52. CTX-M-3 ESBL gene was responsible for the resistance to piperacillin, cephalothin, cefotaxime, cefepime and aztreonam. CTX-M-15 or TEM-52 was especially responsible for the resistance to ceftazidime. Conclusions: These results appear to represent the in vivo evolution of CTX-M-type β-lactamase genes (blaCTX-M-3 → blaCTX-M-15) under the selective pressure of antimicrobial therapy (especially ceftazidime). PCR-RFLP is a reliable method to discriminate CTX-M-15 gene from CTX-M-3 gene. ERIC-PCR analysis revealed that dissemination of CTX-M-3 was not due to a clonal outbreak of a resistant strain but to the intra-species spread of resistance to piperacillin, cephalothin, cefotaxime, cefepime and aztreonam in Korea. Significance and Impact of the Study: This is the first report of the occurrence of CTX-M-1 cluster ESBLs in Korea. A more comprehensive survey of these ESBL types from Korea is urgently needed because of the in vivo evolution of CTX-M-15 from CTX-M-3. The emergence of these CTX-M-type ESBLs suggests that diagnostic laboratories should screen for ESBLs with ceftazidime as well as cefotaxime; they should still perform clavulanate synergy tests on resistant isolates.
AB - Aims: Among 365 Escherichia coli isolated in 2003, 31 cefotaxime-resistant isolates were obtained from clinical specimens taken from adults hospitalized in Busan, Korea. Six extended-spectrum β-lactamase (ESBL)-producing isolates were investigated further to determine the mechanism of resistance. Methods and Results: These isolates were analysed by antibiotic susceptibility testing, pI determination, plasmid profiles, transconjugation test, PCR-restriction fragment length polymorphism (RFLP), enterobacterial repetitive consensus (ERIC)-PCR and DNA sequencing. All six of these isolates were found to contain the CTX-M-type ESBL genes. Five clinical isolates and their transconjugants produced CTX-M-3. One clinical isolate (K17391) and its transconjugant (trcK17391) produced CTX-M-15. Five clinical isolates also produced another TEM-1. One clinical isolate (K12776) also contained another TEM-52. CTX-M-3 ESBL gene was responsible for the resistance to piperacillin, cephalothin, cefotaxime, cefepime and aztreonam. CTX-M-15 or TEM-52 was especially responsible for the resistance to ceftazidime. Conclusions: These results appear to represent the in vivo evolution of CTX-M-type β-lactamase genes (blaCTX-M-3 → blaCTX-M-15) under the selective pressure of antimicrobial therapy (especially ceftazidime). PCR-RFLP is a reliable method to discriminate CTX-M-15 gene from CTX-M-3 gene. ERIC-PCR analysis revealed that dissemination of CTX-M-3 was not due to a clonal outbreak of a resistant strain but to the intra-species spread of resistance to piperacillin, cephalothin, cefotaxime, cefepime and aztreonam in Korea. Significance and Impact of the Study: This is the first report of the occurrence of CTX-M-1 cluster ESBLs in Korea. A more comprehensive survey of these ESBL types from Korea is urgently needed because of the in vivo evolution of CTX-M-15 from CTX-M-3. The emergence of these CTX-M-type ESBLs suggests that diagnostic laboratories should screen for ESBLs with ceftazidime as well as cefotaxime; they should still perform clavulanate synergy tests on resistant isolates.
UR - http://www.scopus.com/inward/record.url?scp=16444381291&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=16444381291&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2672.2004.02526.x
DO - 10.1111/j.1365-2672.2004.02526.x
M3 - Article
C2 - 15752339
AN - SCOPUS:16444381291
SN - 1364-5072
VL - 98
SP - 921
EP - 927
JO - Proceedings of the Society for Applied Bacteriology
JF - Proceedings of the Society for Applied Bacteriology
IS - 4
ER -