Resistance to carbapenems in sequence type 11 Klebsiella pneumoniae is related to DHA-1 and loss of OmpK35 and/or OmpK36

2 754

Cited 0 times in

Authors: So Youn Shin ; Il Kwon Bae ; Juwon Kim ; Seok Hoon Jeong ; Dongeun Yong ; June Myung Kim ; Kyungwon Lee

MeSH: Adult ; Aged ; Anti-Bacterial Agents/pharmacology* ; Bacterial Proteins/analysis ; Carbapenems/pharmacology* ; Cluster Analysis ; DNA, Bacterial/chemistry ; DNA, Bacterial/genetics ; Drug Resistance, Bacterial* ; Electrophoresis, Gel, Pulsed-Field ; Electrophoresis, Polyacrylamide Gel ; Female ; Genotype ; Humans ; Klebsiella Infections/microbiology* ; Klebsiella Infections/mortality ; Klebsiella pneumoniae/chemistry ; Klebsiella pneumoniae/classification ; Klebsiella pneumoniae/drug effects* ; Klebsiella pneumoniae/genetics ; Male ; Middle Aged ; Molecular Typing ; Polymerase Chain Reaction ; Porins/analysis ; Porins/deficiency* ; Proteome/analysis ; Republic of Korea ; Sequence Analysis, DNA

Keywords: Adult ; Aged ; Anti-Bacterial Agents/pharmacology* ; Bacterial Proteins/analysis ; Carbapenems/pharmacology* ; Cluster Analysis ; DNA, Bacterial/chemistry ; DNA, Bacterial/genetics ; Drug Resistance, Bacterial* ; Electrophoresis, Gel, Pulsed-Field ; Electrophoresis, Polyacrylamide Gel ; Female ; Genotype ; Humans ; Klebsiella Infections/microbiology* ; Klebsiella Infections/mortality ; Klebsiella pneumoniae/chemistry ; Klebsiella pneumoniae/classification ; Klebsiella pneumoniae/drug effects* ; Klebsiella pneumoniae/genetics ; Male ; Middle Aged ; Molecular Typing ; Polymerase Chain Reaction ; Porins/analysis ; Porins/deficiency* ; Proteome/analysis ; Republic of Korea ; Sequence Analysis, DNA

Abstract: This study investigated the molecular mechanisms of carbapenem resistance in clinical isolates of Klebsiella pneumoniae from Korea and the clinical outcomes of resistant K. pneumoniae infection. Sixteen K. pneumoniae isolates showing resistance to carbapenems collected from a tertiary-care hospital were examined for the mechanisms of carbapenem resistance. PCR and sequencing experiments detected the blaDHA-1 AmpC β-lactamase gene in all 16 clinical isolates, whilst the bla genes of extended-spectrum β-lactamases were detected in 12 of 16 isolates. SDS-PAGE experiments indicated that all the isolates lacked the 35 kDa and/or 36 kDa outer-membrane proteins (OMPs). Sequence analysis of the corresponding OMP genes revealed various alterations. PFGE analysis demonstrated that there were no major clonal relationships among the K. pneumoniae isolates. However, multilocus sequence typing experiments showed that all isolates shared the same sequence type (ST), ST11, except for one isolate of ST48. The crude mortality rate of infected patients was 81.8 %. Carbapenem resistance was mainly due to a combination of DHA-1 AmpC β-lactamase coupled with the loss of OmpK35 and/or OmpK36 and was associated with poor clinical outcome.