Carbapenem and cefoxitin resistance of Klebsiella pneumoniae strains associated with porin OmpK36 loss and DHA-1 β-lactamase production
Braz. j. microbiol
;
44(2): 435-442, 2013. ilus, tab
Article
in English
| LILACS
| ID: lil-688580
ABSTRACT
Clinical isolates of carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) strains are being increased worldwide. Five pan-resistant K. pneumoniae strains have been isolated from respiratory and ICU wards in a Chinese hospital, and reveal strong resistance to all β-lactams, fluoroquinolones and aminoglycosides. Totally 27 β-lactamase genes and 2 membrane pore protein (porin) genes in 5 K. pneumoniae strains were screened by polymerase chain reaction (PCR). The results indicated that all of 5 K. pneumoniae strains carried blaTEM-1 and blaDHA-1 genes, as well as base deletion and mutation of OmpK35 or OmpK36 genes. Compared with carbapenem-sensitive isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the resistant isolates markedly lacked the protein band of 34-40 kDa, which might be the outer membrane proteins of OmpK36 according to the electrophoresis mobility. In addition, the conjugation test was confirmed that blaDHA-1 mediated by plasmids could be transferred between resistant and sensitive strains. When reserpine (30 µg/mL) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) (50 µg/mL) were added in imipenem and meropenem, the MICs had no change against K. pneumoniae strains. These results suggest that both DHA-1 β-lactamase and loss or deficiency of porin OmpK36 may be the main reason for the cefoxitin and carbapenem resistance in K. pneumoniae strains in our hospital.
Full text:
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Index:
LILACS (Americas)
Main subject:
Beta-Lactamases
/
Carbapenems
/
Cefoxitin
/
Porins
/
Drug Resistance, Bacterial
/
Klebsiella pneumoniae
/
Anti-Bacterial Agents
Type of study:
Risk factors
Limits:
Humans
Country/Region as subject:
Asia
Language:
English
Journal:
Braz. j. microbiol
Journal subject:
Microbiology
Year:
2013
Type:
Article
Affiliation country:
China
Institution/Affiliation country:
Third Affiliated Hospital of Suzhou University/CN
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