Identification and characterization of a new porin gene of Klebsiella pneumoniae: Its role in beta-lactam antibiotic resistance

Citation
A. Domenech-sanchez et al., Identification and characterization of a new porin gene of Klebsiella pneumoniae: Its role in beta-lactam antibiotic resistance, J BACT, 181(9), 1999, pp. 2726-2732
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF BACTERIOLOGY
ISSN journal
0021-9193 → ACNP
Volume
181
Issue
9
Year of publication
1999
Pages
2726 - 2732
Database
ISI
SICI code
0021-9193(199905)181:9<2726:IACOAN>2.0.ZU;2-C
Abstract
Klebsiella pneumoniae porin genes were analyzed to detect mutations account ing for the porin deficiency observed in many beta-lactam-resistant strains . PCR and Southern blot analysis revealed the existence of a third porin ge ne in addition to the OmpK36 and OmpK35 porin genes previously described. T his new porin gene was designated ompK37 and is present in all of the clini cal isolates tested. The OmpK37 porin gene was cloned, sequenced, and overe xpressed in Escherichia coli. In contrast to that of the major porins, OmpK 37 porin expression was only detectable by Western blot analysis in porin-d eficient beta-lactam-resistant strains, suggesting strong down regulation u nder standard laboratory conditions. Functional characterization suggested a narrower pore for the OmpK37 porin than for K. pneumoniae porins OmpK36 a nd OmpK35, This correlated with the susceptibility to certain beta-lactam a ntibiotics, since a K. pneumoniae strain expressing porin OmpK37, but not p orin OmpK36 or OmpK35, was less susceptible to beta-lactam antibiotics than the same strain expressing either porin OmpK36 or OmpK35.