Characterization of the chromosomal class A beta-lactamase CKO from Citrobacter koseri

FEMS Microbiol Lett. 2006 Jan;254(2):285-92. doi: 10.1111/j.1574-6968.2005.00028.x.

Abstract

The gene bla(CKO) encoding the chromosomal class A beta-lactamase of Citrobacter koseri was cloned and sequenced. CKO was found to display only 41% identity with SED-1 from Citrobacter sedlakii and 36% with CdiA from Citrobacter amalonaticus (formerly Citrobacter diversus). No transcriptional regulator was found upstream from bla(CKO). Silent and missense mutations were detected in four bla(CKO) genes amplified from different C. koseri clinical isolates, but the CKO variants displayed identical biochemical behaviours. A bla(CKO)-specific polymerase chain reaction confirmed that bla(CKO) is present only in C. koseri and therefore represents an interesting tool with which to differentiate C. koseri from the other Citrobacter spp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Anti-Bacterial Agents / pharmacology
  • Chromosomes, Bacterial*
  • Citrobacter koseri / classification
  • Citrobacter koseri / drug effects
  • Citrobacter koseri / enzymology*
  • Citrobacter koseri / genetics
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Species Specificity
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism
  • beta-Lactams / pharmacology

Substances

  • Anti-Bacterial Agents
  • beta-Lactams
  • beta-Lactamases

Associated data

  • GENBANK/AF477396
  • GENBANK/AJ609503
  • GENBANK/AJ609504
  • GENBANK/AJ609505
  • GENBANK/AJ609506