Sequence analysis and biochemical characterisation of chromosomal CAV-1 (Aeromonas caviae), the parental cephalosporinase of plasmid-mediated AmpC 'FOX' cluster

FEMS Microbiol Lett. 2003 May 16;222(1):93-8. doi: 10.1016/S0378-1097(03)00253-2.

Abstract

Aeromonas caviae CIP 74.32 was resistant to amoxicillin, ticarcillin and cephalothin, and susceptible to cefoxitin, cefotaxime, ceftazidime, aztreonam and imipenem. This strain produced a cephalosporinase (pI 7.2) and an oxacillinase (pI 8.5). The cephalosporinase gene cav-1 was cloned and sequenced. Unlike A. caviae donor, Escherichia coli pNCE50 transformant producing CAV-1 beta-lactamase was resistant to cefoxitin. The deduced protein sequence CAV-1 contained 382 amino acids, and shared >96% homology with FOX-1 to FOX-5 cephalosporinase. CAV-1 presented only two amino acid substitutions (Thr270Ser and Arg271Ala) with FOX-1. CAV-1 is the chromosomal putative ancestor of the FOX family, a cluster of class C/group 1 plasmidic cephalosporinases spreading in Klebsiella and E. coli clinical isolates via conjugative plasmids.

MeSH terms

  • Aeromonas / drug effects
  • Aeromonas / enzymology*
  • Aeromonas / genetics*
  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins*
  • Cefoxitin / pharmacology
  • Cephalosporinase / chemistry*
  • Cephalosporinase / genetics*
  • Chromosomes, Bacterial
  • Molecular Sequence Data
  • Plasmids
  • beta-Lactam Resistance*
  • beta-Lactamases / chemistry
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Cefoxitin
  • Cephalosporinase
  • beta-lactamase FOX-5
  • AmpC beta-lactamases
  • beta-Lactamases