Open AccessSequence analysis and biochemical characterisation of chromosomal CAV‐1 ( Aeromonas caviae ), the parental cephalosporinase of plasmid‐mediated AmpC ‘FOX’ cluster 1
Author(s) -
Fosse Thierry,
GiraudMorin Chantal,
Madinier Isabelle,
Labia Roger
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00253-2
Subject(s) - cefoxitin , aeromonas caviae , biology , microbiology and biotechnology , plasmid , aztreonam , imipenem , ceftazidime , cefotaxime , escherichia coli , operon , aeromonas , genetics , gene , antibiotic resistance , antibiotics , bacteria , pseudomonas aeruginosa , staphylococcus aureus
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 (p I 7.2) and an oxacillinase (p I 8.5). The cephalosporinase gene cav‐1 was cloned and sequenced. Unlike A. caviae donor, Escherichia coli pNCE50 transformant producing CAV‐1 β‐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.