Open AccessDiversity of chromosomal AmpC β‐lactamases from Enterobacter cloacae isolates in a Portuguese hospital
Author(s) -
Conceição Teresa,
Faria Nuno,
Lito Luı́s,
Melo Cristino José,
Salgado Maria José,
Duarte Aida
Publication year - 2004
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)00891-7
Subject(s) - enterobacter cloacae , cefepime , biology , microbiology and biotechnology , cephalosporin , isoelectric focusing , plasmid , enterobacteriaceae , antibiotic resistance , gene , antibiotics , genetics , imipenem , escherichia coli , biochemistry , enzyme
Six clinical isolates of Enterobacter cloacae isolated in a Portuguese hospital, between April 1999 and November 2000, demonstrated resistance to almost all broad‐spectrum cephalosporins, except to cefepime. These isolates were susceptible to quinolones and to aminoglycosides. Isoelectric focusing demonstrated production of β‐lactamases with p I s>8.0 and by all six isolates, exhibiting a cephalosporinase phenotype. The results of pulsed field gel electrophoresis revealed that these isolates were genetically unrelated. The amino acid sequence of six AmpC β‐lactamases (Eclo1FF, Eclo6FF, Eclo9FF, Eclo10FF, Eclo11FF and Eclo15FF) shared 97–99% homology with the chromosomal AmpC β‐lactamase from E. cloacae P99 and 86–87% homology with those of two plasmid‐mediated AmpC β‐lactamases, MIR‐1 and ACT‐1. This is the first report of chromosomal AmpC β‐lactamase production by E. cloacae isolates in a Portuguese hospital.