Affiliation:
1. Laboratoire de Bactériologie, Faculté de Médecine, 63001 Clermont-Ferrand Cedex,1 and
2. UMR 175, CNRS-MNHN, 29000 Quimper,2 France
Abstract
ABSTRACT
A clinical strain of
Proteus mirabilis
(CF09) isolated from urine specimens of a patient displayed resistance to amoxicillin (MIC >4,096 μg/ml), ticarcillin (4,096 μg/ml), cefoxitin (64 μg/ml), cefotaxime (256 μg/ml), and ceftazidime (128 μg/ml) and required an elevated MIC of aztreonam (4 μg/ml). Clavulanic acid did not act synergistically with cephalosporins. Two β-lactamases with apparent pIs of 5.6 and 9.0 were identified by isoelectric focusing on a gel. Substrate and inhibition profiles were characteristic of an AmpC-type β-lactamase with a pI of 9.0. Amplification by PCR with primers for
ampC
genes (
Escherichia coli
,
Enterobacter cloacae
, and
Citrobacter freundii
) of a 756-bp DNA fragment from strain CF09 was obtained only with
C. freundii
-specific primers. Hybridization results showed that the
ampC
gene is only chromosomally located while the
TEM
gene is plasmid located. After cloning of the gene, analysis of the complete nucleotide sequence (1,146 bp) showed that this
ampC
gene is close to
bla
CMY-2
, from which it differs by three point mutations leading to amino acid substitutions Glu → Gly at position 22, Trp → Arg at position 201, and Ser → Asn at position 343. AmpC β-lactamases derived from that of
C. freundii
(LAT-1, LAT-2, BIL-1, and CMY-2) have been found in
Klebsiella pneumoniae
,
E. coli
, and
Enterobacter aerogenes
and have been reported to be plasmid borne. This is the first example of a chromosomally encoded AmpC-type β-lactamase observed in
P. mirabilis
. We suggest that it be designated CMY-3.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Reference34 articles.
1. The structure of β-lactamases.;Ambler R. P.;Philos. Trans. R. Soc. Lond. B.,1980
2. Barnaud
G.
Arlet
G.
Gaillot
O.
Lagrange
P. H.
Philippon
A.
A novel AmpC plasmid-mediated β-lactamase with the AmpR gene in Salmonella enteritica (serovar enteritidis) abstr. 26/C3
Program and abstracts of the 16th Interdisciplinary Meeting on Anti-Infectious Chemotherapy. Paris France
1996
101
3. Characterization of the plasmidic beta-lactamase CMY-2, which is responsible for cephamycin resistance
4. Characterization of beta-lactamase gene blaPER-2, which encodes an extended-spectrum class A beta-lactamase
5. Comparative characterization of the cephamycinase blaCMY-1 gene and its relationship with other beta-lactamase genes
Cited by
53 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献