ABSTRACT
The aim of this study was to investigate the prevalence and diversity of plasmid-mediated AmpC cephalosporinases (PAcBLs) in clinical isolates of Enterobacteriaceae collected between 2003 and 2007 from three Algiers hospitals. Antibiograms were determined on Mueller-Hinton agar plates using the disk diffusion method, and minimum inhibitory concentrations were determined by Etest. Isolates resistant to cefoxitin or ceftazidime were screened for bla(CMY), bla(DHA), bla(FOX) and bla(ACC) as well as extended-spectrum beta-lactamase (ESBL) genes by polymerase chain reaction (PCR). PCR products were sequenced by the Sanger method. Plasmid incompatibility grouping was conducted by PCR-based replicon typing. The prevalence of PAcBLs was 2.18% (11/505), comprising 8 CMY-2 and 3 DHA-1 enzymes. CTX-M-15 was co-produced with CMY-2 in three isolates and with DHA-1 in one isolate; the two remaining DHA-1-producers co-expressed SHV-12 ESBL. This is the first report of plasmid-mediated AmpC from Algeria, with the first detection of DHA-1 in Enterobacter cloacae.
Subject(s)
Bacterial Proteins/genetics , Cross Infection/epidemiology , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/drug effects , Plasmids/genetics , beta-Lactamases/genetics , Algeria/epidemiology , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Cefoxitin/pharmacology , Ceftazidime/pharmacology , Cross Infection/microbiology , Enterobacteriaceae/enzymology , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/microbiology , Hospitals , Humans , Microbial Sensitivity Tests , Polymerase Chain Reaction , Prevalence , beta-Lactam Resistance , beta-Lactamases/metabolismSubject(s)
Proteus vulgaris/enzymology , Providencia/enzymology , beta-Lactamases/genetics , Algeria , Cefepime , Cefotaxime/pharmacology , Ceftazidime/pharmacology , Cephalosporins/pharmacology , Imipenem/pharmacology , Microbial Sensitivity Tests , Piperacillin/pharmacology , Polymerase Chain Reaction , Proteus vulgaris/drug effects , Proteus vulgaris/genetics , Providencia/drug effects , Providencia/geneticsABSTRACT
OBJECTIVES: The aim of this study is to evaluate the prevalence and diversity of extended-spectrum beta-lactamases (ESBLs) in Enterobacter cloacae clinical isolates collected from Algerian hospitals and to verify the association with qnr genes. METHODS: MICs were determined by Etest for isolates giving positive double-disc synergy tests, and all isolates were screened by PCR and sequenced, respectively, for bla(TEM), bla(CTX-M), bla(SHV) and bla(VEB) genes and for qnr genes (qnrA, qnrB, qnrS), using specific primers. RESULTS: The prevalence of ESBLs was 25/141 (17.7%) with 11, 9, 4 and 1 isolates testing positive for genes encoding CTX-M-15, CTX-M-3, SHV-12 and VEB-1, respectively. Two SHV-12 producers and one CTX-M-15 producer expressed QnrS1, one isolate produced CTX-M-15 and QnrB1 and one SHV-12 producer co-expressed QnrS1 and QnrB4. qnrA was not detected in our collection, and qnr alleles were not detected in non-ESBL-producing isolates. CONCLUSIONS: SHV-12, QnrS1, QnrB1 and QnrB4 were reported for the first time in Algeria. This study also described a co-expression of qnrS1 and qnrB4 by an SHV-12 producer isolate.
