Document Detail


A highly carbapenem-resistant Pseudomonas aeruginosa isolate with a novel blaVIM-4/blaP1b integron overexpresses two efflux pumps and lacks OprD.
MedLine Citation:
PMID:  17483142     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: A Pseudomonas aeruginosa clinical isolate that exhibited high-level carbapenem resistance and produced metallo-beta-lactamase (MBL) was recovered from a Greek patient. This study was conducted to determine the underlying mechanisms that conferred the carbapenem resistance phenotype. METHODS: MICs were determined by Etest and Etest MBL. PCR assays were performed for identification of bla(VIM-type), other antibiotic resistance and efflux pump genes and mapping of class 1 integrons. Expression of efflux pump genes was quantified by real-time PCR. Nucleotide sequencing was used to determine the bla(VIM) allele. The location of the MBL allele was investigated by mating experiments, plasmid analysis and hybridization studies. RESULTS: The isolate was highly carbapenem-resistant (MICs of imipenem and meropenem were 512 and 128 mg/L, respectively) and multidrug-resistant. It harboured the beta-lactamase genes bla(VIM-4) and bla(P1b) in a novel class 1 integron named InV4P1, and a second integron with aac(6')-Ib and bla(OXA-35) gene cassettes. The isolate was deficient in porin OprD and overexpressed efflux pumps MexAB-OprM and MexXY-OprM. Conjugation experiments failed to detect transferable MBL determinants, plasmids were not visualized and bla(VIM) was detected by PCR in the chromosomal band. CONCLUSIONS: Multiple carbapenem resistance mechanisms are demonstrated to coexist in a single P. aeruginosa isolate and might confer the high-level carbapenem resistance.
Authors:
Maria Maniati; Alexandros Ikonomidis; Paraskevi Mantzana; Alexandros Daponte; Antonios N Maniatis; Spyros Pournaras
Publication Detail:
Type:  Journal Article     Date:  2007-05-04
Journal Detail:
Title:  The Journal of antimicrobial chemotherapy     Volume:  60     ISSN:  0305-7453     ISO Abbreviation:  J. Antimicrob. Chemother.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-06-19     Completed Date:  2007-09-17     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7513617     Medline TA:  J Antimicrob Chemother     Country:  England    
Other Details:
Languages:  eng     Pagination:  132-5     Citation Subset:  IM    
Affiliation:
Department of Microbiology, Medical School, University of Thessaly, Larissa, Greece.
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MeSH Terms
Descriptor/Qualifier:
Aged
Anti-Bacterial Agents / pharmacology*
Bacterial Proteins / genetics,  metabolism
Carbapenems / pharmacology*
Drug Resistance, Multiple, Bacterial / genetics*
Female
Greece
Humans
Integrons / genetics*
Microbial Sensitivity Tests
Porins / metabolism
Pseudomonas Infections / microbiology
Pseudomonas aeruginosa / drug effects*,  enzymology,  genetics,  isolation & purification
beta-Lactam Resistance
beta-Lactamases / genetics*,  metabolism
Chemical
Reg. No./Substance:
0/Anti-Bacterial Agents; 0/Bacterial Proteins; 0/Carbapenems; 0/Porins; 148412-32-2/OprD protein, Pseudomonas aeruginosa; EC 3.5.2.6/beta-Lactamases; EC 3.5.2.6/beta-lactamase bla(VIM-4), Pseudomonas aeruginosa

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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