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Jean-marie Pagès - One of the best experts on this subject based on the ideXlab platform.
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Enterobacter Aerogenes and Enterobacter cloacae versatile bacterial pathogens confronting antibiotic treatment
Frontiers in Microbiology, 2015Co-Authors: Anne Davinregli, Jean-marie PagèsAbstract:Enterobacter Aerogenes and E. cloacae have been reported as important opportunistic and multiresistant bacterial pathogens for humans during the last three decades in hospital wards. These Gram-negative bacteria have been largely described during several outbreaks of hospital-acquired infections in Europe and particularly in France. The dissemination of Enterobacter sp. is associated with the presence of redundant regulatory cascades that efficiently control the membrane permeability ensuring the bacterial protection and the expression of detoxifying enzymes involved in antibiotic degradation/inactivation. In addition, these bacterial species are able to acquire numerous genetic mobile elements that strongly contribute to antibiotic resistance. Moreover, this particular fitness help them to colonize several environments and hosts and rapidly and efficiently adapt their metabolism and physiology to external conditions and environmental stresses. Enterobacter is a versatile bacterium able to promptly respond to the antibiotic treatment in the colonized patient. The balance of the prevalence, E. Aerogenes versus E. cloacae, in the reported hospital infections during the last period, questions about the horizontal transmission of mobile elements containing antibiotic resistance genes, e.g., the efficacy of the exchange of resistance genes Klebsiella pneumoniae to Enterobacter sp. It is also important to mention the possible role of antibiotic use in the treatment of bacterial infectious diseases in this E. Aerogenes/E. cloacae evolution.
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occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter Aerogenes and klebsiella pneumoniae isolates producing extended spectrum β lactamases
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Quetien Tran, Jean-marie Pagès, Myrielle Dupont, Jacqueline Chevalier, Jeanphilippe Lavigne, A Sotto, Anne DavinregliAbstract:We investigated the occurrence of multidrug resistance in 44 Enterobacter Aerogenes and Klebsiella pneumoniae clinical isolates. Efflux was involved in resistance in E. Aerogenes isolates more frequently than in K. pneumoniae isolates (100 versus 38% of isolates) and was associated with the expression of phenylalanine arginine β-naphthylamide-susceptible active efflux. AcrA-TolC overproduction in E. Aerogenes isolates was noted. An analysis of four E. Aerogenes isolates for which cefepime MICs were high revealed no modification in porin expression but a new specific mutation in the AmpC β-lactamase.
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quinoline derivatives as promising inhibitors of antibiotic efflux pump in multidrug resistant Enterobacter Aerogenes isolates
Current Drug Targets, 2006Co-Authors: Abdallah Mahamoud, Jacqueline Chevalier, Anne Davinregli, Jacques Barbe, Jean-marie PagèsAbstract:Efflux pumps protect the bacterial cell by expelling toxic compounds before they reach intracellular targets. Because this mechanism actively contributes to the resistance of a given bacterium to more than one class of antibiotics, molecules that are able to block the relevant efflux pump are of potential significance to combat drug resistance caused by efflux pumps. Different quinoline derivatives including alkoxy, alkylamino, thioalkoxy and chloroquinolines have been previously reported to make Enterobacter Aerogenes resistant isolates that over express the mechanism of efflux, noticeably more susceptible to structurally unrelated antibiotics. In addition, various quinoline derivatives significantly increase the intracellular concentration of chloramphenicol as reported with other inhibitors, thereby suggesting the inhibition of the drug transport by AcrAB-TolC pump, which is fully active in the clinicaly resistant isolates investigated. Here, we discuss the respective properties of this molecular family, taking into account the recent insights into the structural data of AcrB pump.
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chloramphenicol and expression of multidrug efflux pump in Enterobacter Aerogenes
Biochemical and Biophysical Research Communications, 2005Co-Authors: Didier Ghisalberti, Jean-marie Pagès, Muriel Masi, Jacqueline ChevalierAbstract:Chloramphenicol has been reported to act as an inducer of the multidrug resistance in Escherichia coli. A resistant variant able to grow on plates containing 64 microg/ml chloramphenicol was obtained from the Enterobacter Aerogenes ATCC 13048-type strain. Chloramphenicol resistance was due to an active efflux of this antibiotic and it was associated with resistance to fluoroquinolones and tetracycline, but not to aminoglycoside or beta-lactam antibiotics. MDR in the chloramphenicol-resistant variant is linked to the overexpression of the major AcrAB-TolC efflux system. This overexpression seems unrelated to the global Mar and the local AcrR regulatory pathways.
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Successive emergence of Enterobacter Aerogenes strains resistant to imipenem and colistin in a patient
Antimicrobial Agents and Chemotherapy, 2005Co-Authors: Aurélie Thiolas, C. Bollet, Jean-marie PagèsAbstract:Enterobacter Aerogenes is an agent of hospital-acquired infection that exhibits a remarkable resistance to beta-lactam antibiotics during therapy. Five successive isolates of E. Aerogenes infecting a patient and exhibiting a multiresistance phenotype to beta-lactam antibiotics and fluoroquinolones were investigated. Among these clinical strains, four presented resistant phenotypes during successive imipenem and colistin treatments. The involved resistance mechanisms exhibited by the successive isolates were associated with alterations of the outer membrane that caused a porin decrease and lipopolysaccharide modifications.
Jacqueline Chevalier - One of the best experts on this subject based on the ideXlab platform.
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occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter Aerogenes and klebsiella pneumoniae isolates producing extended spectrum β lactamases
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Quetien Tran, Jean-marie Pagès, Myrielle Dupont, Jacqueline Chevalier, Jeanphilippe Lavigne, A Sotto, Anne DavinregliAbstract:We investigated the occurrence of multidrug resistance in 44 Enterobacter Aerogenes and Klebsiella pneumoniae clinical isolates. Efflux was involved in resistance in E. Aerogenes isolates more frequently than in K. pneumoniae isolates (100 versus 38% of isolates) and was associated with the expression of phenylalanine arginine β-naphthylamide-susceptible active efflux. AcrA-TolC overproduction in E. Aerogenes isolates was noted. An analysis of four E. Aerogenes isolates for which cefepime MICs were high revealed no modification in porin expression but a new specific mutation in the AmpC β-lactamase.
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quinoline derivatives as promising inhibitors of antibiotic efflux pump in multidrug resistant Enterobacter Aerogenes isolates
Current Drug Targets, 2006Co-Authors: Abdallah Mahamoud, Jacqueline Chevalier, Anne Davinregli, Jacques Barbe, Jean-marie PagèsAbstract:Efflux pumps protect the bacterial cell by expelling toxic compounds before they reach intracellular targets. Because this mechanism actively contributes to the resistance of a given bacterium to more than one class of antibiotics, molecules that are able to block the relevant efflux pump are of potential significance to combat drug resistance caused by efflux pumps. Different quinoline derivatives including alkoxy, alkylamino, thioalkoxy and chloroquinolines have been previously reported to make Enterobacter Aerogenes resistant isolates that over express the mechanism of efflux, noticeably more susceptible to structurally unrelated antibiotics. In addition, various quinoline derivatives significantly increase the intracellular concentration of chloramphenicol as reported with other inhibitors, thereby suggesting the inhibition of the drug transport by AcrAB-TolC pump, which is fully active in the clinicaly resistant isolates investigated. Here, we discuss the respective properties of this molecular family, taking into account the recent insights into the structural data of AcrB pump.
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chloramphenicol and expression of multidrug efflux pump in Enterobacter Aerogenes
Biochemical and Biophysical Research Communications, 2005Co-Authors: Didier Ghisalberti, Jean-marie Pagès, Muriel Masi, Jacqueline ChevalierAbstract:Chloramphenicol has been reported to act as an inducer of the multidrug resistance in Escherichia coli. A resistant variant able to grow on plates containing 64 microg/ml chloramphenicol was obtained from the Enterobacter Aerogenes ATCC 13048-type strain. Chloramphenicol resistance was due to an active efflux of this antibiotic and it was associated with resistance to fluoroquinolones and tetracycline, but not to aminoglycoside or beta-lactam antibiotics. MDR in the chloramphenicol-resistant variant is linked to the overexpression of the major AcrAB-TolC efflux system. This overexpression seems unrelated to the global Mar and the local AcrR regulatory pathways.
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the acrab tolc pump is involved in macrolide resistance but not in telithromycin efflux in Enterobacter Aerogenes and escherichia coli
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Renaud Chollet, Jacqueline Chevalier, Andre Bryskier, Jean-marie PagèsAbstract:The role of the AcrAB-TolC pump in macrolide and ketolide susceptibility in Escherichia coli and Enterobacter Aerogenes was studied. Efflux pump inhibitor restored erythromycin, clarithromycin, and telithromycin susceptibilities to multidrug-resistant isolates. No modification of telithromycin accumulation was detected in E. Aerogenes acrAB or tolC derivatives compared to that in the parental strain. Two independent efflux pumps, inhibited by phenylalanine arginine β-naphthylamide, expel macrolides and telithromycin in E. Aerogenes.
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rama is an alternate activator of the multidrug resistance cascade in Enterobacter Aerogenes
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Renaud Chollet, Jean-marie Pagès, C. Bollet, Jacqueline Chevalier, Anne DavinregliAbstract:Multidrug resistance (MDR) in Enterobacter Aerogenes can be mediated by induction of MarA, which is triggered by certain antibiotics and phenolic compounds. In this study, we identified the gene encoding RamA, a 113-amino-acid regulatory protein belonging to the AraC-XylS transcriptional activator family, in the Enterobacter Aerogenes ATCC 13048 type strain and in a clinical multiresistant isolate. Overexpression of RamA induced an MDR phenotype in drug-susceptible Escherichia coli JM109 and E. Aerogenes ATCC 13048, as demonstrated by 2- to 16-fold-increased resistance to β-lactams, tetracycline, chloramphenicol, and quinolones, a decrease in porin production, and increased production of AcrA, a component of the AcrAB-TolC drug efflux pump. We show that RamA enhances the transcription of the marRAB operon but is also able to induce an MDR phenotype in a mar-deleted strain. We demonstrate here that RamA is a transcriptional activator of the Mar regulon and is also a self-governing activator of the MDR cascade.
C. Bollet - One of the best experts on this subject based on the ideXlab platform.
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Successive emergence of Enterobacter Aerogenes strains resistant to imipenem and colistin in a patient
Antimicrobial Agents and Chemotherapy, 2005Co-Authors: Aurélie Thiolas, C. Bollet, Jean-marie PagèsAbstract:Enterobacter Aerogenes is an agent of hospital-acquired infection that exhibits a remarkable resistance to beta-lactam antibiotics during therapy. Five successive isolates of E. Aerogenes infecting a patient and exhibiting a multiresistance phenotype to beta-lactam antibiotics and fluoroquinolones were investigated. Among these clinical strains, four presented resistant phenotypes during successive imipenem and colistin treatments. The involved resistance mechanisms exhibited by the successive isolates were associated with alterations of the outer membrane that caused a porin decrease and lipopolysaccharide modifications.
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rama is an alternate activator of the multidrug resistance cascade in Enterobacter Aerogenes
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Renaud Chollet, Jean-marie Pagès, C. Bollet, Jacqueline Chevalier, Anne DavinregliAbstract:Multidrug resistance (MDR) in Enterobacter Aerogenes can be mediated by induction of MarA, which is triggered by certain antibiotics and phenolic compounds. In this study, we identified the gene encoding RamA, a 113-amino-acid regulatory protein belonging to the AraC-XylS transcriptional activator family, in the Enterobacter Aerogenes ATCC 13048 type strain and in a clinical multiresistant isolate. Overexpression of RamA induced an MDR phenotype in drug-susceptible Escherichia coli JM109 and E. Aerogenes ATCC 13048, as demonstrated by 2- to 16-fold-increased resistance to β-lactams, tetracycline, chloramphenicol, and quinolones, a decrease in porin production, and increased production of AcrA, a component of the AcrAB-TolC drug efflux pump. We show that RamA enhances the transcription of the marRAB operon but is also able to induce an MDR phenotype in a mar-deleted strain. We demonstrate here that RamA is a transcriptional activator of the Mar regulon and is also a self-governing activator of the MDR cascade.
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omp35 a new Enterobacter Aerogenes porin involved in selective susceptibility to cephalosporins
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Charleric Bornet, Anne Davinregli, C. Bollet, Nathalie Saint, Lilia Fetnaci, Myrielle Dupont, Jean-marie PagèsAbstract:In Enterobacter Aerogenes, β-lactam resistance often involves a decrease in outer membrane permeability induced by modifications of porin synthesis. In ATCC 15038 strain, we observed a different pattern of porin production associated with a variable antibiotic susceptibility. We purified Omp35, which is expressed under conditions of low osmolality and analyzed its pore-forming properties in artificial membranes. This porin was found to be an OmpF-like protein with high conductance values. It showed a noticeably higher conductance compared to Omp36 and a specific location of WNYT residues in the L3 loop. The importance of the constriction region in the porin function suggests that this organization is involved in the level of susceptibility to negative large cephalosporins such as ceftriaxone by bacteria producing the Omp35 porin subfamily.
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resistance to imipenem cefepime and cefpirome associated with mutation in omp36 osmoporin of Enterobacter Aerogenes
Biochemical and Biophysical Research Communications, 2004Co-Authors: Aurélie Thiolas, Jean-marie Pagès, Anne Davinregli, Charleric Bornet, C. BolletAbstract:Enterobacter Aerogenes develops increased multidrug resistance via a functional alteration of outer-membrane permeability associated with a decrease in porin function. We have sequenced the gene coding the major porin of Enterobacter Aerogenes, omp36. The sequence shows a high similarity with the Klebsiella pneumoniae ompK36 gene and is closely related to the Enterobacterial OmpC family. Sequence analysis of several Omp36 issued from clinical strains indicated variability in putative cell-surface exposed domains. Interestingly, substitution Gly112Asp was observed in the conserved eyelet L3 region of the porin produced by two strains, C and 3. This substitution is associated with a high general beta-lactam resistance observed in these isolates and with alteration of pore properties previously described in strain 3 porin [Mol. Microbiol. 41 (2001) 189]. This is the first genetic identification of impermeability-mediated resistance to beta-lactams in various clinical E. Aerogenes strains.
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imipenem and expression of multidrug efflux pump in Enterobacter Aerogenes
Biochemical and Biophysical Research Communications, 2003Co-Authors: Charleric Bornet, Jean-marie Pagès, Anne Davinregli, Renaud Chollet, Jacqueline Chevalier, Monique Mallea, C. BolletAbstract:Imipenem is often used to treat intensive care unit patients infected by Enterobacter Aerogenes, but it is leading to an increasing number of antibiotic resistant strains. Clinical isolates and imipenem resistant variants presented a high level of resistance to beta-lactam antibiotic group and to chemically unrelated drugs. We report here that imipenem selects strains which contain active efflux pumps ejecting various unrelated antibiotics including quinolones, tetracycline, and chloramphenicol. An increase of AcrA, an efflux pump component, was observed in the imipenem resistant variants. The overexpression of marA, involved in the genetic control of membrane permeability via porin and efflux pump expression, indicated the activation of the resistance genetic cascade in imipenem resistant variants.
Anne Davinregli - One of the best experts on this subject based on the ideXlab platform.
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Enterobacter Aerogenes and Enterobacter cloacae versatile bacterial pathogens confronting antibiotic treatment
Frontiers in Microbiology, 2015Co-Authors: Anne Davinregli, Jean-marie PagèsAbstract:Enterobacter Aerogenes and E. cloacae have been reported as important opportunistic and multiresistant bacterial pathogens for humans during the last three decades in hospital wards. These Gram-negative bacteria have been largely described during several outbreaks of hospital-acquired infections in Europe and particularly in France. The dissemination of Enterobacter sp. is associated with the presence of redundant regulatory cascades that efficiently control the membrane permeability ensuring the bacterial protection and the expression of detoxifying enzymes involved in antibiotic degradation/inactivation. In addition, these bacterial species are able to acquire numerous genetic mobile elements that strongly contribute to antibiotic resistance. Moreover, this particular fitness help them to colonize several environments and hosts and rapidly and efficiently adapt their metabolism and physiology to external conditions and environmental stresses. Enterobacter is a versatile bacterium able to promptly respond to the antibiotic treatment in the colonized patient. The balance of the prevalence, E. Aerogenes versus E. cloacae, in the reported hospital infections during the last period, questions about the horizontal transmission of mobile elements containing antibiotic resistance genes, e.g., the efficacy of the exchange of resistance genes Klebsiella pneumoniae to Enterobacter sp. It is also important to mention the possible role of antibiotic use in the treatment of bacterial infectious diseases in this E. Aerogenes/E. cloacae evolution.
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occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter Aerogenes and klebsiella pneumoniae isolates producing extended spectrum β lactamases
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Quetien Tran, Jean-marie Pagès, Myrielle Dupont, Jacqueline Chevalier, Jeanphilippe Lavigne, A Sotto, Anne DavinregliAbstract:We investigated the occurrence of multidrug resistance in 44 Enterobacter Aerogenes and Klebsiella pneumoniae clinical isolates. Efflux was involved in resistance in E. Aerogenes isolates more frequently than in K. pneumoniae isolates (100 versus 38% of isolates) and was associated with the expression of phenylalanine arginine β-naphthylamide-susceptible active efflux. AcrA-TolC overproduction in E. Aerogenes isolates was noted. An analysis of four E. Aerogenes isolates for which cefepime MICs were high revealed no modification in porin expression but a new specific mutation in the AmpC β-lactamase.
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quinoline derivatives as promising inhibitors of antibiotic efflux pump in multidrug resistant Enterobacter Aerogenes isolates
Current Drug Targets, 2006Co-Authors: Abdallah Mahamoud, Jacqueline Chevalier, Anne Davinregli, Jacques Barbe, Jean-marie PagèsAbstract:Efflux pumps protect the bacterial cell by expelling toxic compounds before they reach intracellular targets. Because this mechanism actively contributes to the resistance of a given bacterium to more than one class of antibiotics, molecules that are able to block the relevant efflux pump are of potential significance to combat drug resistance caused by efflux pumps. Different quinoline derivatives including alkoxy, alkylamino, thioalkoxy and chloroquinolines have been previously reported to make Enterobacter Aerogenes resistant isolates that over express the mechanism of efflux, noticeably more susceptible to structurally unrelated antibiotics. In addition, various quinoline derivatives significantly increase the intracellular concentration of chloramphenicol as reported with other inhibitors, thereby suggesting the inhibition of the drug transport by AcrAB-TolC pump, which is fully active in the clinicaly resistant isolates investigated. Here, we discuss the respective properties of this molecular family, taking into account the recent insights into the structural data of AcrB pump.
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rama is an alternate activator of the multidrug resistance cascade in Enterobacter Aerogenes
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Renaud Chollet, Jean-marie Pagès, C. Bollet, Jacqueline Chevalier, Anne DavinregliAbstract:Multidrug resistance (MDR) in Enterobacter Aerogenes can be mediated by induction of MarA, which is triggered by certain antibiotics and phenolic compounds. In this study, we identified the gene encoding RamA, a 113-amino-acid regulatory protein belonging to the AraC-XylS transcriptional activator family, in the Enterobacter Aerogenes ATCC 13048 type strain and in a clinical multiresistant isolate. Overexpression of RamA induced an MDR phenotype in drug-susceptible Escherichia coli JM109 and E. Aerogenes ATCC 13048, as demonstrated by 2- to 16-fold-increased resistance to β-lactams, tetracycline, chloramphenicol, and quinolones, a decrease in porin production, and increased production of AcrA, a component of the AcrAB-TolC drug efflux pump. We show that RamA enhances the transcription of the marRAB operon but is also able to induce an MDR phenotype in a mar-deleted strain. We demonstrate here that RamA is a transcriptional activator of the Mar regulon and is also a self-governing activator of the MDR cascade.
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omp35 a new Enterobacter Aerogenes porin involved in selective susceptibility to cephalosporins
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Charleric Bornet, Anne Davinregli, C. Bollet, Nathalie Saint, Lilia Fetnaci, Myrielle Dupont, Jean-marie PagèsAbstract:In Enterobacter Aerogenes, β-lactam resistance often involves a decrease in outer membrane permeability induced by modifications of porin synthesis. In ATCC 15038 strain, we observed a different pattern of porin production associated with a variable antibiotic susceptibility. We purified Omp35, which is expressed under conditions of low osmolality and analyzed its pore-forming properties in artificial membranes. This porin was found to be an OmpF-like protein with high conductance values. It showed a noticeably higher conductance compared to Omp36 and a specific location of WNYT residues in the L3 loop. The importance of the constriction region in the porin function suggests that this organization is involved in the level of susceptibility to negative large cephalosporins such as ceftriaxone by bacteria producing the Omp35 porin subfamily.
Monique Mallea - One of the best experts on this subject based on the ideXlab platform.
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inhibitors of antibiotic efflux in resistant Enterobacter Aerogenes and klebsiella pneumoniae strains
Antimicrobial Agents and Chemotherapy, 2004Co-Authors: Jacqueline Chevalier, Monique Mallea, Jerome Bredin, Abdallah Mahamoud, Jacques Barbe, Jean-marie PagèsAbstract:In Enterobacter Aerogenes and Klebsiella pneumoniae, efflux provides efficient extrusion of antibiotics and contributes to the multidrug resistance phenotype. One of the alkoxyquinoline derivatives studied here, 2,8-dimethyl-4-(2'-pyrrolidinoethyl)-oxyquinoline, restores noticeable drug susceptibility to resistant clinical strains. Analyses of energy-dependent chloramphenicol efflux indicate that this compound inhibits the efflux pump mechanism and improves the activity of structurally unrelated antibiotics on multidrug-resistant E. Aerogenes and K. pneumoniae isolates.
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imipenem and expression of multidrug efflux pump in Enterobacter Aerogenes
Biochemical and Biophysical Research Communications, 2003Co-Authors: Charleric Bornet, Jean-marie Pagès, Anne Davinregli, Renaud Chollet, Jacqueline Chevalier, Monique Mallea, C. BolletAbstract:Imipenem is often used to treat intensive care unit patients infected by Enterobacter Aerogenes, but it is leading to an increasing number of antibiotic resistant strains. Clinical isolates and imipenem resistant variants presented a high level of resistance to beta-lactam antibiotic group and to chemically unrelated drugs. We report here that imipenem selects strains which contain active efflux pumps ejecting various unrelated antibiotics including quinolones, tetracycline, and chloramphenicol. An increase of AcrA, an efflux pump component, was observed in the imipenem resistant variants. The overexpression of marA, involved in the genetic control of membrane permeability via porin and efflux pump expression, indicated the activation of the resistance genetic cascade in imipenem resistant variants.
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inhibitors of antibiotic efflux pump in resistant Enterobacter Aerogenes strains
Biochemical and Biophysical Research Communications, 2002Co-Authors: Monique Mallea, Jacqueline Chevalier, Annie Eyraud, Jean-marie PagèsAbstract:Enterobacter Aerogenes, a nosocomial pathogen, is frequently exhibiting multidrug resistance mechanisms associated with a change in membrane permeability. In clinical isolates, active efflux plays a prominent role in antibiotic resistance. We report here the effect of three unrelated compounds that are able to restore a noticeable antibiotic susceptibility to resistant strains. The targeting of various parameters which contribute to the efficacy of the efflux mechanism, such as energy, flux selectivity, or functional assembly of the membrane complex, increases the intracellular chloramphenicol concentration in resistant isolates.
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mar operon involved in multidrug resistance of Enterobacter Aerogenes
Antimicrobial Agents and Chemotherapy, 2002Co-Authors: Renaud Chollet, Jean-marie Pagès, C. Bollet, Jacqueline Chevalier, Monique Mallea, Anne DavinregliAbstract:We determined the sequence of the entire marRAB operon in Enterobacter Aerogenes. It is functionally and structurally analogous to the Escherichia coli operon. The overexpression of E. Aerogenes MarA induces a multidrug resistance phenotype in a susceptible strain, demonstrated by a noticeable resistance to various antibiotics, a decrease in immunodetected porins, and active efflux of norfloxacin.
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most Enterobacter Aerogenes strains in france belong to a prevalent clone
Journal of Clinical Microbiology, 1999Co-Authors: C Bosi, Jean-marie Pagès, Charleric Bornet, Monique Mallea, A Davinregli, C. BolletAbstract:The aim of this study was to determine the distribution in France of the Enterobacter Aerogenes prevalent clone isolated in the hospitals of the Marseille area (A. Davin-Regli, D. Monnet, P. Saux, C. Bosi, R. Charrel, A. Barthelemy, and C. Bollet, J. Clin. Microbiol. 34:1474-1480, 1996). A total of 123 E. Aerogenes isolates were collected from 23 hospital laboratories and analyzed by random amplification of polymorphic DNA and Enterobacterial repetitive intergenic consensus-PCR to determine their epidemiological relatedness. Molecular typing revealed that 21 of the 23 laboratories had isolated this prevalent clone harboring the plasmid encoding for extended-spectrum beta-lactamase of the TEM-24 type. Most isolates were susceptible only to imipenem and gentamicin. Their dissemination seems to be clonal and was probably the result of the general use of broad-spectrum cephalosporins and quinolones. Four isolates showed an alteration of their outer membrane proteins, causing decrease of susceptibility to third-generation cephalosporins and imipenem and leading to the critical situation of having no alternative therapeutic. The large dissemination of the E. Aerogenes prevalent clone probably results from its good adaptation to the antibiotics administered in France and the hospital environment, particularly in intensive care units.