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1.
J Infect Chemother ; 20(6): 394-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24767465

RESUMEN

Few reports described infections with CC398 methicillin-susceptible Staphylococcus aureus (MSSA). We compared the genetic background of CC398 MSSA strains from nasal carriage and knee arthroplasty infection. DNA microarray analysis shows acquisition of particular adhesin, iron capture system and immune defense evasion mechanisms. These characteristics could explain pathogenesis in this type of infection.


Asunto(s)
Portador Sano/microbiología , Cavidad Nasal/microbiología , Infecciones Relacionadas con Prótesis/microbiología , Staphylococcus aureus/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Agricultura , ADN Bacteriano/análisis , ADN Bacteriano/genética , Femenino , Francia , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina , Persona de Mediana Edad , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Adulto Joven
3.
Antimicrob Agents Chemother ; 57(5): 2410-2, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23478954

RESUMEN

A Proteus mirabilis clinical strain (7001324) was isolated from urine sample of a patient hospitalized in a long-term-care facility. PCR and cloning experiments performed with this strain identified a novel TEM-type ß-lactamase (TEM-187) differing by four amino acid substitutions (Leu21Phe, Arg164His, Ala184Val, and Thr265Met) from TEM-1. This characterization provides further evidence for the diversity of extended-spectrum ß-lactamases (ESBL) produced by P. mirabilis and for their potential spread to other Enterobacteriaceae due to a lack of sensitive detection methods used in daily practice.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Proteus mirabilis/efectos de los fármacos , beta-Lactamasas/genética , Sustitución de Aminoácidos , Secuencia de Bases , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Infecciones por Proteus/tratamiento farmacológico , Infecciones por Proteus/microbiología , Proteus mirabilis/enzimología , Proteus mirabilis/genética , Proteus mirabilis/aislamiento & purificación , beta-Lactamasas/metabolismo
4.
J Antimicrob Chemother ; 68(5): 1032-5, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23302581

RESUMEN

OBJECTIVES: This study reports details on Escherichia coli isolates recovered from a cystic fibrosis (CF) patient in order to understand how this pathogen adapts to and resists broad-spectrum antipseudomonal therapy in this context. METHODS: Five E. coli isolates were obtained from various clinical samples (airways, urine or dialysis catheter) over a 7 month period covering a double-lung transplantation. All isolates were analysed in terms of clonality [enterobacterial repetitive intergenic consensus (ERIC)-PCR and multilocus sequence typing], virulence profiles (phylogroup and search for 15 virulence genes), growth patterns (morphotype, biofilm-forming ability and growth rate), hypermutability and antimicrobial susceptibility, with molecular characterization of ß-lactamases and porins. RESULTS: The five isolates shared similar ERIC-PCR profiles and sequence types (ST1193) and exhibited the same virulence profile. The respiratory isolates were strong mutators, exhibited mucoid or small-colony morphotypes, exhibited strong biofilm-forming ability and grew slowly compared with the others. All isolates were highly resistant to ceftazidime. The respiratory isolates showed reduced susceptibility to cefepime and high resistance to aztreonam. The patient had received a 31 day course of ceftazidime/aztreonam until transplantation. All isolates harboured the same wild-type chromosomal AmpC. A CMY-2 enzyme was detected in the non-respiratory isolates. The respiratory isolates harboured L293S and V211A/L293S new CMY-2 variants, which were designated CMY-94 and CMY-95, respectively. OmpF porin loss was observed in the non-respiratory isolates. CONCLUSIONS: Our study shows that, similarly to Pseudomonas aeruginosa, E. coli can undergo phenotypic and genomic changes in the CF context. For the first time, we identified an in vivo expanded-spectrum evolution of the CMY-2 ß-lactamase, during bacterial persistence in the CF lung.


Asunto(s)
Fibrosis Quística/complicaciones , Microbiología Ambiental , Infecciones por Escherichia coli/microbiología , Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , beta-Lactamasas/genética , Adaptación Biológica , Antibacterianos/farmacología , Análisis por Conglomerados , Escherichia coli/clasificación , Escherichia coli/genética , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Factores de Virulencia/genética
7.
Diagn Microbiol Infect Dis ; 74(1): 95-7, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22749243

RESUMEN

We investigated the clinical and microbiological epidemiology of AmpC plasmidic cephalosporinases (pAmpC) in Klebsiella pneumoniae strains resistant to ceftazidime, during a 3-year period (2007-2009). Among 1505 K. pneumoniae, 7 were pAmpC producers. Molecular characterization revealed the spread of a ST37 strain producing DHA-1 within intensive care units and the diffusion of the same plasmid among unrelated strains.


Asunto(s)
Proteínas Bacterianas/genética , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Plásmidos , beta-Lactamasas/genética , Adulto , Anciano , Antibacterianos/farmacología , Ceftazidima/farmacología , Femenino , Humanos , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Epidemiología Molecular , Resistencia betalactámica
8.
Scand J Infect Dis ; 44(8): 610-4, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22385370

RESUMEN

Twenty-one isolates of Staphylococcus epidermidis from 9 patients with persistent prosthetic joint infections were analysed by pulsed-field gel electrophoresis and antibiotic susceptibility assays. In 7 of these cases, the S. epidermidis isolate was different from that of the initial episode. In 1 further case, the superinfection was polyclonal. Recurrence, i.e., renewed isolation of a clone identical to that of an initial episode, occurred in 3 cases, 1 of which was in the absence of superinfection. A high degree of antibiotic resistance was demonstrated, including methicillin in 17 of 21 strains. In conclusion, a frequent occurrence of superinfection and a high degree of resistance make management of these infections complex.


Asunto(s)
Prótesis Articulares/microbiología , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Enfermedad Crónica , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Masculino , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Staphylococcus epidermidis/genética , Sobreinfección/microbiología
10.
J Infect ; 64(2): 169-75, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22115736

RESUMEN

OBJECTIVES: Little is known about Escherichia coli Orthopaedic Implant Infections (OII) pathogenesis. Thus, we compared 30 clinical strains isolated in this context with 30 clinical strains of faecal origin, in order to identify phenotypic and genetic features related to E. coli OII. METHODS: Phylogenetic analysis and detection of 19 virulence genes were performed by PCR. Ability to form biofilm was studied using the crystal violet reference method and the innovative BioFilm Ring Test(®). RESULTS: Most of the OII isolates (56.7%) belonged to the virulence-associated phylogenetic group B2, but did not present a specific set of virulence factors. S fimbriae was the only adhesin significantly associated with OII isolates. Isolates varied greatly in their ability to form biofilm but OII isolates did not produce significantly more biofilm in vitro than isolates of faecal origin, whatever the method used. CONCLUSIONS: Neither a specific pathogenic signature nor an increased ability to form biofilm in vitro was detected in E. coli strains isolated from OII. Nevertheless, genetic properties of these isolates could provide a clue to their origin. Hence, we found that virulence factors of uropathogenic strains and urological disorders were frequently detected among our OII cohort.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Infecciones Relacionadas con Prótesis/microbiología , Adhesinas de Escherichia coli/análisis , Anciano , Anciano de 80 o más Años , Biopelículas/crecimiento & desarrollo , Escherichia coli/aislamiento & purificación , Escherichia coli/fisiología , Heces/microbiología , Femenino , Proteínas Fimbrias/análisis , Humanos , Masculino , Persona de Mediana Edad , Filogenia , Factores de Virulencia/genética
11.
J Clin Microbiol ; 50(1): 184-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22090399

RESUMEN

Sternal osteitis, a potential consequence of cardiac surgery, remains rare. The bacteria involved belong mostly to the genus Staphylococcus. Sternal infections caused by Serratia marcescens are exceptional. We report an unusual recurrence of sternal infection with S. marcescens, 15 years after the initial episode. The identities of the isolates were determined by genomic analysis.


Asunto(s)
Osteítis/diagnóstico , Osteítis/microbiología , Infecciones por Serratia/diagnóstico , Infecciones por Serratia/microbiología , Serratia marcescens/aislamiento & purificación , Análisis por Conglomerados , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación Molecular , Osteítis/patología , Recurrencia , Infecciones por Serratia/patología , Esternón/microbiología , Esternón/patología
12.
Cytokine ; 56(2): 290-7, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21764597

RESUMEN

INTRODUCTION: We investigated the role of PI3-K, MAP kinases, and heterotrimeric G proteins in inducing cytokines production in human whole blood cultures stimulated by viable Escherichia coli (E. coli) clinical strains. MATERIALS AND METHODS: We used eight E. coli strains that belong to different phylogenetic groups and presented by different antibiotic resistance patterns. Whole blood from healthy volunteers was incubated at 37°C for 150min, with lipopolysaccharide (LPS) from E. coli O111:B4 or selected viable E. coli clinical strains, with or without SB202190 (p38 inhibitor), PD98059 (ERK inhibitor), PTX (pertussis toxin; heterotrimeric G proteins inhibitor), wortmaninn (PI3-K inhibitor). The TNF-α, IL-1ß, IL-10 and IFN-γ concentrations were measured in culture supernatants (ELISA). RESULTS: IL-10 and IFN-γ were not detectable. Susceptible strains induced higher TNF-α and IL-1ß productions than ß-lactam resistant strains (p<0.05), with no difference between phylogenetic groups. A transformed strain carrying a plasmid-mediated AmpC-ß-lactamase gene (CMY-2) induced lower TNF-α and IL-1ß production than the parent wild type strain (p<0.05). SB202190 (p38 inhibitor) and PD98059 (ERK inhibitor) reduced TNF-α concentrations by, respectively, 80% (p<0.05) and 50% (p<0.05). Wortmaninn (PI3-K inhibitor) had no significant effect. PTX (heterotrimeric G proteins inhibitor) altered TNF-α production after viable bacteria stimulation (1.7-fold increase; p<0.05) but not after LPS (TLR-4) stimulation. Regarding IL-1ß, wortmaninn, SB202190 and PTX had no significant effect whereas PD98059 significantly decreased production in whole cell cultures (p<0.05). CONCLUSION: Susceptible strains induce greater TNF-α and IL-1ß productions than resistant strains. ERK kinase plays a major role in viable E. coli strains inducing TNF-α and IL-1ß production. E. coli exerts an effect on the pertussis toxin-sensitive G-protein through a TLR-4-independent mechanism.


Asunto(s)
Citocinas/biosíntesis , Escherichia coli/fisiología , Proteínas de Unión al GTP/metabolismo , Mediadores de Inflamación/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Filogenia , Proteínas Proto-Oncogénicas c-akt/metabolismo , Recuento de Colonia Microbiana , Farmacorresistencia Bacteriana , Escherichia coli/clasificación , Escherichia coli/efectos de los fármacos , Femenino , Humanos , Masculino
13.
Soins ; (754): 21-4, 2011 Apr.
Artículo en Francés | MEDLINE | ID: mdl-21574307

RESUMEN

A study was carried out in 2008 at the university hospital of Nantes to determine a target for the consumption of alcohol-based disinfectants per patient and per day of hospitalisation. The study involved healthcare professionals and was based on a methodological double approach of self-estimation and analysis of nursing records.


Asunto(s)
Desinfectantes , Adhesión a Directriz/estadística & datos numéricos , Desinfección de las Manos , Francia , Desinfección de las Manos/normas , Humanos
14.
Diagn Microbiol Infect Dis ; 67(3): 277-81, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20462724

RESUMEN

We investigated the prevalence and epidemiology of AmpC plasmidic cephalosporinases in Escherichia coli clinical strains resistant to third-generation cephalosporins during a 5-year period at Nantes University Hospital, France (3100 beds). The prevalence and diversity of plasmidic cephalosporinase did not increase during the study period (0.09% of 25 861 E. coli isolates); only CMY-2 producers were detected (and 1 new variant, with a Y-to-C substitution at position 219). CMY-2-producing strains belonged to the 4 main phylogenetic groups and to 11 different sequence types. Three sequence types included more than 1 isolate (ST156, ST46, and ST354).


Asunto(s)
Proteínas Bacterianas/biosíntesis , Infecciones por Escherichia coli/epidemiología , Escherichia coli/clasificación , Escherichia coli/enzimología , Plásmidos , beta-Lactamasas/biosíntesis , Antibacterianos/farmacología , Técnicas de Tipificación Bacteriana , Cefalosporinas/farmacología , Análisis por Conglomerados , Dermatoglifia del ADN , ADN Bacteriano/química , ADN Bacteriano/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Francia/epidemiología , Genotipo , Hospitales de Enseñanza , Humanos , Prevalencia , Análisis de Secuencia de ADN , Resistencia betalactámica
15.
Microb Drug Resist ; 16(2): 123-8, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20370509

RESUMEN

The epidemiology of patients associated with ampicillin-resistant Enterococcus faecium (ARE) was investigated by combining both clinical approach and molecular analysis in a kidney transplant patient's ward. A case-control study was performed to identify risk factors for ARE by matching each patient with ARE with two control patients without any isolated E. faecium strain. ARE isolates were characterized by pulsed-field gel electrophoresis. From June 2004 to May 2006, 18 cases with clinical ARE samples were detected and compared with 35 control patients. By univariate analysis, recurrent urinary tract infections (UTIs) (odds ratio [OR], 4.9; 95% confidence interval [CI], 1.0-25.6), mean number of hospitalization days in the last year (p < 0.003), pyelonephritis or UTI (OR, 9.6; 95% CI, 2.2-46.1), oral third-generation cephalosporin use (OR, 12.42; 95% CI, 2.04-109.1), and fluoroquinolone use (OR, 4.4; 95% CI, 1.1-18.2) were significantly associated with ARE urinary tract colonization. By conditional logistic regression, hospitalization >21 days within 1 year (adjusted OR [aOR], 6.9; 95% CI, 1.0-46.5), recent medical history of pyelonephritis or UTI (aOR, 8.6; 95% CI, 1.5-49.1), and prior oral third-generation cephalosporin use (aOR, 13.1; 95% CI, 1.2-142.6) were identified as independent factors associated with ARE urinary tract colonization. Genotyping revealed a heterogeneous epidemiological situation with two major clones in patients hospitalized in successive rooms and 10 different single pulsotypes. Emergence of highly resistant enterococcal strains is a collateral damage from antibiotic prescription and represents a potential source of patient-to-patient transmission. Combining epidemiological approach and molecular analysis is a powerful tool to delineate mechanisms of emerging resistance. Improving our knowledge on ARE emergence in high antibiotic pressure hospital wards is a key factor to better control these colonizations/infections and to prevent the emergence of vancomycin-resistant E. faecium.


Asunto(s)
Resistencia a la Ampicilina , Infección Hospitalaria/transmisión , Enterococcus faecium , Unidades Hospitalarias , Trasplante de Riñón , Anciano , Ampicilina/farmacología , Ampicilina/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Estudios de Casos y Controles , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Electroforesis en Gel de Campo Pulsado , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/genética , Enterococcus faecium/crecimiento & desarrollo , Enterococcus faecium/aislamiento & purificación , Femenino , Unidades Hospitalarias/estadística & datos numéricos , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Factores de Riesgo , Sistema Urinario/microbiología , Infecciones Urinarias/epidemiología , Infecciones Urinarias/microbiología , Infecciones Urinarias/transmisión
16.
Antimicrob Agents Chemother ; 54(5): 2216-8, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20145079

RESUMEN

Extended-spectrum AmpC beta-lactamase (ESAC) Escherichia coli producers were investigated over a 5-year period. Eleven isolates presenting a strong ampC promoter and different strategic AmpC mutations, including two newly described modifications (A292V and an L-A-A insertion at 295), were characterized. All the isolates belonged to phylogenetic group A and to the ST23 complex.


Asunto(s)
Proteínas Bacterianas/genética , Infecciones por Escherichia coli/tratamiento farmacológico , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Filogenia , Resistencia betalactámica/genética , beta-Lactamasas/genética , Cefepima , Cefotaxima/farmacología , Ceftazidima/farmacología , Cefalosporinas/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Infecciones por Escherichia coli/microbiología , Francia , Hospitalización , Humanos , Datos de Secuencia Molecular , Mutación , Regiones Promotoras Genéticas/genética
17.
Diagn Microbiol Infect Dis ; 66(1): 1-6, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19775845

RESUMEN

Risk factors for imipenem (IMP)-resistant Pseudomonas aeruginosa (IRPA) digestive carriage were analyzed, and genetic events contributing to select resistant isolates in patients exposed to IMP were investigated. Among the 150 patients with hospital-acquired P. aeruginosa digestive carriage, 38 isolates were IRPA. DNA pulsotypes revealed 16 distinct clones. In 4 patients, a second P. aeruginosa isolate showed resistance to IMP compared with the initial susceptible isolate. By comparing the different oprD sequences between IMP-susceptible P. aeruginosa and IRPA strains, a genetic event was systematically found for each resistant isolate, leading to either the absence of OprD or a truncated porin. The multivariate analysis demonstrated that prior IMP exposure was associated with IRPA carriage. In summary, we confirmed that IMP use selects for IRPA in the gut flora. Cross-transmission, however, was frequently observed in intensive care units. Combining epidemiologic approach and molecular analysis is a powerful tool to delineate mechanisms of emerging resistance.


Asunto(s)
Antibacterianos/farmacología , Portador Sano/microbiología , Infección Hospitalaria/microbiología , Imipenem/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Recto/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Estudios de Cohortes , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Modelos Logísticos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Porinas/genética , Estudios Prospectivos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , Factores de Riesgo
18.
Diagn Microbiol Infect Dis ; 64(4): 462-3, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19631103

RESUMEN

We report on a Klebsiella pneumoniae clinical isolate coproducing bla(DHA-1), bla(SHV-2a), qnrB4, and aac(6')-Ib-cr genes. Molecular analysis demonstrated the presence of this combination on the same large plasmid. Despite a negative result for extended-spectrum beta-lactamase (ESBL) by Vitek2(R) system (bioMérieux, Marcy-l'Etoile, France), an ESBL was detected by a double-disk test. Phenotypic techniques and molecular analysis are key approaches to determine coresistance.


Asunto(s)
Farmacorresistencia Bacteriana , Genes Bacterianos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Francia , Humanos , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Plásmidos , Adulto Joven
20.
Diagn Microbiol Infect Dis ; 64(4): 455-7, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19446979

RESUMEN

Qnr determinants have now been found worldwide. In 2008, among 6150 Enterobacteriaceae, 12 isolates belonging to different bacterial species showing an unusual quinolone resistance pattern on Vitek2 system were investigated. Of 12, 11 harbored a qnr gene. Without QRDR modifications, qnr genes can be detected based on a Vitek2 resistance phenotype.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana/métodos , Quinolonas/farmacología , Dermatoglifia del ADN , ADN Bacteriano/genética , Humanos
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