title: Carbapenem-resistant Pseudomonas aeruginosa: association with virulence genes and biofilm formation.
abstract: Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case-control study in the Uberlândia Federal University - Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for blaSPMgene and 5.3% positive for blaVIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil. Electronic address: iara_rossi@hotmail.com.
authors.forename: Iara
authors.initials: I
authors.lastname: Rossi Gonçalves
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
authors.forename: Raquel Cristina Cavalcanti
authors.initials: RCC
authors.lastname: Dantas
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
authors.forename: Melina Lorraine
authors.initials: ML
authors.lastname: Ferreira
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
authors.forename: Deivid William da Fonseca
authors.initials: DWDF
authors.lastname: Batistão
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
authors.forename: Paulo Pinto
authors.initials: PP
authors.lastname: Gontijo-Filho
authors.affiliation: Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
authors.forename: Rosineide Marques
authors.initials: RM
authors.lastname: Ribas
mesh_terms: D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics*; D018441:Biofilms / Q000254:growth & development*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D012307:Risk Factors; D016019:Survival Analysis; D037521:Virulence Factors / Q000235:genetics*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D001618:beta-Lactamases; C063912:carbapenemase
keywords: Biofilm; Metallo-β-lactamases; Pseudomonas aeruginosa; Resistance; Virulence