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 blaSPM gene 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.

Molecular analysis of Pseudomonas aeruginosa isolated from clinical, environmental and cockroach sources by ERIC-PCR

“…Ding et al [ 25 ] in a Meta-analyses of 50 studies published from 2010 to 2014 investigated antimicrobial-resistant P. aeruginosa and reported the varied prevalence of resistance, with high levels of resistance to gentamicin. Gonçalves et al [ 26 ] reported that 73.9% of P. aeruginosa were multidrug-resistant and 43.9% were resistant to carbapenems. Khosravi et al also found high-level resistance to gentamicin, ciprofloxacin, meropenem, piperacillin/tazobactam and imipenem, and no resistance to colistin among P. aeruginosa strains isolated from burn patients in a burn center of Ahvaz; Southeast of Iran [ 27 ].…”

Avaliação temporal do perfil de resistência de pseudomonas aeruginosa isoladas de pacientes internados em hospital oncológico em Belém-PA, Brasil em 2017

“…Hospitais oncológicos figuram como áreas de alto risco para aquisição de infeções considerando: tempo de internação, a utilização de imunossupressores e/ou antibióticos, procedimentos invasivos (intubação traqueal, cateterização venosa central, sondagem vesical, e outros), doença de base concomitante, condições nutricionais, extremos de idade, dentre outros aspectos 11,12,13,14,15 .…”

Molecular Characterization of Biofilm-Producing Pseudomonas aeruginosa Isolated from Healthy Pigs and Chicken in India

“…Moreover, they reported that isolates of burn infection had the highest frequency of virulence genes. Gonçalves et al (2017) also reported the biofilm producing P. aeruginosa isolated from clinical samples in Brazil and most of the strains were found to be positive for aprA, plcH, plcN, lasA, lasB and toxA genes which can further contribute to a worse prognosis associated with severe infections.…”