Nosocomial infections with metallo-beta-lactamase-producing Pseudomonas aeruginosa : molecular epidemiology, risk factors, clinical features and outcomes

• Published in: The Journal of hospital infection Vol. 87; no. 4; pp. 234 - 240
• Main Authors: Lucena, A, Dalla Costa, L.M, Nogueira, K.S, Matos, A.P, Gales, A.C, Paganini, M.C, Castro, M.E.S, Raboni, S.M
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2014; Elsevier
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Proteins - metabolism; beta-Lactamases - metabolism; Biological and medical sciences; Brazil - epidemiology; Case-Control Studies; Child; Cross Infection - epidemiology; Cross Infection - microbiology; Cross Infection - pathology; Cross Infection - prevention & control; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Electrophoresis, Gel, Pulsed-Field; Female; General aspects; Hospitals, Teaching; Human infectious diseases. Experimental studies and models; Humans; Infection Control - methods; Infectious Disease; Infectious diseases; Male; Medical sciences; Metallo-β-lactamase; Middle Aged; Nosocomial infections; Polymerase Chain Reaction; Pseudomonas aeruginosa; Pseudomonas aeruginosa - classification; Pseudomonas aeruginosa - enzymology; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - isolation & purification; Pseudomonas Infections - epidemiology; Pseudomonas Infections - microbiology; Pseudomonas Infections - pathology; Pseudomonas Infections - prevention & control; Retrospective Studies; Risk Factors; Sequence Analysis, DNA; Survival Analysis; Treatment Outcome; Young Adult; Brazil; Metallo-β-lactamase; Pseudomonas aeruginosa; Nosocomial infections; Pseudomonadales; Nosocomial infection; Prognosis; Enzyme; β-Lactamase; Symptomatology; Risk factor; Molecular epidemiology; Bacteria; Hydrolases; Pseudomonadaceae; Public health
• ISSN: 0195-6701; 1532-2939
• DOI: 10.1016/j.jhin.2014.05.007

Summary Background Metallo-β-lactamases (MBLs) have emerged as one of the most important bacterial resistance mechanisms because of their ability to hydrolyse virtually all β-lactam agents. MBL-producing Pseudomonas aeruginosa (MBL-PA) are an important cause of nosocomial infections, particularly in intensive care units (ICUs), where they are associated with serious infections and present a significant clinical risk. Aim To assess the molecular epidemiology, risk factors and outcomes of nosocomial infections caused by MBL-PA in a teaching hospital in Southern Brazil. Methods From January 2001 to December 2008, 142 carbapenem-resistant P. aeruginosa strains were isolated from distinct clinical samples from hospitalized patients. These isolates were screened for MBLs, and underwent polymerase chain reaction, sequencing and pulsed-field gel electrophoresis (PFGE). Patients infected with carbapenem-resistant MBL-PA were considered as cases, and patients infected with non-MBL-PA were considered as controls. Findings Eighty-four of 142 patients with positive carbapenem-resistant P. aeruginosa cultures met the criteria of the Centers for Disease Control and Prevention for infection. Fifty-eight patients were infected with MBL-PA (69%) and 26 patients were infected with non-MBL-PA (31%). Multi-variate analysis revealed that ICU stay [ P  = 0.003, odds ratio (OR) 4.01, 95% confidence interval (CI) 1.15–14.01] and urinary tract infection ( P  = 0.001, OR 9.67, 95% CI 1.72–54.48) were important risk factors for MBL-PA infection. Patients infected with MBL-PA showed faster onset of infection ( P  = 0.002) and faster progression to death ( P  = 0.04). Conclusions These results showed the severity of MBL-PA infections, and demonstrated the urgent need for strategies to improve infection control measures to prevent an increase in these nosocomial infections.