Detecção de metalo-beta-lactamases em amostras hospitalares de Pseudomonas aeruginosa e Acínetobacter baumonnii

Abstract

Introduction and objective: P. aeruginosa and A. baumannii are the most prevalent etiological agents of hospital infections among non-fermentative gram-negative bacilli. Carbapenem resistance among these pathogens has become a therapeutic problem worldwide. Metallo-beta-lactamases (MBL) production has emerged as one of the mechanisms responsible for this resistance. The aim of the present study was to assess MBL production in clinical isolates of P. aeruginosa and A. baumannn from inpatients at Hospital Estadual Azevedo Lima, Niterói, RJ. Material and methods: A total of 400 strains of P. aeruginosa (286) and A. baumanii (114) were identified through commercial systems. Antimicrobial susceptibility was tested by disk diffusion. Isolates resistant to ceftazidime were screened for MBL production by disk approximation test. Results: MBL production was detected in 49 (17.1%) P. aeruginosa isolates and in 20 (17.5%) A. baumanii isolates. Most P. aeruginosa and A. baumanii samples were resistant to all antimicrobial agents. Conclusion: Production of MBL is one of the mechanisms of carbapenem resistance and other beta-lactams among P. aeruginosa and A. baumannn isolates in the investigated hospital. The rapid detection of this resistance phenotype is essential to implement strict infection control procedures and initiate appropriate empirical therapy.