Perfil de resistência de cepas de pseudomonas aeruginosa em três centros de saúde do Estado do RN

Abstract

The enhanced antimicrobial resistance in Pseudomonas aeruginosa is a remarkable example of how the bacteria can maintain and express the new genetic information conferring resistance to one or more drugs. In the present study we evaluated the profile of antimicrobial susceptibility in isolates of P. aeruginosa from three major Rio Grande do Norte state reference centers: Laboratory Dr. Almino Fernandes (LACEN-RN), Laboratory of Clinical Analysis of HUOL and Analysis Laboratory of Clinical Hospital Giselda Trigueiro (HGT). The isolates were obtained between January 2013 and June 2014, in which 113 strains were isolated from various clinical specimens by spontaneous demand. The species of P. aeruginosa was first recognized in home laboratories and confirmed by phenotypic tests, the Mycobacteria Laboratory (LABMIC) of the Federal University of Rio Grande do Norte - UFRN. The determination of antimicrobial susceptibility was given through the disk diffusion test. After determining the resistance profile, the samples were subjected to confirmatory phenotypic evaluation to beta lactamase producing AmpC type detection and Metallo Beta Lactamase. Of the 113 isolates 67.2% (n = 76) showed resistance profile of the at least one class of antimicrobials. All strains of P. aeruginosa were susceptible to Polymyxin B. The highest resistance rates were checked against the ofloxacin 57.5% (n = 65), Ciprofloxacin 55.7% (n = 63), Norfloxacin 55.7% (n = 63), Ticarcillin-clavulanic acid 43.3% (n = 49) Ceftazidime 41.5% (n = 47), Meropenem 39.8% (n = 45), and Aztreonam Cefepime 38.9% (n = 44), Imipenem 36.2% (n = 41 ) Tobramycin 36.2% (n = 41), piperacillin-tazobactam 28.3% (n = 32) and amikacin 28.3% (n = 32). Of the 113 strains studied, 46 (40.7%) showed positive phenotypic results for the production of β-lactamases AmpC type of approach through the disk method. Fifty (44%) isolates showed resistance to at least one of the evaluated carbapenems, and these were subjected to phenotypic screening test for production Metallo Beta Lactamase - MBL, by blocking enzymatic test with discs combined with EDTA. Of the 50 samples with resistance to carbapenems, 21 (42%) showed positive phenotypic test for the production of metallo-β-lactamase producing considered presumptively with MBL. The data demonstrate high production of β-lactamases type ampC Metallo-and β-lactamase. It was also observed high antimicrobial resistance rates, especially carbapenems. Therefore it is concluded that early identification of pathogens and analysis of microorganisms to antimicrobial resistance constitute an important tool to assist clinicians in the treatment of infections.