Avaliação fenotípica da resistência a fármacos antimicrobianos e metais pesados de amostras de Pseudomonas aeruginosa isoladas de pacientes hospitalizados

Abstract

Antimicrobial drugs represent a fundamental resource in medicine, with immeasurable impacts on therapeutic approaches, however the dissemination of bacterial resistance to antimicrobial drugs is a major challenge for health professionals. Heavy metals are natural elements present in various ecosystems, although anthropogenic activities are favoring the accumulation of heavy metals that consequently select and contribute to the promotion of bacterial resistance. Pseudomonas aeruginosa, a non-fermenting Gram-negative rod, is considered an opportunistic pathogen, especially as an agent of healthcare-related infections. This study aims at the phenotypic evaluation of 44 hospital clinical specimens of P. aeruginosa to 5 antimicrobials: What are, meropenem, amicacin, ceftazidime, piperacillin+tazobactam and ciprofloxacin, as well as 4 heavy metals: Zinc, silver, cadmium and copper. The antimicrobial susceptibility profile was determined by the evaluation of the minimum inhibition concentration (MIC) and, for heavy metals, tests were performed on solid medium [Tryptic Soy Agar (TSA)] and liquid [Mueller Hinton Broth (MHB)]. The results identified higher percentages of resistance to β-lactam drugs, among them, especially ceftazidime. Regarding heavy metals, high rates of resistance to zinc, cadmium and copper were detected. A considerable increase in silver MIC was observed for most samples, which represents a warning sign for the use of this metal in clinical practice. Resistance to antimicrobial drugs and heavy metals is a worrying reality and all efforts to control their evolution should be avoided