Phenotypic and genotypic characterization of antimicrobial resistance in rapidly growing mycobacteria

Abstract

Rapidly growing mycobacteria can cause pulmonary infections, infections related to cutaneous trauma and healthcare associated infections. Pulmonary infections are virtually incurable despite of use of antimicrobials with in vitro activity if treatment does not include surgical resection of the affected area. There are a limited number of therapeutic options for the treatment of these infections and an even smaller is the group of antimicrobials that achieve adequate intracellular concentration particularly in the phagosome. Besides cases of pulmonary infections, since 1998 a growing number of cases and outbreaks of infections related to surgical procedures have been reported in Brazil. These outbreaks have occurred in many cities in different Brazilian states, totaling approximately 2,200 notified cases.The lack of Brazilian publications that could support guidelines and therapeutic approaches for the treatment of infections caused by rapidly growing mycobacteria, the predominance of a single clone of a single species Mycobacterium massiliense in different Brazilian states, treatment failures, recurrences and the limited number of antimicrobials available for the treatment of these infections indicate the need to evaluate the susceptibility pattern of different species for antimicrobials tested in combination and alone. The study of the cidal activity of antimicrobials inside the macrophage, characterization of genetic determinants of resistance and their genetic context would contribute to identify potentially better treatment approaches and would contribute to the understanding of antimicrobial resistance evolution in this group of pathogens. This study will generate relevant data to support empiric therapy of these infections in Brazil and will contribute to elucidate the mechanisms of resistance of this group of pathogens. (AU)