POLYMYXIN B RESISTANCE IN GRAM-NEGATIVE BACTERIA CARBAPENEM RESISTANT ISOLATED IN HOSPITALS IN RIO GRANDE DO NORTE, BRAZIL
Gram-negative bacteria; Polymyxin B; Drug resistance; Carbapenems;
Bacterial resistance is a worldwide public health problem recognized. High prevalence of Gram-negative bacilli infections and their spread in the hospital environment, mainly by carbapenem resistant strains is a recurrent concern due to its adaptive success and the ability to acquire more antimicrobial resistance genes. In this panoramana, the emergence of resistance to carbapenems and the difficulty in developing new drugs, many authors postulate a return to the pre-antibiotic era, Although a more sustainable alternative is return of abdicated antimicrobials such as polymyxins. For a better understanding of the emergency reality in the trend of the therapeutic fragility, local epidemiological data are fundamental. In order to provide data, we carried out an unpublished study in the state of Rio Grande do Norte, whose main objective was to evaluate the profile of polymyxin B resistance in bacilli Gram-negative carbapenem resistant from clinical samples from health reference centers. One hundred and seventy-four BGNs were collected from infected or colonized patients. These isolates were submitted to a manual biochemical tests for species identification, confirmatory phenotypic analysis (modified Hodge assay and metallo-β-lactamases selection) and determination of the minimum bactericidal concentration (MBC) to polymyxin B were performed, values of CBM50 and CBM90 were calculated for each species. Of these strains, 105 (60.3%) were confirmed as producers of metallo-β-lactamases, more than half among to the genus Acinetobacter spp. Other species such as Pseudomonas aeruginosa and Klebsiella pneumoniae also expressed the same phenotype. Regarding susceptibility to polymyxin B, 53 (30.5%) were resistant to polymyxin B, with CBMs ranging from ≥4μg / mL to ≤64μg / mL. It is hoped that these results can be extended and used as a reference at a State level, preventing the dispersion of this resistance and also serving as a more national data to build a more reliable profile regarding the epidemiology of this resistance that despite rare already points out its emergency.