Resistência bacteriana em bacilos Gram-negativos: a importância dos testes fenotípicos

• Autor(a) principal: França, Marcelle Susanne Santos
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/43156
• topic: Resistência bacteriana; Bacterial resistance; Bacilos Gram-negativos; Gram-negative bacilli; Testes fenotípicos; Phenotypyc tests; ESBL; ESBL; AmpC; AmpC; MBL,KPC; MBL,KPC; CNPQ::OUTROS::BIOMEDICINA; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Gram-negative bacilli are often frequent participants in hospital infections, mainly immunosuppressed patients. In this way, they are very exposed to treatment at-tempts, with beta-lactams being the most used class against them. This can often lead to cases of multidrug resistance, both to various types of beta-lactams and to other classes, as these bacteria may have several mechanisms that make it capable of inhibiting or reducing the effect of an antimicrobial. This work aimed to carry out a bibliographic review on bacterial resistance in Gram-negative bacilli, in scientific da-tabases, in order to gather knowledge about this subject. The main phenotypic tests used for the detection of resistance in these bacteria are disc diffusion techniques, disk approach for extended spectrum beta-lactamases (ESBL), detection test for chromosomal enzymes (AmpC), EDTA test for metallo-beta-lactamases (MBL) and test for carbapenemases. However, since this type of test can be difficult to interpret when there is production of ESBL and metallo-beta-lactamases, for example, the search for new phenotypic tests that are more sensitive, specific and fast remains constant. The main mechanisms of resistance are alteration of permeability, altera-tion of the site of action of the drug, expression of efflux pumps, alteration in the metabolic pathways and production of enzymes that inhibit the action of the antibacterial, being this enzyme production the most frequent mechanism and that ESBL, AmpC, MBL and carbapenemases, such as KPC. This type of resistance is spreading throughout the world and also in Brazil, where it has a high prevalence of ESBLs of type CTX-M and metallo-beta-lactamases. Thus, the correct interpretation of the phenotypic tests can significantly contribute to the reduction of resistance induction and to the formation of an epidemiological database, even if those used are still not ideal, and its clinical practice still presents great value.