Caracterização da resistência aos antimicrobianos em enterobactérias isoladas de leite pasteurizado comercializado no município do estado do Rio de Janeiro

• Autor(a) principal: Cirino, Fabiane Paula Soares da Costa
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14385
• topic: Pasteurized milk; Enterobacteria; Antimicrobial resistance; Leite pasteurizado; Enterobactérias; Resistência aos antimicrobianos; Leite - Contaminação - Rio de Janeiro (RJ); Leite - Pasteurização - Rio de Janeiro (RJ); Leite - Microbiologia; Enterobactérias; Drogas - Resistência em microorganismos; Farmacorresistência bacteriana; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::MICROBIOLOGIA APLICADA::MICROBIOLOGIA MEDICA

Milk is one of the most nutritionally complete foods, being rich in nutrients essential to the growth and maintenance of a balanced life and the process of pasteurization should contribute to the reduction of the incidence of important pathologies in humans. The objective of this study was to identify and determine the antimicrobial susceptibility profile of enterobacteria recovered from samples of pasteurized milk from two commercial brands, commercialized in the city of Rio de Janeiro. Thus, 15 milk samples of each brand were commercially purchased, making a total of 30 analyzed samples. The selective isolation was performed in BHI broth containing the antimicrobial ampicillin disk associated with sulbactan (10 / 10ug), to favor the isolation of resistant enterobacteria. From the growth, the cultures were seeded in EMB agar and, later, the presumptive colonies were stocked in Skim Milk (glycerol-10%) for later identification. The morpho-tinorial characteristics were observed by Gram staining and for the identification of the species were used conventional methodology and MALDI-TOF-MS. The antimicrobial susceptibility test was performed using the agar diffusion method, according to the CLSI (2016) reading criteria and recommendations. 25 antimicrobials tested were. The presence of resistance genes and the phylogenetic groups of <i>Escherichia coli</i> were determined using the polymerase chain reaction (PCR) technique. A total of 83 enterobacterial strains were identified, including <i>Enterobacter cloacae</i> (n = 35; 42%), <i>Raoultella ornithinolytica</i> (n = 25; 30%), <i>Escherichia coli</i> (n = 20; 24%) and <i>Hafnia alvei</i> = 03, 0.4%). Considering the brands studied, brand A presented a higher percentage of isolates of enterobacteria than brand B, 64 strains (77%) and 19 strains (23%), respectively. For the identification of the strains, the physiological characterization and the mass spectrometry (MALDI-TOF MS) were used, obtaining a concordance of 70% between the two methods. Susceptibility to all antimicrobials tested in <i>E. coli</i> (90%, n = 18/20), <i>E. cloacae complex</i> (26%, n = 9/35) and <i>R. ornithinolytica</i> (4%; n = 1/25 ). No amplification was observed in the PCR for the genes blaTEM, blaSHV, blaOXA-1LIKE, bla CTX-M, bla VEB, bla PER and blaGES, qnrA, qnrB, qnrS, qepA, catA, cmlA, floR, sul1, sul2, intl1 and aac (3) -IV, aphA1. All strains of <i>E. coli</i> were from phylogenetic group A (n = 20; 100%), related to commensal strains. In conclusion, the present research contributed to the knowledge of the species of enterobacteria and the profile of susceptibility to the antimicrobials that can be served through the pasteurized milk commercialized in the city of Rio de Janeiro.