Acinetobacter spp. em indivíduos com fibrose cística: identificação das espécies, resistência a antimicrobianos e relação clonal

• Autor(a) principal: Rocha, Géssica de Araújo
• Data de Publicação: 2013
• 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/1/14392
• topic: Cystic fibrosis; Acinetobacter spp; Resistance; Profile clonal; Bacterial identification; Fibrose cística; Acinetobacter spp; Resistência; Perfil clonal; Identificação bacteriana; Fibrose cística; Acinetobacter spp; Resistência microbiana a medicamentos; Bactérias; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA

The genus Acinetobacter, particularly the species A. baumannii, has emerged as a global public health problem, able to persist in the environment for a long time and presenting multidrug resistance to a wide range of antimicrobial. Interestingly this genus is unusual in Cystic Fibrosis (CF). One hypothesis raised by us is that the low frequency could be related, in part, with the colonization by other species of the genus, which are difficult to characterize laboratory and may be misidentified. Considering this, and the lack of wide ranging studies about the role of this microorganism in CF patients, this study aimed to identify the species of the genus Acinetobacter, to investigate the presence of resistance genes, determine the profile antimicrobial susceptibility and clonal relationship among samples obtained from CF patients treated at two centers of reference in Rio de Janeiro. Thirty-eight isolates of Acinetobacter spp. Isolated from 29 CF patients from June 2005 to March 2010, were identified by phenotypic methods and for four different molecular techniques. The profile of susceptibility to 11 antimicrobials used in clinical practice was performed by agar diffusion. Minimum Inhibitory Concentrations for tobramycin and polymyxin were determined by microdilution methods and diffusion gradient (E-test). The research β-lactamase resistance genes were performed by PCR and species genotyping was performed by PFGE. In this study, Acinetobacter spp. was more frequent in pediatric patients, with a high percentage of species A. not baumannii isolates. Of the different molecular techniques used to identification, the partial sequencing of the rpoB gene proved to be the most accurate method. Diverging from what is observed in the hospital samples, samples of CF patients in this study, including strains of A. Baumannii, showed high percentages of susceptibility to most antimicrobials, having only two multidrug resistance samples, both carry the gene blaOXA-23-like. Genes encoding CTX-M-15 and SHV-121 were first detected in A. baumannii and A. pitti isolated of patient with CF, all were resistant to cefepime or cefotaxime. There was clonal wide diversity among the samples. However, two clones of A. pittii, carrying blaCTX-M-15 and blaSHV-121, were shared by different patients in the same period. These results point to an epidemiological characteristic of this group of patients treated in reference centers included in the study, distinct from other hospitalized patients in the same centers. Alerting us to the clinical importance of the species A. not baumannii and its potential as a source of resistance genes silent transmission.