Achromobacter spp na Fibrose Cística: Identificação das espécies, susceptibilidade a antimicrobianos e atributos de virulência

• Autor(a) principal: Pereira, Rosana Helena Vicente
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14372
• topic: Cystic Fibrosis; Identification; Resistance; Virulence; Fibrose cística; Identificação; Resistência; Virulência; Fibrose cística; Fibrose cística Fisiopatologia; Achromobacter Classificação; Achromobacter denitrificans Patogenicidade; Achromobacter denitrificans Virologia; Resistência Beta Lactâmica Efeito de drogas; Pneumopatias Etiologia; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA

The genus Achromobacter, especially A. xylosoxidans, has emerged as an important lung pathogen related to Cystic Fibrosis (CF). Species identification is hampered by phenotypic and genotypic similarity between them, which may underestimate the actual frequency and significance of different species. Factors related to virulence and antimicrobial resistance are poorly understood. The aims of this study were to compare different methodologies for identifying species of Achromobacter spp; analyze the antimicrobial resistance profiles, and study virulence attributes (types of motility and biofilm formation) in isolates from CF patients treated at two centers of reference of Rio de Janeiro. A total of 129 Achromobacter spp isolates obtained from 38 patients were analyzed. The isolates were identified by phenotypic testing, by sequencing the gene rrs and PCR for gene blaOXA-114-like intrinsic to A. xylosoxidans. The clonal relatedness was assessed by Pulsed Field Gel Electrophoresis (PFGE). Phenotypic tests and sequencing identified 93.8 % (n=122) of the isolates as A. xylosoxidans, one as A. denitrificans. and seven were identified only at genus. The 122 isolates were positive for blaOXA -114-like gene. The PFGE showed 22 clonal groups. 63 isolates representative of each clonal group per patient were selected for identification by restriction analysis of amplified ribosomal DNA (ARDRA). All samples were identified: 56 (88.9 %) A. xylosoxidans, one (1.5%) A.denitrificans three A. insolitus (4.8%) and three (4.8%) A. piechaudii. The majority (n = 101) of 122 isolates of A. xylosoxidans was strong biofilm (BF) producers and showed motility of swimming type (n=118, 96.7%) and swarming (n=99, 81%). All positive isolates for swarming were also positive for swimming. There was significance between the production of BF and the types of motility, suggesting that they may favor the production of BF. Non xylosoxidans Achromobacter were mostly BF producers, with concurrence of the types of motility. Of the 122 samples of A. xylosoxidans submitted to MIC by E-test®, most were sensitive to ceftazidime, imipenem, ciprofloxacin (CIP) and trimethoprim/sulfamethoxazole (SUT), however, 46 % of the samples were not sensitive to CIP. The seven non xylosoxidans Achromobacter isolates were not susceptible to the antibiotics tested. The 129 Achromobacter spp isolates were negative for blaSPM-1, blaVIM-2 and blaKPC-2 genes. The distribution of resistance markers between the clonal groups of A. xylosoxidans isolated from patients with chronic colonization, showed that resistance to CIP and SUT were most frequent markers among clonal groups. Regardless of the molecular technique employed A. xylosoxidans was the predominant species. However, the role of emerging species cannot be excluded from this scenario, since all showed similar virulence profile of the predominant species.