Comparação de métodos convencionais e semi-automatizados para identificação de Enterococcus spp.frente à biologia molecular em identificações discrepantes

• Autor(a) principal: Donato, Silvia Tavares
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/1764
• topic: Strepto-Enterococcus; Reação em Cadeia da Polimerase; Enterococcus

The Enterococcus are Gram-positive cocci catalase negative - which inhabit the gastrointestinal, and genitourinary tract. They are identified manually and the procedure is based on the classic of Facklam, by semi-authomatized and automatized systems as well as by Molecular Biology. Due to the diversity of identification methods and aiming to verify the concordance among some methods, it was accomplished the identification of 62 bacteria strains proceeding from the collection of the Centro Especializado em Micologia Médica (CEMM) of the Federal University of Ceará, in Brazil. They were presumably identified as Enterococcus sp. e Enterococcus faecalis by the Facklam scheme. This study was begun with the identification for two manual methods, modified from the Facklam scheme – Modified 1 and Modified 2- and semi-automatized – API 20 Strep. For the inconsistent results definition we used the semi-automatized – BBL and the Molecular Biology- PRC. The Franklin scheme identified 16% (10) as strains of the genre Enterococcus sp. and 52% (84) as E. faecalis. The Modified Scheme 1 presented the following identification: 82, 2% (51) E. faecalis, 9, 7% (6) E. mundtii and 8, 1% (5) E. gallinarum. The Modified 2 identified 98, 4% (61) E. faecalis and 1, 6% (1) E. gallinarum. The API 20 Strep identified 51,6% (32) E. faecalis, 19,4% (12) A viridans, 13,0% (8) E. avium, 4,8% (3) S. agalactiae, 3,2% (2) E. faecium, 1,6% (1) S. acidominimus, 1,6% (1) Leuconoctocc sp., 1,6% (1) S. uberis, 1,6% (1) A. adiacens and1,6% (1) unacceptable. It was made the selection of 10 sample (strains), among them, the ones numbered (05, 13, 15, 20, 27, 31, 32, 33, 50 and 60), which presented discordant results among the systems Modified 1, Modified 2 and API 20 Strep to be identified by BBL Crystal and by PCR. The BBL identified 6 samples as E. faecium, including the control- strain E. faecalis ATCC 29212 and did not identify 4 samples. In the PCR, one sample did not amplify and 9 were identified as Streptococcus spp. One sample was identified as positive for the genre Enterococcus, but it did not for the species E. faecalis and 1 (one) was amplified for the species S. agalactiae. None of the samples presented were positive for the species E. gallinarum. The control-sample – E. faecalis ATCC 29212 – was correctly amplified. With the analysis of the results, it was noticed that there was identification concordance of the 62 strains in 84% of the samples among the manual systems (Facklam, Modified 1 and Modified 2) and in 52% of the samples among the manual and semi-automatized systems (API 20 Strep). In 10 samples with disagreeing results there was no identification concordance among the manual systems, API 20 Strep and the BBL. A PCR agreed with the manual systems and the BBL and did not agree with the API 20 step, in genre, in one sample. Correlating the PCR with the API 20 Strep, there was agreement, in genre, in 01 sample and disagreement with the other systems.