Desenvolvimento de tecnicas moleculares para o diagnostico diferencial do virus da bronquite infecciosa e do pneumovirus aviario

by Freitas D'Arce, Regina Celia

Abstract (Summary)
The aim of this study was the development of molecu1ar techniques able to differentiate Infectious Bronchitis Virus (IBV), responsible for high 'contagious acute respiratory and renal infections in chickens, and Avian Pneumovirus (APV), causal agent of Turkey Rhinotracheitis and associated to Swollen head Syndrome (SHS) in chickens. APV and IBV strains, representatives of subtypes A and B and serotype Massachussets, were multiplied in Chicken Embryo Related (CER) cell line and embrionated eggs, respectively. The techniques of RNA extraction, RT -PCR, APV subtype-specific nested-PCR and RT -PCR-RFLP for IBV diagnosis were adapted, and then tested in experimentally infected chickens. Both viruses were detected by RT -PCR and/or nested-PCR in the groups infected with the agents separately or in co-infection, mainly at 3rd end 6th day post infection. Moreover, these techniques were utilised in clinical field samples from chicken and turkey flocks with respiratory problems and positive APV and IBV serology. Eight APV were detected, all of them classified as subtype A, where four samples were isolated. In the case of IBV, three field samples were detected, originating two viral isolation, all different from vaccine serotype by RFLP. The PCR products were sequenced, confirming the APV nested-PCR and IBV RFLP classification. IBV sequence analysis showed that the Brazilian field samples detected in this study are distinct from all serotype described 50 far. These optimised techniques could be useful to direct differentiation of APV subtypes A and B, and IBV field and vaccine strains, proving to be a valuable molecular epidemiological tool
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Clarice Weis Arns; Clarice Weis Arns [Orientador]; Maria Silvia Viccari Gatti; Paulo Michel Roeche; Jose Antonio Jerez; Alda Maria Backx Noronha Madeira; João Pessoa Araujo; Marcelo Brocchi

School:Universidade Estadual de Campinas

School Location:Brazil

Source Type:Master's Thesis



Date of Publication:12/13/2004

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