tailieunhanh - Báo cáo khoa học: "Phenotyping of E. coli serotypes associated to oedema disea"

Tuyển tập các báo cáo nghiên cứu về bệnh học thý y được đăng trên tạp chí Acta Veterinaria Scandinavica cung cấp cho các bạn kiến thức về bệnh thú y đề tài: Phenotyping of E. coli serotypes associated to oedema disease. | Acta Veterinaria Scandinavica BioMed Central Research Phenotyping of E. coli serotypes associated to oedema disease Sigbrit Mattsson and Per Wallgren Open Access Address National Veterinary Institute SVA 751 89 Uppsala Sweden Email Sigbrit Mattsson - Per Wallgren - Corresponding author Published 2 June 2008 Received 28 December 2007 Acta Veterinaria Scandinavian 2008 50 13 doi 1751-0147-50-13 Accepted 2 June 2008 This article is available from http content 50 1 13 2008 Mattsson and Wallgren licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Oedema disease is a severe disease mainly affecting recently weaned pigs. It is caused by E. coli strains that express fimbriae F18 and produce verotoxin 2e mainly belonging to serotype O138 O139 or OI4I. The aim of this study was to compare E. coli isolates within these serotypes with respect to diversity. Methods Faecal E. coli strains belonging to serotypes O138 O139 and O141 isolated during the period 1994-1998 from Swedish pigs aged less than 12 weeks were compared using a biochemical fingerprinting system. Aiming to compare the results obtained over time also strains isolated during 1964-67 and 1975-80 were included in the study. The study comprised 129 263 and 95 isolates of E. coli serotype O138 O139 and O141 respectively. Results Biochemical phenotypes BPTs were defined. At each sampling occasion each herd could only contribute with one isolate per BPT. Consequently all but one of identical BPTs identified at a specific sampling occasion was omitted. The final number of isolates from 1994-98 that was compared included 64 182 and 41 isolates of serotypes O138 O139 and O141 respectively. .