Typing of avian pathogenic Escherichia coli strains by REP-PCR

Author(s)

Marcelo Brocchi ^[1] ; Alessandra Ferreira ^[2] ; Marcelo Lancellotti ^[3] ; Eliana G. Stehling ^[4] ; Tatiana A. Campos ^[5] ; Gerson Nakazato ^[6] ; Antonio F. Pestana de Castro ^[7] ; Wanderley D. Silveira ^[8]

Affiliation

^[1] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

^[2] Universidade de São Paulo, Ribeirão Preto. Faculdade de Medicina de Ribeirão Preto. IIIDepto Biologia Celular, Molecular e Bio-Agentes Patogênicos

^[3] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

^[4] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

^[5] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

^[6] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

^[7] Universidade de São Paulo. Instituto de Ciências Biomédicas II. IIDepto Microbiologia - Brasil

^[8] Universidade Estadual de Campinas. Instituto de Biologia. Depto Microbiologia e Imunologia - Brasil

• Document type: Journal article
• Source: Pesquisa Veterinária Brasileira; v. 26, n. 2, p. 69-73, 2006-06-00.

Abstract

In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet. (AU)