Collibacillosis is considered one of the major diseases of the modern poultry industry, due to the significant losses it causes. Escherichia coli contributes not only to the disease itself, by causing weight loss of the birds, but also to the increase in carcasses condemnation during slaughter and processing. Detection of virulence factors in E. coli strains of the APEC pathotype contributes to the characterization and pathogenicity of this agent. PCR techniques have been very helpful in the search for genes that encode those virulence factors. This study aimed to detect the gene Fel A of E. coli by PCR and relate its positivity to low weight in broiler flocks with airsacculitis as diagnosed by the health inspection service. The study involved 40 flocks of broilers slaughtered in a single poultry slaughterhouse, under Federal Sanitary Inspection, located in the state of Rio Grande do Sul, Brazil. Three broilers were randomly selected to obtain one "pool" of three tracheas for each PCR. DNA was extracted using phenol-chloroform and amplified using a pair of primers specific to gene Fel A of E. coli. Of the 40 flocks analyzed by PCR, 35% (14/40) were positive for the gene Fel A. PCR was an effective technique for the detection of gene Fel A in broiler flocks. There was a relationship between the presence of the gene Fel A, weight loss, and increase of the airsacculitis rate.
Avian; collibacillosis; virulence factors; fimbriae F11; chronic respiratory disease