Frequency of iucD, tsh, and iss genes among Escherichia coli isolates in broilers infected with colibacillosis

Escherichia coli (E. coli) is component of normal flora of the human intestine, mammals and birds, however, some strains of E. coli due to have virulence factors, are pathogenic. The aim of current study was to determine the frequency of iucD, tsh, and iss genes in broiler flocks infected with colibacillosis in east Azarbaijan-Iran. One Hundred and seventeen E. coli isolates from colibacillosis infected broilers with pericarditis, perihepatitis, and air sacculitis investigated. First, standard screening tests and culture was done, and then standard primers and PCR was used for genotype evaluation of isolates in regard of iucD, tsh, and iss genes. In 29 samples (24.78%) all genes (iucD, iss, and tsh) was positive, and 29 (24.78%), 39 (33.33%), and 44 (37.60%) of samples was positive in regard of dual combinations of genes tsh/iss, tsh/iucD, and iss/iucD, respectively. In addition, 34.18%, 37.60%, and 91.45% of isolates possess tsh, iss, and iucD, respectively. Our results indicated which higher percent of evaluated isolates have the ability to produce aerobactin, and the various combination of genes seen in 24.785 to 37.60% of isolates. It seems more investigation needed to evaluation of virulence factors of east Azarbaijan broilers.