Phenotypic and genotypic detection of aerobactin system among Escherichia coli isolates from cases of poultry colibacillosis

The purposes of this study were to detect the frequency of aerobactin production and the presence of iucD gene, which is involved in biosynthesis of aerobactin system, among Escherichia coli isolates from cases of avian colibacillosis. Fifty E. coli isolates recovered from pericarditis lesions of poultry colibacillosis were collected from broiler farms in provinces of Tehran, Alborz, and Ghazvin and were tested for their ability to produce aerobactin and the presence of iucD gene. Phenotypic determination was performed according to the method described previously. The isolates were examined by PCR for the presence of iucD gene. Out of 50 E. coli isolates, 43 (86%) had ability to produce aerobactin. PCR showed that out of 50 E. coli isolates, 48 (96%) possessed aerobactin encoding gene (iucD). However, the iucD gene was not detected in two isolates that were negative in phenotypic examination. The findings of the present study showed that high percentages of avian pathogenic E. coli isolates are able to produce aerobactin. Considering similar studies completed by other researchers, especially the comparative studies with E. coli isolates from apparently healthy animals, a strong association between the aerobactin production and virulence of poultry E. coli isolates is emphasized.