Phylogenic typing of Escherichia coli isolated from broilers with collibacillosis in Tabriz, North West of Iran

In this study, to know about the phylogeny of escherichia coli isolated from broilers with collibacillosis intabriz, 70 e. coli isolates recovered from broilers with collibacillosis were characterized for phylogeneticgroup (a, b1, b2, d) by multiplex pcr. of the all 70 samples, 35 (50%) isolates were classified as type a,32 (45%) as type d, 2 (2.8%) as type b1 and 1 (2.8%) as type b2. this study demonstrates the highprevalence of e. coli types a and d in infected broilers. this shows that the collibacilosis-causing e. colibacteria are typical commensals, type a alongside pathogenic type, d in iran. it is possible that this type ofe. coli could acquire virulence genes from pathogenic types. of course, such a claim needs further study.