Colibacillosis is one of the most common infectious bacterial disease of poultry. A total of 170 Escherichia coli isolates obtained from broiler and layer flocks implicated with colibacillosis between 2011-2014 were subjected to phylogenetic analysis. From 150 E. coli wehich were isolated from typical lesions of local and systemic colibacillosis, 54 (31.8%), 37 (21.7%), 36 (21.2%) and 43 (25.3%) isolates determined as belonged to groups A, B1, B2 and D, respectively. The distribution of phylogenetic types for 20 isolates, obtained from apparently healthy birds as controls, were 9 (45%), 5 (25%), 1 (5%) and 5 (25%) for A, B1, B2 and D, respectively. Overall, the phylogenetic Determination revealed the B2 groups as predominant isolates in diseased birds , whereas the A group was apparently predominant in healthy birds. Results of this study represent genotypic diversity among different manifestations of avian colibacillosis.

Keywords