Antibiotic Resistance Profile in Relation to Phylogenetic Background in Escherichia coli Isolated From Fecal Samples of Healthy Ostrich

E. coli is regarded as a reservoir for antibiotic resistance in foods of animal origin. E. coli can be categories into four main phylogenetic groups (A, B1, B2 and D). The commensal E. coli strains mostly are assigned to the phylo-groups A and B1.. The purposes of this study were to determine the phylogenetic group/subgroups and antibiotic resistance patterns of ostrich E. coli isolates in Iran.. A total of 126 E. coli isolates were obtained from cloacae swabs of the healthy ostrich in Kerman, Iran. The E. coli isolates were confirmed using biochemical API 20E identification system. The confirmed isolates were studied to determine phylogenetic background by PCR. The isolates were tested for antibiotic resistance against 12 different antibiotic disk by disk diffusion method.. Phylotyping of E. coli isolates indicated that 74 isolates belonged to A, 27 isolates to B1, 7 isolates to B2, and 18 isolates to D groups. Also the isolates fell into six phylogenetic subgroups, including 34 isolates in A0, 40 isolates in A1, one isolate in B22, 6 isolates in B23, 11 isolates in D1 and 7 isolates in subgroup D2. In the examined E. coli isolates, the maximum rate of resistance was against tetracycline, and the minimum rate of resistance was against amoxicillin. Twenty three antibiotic resistance patterns were detected among the isolates. The cefoxitin and tetracycline resistance pattern was the most prevalent in the isolates that belonged to phylo-group A.. In conclusion, the result of the present study revealed a low frequency of antibiotic resistance in ostrich E. coli isolates. The antibiotic resistance patterns were in relation to A and D phylogenetic groups. Further studies are needed to better understand the distribution of phylogenetic groups in poultry isolates..