Aim: The purpose of this study was to investigate the presence of Escherichia coli (E. coli) O157:H7 strain in cloacal swab samples of clinically healthy commercial layers.

Materials and Methods: A total of 200 cloacal swab samples were collected from laying hens at 10 different layer flocks in Konya province. All samples were examined by bacteriological culture method. Verotoxin productions of isolates were detected by lateral flow assay kit.

Results: A total of 19 sorbitol negative E. coli strains were isolated from 19 (9.5%) of 200 cloacal swap samples. Three (1.5%) of the isolates were identified as E. coli O157 and one (0.5%) of them was found E. coli O157:H7 positive. The production of verotoxin 1 and 2 was detected in E. coli O157:H7 isolate.

Conclusion: It may be stated that the occurrence of E. coli O157 and E. coli O157:H7 in cloacal swap samples of layers may be important in veterinary and human public health.