ATYPICAL ESCHERICHIA-COLI STRAINS AND THEIR ASSOCIATION WITH POULT ENTERITIS AND MORTALITY SYNDROME

To date, no definitive etiology has been described for Poult Enteritis and Mortality Syndrome (PEMS). However, two atypical Escherichia coli colony types are isolated consistently from moribund and dead poults afflicted with PEMS. To test the infectivity of these E. coli strains, poults were placed into floor pens in three isolation treatment rooms : 1) Control: no bacterial challenge, 2) E. coli colony Types 1 or 2 p osthatch oral challenge: 10(8) cfu/per poult at 1 d, and 3) E. coli co lony Types 1 or 2 posthatch oral challenge: 10(8) cfu/per poult at 6 d . Daily intramuscular injections of cyclophosphamide (100 mu g per pou lt) from 1 to 5 d posthatch were given to half of the poults in each t reatment. Atypical E. coli challenge caused BW depression, and cycloph osphamide treatment exacerbated the response. All E. coli-challenged p oults developed diarrhea similar to PEMS. Mortality was increased by b oth atypical E. coli colony types, but at 21 d E. coli colony Type 2 c aused greater mortality than colony Type 1. With cyclophosphamide trea tment, mortality was exacerbated with both colony types, but colony Ty pe 2 at 1 d caused the greatest mortality. Ultrastructural damage to i leum epithelium cell microvilli and subcellular organelles indicated t hat part of the BW depression could be attributed to malabsorption of nutrients. It was concluded that the atypical E. coli colony Types 1 a nd 2 play a significant role in the PEMS disease.