One of the most important problems in young calves, Neonatal calf diarrhea or what is called undifferentiated diarrhea beside calf pneumonia are considered the most dangerous life threatening, economic problems of the young growing calves. In the current study, a total number of 160 fecal samples collected from cattle and buffalo calves under one month old
were examined bacteriologically for isolation of E. coli. All 44 (27.5%) E. coli isolates recovered from fecal samples collected from diarrheic calves were confirmed by PCR targeting 16SrRNA gene. All E. coli isolates were typed by serogrouping into O146 (50%), O1 & O119 (13.5%), O78 (9.25%) and O26 & O127 (6.8%). Epidemiology of E. coli was studied where; a higher prevalence rate was recorded in cattle calves (32.46 %) than buffalo calves (22.89%). A higher prevalence was found in female calves (34.6%) than male calves (21.1%). In different seasons, the higher incidence was in summer (38.7%) followed by winter (31.5%), spring (22.5%) and autumn (21.5%). The antibiotic susceptibility was also evaluated, where the isolates exhibited a high resistance to Enrofloxacin (91%), in the same time the isolates were sensitive to Sulphmethoxazole Trimethoprim (54.5%), followed by amoxicillin / Calvulanic acid (29.5%)