Enterohaemorrhagic Escherichia coli (E.coli O157): A Case Report from Nepal

E.coli O157 is one of the important causes of bloody diarrhea which can be self-limiting or may complicate into Haemolytic Ureaemic Syndrome (HUS). We are reporting a case of Enterohaemorrhagic Escherichia coli (E.coli O157) in a thirty year old male who presented to the surgical OPD of Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal with the complaint of bloody diarrhea and abdominal pain along with the history of consumption of food in local restaurant. Stool sample of the patient was processed to find out the cause of bloody diarrhea. Microscopic examination of the stool sample revealed plenty of red blood cells but no pus cells. Stool culture on MacConkey agar revealed lactose fermenting (pink) colonies whereas on sorbitol MacConkey agar, sorbitol fermenting (pink) and non-sorbitol fermenting (pale) colonies were isolated. Both the sorbitol fermenting and non-fermenting isolates were identified as Escherichia coli on the basis of biochemical tests. The non-sorbitol fermenting colonies which were identified as Escherichia coli were serotyped which were positive on polyvalent antisera 3 and monovalent antisera O157. Therefore, on the basis of biochemical reaction and serotyping, Escherichia coli O157 (Enterohaemorrhagic E. coli) was identified as the cause of the bloody diarrhea. The patient was managed symptomatically without any antibiotics and got improved in few days without any complication.