Abstract

ISOLATION AND IDENTIFICATION OF ESCHERICHIA COLI O157:H7, O26:H11 AND O111:H8 USING CULTURE AND SEROLOGICAL TECHNIQUE IN KHARTOUM STATE SUDAN – 2019

Rolla Abdalkader Ahmed* and Hassan Abd Alaziz Musa

Abstract

Most E.coli are considered as commensal of the human and animals intestine and are harmless. Some serotypes are pathogenic. One of the most important pathogenic serotype is E. coli O157:H7 which cause Enterohaemorrhagic diarrhea. The non-O157 strains were found to cause similar illnesses, mostly by Enterohaemorrhagic Escherichia coli (EHEC) O26:H11 and O111:H8 This study was conducted to look for the presence of E. coli O157:H7 and related serotypes E. coli O26:H11 and E. coli O111:H8 in Sudanese patients having diarrhea using MacConkey agar (MAC) and Sorbitol-MacConkey agar (S-MAC) and serology at hospitals in Khartoum State, Sudan. A total number of 100 patients having diarrhea were included in this study. Identification of the organism was done using culture of the stool specimens on (MAC) and (S-MAC) followed by biochemical tests and serological identification. The result of culture showed that 89 isolates were identified as E.coli on MAC. 29 were identified as non sorbitol fermenter E.coli and 60 were identified as sorbitol fermenter E.coli on S-MAC. The serological tests showed that 25 out of 29 non sorbitol fermenter were E.coli O157 H7 while 53 out of the 60 sorbitol fermenter were identified as E.coli O26 H11 and the remaining 7 were E.coli O111 H8. As conclusion the commonest serotype identified in Sudan was E.coliO26:H11 (53 isolates) followed by E.coli O157 H7(25 isolates).

Keywords: Enterohaemorrhagic Escherichia coli (EHEC), sorbitol, serotypes.