Verotoxigenic escherichia coli 0157 among chronic renal failure patients

ABSTRACT

Escherichia coli 0157 has become an enteric pathogen of increasing importance. In this initial survey, which is confined to uraemic patients, the frequency of isolation of verotoxin [shiga-like toxin] producing E. coli 0157 from stools of 160 uraemic patients was 3.1%. The frequency of isolation rises to 4. 5% among uraemic patients with a prodroma of diarrheal illness and rises to 50% [P < 0.05] when uraemic patients were accompanied by a prodrome of diarrhea and bleeding tendencies in a syndrome known as haemolytic uraemic syndrome [HUS]. E. coli 0157 was isolated from stools of 4 out of 8 [50%] cases of HUS, thus it is considered the most important cause of diarrhea associated HUS. E. coli 0157 was found to be an infrequent enteric pathogen among other pathogenic bacterial organisms causing diarrheal prodroma in uraemic patients lout of 22 [4.5%]. Campylobacter spp., on the other hand was the commonest pathogen isolated 7 out of 22 [31.8%]. Rapid screening for E. coli 0157 was done by culturing on selective sorbitol MacConkey agar and non sorbitol fermenting colonies were tested by latex agglutination with E. coli 0157 antiserum. Shiga-like toxin production of E. coli 0157 was then assayed by verocytotoxicity because it is the better marker of the pathogenic potential of a strain than serotyping. Variations among strains of E. coli 0157 as regards shiga-like toxin production yield were noticed, with the highest titre obtained from strains isolated from HUS patients. Old age, female predominance, fever, ingestion of anti motility and antimicrobial drugs especially trimethoprim-sulfamethoxazole were the commonest risk factors observed for patients who developed HUS after a prodroma of E. coli 0157 diarrhea. We concluded that, it is the responsibility of microbiologists to make physicians and pediatricians aware about the importance of this newly discovered enteric pathogen and its greatest complication HUS