Prevalence and characterization of verotocytoxin producing Escherichia coli O157 from diarrhoea patients in Morogoro, Tanzania.

Escherichia coli O157:H7 is an important agent of haemorrhagic colitis and haemolytic uraemic syndrome in children less than five years old and elderly people. The objective of this study was to investigate the prevalence of verotocytoxin producing E. coli 0157 (VTEC O157) among human patients with diarrhoea in Morogoro, Tanzania. Faecal samples originating from 275 human patients with diarrhoea were screened for presence of E. coli O157:H7. A total of 96 E. coli isolate were identified. Of these, 10 isolates were grouped into sorbitol non-fermenting and glucuronide negative and 49 isolates were sorbitol positive and glucuronide positive. The remaining 37 were sorbitol negative and glucuronide positive. Using the polymerase chain reaction techniques, a total often verotocytocin producing E. coli isolated in this study were used. The overall two (15%) and one (7%) of the isolated of E. coli possessed both attaching and effacing (eae A) and enterohemolysin (ehly) A genes respectively. Other enterobacterial agents including Pseudomonas spp, Proteus spp and coliforms were also isolated. The VTEC O157 isolates were 100% resistant to oxytetracycline, chloramphenicol, streptomycin, and amoxyclav. In conclusion, the isolation of diarrhoeaogenic E. coli O157:H7 in this region suggests that the pathogen is an important aetiology of acute gastroenteritis in Tanzania. There is therefore, need to improve sewage and refuse disposal system, the provision of safe potable water, sanitation, personal hygiene and health education in order to reduce infection with this and other enteric pathogens.