Isolation and Identification of Escherichia coli O157:H7 from Raw Salad Vegetables Sold in Sokoto Metropolis, Nigeria

The presence of Escherichia coli O157:H7 in fresh salad vegetables was evaluated in this study.  One hundred and fifty (150) Salad vegetable samples (lettuce, cabbage and spring onion) were aseptically  collected from two different markets (Ramin Kura and Meat and vegetables market) in Sokoto metropolis.  Isolates from the samples were fully characterized by using standard methods. Antimicrobial susceptibility  patterns of seven (7) E. coli O157H7 isolates were investigated using 8 commonly used antibiotic, showed  level of antimicrobial resistance. Out of the 19 E. coli identified only 7 were E. coli O157:H7. The  occurrence of E. coli O157:H7 in lettuce, cabbage and spring onion were 2 (1.33%), 3(2.00%) and  2(1.33%) respectively. The highest occurrence rate observed from this study was in cabbage 3(2.00%).  Samples obtained from Meat and vegetables market have more occurrence of E. coli O157:H7 than  samples obtained from the Ramin kura market. Oflaxacin 40(mm), ciprofloxacin 33 (mm) and  nitrofurantoin 32 (mm) showed high antibacterial activity while Augmentin did not show any activity.  Presence of Escherichia coli O157:H7 in salad vegetables serve as potential risk of infection to the  consumers.