Molecular Identification and Prevalence of Bacterial Isolates from Vegetables Salad Purchased from Fast Food Centres in Two Local Government Areas in Port Harcourt Metropolis, Rivers State, Nigeria

Introduction: The importance of daily consumption of fresh fruits and vegetables in our diet cannot be over emphasised. The desire to eat a balanced diet rich in vegetables have driven some people to rely already prepared vegetables salad from fast food centres to meet the need.

Aim: The aim of this study was to identify bacteria associated with vegetables salad in Port Harcourt metropolis and determine susceptibility of isolated bacteria from food centres located in the Local Government Areas.

Study Design: A total of 200 samples of already prepared vegetables salad were examined which comprises of four samples from each of five different fast food centres in each of the 10 communities in Port Harcourt metropolis.

Methodology: 10 g of vegetables salad was weighed and added to 90 ml of sterile distilled water and subsequent serial dilution was made by adding 1 ml to 9 ml of diluents up to 10-3. An aliquot of 0.1ml of last dilution was plated by spread plate technique MacConkey agar, Tryptone soy agar, Salmonella Shigella agar and mannitol soy agar in duplicate. The inoculated plates were incubated at 37°C for 18-24 hrs and examined for growth. Antibiogram of the isolates were carried out using Mueller Hinton agar. The isolates were subjected to molecular analysis for identification before susceptibility testing.

Results: The bacteria isolated from the vegetables salad were Staphylococcus aureus 114(38%), E. coli 93(31%), B. cereus 30(10%), Pseudomonas sp. 26(9%), Klebsiella sp. 12 (4%), Alcaligenes sp. 7(2%), Acinetobacter 5(2%), Lysinnibacilus 6(2%), Enterobacter sp. 4(1%) and Providencia sp. 2(1%). The resistance genes detected in the isolates were CTX-M, SHV and VanB.

Conclusion: The microbiological quality and safety of ready to eat salad sold in Port Harcourt seems to be a challenge despite the advances in technology and awareness that has been created.