Occurrence of Virulent and Antibiotic Resistant Staphylococcus aureus in Selected Ready-To-Eat Foods in Obio/Akpor, Rivers State, Nigeria

Abstract

Aims: Ready-to-eat (RTE) foods contaminated with Staphylococcus aureus or its heat-stable toxins have been implicated in food-borne illnesses lately and are now a public health concern. This study is aimed at determining the microbial safety of RTE snacks (meat-pie, Egg-roll, Doughnut, Burns and Puff-puff) sold in Obio/Akpor LGA, Rivers State. Study Design:  This work is based on a completely randomized design with two replications and the average values calculated for the mean comparison. Place and Duration of Study: Imadavistic Laboratory, Osaks House, East-West Road Port Harcourt, Nigeria, between December 2021 and November, 2022. Methodology: A total of 100 samples of RTE food Snacks were randomly purchased and examined for proximate composition, microbial quality, and occurrence of antibiotic-resistant and virulent genes using standard conventional and molecular methods. Results: Puff-puff had the highest moisture, fiber and ash content while egg-roll had the highest crude fat, also meat-pie had the highest carbohydrate and protein content. Microbial counts ranged from 3.5×103 to 1.5×106cfu/g with 44 samples unsatisfactory and 39 at borderline by food regulatory standard. Presumptive S. aureus count ranged from 1.4×103 to 4.6×106 cfu/g, with 5 classified as potentially hazardous, 14 as unsatisfactory and 49 as borderline, 16 as satisfactory, and 16 with no detection. The 34 confirmed S. aureus showed varying resistance to cloxacillin 31(91.18%), cefuroxime 28 (82.35%), ceftazidime and erythromycin 25 (73.53%), gentamicin 18 (52.94%) and augmentin 13 (38.24%). Multi-drug resistance ranged from 3 to 5 antibiotic classes. Nine isolates produced the expected band of 250bp with SEA while 3 produced the band of 400bp with SEB. Conclusion: There is a correlation of statistically significant difference (p<0.5) between the four types of RTE food and enterotoxin A, therefore confirming that RTE foods serve as a reservoir of antibiotic resistant and virulence gene bearing S. aureus.