What went wrong?

Approximately a quarter of the population naturally carries the Staphylococcus aureus as normal and nose flora. In this food safety breach scenario, the bacteria most likely entered the food facility through direct contact with workers who had respiratory illnesses and poor personal hygiene practices, such as inadequate hand washing and not using gloves or masks. The unsanitary conditions during the initial processing of raw materials may have facilitated the entry of the bacteria into the facility.

The incoming raw materials were initially checked for the presence of microbial indicators and considered safe. During processing, the bacteria would have adhered to the equipment due to lack of personal hygiene of workers. If the equipment was not adequately disinfected at the end of the day, biofilms could have formed, allowing the bacteria to persist in the production facility. Since the processing procedures and equipment storage typically occur at room temperature, which is favourable for bacterial growth, the microorganism would have continued to multiply.

However, after the initial processing with contaminated equipment, the excess raw materials might not have been stored at the correct temperatures post the trimming step. They were left at room temperature for a significant duration of time, providing a nutrient-rich environment for the bacteria to proliferate due to the absence of competing organisms and temperature abuse. As a result, the bacteria produced toxins during this extended period before reaching the flash frying stage.

Although the chicken nuggets were subjected to flash frying at a high temperature of 180°C for 3-4 minutes, which should have killed all the bacteria, the heat-stable toxin remained in the food. Furthermore, the toxin remained stable even during frozen conditions, leading to food intoxication in customers when consumed.