Efficacy of oxidative disinfectants, quaternary ammonium compounds and dry heat on the inactivation of Salmonella Enteritidis in different cellular states

The investigation of disinfection methods with different antimicrobial mechanisms is of utmost importance in determining inactivation kinetics pertaining to various cellular states of Salmonella. The present study evaluated the effectiveness of different conventional and novel disinfectants against the inactivation of suspended and desiccated Salmonella enterica Enteritidis FUA1946. A comparative study was conducted to evaluate the efficacy of various disinfection methods, including dry heat, membrane-acting benzalkonium chloride (BAC), conventional oxidizing agents such as peracetic acid (PAA) and hydrogen peroxide (H₂O₂) in the inactivation of S. Enteritidis. Further, the efficacy of novel oxidizers such as plasma-activated water bubbles (PAWB) and plasma-activated hydrogen peroxide water bubbles (PAHP-WB) was evaluated against the suspended and desiccated S. Enteritidis. The results showed that the disinfectant concentration, treatment temperature, and treatment time significantly affected the susceptibility of the S. Enteritidis to disinfection methods. Compared to the surface-dried cells, the S. Enteritidis suspensions displayed a higher lethality to the tested disinfectants. The results revealed a greater resistance of the air-dried and equilibrated S. Enteritidis on the stainless steel to dry heat, BAC, H₂O₂, and PAWB. The PAA treatment 40 °C displayed high efficacy against the S. Enteritidis on the stainless steel. This emphasizes the need to incorporate effective disinfection programmes to prevent the spread of S. Enteritidis in dry processing environments. Moreover, conducting a comparative analysis of the diverse cellular states of bacteria is crucial in the context of disinfection of the low-a_w food processing industry.