Inactivation and Subsequent Growth Kinetics of Listeria monocytogenes After Various Mild Bactericidal Treatments

Abstract

This study was carried out to investigate the effects of mild heat, lactic acid, benzalkonium chloride and nisin treatments on the inactivation, sublethal injury, and subsequent growth of Listeria monocytogenes. Results showed that the Bigelow model successfully described the thermal inactivation kinetics, while the Log-linear model with tail consistently offered the most accurate fit to LA, BC, and nisin inactivation curves of cells. Differential plating indicated that percentage of sublethal injury for nisin treated cells was significantly higher than that for the other three treatments. Compared to non-treated cells, significant extension of lag time was observed for all treated cells. The longer exposures to heat treatment contributed to the extended lag time of the survivors. While for LA, BC and nisin treated cells, the longest lag time was not observed at the most severe treatment conditions. The correlation analysis of sublethal injury percentage on the duration of lag time revealed that only heat treatment showed the significant correlation. Overall, the lag time analysis could evaluate a wide range of bacterial injury. Lag time of treated cells was significantly influenced by stress treatments and temperatures of recovery, however, there were not any significant changes in the maximum specific growth rate between treated and non-treated cells under isothermal recovery conditions. The information generated from this study is valuable for utilizing intervention strategies in the elimination or growth inhibition of L. monocytogenes.

Pseudomonas fluorescens Cells’ Recovery after Exposure to BAC and DBNPA Biocides

“…Apart from the biocides’ mechanism of action, the overnight step conditions [ 39 , 40 ] (time, temperature, and nutritional medium) also played an important role on cells’ recovery time and extent. Taking this into account, the overnight step conditions used in this work were chosen to match the optimal growth conditions of normal P. fluorescens cells.…”

Ефективність Використання Про Біотичних Мікроорганізмів Bacillus Spp. Для Санітарних Обробок Поверхонь

“…Chinese scientists, who studied the growth of bacteria of the genus Listeria spp. in various treatments, claimed that only heat treatment damages the bacterial cell, the time and temperature of treatment significantly reduces the growth and development of microorganisms (Fang et al, 2021).…”

The Hormetic Effect Observed for Benzalkonium Chloride and Didecyldimethylammonium Chloride in Serratia sp. HRI

“…In terms of Quaternary Ammonium Compound (QAC) exposure at sub-MIC levels, current literature shows either no significant effect or an inhibitory effect on bacterial growth rate and cell density [ 9 , 10 ]. Recent studies found no significant difference in growth rates for Escherichia coli and Listeria monocytogenes respectively, after exposure to sub-MIC levels of benzalkonium chloride (BAC) when compared to unchallenged controls [ 9 , 11 ]. Whereas for S. marcescens , cell density decreased for both resistant and susceptible strains, even at the lowest concentration of BAC [ 12 ].…”