Freezing stress and meat juice model alter the biofilm formation ability, gene expression, and disinfectant resistance in Salmonella serotypes

Abstract

Salmonella, with its ability to survive under various environmental stress conditions, can pose a potential threat to public health, food safety, and environmental contamination by increasing its capacity to form biofilms and resist antimicrobial agents. This study aimed to investigate the effects of different meat juice models (cattle, sheep and goat meat juice) and freezing time (0–30 days) on the biofilm formation ability, AdrA and BapA genes expression, and disinfectant resistance in Salmonella serotypes. Biofilm formation ability was measured by colony counting method, the gene expression level was evaluated using real-time quantitative polymerase chain reaction (qPCR), and resistance to acetic acid (AA) and benzalkonium chloride (BAC) was measured by determining the minimum inhibitory concentration (MIC). The most significant increase in biofilm formation ability was observed in Salmonella Typhimurium (S. Typhimurium) in goat meat juice model. Salmonella Enteritidis (S. Enteritidis) in the cattle meat juice model exhibited a 12-fold increase in AdrA gene expression. Up-regulation of AdrA expression (up to 11-fold) was also determined in S. Typhimurium in goat meat juice model. Meanwhile, BapA gene was up-regulated up to 4.5-fold in S. Typhimurium in cattle meat juice. However, goat meat juice had no significant effect on the expression of BapA gene in Salmonella. The frozen sheep meat juice significantly increased the resistance of Salmonella to AA and BAC. The results indicated that Salmonella serotypes respond significantly to the freezing period and type of meat juice, which can be useful in controlling and eliminating Salmonella in the food industry.