# From Dormancy to Eradication: Strategies for Controlling Bacterial Persisters in Food Settings
## 6 Implications of Persister Cells in the Food Industry
These bacteria can persist in foods such as frozen meat (for more than a year), milk (up to 4 months), or canned foods, being able to produce toxins in environments until 15% of NaCl [46]. Studies have shown that _S. aureus_ persister cells can emerge stochastically during the stationary phase, primarily triggered via ATP depletion [54; 55]. This contrasts with _E. coli_ and _L. monocytogenes_, for which persister formation is closely linked to toxin-antitoxin modules and the stringent response. Moreover, _Salmonella_ spp. and _Campylobacter jejuni_ are notable for their persistence in dry food-processing environments, meat and poultry products, both fresh and frozen (up to 1 year for _Salmonella_ and 60 days for _Campylobacter_), vegetables and fruits, dairy products (20 days to 1 year for _Salmonella_ and 22 days to 8 months for _Campylobacter_, depending on the dairy product) [46]. Recent studies indicate that _C. jejuni_ forms persister cells when exposed to antibiotics such as ciprofloxacin and penicillin G [56; 57]. However, research on _C. jejuni_ persisters remains limited. Table 2 compiles information on foodborne bacteria and persister cells' formation (whenever detailed information could be retrieved from previous publications). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Microorganism** & **Production Inducers** & \begin{tabular}{c} **Persister Cells** \\ **Development Mechanism** \\ \end{tabular}  & **Food Type** & **References** \\ \hline \multirow{4}{*}{_L. monocytogenes_} & Environmental triggers & \multirow{4}{*}{ \begin{tabular}{c} Food-processing environment, \\ meat, dairy (milk, soft cheese, \\ and butter), leafy greens \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} **References** \\ **(**vegetables and fruits),** \\ **seedaof** \\ \end{tabular}  } \\  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \hline \multirow{4}{*}{_B. cereus_} & \multirow{4}{*}{Heat and desiccation} & \multirow{4}{*}{\ \begin{tabular}{c} Spore formation and \\ biofilms \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} Cooked foods, rice, canned \\ products, salted and smoked \\ fish, milk and dairy, and meat \\ \end{tabular}  } \\  & & & & \\ \cline{1-1}  & & & & \\ \  
The food industry faces a unique challenge in controlling bacterial persistence. Food processing and preservation often involve conditions such as fluctuating salt, temperature, pH, and nutrient availability, which can trigger bacteria to enter a persister state. One major contributor to persister formation is the activation of TA systems. These systems are versatile and respond to various stresses common in food-processing environments, such as nutrient limitation (e.g., during preservation) and high salt concentrations (e.g., in salted or fermented foods). TA systems are also key players in biofilm formation, which further protects persister cells. Another important mechanism is the stringent response, triggered by nutrient scarcity. This response activates stress survival pathways and can be induced during minimal processing or long-term storage. Additionally, the use of sanitizers and disinfectants can inadvertently activate the SOS response, increasing persister formation and antimicrobial tolerance. Finally, the presence of biofilms in food-processing environments further complicates control efforts since these structures provide a protective environment for persister cells and act as reservoirs for spoilage or pathogens, increasing the risk of contamination and foodborne illnesses.