# From Dormancy to Eradication: Strategies for Controlling Bacterial Persisters in Food Settings
## 6 Implications of Persister Cells in the Food Industry  
Although studies on persister cells specifically related to food safety are limited, their formation mechanisms, survival, and regrowth have been well documented, as described in the previous sections. Persister cells can survive adverse conditions such as heat, cold, and chemical treatments without undergoing genetic mutations. This resilience poses significant challenges to food safety, as these cells can survive sanitation procedures and later regrow, leading to food contamination or spoilage. The presence of persister cells is particularly worrying when foodborne pathogens are present, namely _Salmonella_ spp., _E. coli_, _S. aureus_, _L. monocytogenes_, or _B. cereus_. These microorganisms can form biofilms on food surfaces and equipment, impeding their elimination. [PERSON] et al. [44] showed that persister cells from _B. cereus_ and _Pseudomonas fluorescens_ are able to survive biocide exposure. Similarly, _B. cereus_ spores have been found to survive cooking processes in rice dishes and later reactivate, posing further risks to food safety [45]. Additionally, _Bacillus_ may also be found in meat products (producer of toxins in temperatures of 17 \({}^{\circ}\)C), spices (dry garlic, laurel, or pepper), dairy, salted and smoked fish, bakery products (flour and dough), and canned foods [46]. _L. monocytogenes_ is another pathogen known for its persistence under extreme conditions, such as high salt concentrations and low temperatures. Its ability to form biofilms on surfaces in food-processing environments makes it difficult to eradicate, even with aggressive cleaning and disinfection protocols [47, 48]. Recent research identified stress survival islets (SSIs) in _L. monocytogenes_ that contribute to their ability to survive under various environmental stresses [49]. Moreover, toxin-antitoxin systems in _L. monocytogenes_ are overexpressed in response to antibiotic exposure, further complicating efforts to control its persistence [50]. In a recent study, [PERSON] et al. [51] also tested the presence of _L. monocytogenes_ persists in a simulated processing plant of leafy green products (fresh fruits and vegetables), as well as packing houses. Their main findings were that _L. monocytogenes_ persists' formation remained steady in nutrient-rich environment and decreased in a nutrient-poor one. This showed a connection between nutrient availability and persister \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Type of Persister** & **Production Stage** & **Formation Mechanism** & **References** \\ \hline Type I & Stationary phase & TA systems, SOS response (connected with TA system and efflux pumps), and spores & [15, 19, 20] \\ Type II & Continuous growth at slow rate & TA systems, stringent response, and SCVs & [15] \\ Type III & Induced by specific antibiotics & TA systems, hunker theory, PaSH, and L-form bacteria & [17, 18, 20] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Different types of persisters and their formation mechanisms. formation. In addition, chloride treatments were also tested regarding their sanitization properties against _Listeria_ persisters. The authors observed that an exposer at a concentration of 100 mg/L over two minutes decreased the number of persister cells. Recently, several reviews have featured the factors that contribute to the persistence of _Listeria_ in food processing, as well as strategies and interventions [52; 53]. _Listeria_ persisters may be found in several foods, such as seafood (frozen shellfish and shrimp), meat or poultry (in frozen meat up to 20 days in lamb, 14 months in pork, and 9 months in beef), sandwich or deli meat, vegetables and greens (up to 600 days), and dairy (more than 4 months), as well as its processing facilities [46]. _S. aureus_, a common commensal bacterium, poses a significant risk in food-processing environments due to its biofilm-forming capabilities and potential for producing enterotoxins that can lead to gastrointestinal intoxication.