# From Dormancy to Eradication: Strategies for Controlling Bacterial Persisters in Food Settings
## 5 Mechanisms of Persister Cell Formation
### Other Systems and Forms Contributing to Persistence  
In the food industry, bacterial persistence extends beyond individual persister cells to include systems and forms that present significant challenges to food safety: biofilms. These structured bacterial communities are embedded in a protective matrix, commonly found on food processing surfaces, where they shield pathogens from cleaning and disinfection procedures [36]. Small colony variants (SCVs), with their slow growth and altered metabolism, can persist in food products and equipment, increasing the risk of contamination and spoilage. SCVs are similar to persisters since they are very hard to grow in the lab and to destroy using conventional methods. The foodborne pathogen _S. aureus_, when in harsh conditions, is known to produce biofilms, but also, these biofilms may harbor persisters, as well as SCVs. SCVs have been identified in several food samples and are described as the survival strategy of _S. aureus_ alongside biofilm formation to endure acidic pH environments [35]. In addition, SCVs in _S. aureus_ also have a high biofilm-producing capacity contributing to the persistence of this species in food-industry settings [37]. Other known foodborne microorganisms like _Listeria monocytogenes_[38], _Bacillus cereus_[39], or _P. aeruginosa_[40] have also been studied regarding their capacity to produce SCVs and their survival strategies.  
L-form bacteria, which lack a cell wall and are resistant to standard antimicrobial treatments, can survive in processed foods or under certain production conditions. It is possible that persister cells, present on _Listeria_ enrichment media (LIM), can later form L-form colonies. L-form cells themselves could also be considered a type of persister, as they, unlike their walled counterparts, can grow in the presence of beta-lactam antibiotics. This phenomenon was described by [PERSON] et al. [41] in _E. coli_.  
Finally, spores and intracellular persisters are two survival strategies employed by various bacteria, including members of the genus _Salmonella_, _Listeria_, and _Bacillus_, to with  
Figure 3: Representation of bacterial population decay in the presence of an antibiotic. The vertical axis represents the proportion of surviving cells, the horizontal axis represents exposer time (min). In this representation, it is possible to see a steep reduction in bacterial cells (non-persisters susceptible to antibiotic activity) in the first 500 min of exposer and the appearance of a power-law-like tail representing persisters survival. Figure adaptation from [PERSON] et al. [10].  
stand extreme processing conditions such as heat, drying, and chemical sanitization. These mechanisms contribute to recurring contamination in food systems. While not extensively covered in this review, these forms of persistence have been discussed by [PERSON] et al. [42] in the context of their potential inactivation by antimicrobial peptides (AMPs), or by [PERSON] et al. [43] with the discovery of enzymes with lytic activity against spores produced by some _Bacillus_ genera. Together, these strategies emphasize the multifaceted nature of bacterial survival and underscore the need for diverse and combined eradication approaches.  
Although persistence itself is non-heritable, the frequency of persister cells in a given population is indeed a heritable trait. Several studies have shown that increased exposure to stressors, including antibiotics, leads to a higher frequency of persister cell production and enhanced fitness [6, 8].  
Table 1 summarizes and associates the different mechanisms of formation discussed above to the different types of persisters for better understanding.