# Clarifying the Dual Role of Staphylococcus spp. in Cheese Production

## TL;DR

This paper reviews the dual role of Staphylococcus species in cheese, highlighting harmful and beneficial strains and their implications for food safety and cheese quality.

## Contribution

The paper provides a comprehensive review of the risks and benefits of Staphylococcus spp. in cheese production, offering a framework for evaluating their roles.

## Key findings

- Some Staphylococcus species, like S. aureus, produce enterotoxins that cause foodborne illness.
- Certain coagulase-negative staphylococci contribute positively to cheese ripening and flavor.
- Environmental factors and quorum sensing regulate enterotoxin gene expression in cheese conditions.

## Abstract

Staphylococcus spp. present a dual role in cheese production as some species are pathogenic, while others bring beneficial characteristics. Coagulase-positive staphylococci (CoPS), particularly Staphylococcus aureus, are of concern due to their ability to produce enterotoxins linked to foodborne outbreaks. These toxins, encoded by staphylococcal enterotoxin (SE) genes, cause gastroenteritis, especially vomiting. Many members of the genus harbor a plethora of virulence genes and are able to form biofilms. The prevalence of antibiotic-resistant strains, including methicillin-resistant S. aureus (MRSA), complicates control. In contrast, some members of the coagulase-negative staphylococci (CoNS) group, such as Staphylococcus carnosus, Staphylococcus condimenti, Staphylococcus equorum, Staphylococcus piscifermentans, Staphylococcus succinus, and Staphylococcus xylosus, contribute to ripening, influencing flavor and texture. Some are even considered safe and studied for their ability to inhibit pathogens. Expression of enterotoxin genes in Staphylococcus, particularly S. aureus, is influenced by environmental factors and can be regulated by different mechanisms including quorum sensing. Understanding gene expression in conditions found during cheese production and ripening can help in formulating effective interventions. Risks posed by enterotoxin-producing Staphylococcus in cheese are evident, with numerous outbreaks reported worldwide. Moreover, several species present risks to both animal and human health. Effective control measures include adherence to microbiological criteria in foods, animal health monitoring, good manufacturing practices (GMP), temperature control, proper ripening conditions and hygiene. This review compiles and discusses existing knowledge on CoPS and CoNS in cheeses, providing a framework for evaluating their risks and benefits and guiding future studies in cheese microbiology.