Culture-Dependent and Culture-Independent Nucleic-Acid-Based Methods Used in the Microbial Safety Assessment of Milk and Dairy Products

Despite great advances in the diagnostics and better awareness for food safety and security worldwide, significant numbers of foodborne outbreaks have been traced back to the consumption of milk and dairy products contaminated with pathogenic bacteria, such as Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., Campylobacter spp., and pathogenic Escherichia coli. Several culture-dependent and culture-independent nucleic acid-based methods have been proposed to identify, detect, and type milk- and dairyborne pathogenic bacteria. In our review, we will provide an overview on why it is of utmost importance to ascertain the presence of pathogenic microorganisms in milk and milk products; thereafter, we will describe the most commonly used culture-dependent and culture-independent methods, as well as the most attractive ones with regard to their future exploitation, providing the reader with new insights into how and when they can be exploited to ensure the enumeration, and accurate detection at both species and strain level of the most important milk- and dairyborne pathogenic bacteria, even if in a viable but nonculturable state.