Bacteriophages on dairy foods

Abstract

This review focuses on the impact of bacteriophages on the manufacture of dairy foods. Firstly, the impact of phages of lactic acid bacteria in the dairy industry, where they are considered enemies, is discussed. The sources of phage contamination in dairy plants are detailed, with special emphasis on the rise of phage infections related to the growing use of cheese whey as ingredient. Other topics include traditional and new methods of phage detection, quantification and monitoring, and strategies of phage control in dairy plants, either of physical, chemical or biological nature. Finally, the use of phages or purified phage enzymes as allies to control pathogenic bacteria in the food industry is reviewed.

Diversity and Local Coadaptation of Escherichia coli and Coliphages From Small Ruminants

“…Conversely, high levels of non-pathogenic E. coli in raw milk cheeses may contribute to the development of desirable characteristics of some of these products (Zago et al, 2007). The main advantage of using phages as biocontrol agents against undesired bacteria in cheese is that the specificity of phage-host spare the microbiota responsible for infusing natural flavors from being killed during treatment (Pujato et al, 2018). Conversely, the narrow host range limits the use of a single-phage treatments and multiple phage species are often mixed into cocktails (Abedon et al, 2017).…”

Application of Bacteriophages in Nanotechnology

“…It was the first step toward the control of the use of antibiotics in agro-food production, as it is a major source of bacterial resistance acquisition [ 87 ]. Phages were used to protect dairy products [ 88 ], fruits [ 89 ], vegetables [ 90 ], meat [ 91 ], and fish [ 92 ]. Developments in the utilization of phages as antimicrobial agents in plant and animal agriculture at the farm level are summarized in a recent review by Svircev et al [ 93 ].…”

Inkjet Printed Interdigitated Biosensor for Easy and Rapid Detection of Bacteriophage Contamination: A Preliminary Study for Milk Processing Control Applications

“…The impedance data were analyzed by two methods, i.e., impedance variation analysis at fixed frequency and equivalent modeling of the impedance data. First, we analyzed the 100 mHz impedance variations obtained within the test and control experiment with respect to the 4 h value, when the bacteria were inoculated in the wells, as described in Equation (1).…”

“…This is probably due to the fact that the lysed bacteria still absorb at 600 nm. Pujato et al (2018) observed that turbidity was only positive for 90% of a group of samples for which lysis plaques were observed on plaque assays [1]. This proves that even standard detection techniques are not always reliable, reinforcing the importance of the introduction of a new phage detection method.…”

“…This action is particularly detrimental in those processes where bacteria are used to produce fermented foods, e.g., cheese, which is based on the controlled fermentation of milk by selected bacterial cultures, mostly composed of Lactococcus species. Therefore, the presence of phages in the production plants could result in premature bacterial death and cause unsuccessful cheese production, with concomitant economical and time losses [1]. Since the amount of milk used in the plants is in the order of tons, the losses could be massive; additionally, the strategies to control phages in dairy facilities (such as factory/equipment design, sanitation, and culture rotations), are expensive and time consuming [1].…”