Inactivation of foodborne pathogens on food packaging and in cow milk by exposure to a Nd:YAG laser

Abstract

This study demonstrates the inhibition of selective foodborne pathogenic bacteria by exposure to a 355 and 266 nm Nd:YAG laser. In baseline assay P. aeruginosa showed maximum inhibition followed by Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Listeria monocytogenes grown on agar surface. Cell lysis was confirmed by confocal microscopy for all pathogens. In liquid media, P. aeruginosa was irradiated with the third harmonic of a Nd:YAG laser pulse energy of 185 mJ, which was able to reduce the population of 1.65 × 105 by 4.7 logs, while P. aeruginosa could only be reduced by 0.73 log/cm2 on packaging material surface. In the final phase, the laser’s potential was preliminarily tested for sterilization of raw cow milk. The reduction patterns of E. coli, Salmonella sp. yeasts and Lactobacillus sp. were 30%, 25%, 47%, and 30%, respectively, in raw milk, moreover, laser exposure had no significant impact on physio-chemistry of milk. Therefore, results indicate the potential application of laser in packing materials and milk sterilization at the industrial level.

Contaminants in the cow's milk we consume? Pasteurization and other technologies in the elimination of contaminants

“…219 Exposure of milk to Nd: YAG laser did not alter the physicochemical properties of milk, but the percentage of reduction was low for E.coli (30%), Salmonella sp (25%), yeasts (47%), and Lactobacillus sp (30%). 223 The combination of ultrasound with hydrogen peroxide and an active lactoperoxidase system was able to guarantee the microbial quality of milk as it was able to completely inactivate Staphylococcus aureus, Listeria monocytogenes, Lactobacillus plantarum, Lactobacillus pentosus, Salmonella Typhimurium, Escherichia coli, and Pseudomonas fluorescens at 10 minutes at an amplitude of 125 μm. 220 The application of ultrasound in combination with variations in temperature, time, and constant pressure (manothermosonication) achieved minimal reductions of up to 1.6 log CFU/ml for E. coli and P.fluorescens and 1.05 log CFU/ml for S. aureus.…”

Presence and persistence of Pseudomonas sp. during Caspian Sea-style spontaneous milk fermentation highlights the importance of safety and regulatory concerns for traditional and ethnic foods

“…P. aeruginosa is considered an opportunistic pathogen, able to cause urinary tract infections, respiratory dermatitis, soft tissue infections, bacteremia, gastrointestinal infections, and a variety of systemic infections (Lucchetti-Miganeh et al, 2014;Sader et al, 2015;Castaldo et al, 2017). In this sense, great efforts are being explored to prevent contamination by Pseudomonas in dairy products (Meesilp & Mesil, 2018;Nan et al, 2016;Picoli et al, 2017;Yasmin et al, 2017).…”

Isolation, Identification and Characterization of Two Kinds of Deep-Sea Bacterial Lipopeptides Against Foodborne Pathogens

“…Listeria monocytogenes, Salmonella choleraesuis, Staphylococcus aureus and Pseudomonas aeruginosa are common foodborne pathogens, which often cause serious foodborne diseases and have become a global public health problem (Zarei et al, 2014;Patra and Baek, 2017;Yasmin et al, 2017). However, the overuse of antibiotics, especially different kinds of antibiotics, has led to the increase of multidrug resistant bacteria and the accelerated spread of antibiotic resistance genes (Bjerketorp et al, 2021).…”