A total of 958 samples of raw fish, fish products and "frutti di mare" were tested for staphylococci. Among 153 strains isolated and subjected to identification the most frequently present were: S. aureus, S. warneri, S. hominis and S. sciuri. These species stated for 46.4; 20.9; 7.2 and 5.2 percent of the total number of identified staphylococci species, respectively. Atypical coagulase-negative S. aureus represented 11.3 percent of identified strains of this species. With coagulase-negative staphylococci taken into account, presence of staphylococci was confirmed in 69.8 percent of the 275 samples tested, while contamination with coagulase-positive staphylococci was confirmed in 24.7 percent of them

In the present study, silver nanoparticles (AgNPs) synthesized from aqueous leaves extract of Malva crispa and their mode of interaction with food- and water-borne microbes were investigated. Formation of AgNPs was conformed through UV–Vis, FE-SEM, EDS, AFM, and HR-TEM analyses. Further the concentration of silver (Ag) in the reaction mixture was conformed through ICP-MS analysis. Different concentration of nanoparticles (1–3 mM) tested to know the inhibitory effect of bacterial pathogens such as Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhi, Salmonella enterica and the fungal pathogens of Penicillium expansum, Penicillium citrinum, Aspergillus oryzae, Aspergillus sojae and Aspergillus niger. Interestingly, nanoparticles synthesized from 2 to 3 mM concentration of AgNO₃ showed excellent inhibitory activities against both bacterial and fungal pathogens which are well demonstrated through well diffusion, poison food technique, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC). In addition, mode of interaction of nanoparticles into both bacterial and fungal pathogens was documented through Bio-TEM analysis. Further the genomic DNA isolated from test bacterial strains and their interaction with nanoparticles was carried out to elucidate the possible mode of action of nanoparticles against bacteria. Interestingly, AgNPs did not show any genotoxic effect against all the tested bacterial strains which are pronounced well in agarose gel electrophoresis and for supporting this study, UV–Vis and Bio-TEM analyses were carried out in which no significant changes observed compared with control. Hence, the overall results concluded that the antimicrobial activity of biogenic AgNPs occurred without any DNA damage.

Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.

Thyme oil in water nanomulsion was prepared under subcritical water conditions using water and saponin, as solvent and emulsifier, respectively. Gas chromatography revealed that there were 44 bioactive components in the extracted thyme essential oil which, thymol and carvacrol were two mains of them. Experiments were designed based on central composite design and effects of amounts of saponin and thyme essential oil were evaluated on particle size, polydispersity index (PDI) and zeta potential of the prepared nanoemulsions using response surface methodology. Obtained results revealed that more desirable thyme oil nanoemulsions with minimum particle size (184.51 nm) and PDI (0.514), and maximum zeta potential (− 22.51 mV) were prepared using 0.94 g of saponin and 0.28 mL of thyme essential oil. Furthermore, results indicated that prepared nanoemulsion using obtained optimum production conditions had relatively high antioxidant activity (24%) and high antibacterial and antifungal activities against Staphylococcus aureus and Penicillium digitatum.

Background: The incidence of foodborne infectious diseases has been stable and even increased in many countries. Improper use of antibiotics due to the prevalence of microbial diseases has caused drug resistance. So nanotechnology has many attractive applications in the food industry, such as food preservation and food quality control. By the reason, the absorptive and antibacterial features of copper oxide nanoparticles combining with magnesium oxide nanoparticles in killing the bacteria were investigated. Materials and Methods: The antibacterial activities of CuO NP in combination with MgO NP against Escherichia coli and Staphylococcus aureus in culture media and fruit juice (mango, pomegranate, and peach) by agar diffusion and colony count method were explored. Electron microscopy was used to characterize the morphological characteristics of the bacteria tested after treatment with CuO and MgO NPs. Results: The results of one-way ANOVA by 95% confidence showed that CuO and MgO NPs have antimicrobial activity on E. coli and S. aureus. An effect of synergism was observed when combining CuO and MgO NP. Electron microscopy photographs showed that treatment with the combination of MgO and CuO caused damage to the cell membrane. As a result, the leakage of intracellular contents kills the bacteria. Conclusion: The combination of CuO and MgO nanoparticles can successfully control the growth of E. coli and S. aureus in liquid and juice medium. So, this combination treatment can reduce the required amount of CuO and MgO nanoparticles during the pathogen control process in the food industry.

Food safety issues and increases in food borne illnesses have promulgated the development of new sanitation methods to eliminate pathogenic organisms on foods and surfaces in food service areas. Electrolyzed oxidizing water (EO water) shows promise as an environmentally friendly broad spectrum microbial decontamination agent. EO water is generated by the passage of a dilute salt solution (approximately 1% NaCl) through an electrochemical cell. This electrolytic process converts chloride ions and water molecules into chlorine oxidants (Cl2, HOCl/ClO-). At a near-neutral pH (pH 6.3-6.5), the predominant chemical species is the highly biocidal hypochlorous acid species (HOCl) with the oxidation reduction potential (ORP) of the solution ranging from 800 to 900 mV. The biocidal activity of near-neutral EO water was evaluated at 25 °C using pure cultures of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Treatment of these organisms, in pure culture, with EO water at concentrations of 20, 50, 100, and 120 ppm total residual chlorine (TRC) and 10 min of contact time resulted in 100% inactivation of all five organisms (reduction of 6.1-6.7 log10 CFU/mL). Spray treatment of surfaces in food service areas with EO water containing 278-310 ppm TRC (pH 6.38) resulted in a 79-100% reduction of microbial growth. Dip (10 min) treatment of spinach at 100 and 120 ppm TRC resulted in a 4.0-5.0 log10 CFU/mL reduction of bacterial counts for all organisms tested. Dipping (10 min) of lettuce at 100 and 120 ppm TRC reduced bacterial counts of E. coli by 0.24-0.25 log10 CFU/mL and reduced all other organisms by 2.43-3.81 log10 CFU/mL.

In Japan, strategies for ensuring food safety have been developed without reliable scientific evidence on the relationship between foodborne diseases and food sources. This study aimed to provide information on the proportions of foodborne diseases caused by seven major causative pathogens (Campylobacter spp., Salmonella, enterohemorrhagic Escherichia coli [EHEC], Vibrio parahaemolyticus, Clostridium perfringens, Staphylococcus aureus, and norovirus) attributed to foods and to explore factors affecting changes in these source attribution proportions over time using analysis of outbreak surveillance data. For the calculation of the number of outbreaks attributed to each source, simple-food outbreaks were assigned to the single-food category in question, and complex-food outbreaks were classified under each category proportional to the estimated probability. During 2007 to 2018, 8,730 outbreaks of foodborne diseases caused by seven pathogens were reported, of which 6,690 (76.6%) were of unknown source. We estimated the following source attribution proportions of foodborne diseases: chicken products (80.3%, 95% uncertainty interval [UI] 80.1 to 80.4) for Campylobacter spp.; beef products (50.1%, UI 47.0 to 51.5) and vegetables (42.3%, UI 40.9 to 45.5) for EHEC; eggs (34.6%, UI 27.8 to 41.4) and vegetables (34.4%, UI 27.8 to 40.8) for Salmonella; finfish (50.3%, UI 33.3 to 66.7) and shellfish (49.7%, UI 33.3 to 66.7) for V. parahaemolyticus; grains and beans (57.8%, UI 49.7 to 64.9) for S. aureus; vegetables (63.6%, UI 48.5 to 74.6), chicken products (12.7%, UI 4.6 to 21.5), and beef products (11.1%, UI 8.5 to 13.1) for C. perfringens; and shellfish (75.5%, UI 74.7 to 76.2) for norovirus. In this study, we provide the best available evidence-based information to evaluate the link between foodborne diseases and foods. Our results on source attribution for Campylobacter spp. and EHEC suggest that the strict health regulations for raw beef were reflected in the proportions of these diseases attributed to this food.

Alkaline electrolyzed water (REW) is known for its cleaning action. The aim of this work was to assess REW effectiveness in reducing microbial load on surfaces intended for contact with food. Stainlesssteel surfaces were experimentally contaminated, bacterial inactivation was tested before and after treatment with REW. Treatment with REW was operated spraying it on the contaminated plates until drying. Tests were conducted for Salmonella spp., Listeria spp., Staphylococcus aureus and Escherichia coli. The treatment revealed different degrees of sanitizing activity of REW on different bacterial species, with higher efficacy on E. coli and Salmonella spp. than S. aureus, Listeria spp.. Statistical analysis revealed a significant microbial load reduction (p<0.01) after treatment with REW, suggesting that it has a good disinfectant activity which, along with its easy and safe use, makes it a good alternative to many other more widely used disinfectants.

Seaweeds are rich in bioactive compounds which have well-documented antioxidant properties. They also have antimicrobial activities against food pathogenic microorganisms. This study uses an extract of the brown seaweed, Saccharina (Laminaria) japonica, produced by subcritical water hydrolysis (SWH) for investigating its potential to inhibit bacteria. De-oiled S. japonica was obtained by supercritical carbon dioxide extraction. The reaction temperatures for hydrolysis of raw and de-oiled S. japonica were maintained from 200 to 280 °C. The experiment was done with condition 1.3–6.0 MPa for the reaction pressure and 1:10 (w/v) for the ratio of material to water. The antibacterial activities of raw and de-oiled S. japonica produced by SWH were determined by using the agar diffusion method. Antibacterial activity was tested against two Gram-negative (Escherichia coli and Salmonella typhimurium) and two Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus). The antibacterial activities of hydrolysate water with catalyst at 240 °C showed better bacterial inhibition than the others. Strong antibacterial activity was found using de-oiled material with acetic acid added, with a zone of inhibition of S. typhimurium (14.33 ± 0.06 mm) and E. coli (13.00 ± 0.09 mm). On the other hand, the weakest antibacterial inhibition was found for S. aureus (12.83 ± 0.10 mm) and B. cereus (12.50 ± 0.09 mm).