Application of endolysin LysPEF1-1 with cinnamon bark against planktonic and mixed-species biofilm cells of Listeria monocytogenes and Enterococcus faecalis on various food and food contact surfaces

Effectiveness of two sanitation procedures for decreasing the microbial contamination levels (including Listeria monocytogenes) on food contact and non-food contact surfaces in a dessert-processing factory

The aim of the study was to evaluate the microbicidal effectiveness of radiant catalytic ionization (RCI) against Listeria monocytogenes strains in the form of planktonic cells and biofilm on food products and food contact surfaces as a method of food preservation. The study material comprised six strains of L.monocytogenes, isolated from food. Samples of different types of food available by retail (raw carrot, frozen salmon filets, soft cheese) and the fragments of surfaces (stainless steel AISI 304, rubber, milled rock tiles, polypropylene) were used in the experiment. The obtained results showed the effectiveness of RCI in the inactivation of both forms of the tested L. monocytogenes strains on all the surfaces. The effectiveness of RCI for biofilm forms was lower as compared with planktonic forms. The PRR value ranged from 18·19 to 99·97% for planktonic form and from 3·92 to 70·10% for biofilm. The RCI phenomenon induces the inactivation of L.monocytogenes on surfaces of food and materials used in the processing industry to a varying degree, depending on the manner of surface contamination, the properties of the contaminated materials as well as on the origin of the strain and the properties of surrounding dispersive environment in which the micro-organisms were suspended. Searching of new actions aimed at the reduction of the microbial contamination of food and food contact surfaces are extremely important. RCI method has been already described as an effective technique of microbial and abiotic pollution removal from air. However, our studies provide new, additional data related to evaluation the RCI efficacy against microbes on different surfaces, both in planktonic and biofilm form.

Effects of oregano essential oil and carvacrol on biofilms of Staphylococcus aureus from food-contact surfaces

Efficacy of chlorine-based disinfectants (sodium hypochlorite and chlorine dioxide) on Salmonella Enteritidis planktonic cells, biofilms on food contact surfaces and chicken skin

A survey of microbial levels for incoming raw beef, environmental sources, and ground beef in a red meat processing plant

Cold Atmospheric Pressure Plasma Processing for Decontamination of Solid Food and Food Contact Surfaces

Assessment of hygienic quality of surfaces in retail food service establishments based on microbial counts and real-time detection of ATP.

Candida species are significant opportunistic fungal pathogens that can cause various diseases, particularly among individuals with compromised immunity. While there is plenty of literature on Candida in clinical and public settings, incidence on surfaces within student residence halls is still not well understood. The distribution and frequency of Candida species were assessed on surfaces that come into contact with food and non-food items at the Obafemi Awolowo University residence halls in Ile-Ife, Nigeria. Seven out of nine residence halls of the university were studied using a cross-sectional investigation. Sterile swabs were used to collect surface samples from 50 rooms, which were subsequently processed on Hi Chrome Candida Differential Agar and Sabouraud Dextrose Agar. Data analysis was done using the Chi-square test with a significance level of p < 0.05. It was found that Candida species were fairly common, with an occurrence rate of 86%. The contamination rate on non-food contact surfaces was 64% compared to 76% on food contact surfaces. Its dominating species was Candida glabrata, which comprised 28%, followed by Candida albicans 6%, and Candida tropicalis was also 6%. More pronounced co-infections were noticed at the postgraduate hall: food-contact surfaces between the Candida albicans and Candida glabrata comprised 28.6%. The Moremi Hall recorded the greatest percentage of total contamination at 26%. The results stress the need for improved hygienic practices, routine check-ups, and public health programs to avoid opportunistic infections among students, as well as the need to turn attention to the possible danger of fungal contamination in communal living facilities.

Control of Listeria innocua Biofilms on Food Contact Surfaces with Slightly Acidic Electrolyzed Water and the Risk of Biofilm Cells Transfer to Duck Meat

Effect of trisodium phosphate on biofilm and planktonic cells of Campylobacter jejuni, Escherichia coli O157: H7, Listeria monocytogenes and Salmonella typhimurium

In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against Listeria monocytogenes (L. monocytogenes) planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, a disinfection efficacy equal to that of NaClO solutions (pH 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in the case of stainless steel) or higher than (in the case of glass) that of high-ACC NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.

Characterization of persistent Listeria monocytogenes strains from ten dry-cured ham processing facilities

Based on recent risk assessments, up to 83% of listeriosis cases from deli meat in the United States are predicted to be from ready-to-eat deli meats contaminated during processing at retail grocery stores. Listeria monocytogenes is known to use sanitizer tolerance and biofilm formation to survive, but interplay of these mechanisms along with virulence potential and persistence mechanisms specific to deli environments had yet to be elucidated. In this study, 442 isolates from food and nonfood contact surfaces in 30 retail delis over 9 months were tested for inlA premature stop codons (PMSCs); inlA encodes InlA, which is necessary to cause listeriosis. A total of 96 isolates, composed of 23 persistent and 73 transient strains, were tested for adhesion and biofilm-forming ability and sanitizer tolerance. Only 10/442 isolates had inlA PMSCs (p<0.001). Strains with PMSCs were not persistent, even in delis with other persistent strains. Most (7/10) PMSC-containing isolates were collected from food contact surfaces (p<0.001); 6/10 PMSC-containing isolates were found in moderate prevalence delis (p<0.05). Persistent strains had enhanced adhesion on day 1 of a 5-day adhesion-biofilm formation assay. However, there was no significant difference in sanitizer tolerance between persistent and transient strains. Results suggest that foods contaminated with persistent L. monocytogenes strains from the retail environment are (1) likely to have wild-type virulence potential and (2) may persist due to increased adhesion and biofilm formation capacity rather than sanitizer tolerance, thus posing a significant public health risk.

Prevalence of Salmonella enterica Isolated from Food Contact and Nonfood Contact Surfaces in Cambodian Informal Markets

<i>Listeria</i> prevention