N-Halamine modified thermoplastic polyurethane with rechargeable antimicrobial function for food contact surface

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

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

Survival and Persistence of Campylobacter and Salmonella Species under Various Organic Loads on Food Contact Surfaces

A food premise’s sanitation level can be reflected by the cleanliness of its food contact surfaces. Contaminated food contact surfaces along with poor handling methods by food handlers may increase the risk of foodborne diseases through cross-contamination events. This study aimed to assess the microbiological contamination levels on food contact surfaces of 12 residential college cafeterias in a local university and its correlation with the cafeteria’s premise grade. The presence of selected indicator and pathogenic microorganisms (total viable count (TVC), total coliform, Escherichia coli, Staphylococcus aureus, Salmonella spp., and Shigella spp.) on food contact surfaces were also determined. Cutting boards, knives and utensils (cutleries, bowls and plates) that were used for ready-to-eat food were sampled for this study. The cafeteria’s premise grade was obtained based on the food premise inspection report by the university Health Centre. Three cafeterias have significantly higher (p 0.01). This study demonstrated that the sanitation level of food contact surfaces in the residential college cafeterias was only average. Improvements need to be done to increase the sanitation level of the cafeterias, thus assuring the safety of the food for consumers. DOI : http://dx.doi.org./10.17576/JSKM-2018-1602-05

Contaminated surfaces can transmit pathogens to food in industrial and domestic food-handling environments. Exposure to pathogens on food contact surfaces may take place via the cross-contamination of pathogens during postprocessing activities. Formaldehyde-based commercial sanitizers in recent years are less commonly being used within food manufacturing facilities due to consumer perception and labeling concerns. There is interest in investigating clean-label, food-safe components for use on food contact surfaces to mitigate contamination from pathogenic bacteria, including Salmonella. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WD-MAX™, against Salmonella when applied onto various food contact surfaces were evaluated. The efficacy of Activate DA (HMTBa + fumaric acid + benzoic acid) at 1% and 2% and Activate US WD-MAX (HMTBa + lactic acid + phosphoric acid) at 0.5% and 1% against Salmonella enterica (serovars Enteritidis, Heidelberg, and Typhimurium) were evaluated on six different material surfaces: plastic (bucket elevator and tote bag), rubber (bucket elevator belt and automobile tire), stainless steel, and concrete. There was a significant difference in the Salmonella log reduction on the material surfaces due to the organic acid treatments when compared to the untreated surfaces. The type of material surface also had an effect on the log reductions obtained. Stainless steel and plastic (tote) had the highest Salmonella log reductions (3-3.5 logs), while plastic (bucket elevator) and rubber (tire) had the lowest log reductions (1-1.7 logs) after treatment with Activate US WD-MAX. For Activate DA, the lowest log reductions (~1.6 logs) were observed for plastic (bucket elevator) and rubber (tire), and the highest reductions were observed for plastic (tote), stainless steel, and concrete (2.8-3.2 logs). Overall, the results suggested that Activate DA at 2% and Activate US WD-MAX at 1% are potentially effective at reducing Salmonella counts on food contact surfaces by 1.6-3.5 logs.

ObjectivesListeria is a pathogenic bacterium that is widespread in nature and can enter food processing plants through many vectors, like raw materials, process waste and personnel. Food processors work hard to keep Listeria out of the environment, but it can at times be found from food contact surfaces to floor drains. The sanitation can be compounded when equipment is pitted or cracked creating a harborage or niche in which Listeria can grow. Many control strategies for cleaning and biofilm removal have been put into place but may not suffice in eliminating Listeria from the food contact surface or environment. Bacteriophages are now being used to tackle these pathogens in food processing environments. Since they only target specific bacteria, they are harmless to humans, animals and plants, while effectively eliminating Listeria.This study determines the efficacy of a commercially available bacteriophage product, PhageGuard Listex, against Listeria on commonly found materials in food processing plants (stainless steel and UHMW polyethylene). Efficacy was determined by applying two phage concentrations, as well as two exposure times.Materials and MethodsOvernight cultures of L. monocytogenes ATCC13832 and L. innocua ATCC51742 were mixed in equal parts to create a Listeria cocktail (2 × 109 CFU/cm2). Sterile coupons (100 cm2) of stainless steel or UHMW polyethylene were artificially inoculated with the cocktail at 2.5ML/cm2 and left to dry at 37°C until completely dry. Subsequently, coupons were treated with 2 × 107 or 1 × 108 Plaque Forming Units (PFU)/cm2 using a spray system and incubated at room temperature for 1 and 3 h, before retrieval and enumeration of bacteria on selective agar plates. Sample size n:3. Results were analyzed using two-way ANOVA, with Dunnett’s multiple comparisons test on the normalized data.ResultsA dose dependent response to the phage treatment was observed, where an increasing phage concentration resulted in an increase in Listeria kill on both surfaces. On stainless steel, a treatment dose of 2 × 107 PFU/cm2 resulted in a statistically significant bacterial reduction of 1.27 log after 1 h (p value < 0.0001), while application of 1 × 108 PFU/cm2 showed a 2.16 log reduction (p value < 0.0001). On UHMW polyethylene, a bacterial reduction of 0.47 log was observed 1 h after applying 2 × 107 PFU/cm2, while the application of 1 × 108 PFU/cm2 led to a reduction of 1.95 log. However, these reductions were not statistically significant (p value > 0.05). After 3 h of treatment, the reductions were slightly higher in both materials (Table 3). After this time, the difference between control and 5% treatment on UHMW polyethylene obtained a p-value < 0.05.ConclusionPhage technology is an easy and safe intervention which can be used as an additional tool to control Listeria in processing environments. The above results indicate that the commercially available phage solution, PhageGuard Listex, can reduce Listeria contamination on food contact surfaces by 0.4 to 3.4 logs after 3 h of treatment.Table 3Log reduction of Listeria cells after applicatio nof two bacteriophage concentrations, measured at 1 and 3 h post phage treatment

Ninety pig carcasses and twenty one food contact surfaces (FCSs) were tested for Salmonella in a slaughterhouse processing ca. 380 pigs/h between 2014-2015. Sampling was performed during seven sessions. Four carcass sites of 100 cm2 each (back, belly, jowl externally, and the diaphragmatic area internally) were swabbed after evisceration. Meat conveyors and dressing tables were tested swabbing areas of 200 to 400 cm2. After pre-enrichment in buffered peptone water, samples were tested by Salmonella MDS® assay and the presumptive positives were confirmed by the ISO 6579 method. Salmonella isolates were serotyped following the Kauffman-White-Le Minor scheme and genotyped by XbaI pulsed field gel electrophoresis. Salmonella was isolated from 16/90 [17.8%; confidence interval (CI) 95%=11.2-26.9] carcasses and 4/21 (19.0%; CI 95%=7.7-40.0) FCSs. Four serovars were identified on carcasses. S. enterica 4,[5],12:i:-was the most prevalent (43.75%), followed by S. Rissen (31.25%), S. Derby (12.5%) and S. Bovismorbificans (12.5%). Two serovars were found on FCSs, namely S. Derby (75%) and S. Livingstone (25%). During one sampling session, a failure in carcass dehairing occurred and caused significantly higher prevalence of carcass contamination (60%) than in the remaining sessions. Moreover, in the same session, Salmonella prevalence was marginally significantly higher on FCSs than in the remaining sampling days, suggesting that dehairing affects contamination not only on carcasses, but also on the working surfaces.

Low-energy X-ray irradiation effectively inactivates major foodborne pathogen biofilms on various food contact surfaces

This paper presents an investigation into improved, direct Salmonella detection on food contact surfaces using a double-layer planar coil detector and wireless phage-based magnetoelastic (ME) biosensors. Comparing with the single-layer coil detectors used in our previous research, double-layer coils with appropriate designs allow for better magnetic excitation of the biosensor and sensitivity of detection. In this way, a longer stand-off distance (distance between the sensor and detector), which may be necessary for testing surfaces with large roughness and curvatures, can be achieved. In addition, smaller biosensors (e.g., sub-millimeter long) with higher mass sensitivity can also be measured with this sensitive double-layer coil detector. Standard microelectronic fabrication techniques (photolithography, electroplating, etching and sputtering) were used to fabricate double-layer coils with various design parameters, including the thickness of layers, width, height, and spacing of coil turns. Both theoretical calculations and experimental data showed that the above coil geometric parameters have large effects on the signal amplitude, stand-off distance and detection sensitivity. Finally, with the newly fabricated double-layer coil detector, detection of Salmonella on a food-grade, ultra-high-molecular-weight polyethylene (UHMW-PE) surface was demonstrated. Multiple biosensors were measured simultaneously with a longer detection distance (> 1 mm). This double-layer scanning coil detector therefore facilitates the detection of pathogens on food and food contact surfaces.

The bacterial biofilm formation index (BFI) is measured by a microtiter plate assay, and it is typically performed at 72 hr. However, the dynamics of biopolymer formation change during this incubation period. The aims of this study were to follow the biofilm formation dynamics of Vibrio strains isolated from samples of seafood and food contact surfaces (FCS) and to propose a new BFI classification criterion. Samples from seafood (136) and FCS (14) were collected from retail markets in Queretaro, Mexico. The presence of Vibrio spp. was determined, the strains were isolated, and the six major pathogenic species (V. cholerae, V. alginolyticus, V. fluvialis, V. parahaemolyticus, V. vulnificus, V. mimicus) were identified by PCR. The BFI of the isolates was determined by the microtiter plate method. Fifty-one strains were isolated and identified as V. alginolytivcus (25), V. vulnificus (12), V. cholerae (7), V. parahaemolyticus (6), and V. mimicus (1). A quantitative classification criterion of biofilm formation was proposed based on the following factors: BFI dynamics (no formation, continuous increase, and increase followed by decrease), time of maximum BFI (early: 24 hr; late: 48 to 72 hr), and degree of BFI (none, weak, moderate, and strong). A numerical value was assigned to each factor to correlate the resulting BFI profile with a risk level. Thirteen BFI profiles were observed, having risk level values from 0 to 10. Vibrio alginolyticus, V. cholerae, and V. vulnificus showed the highest BFI profile diversities, which included the riskiest profiles. The proposed BFI criterion describes the dynamics of bacterial biopolymer formation and associates them with the possible risk implications. PRACTICAL APPLICATION: In food processing environments, the presence of bacterial biofilms that could include foodborne pathogens might favor cross-contamination due to direct contact or biofilm dispersal into food products. The new quantitative classification criterion for biofilm formation considers their production dynamics over time, the biofilm quantity, and the level of biofilm dispersal. These characteristics are represented by a numerical value that reflects the level of risk associated with the presence of a biofilm-producing strain on a food contact surface.

Incidence and persistence of Listeria monocytogenes in the catfish processing environment and fresh fillets.

Isolation and characterization of Salmonella spp. from food and food contact surfaces in a chicken processing factory

A microbial survey was performed for different red meat processing plants produces retail cuts and ground beef in Istanbul, Turkey. Swab samples from 10 cm2 of surface were obtained from food contact surfaces and environmental surfaces. Total mesophilic aerobic count (TMC), coliform count (CC), Escherichia coli count (ECC) and Escherichia coli O157:H7 were determined for each sample. Average surface counts for TMC from floor, wall, food contact surfaces were between 2.71 to 3.15 log10 CFU / cm2, 0.69 to 1.56 log10 CFU/cm2 , 2.23 to 3.0 log10 CFU/cm2 respectively. Coliforms and Escherichia coli were determined from floor and food contact surfaces. Samples taken from four different wall were negative for Escherichia coli. Any E. coli O157:H7 counts were observed at the samples. Microbial testing for red meat processing plants is one of the most important subject for identifying and monitoring potential hazards as part of HACCP and GMP programs.

FDA promotes assessment of routine restaurant inspection programs to measure trends in the occurrence of risk factors and compare data with national benchmarks. Reductions in the occurrence of risk factors should be accompanied by reductions in the occurrence of foodborne illnesses. The objectives of this study were to: (1) assess changes in risk factor violations in Bloomington restaurants between 2010 and 2015, in order to (2) compare patterns of risk factor violations in Bloomington restaurants that served sporadic Salmonella cases from 2010 to 2015 to these observed trends. FDA-based risk factor surveys were conducted in 2010 and 2015. Food contact surfaces were most frequently cited as out-of-compliance in both years. The proportion of inspections with employee health policy violations were reduced from 2010 to 2015, reflecting inspection priorities that were established after the 2010 survey. From 2010 to 2015, 154 sporadic Salmonella case exposures were reported from Bloomington restaurants. Food contact surfaces (odds ratio [OR] = 2.3; 95% confidence interval [CI] = 1.6, 3.5) and handwash facilities stocked (OR = 2.7; 95% CI = 1.7, 4.0) were more frequently found out-of-compliance in inspections that served sporadic Salmonella cases, in both individual year comparisons and in the overall comparison. The finding that violations such as food contact surfaces not being clean to sight and touch or sanitized before use and handwash facilities not being stocked with hand cleanser, sanitary towels, or hand drying devices, were more likely to be cited in sporadic Salmonella cases than during the FDA-based risk factor survey, suggests that these may contribute to an increased risk of Salmonella transmission in restaurants. Because restaurant inspections represent routine public health activities that are conducted by a broad range of agencies, establishing methods to analyze the results of these inspections across agencies and over time may help us better understand how risk factors cited on routine inspections can predict the likelihood a food establishment will be implicated in a foodborne illness case, in both sporadic cases and outbreaks.

Background: Opportunistic Staphylococcus aureus (S. aureus) may cause a range of infections in humans and animals, from self-limiting to life-threatening. S. aureus might be acquired from food via contaminated hands or food contact surfaces. Orange peel extract has various therapeutic uses. Aim: This study aimed to estimate the antibacterial activity of orange peel extract against Staphylococcus aureus (S. aureus) in vitro by measuring the inhibition zone and MIC. Methods: Staphylococcus aureus was isolated from food contact surfaces on mannitol salt agar in Kufa, Iraq. An aqueous extract of orange peel was prepared. The antimicrobial activities of the orange peel extracts against the recovered S. aureus isolates were tested using the agar well diffusion method by measuring the diameters of the inhibition zone on nutrient agar. Results: The results showed significant antibacterial activity (P<0.05) of orange peels extract at different concentrations. All tested concentrations (10-100 mg/ml) had clear antimicrobial activities against S. aureus. The minimum inhibitory concentration recorded was 10 mg/mL. Such antimicrobial activities were comparable to those of the tested antimicrobials, such as trimethoprim, vancomycin, ciprofloxacin, and chloramphenicol. The lowest anti-S. aureus activities were recorded for azithromycin and clindamycin, with no anti-S. aureus activity for tobramycin. Conclusion: Orange peel extract had antibacterial activity against S. aureus. The correlation of the exponential increase in the diameter of the inhibition zone with increasing the extract concentrations of orange peel extract was well-marked. Therefore, orange peel extracts can be used in food preparations and hand washes to inhibit S. aureus growth.