Category Archives: Decontamination Microbial

Research – Drought-stressed maize is more likely to present mycotoxin risk.

The Cattle Site

The extremely hot weather this summer has meant many maize forage crops have grown under drought stressed conditions, which has increased the likelihood of in-field mycotoxins developing, according to UK agricultural supply company Wynnstay.

Wynnstay dairy specialist Beth Parry urges dairy farmers to be aware of this heightened mycotoxin risk when feeding maize forage this autumn and winter.

“With potentially limited forage stocks following a difficult growing season, farmers are going to need to maximise feed utilisation and digestion to ensure performance isn’t impacted too greatly this winter,” she said.

“In-field mycotoxins are more likely to be present in silages if the crop experienced any kind of stress, such as growing in drought conditions, because moulds and fungi will have had more opportunity to take hold and produce mycotoxins,” she added.

Research – Zearalenone and Its Masked Forms in Cereals and Cereal-Derived Products: A Review of the Characteristics, Incidence, and Fate in Food Processing

MDPI

Zearalenone (ZEA) is known as a Fusarium-produced mycotoxin, representing a risk to cereal food safety with repercussions for economies and worldwide trade. Recent studies have reported the co-occurrence of ZEA and masked ZEA in a variety of cereals and cereal-based products, which may exert adverse effects on public health due to additive/synergistic interactions. However, the co-contamination of ZEA and masked ZEA has received little attention. In order to minimize the threats of co-contamination by ZEA and masked ZEA, it is necessary to recognize the occurrence and formation of ZEA and masked ZEA. This review focuses on the characteristics, incidence, and detection of ZEA and its masked forms. Additionally, the fate of ZEA and masked ZEA during the processing of bread, cake, biscuits, pasta, and beer, as well as the ZEA limit, are discussed. The incidence of masked ZEA is lower than that of ZEA, and the mean level of masked ZEA varies greatly between cereal samples. Published data showed a considerable degree of heterogeneity in the destiny of ZEA during cereal-based food processing, mostly as a result of the varying contamination levels and complicated food processing methods. Knowledge of the fate of ZEA and masked ZEA throughout cereal-based food processing may reduce the likelihood of severe detrimental market and trade ramifications. The revision of legislative limits of masked ZEA may become a challenge in the future. View Full-Text

Research – Interactions Between Infectious Foodborne Viruses and Bacterial Biofilms Formed on Different Food Contact Surfaces

Springer

Bacterial biofilms contribute to contamination, spoilage, persistence, and hygiene failure in the food industry, but relatively little is known about the behavior of foodborne viruses evolving in the complex communities that make up biofilm. The aim of this study was to evaluate the association between enteric viruses and biofilms on food contact surfaces. Formed biofilms of mono- and multispecies cultures were prepared on glass, stainless steel, and polystyrene coupons and 105 pfu/ml of murine norovirus, rotavirus, and hepatitis A virus were added and incubated for 15 min, 90 min, and 24 h. The data obtained clearly demonstrate that the presence of biofilms generally influences the adhesion of enteric viruses to different surfaces. Many significant increases in attachment rates were observed, particularly with rotavirus whose rate of viral infectious particles increased 7000 times in the presence of Pseudomonas fluorescens on polystyrene after 24 h of incubation and with hepatitis A virus, which seems to have an affinity for the biofilms formed by lactic acid bacteria. Murine norovirus seems to be the least influenced by the presence of biofilms with few significant increases. However, the different factors surrounding this association are unknown and seem to vary according to the viruses, the environmental conditions, and the composition of the biofilm.

Research – Pulsed Light Application for Campylobacter Control on Poultry Meat and Its Effect on Colour and Volatile Profile

MDPI

Campylobacter on poultry meat needs to be controlled to reduce the risk of infection caused by the consumption of chicken meat. Pulsed light (PL) application on poultry meat was studied to control Campylobacter spp. The effect of this technology was evaluated regarding poultry meat colour and volatile compound changes. Two breast sample groups were prepared: inoculated with Campylobacter (107 bacteria of Campylobacter jejuni strains) and not inoculated. Samples were submitted to PL, five pulses/s of 300 ms, 1 Hz, and 1 J/cm2 in the apparatus, PL Tecum unit (Claranor). A response surface experimental design was applied regarding the factors of voltage (1828 to 3000 W) and distance to the source UV lamp (2.6 to 5.4 cm). The binomial factorial treatment (voltage and distance) with PL induced different energy doses (fluence J/cm2) received by samples, 2.82 to 9.67 J/cm2. Poultry meat pulsed light treated had a significant decrease of Enterobacteriaceae counts. The treatments applied were unable to reduce 1 log Campylobacter cfu/g of poultry meat. The poultry meat PL treated became slightly light, redder, and yellower than those not treated. PL can decrease the proportion of aldehydes on total volatiles in meat, particularly on those associated with chicken-like, chicken skin-like, and sweet odour notes in fresh poultry meat. Further studies of PL with higher energy doses will be necessary to confirm if there are Campylobacter reductions and about poultry meat treated under storage to evaluate if volatile compounds can affect the flavour of PL-treated meat samples. View Full-Text

Research – Cross-Contamination to Surfaces in Consumer Kitchens Using MS2 as a Tracer Organism in Ground Turkey Patties

Journal of Food Protection

It is estimated that one in five cases of foodborne illnesses is acquired in the home. However, how pathogens move around a kitchen environment when consumers are preparing food is not well characterized. The purpose of this study was to determine the prevalence and degree of cross-contamination across a variety of kitchen surfaces during a consumer meal preparation event. Consumers (n=371) prepared a meal consisting of turkey patties containing the bacteriophage MS2 as a tracer organism and a ready-to-eat lettuce salad. Half were shown a video on proper thermometer use before the trial. After meal preparation, environmental sampling and detection were performed to assess cross-contamination with MS2. For most surfaces, positivity did not exceed 20%, with the exception of spice containers, for which 48% of the samples showed evidence of MS2 cross-contamination. Spice containers also had the highest MS2 concentrations, at a mean exceeding 6 log 10 viral genome equivalent copies (GEC) per surface. The high level of MS2 on spice containers drove the significant differences between surfaces, suggesting the significance of spice containers as a vehicle for cross-contamination, despite the absence of previous reports to this effect. The thermometer safety intervention did not affect cross-contamination. The efficiency of MS2 transfer, when expressed as a percentage, was relatively low, ranging from an average of 0.002 to 0.07%. Quantitative risk assessment work using these data would aid in further understanding the significance of cross-contamination frequency and efficiency. Overall, these data will help create more targeted consumer messaging to better influence consumer cross-contamination behaviors.

Research – Genetic Diversity and Potential Virulence of Listeria monocytogenes Isolates Originating from Polish Artisanal Cheeses

MDPI

Artisanal cheeses can be sources of Listeria monocytogenes and cause disease in humans. This bacterial pathogen is a species of diverse genotypic and phenotypic characteristics. The aim of the study was to characterize 32 isolates of L. monocytogenes isolated in 2014–2018 from artisanal cheeses. The isolates were characterized using whole genome sequencing and bioinformatics analysis. The artisanal cheese isolates resolved to four molecular groups: 46.9% of them to IIa (1/2a-3a), 31.2% to IVb (4ab-4b-4d-4e), 12.5% to IIc (1/2c-3c), and 9.4% to IIb (1/2b-3b-7). Two evolutionary lineages emerged: lineage II having 59.4% of the isolates and lineage I having 40.6%. The sequence types (ST) totaled 18: ST6 (15.6% of the isolates), ST2, ST20, ST26, and ST199 (each 9.4%), ST7 and ST9 (each 6.3%), and ST1, ST3, ST8, ST16, ST87, ST91, ST121, ST122, ST195, ST217, and ST580 (each 3.1%). There were 15 detected clonal complexes (CC): CC6 (15.6% of isolates), CC9 (12.5%), CC2, CC20, CC26, and CC199 (each 9.4%), CC7 and CC8 (each 6.3%), and CC1, CC3, CC14, CC87, CC121, CC195, and CC217 (each 3.1%). The isolates were varied in their virulence genes and the differences concerned: inlactA, LIPI-3, amigtcAautvip, and lntAView Full-Text

RASFF Alerts – Animal Feed – Salmonella – Feather Meal – Soy Flour – Soya Bean Meal

RASFF

Salmonella in feather meal from Russia in Poland and Hungary

RASFF

Salmonella Senftenberg in soy flour from Hungary, via the Netherlands in Italy, Slovenia and Belgium

RASFF

Salmonella Yoruba in Soya bean meal from NL in Finland

Research – Effect of sub-lethal treatment of carvacrol and thymol on virulence potential and resistance to several bactericidal treatments of Staphylococcus aureusResearch –

Journal of Food Protection

This study examined the changes in biofilm-formation ability, hemolytic/lipase/nuclease/protease activities, and resistance to various bactericidal treatments of Staphylococcus aureus after sublethal treatment with carvacrol and thymol. The minimum inhibitory concentrations (MICs) of carvacrol and thymol for S. aureus were 0.4 and 0.3 mg/ml, respectively, and sublethal concentrations (1/2 and 1/4 MIC) were determined based on these concentrations. Sublethal treatment with carvacrol and thymol did not change the protease and lipase activities but reduced the hemolytic and nuclease activities of S. aureus. After sublethal treatment with carvacrol and thymol, the biofilm-formation ability of S. aureus was decreased, which was found to be due to the decrease in cell surface hydrophobicity. In addition, after sublethal treatment with carvacrol and thymol, the resistance of S. aureus to heating and malic acid treatments increased, whereas resistance to ultraviolet and hypochlorous acid (HOCl) decreased, and resistance to hydrogen peroxide (H2O2) did not change. The results of this study show that sublethal treatment with carvacrol and thymol can effectively suppress some virulence factors of S. aureus and that applying HOCl or ultraviolet radiation would be an effective subsequent treatment to inactivate S. aureus after sublethal treatment.

New Zealand – Public health warning for shellfish reduced for West Coast, North Island – PSP Toxins

MPI

New Zealand Food Safety today reduced a public health warning against collecting shellfish in the Waikato and Taranaki region. The public health warning now extends from Albatross Point south to Oakura Beach and no longer applies to Kawhia and Aotea Harbours. More testing is being undertaken to determine the levels of paralytic shellfish toxins in the affected area.

Routine tests on shellfish samples taken from the Aotea/Kawhia Harbour area have shown levels of Paralytic Shellfish Poisoning (PSP) toxins are now within the safe limit of 0.8 mg/kg set by New Zealand Food Safety.

Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina (sea urchin), and all other bivalve shellfish should not be eaten.

Note, cooking shellfish does not remove the toxin.

Pāua, crab, and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed, its contents could contaminate the meat during the cooking process.

Symptoms typically appear between 10 minutes and 3 hours after ingestion and may include:

  • numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
  • difficulty swallowing or breathing
  • dizziness
  • headache
  • nausea
  • vomiting
  • diarrhoea
  • paralysis and respiratory failure and in severe cases, death.

If anyone becomes ill after eating shellfish from an area where a public health warning has been issued, phone Healthline for advice on 0800 61 11 16, or seek medical attention immediately. You are also advised to contact your nearest public health unit and keep any leftover shellfish in case it can be tested.

Monitoring of toxin levels will continue and any changes will be communicated accordingly. Commercially harvested shellfish – sold in shops and supermarkets, or exported – is subject to strict water and flesh monitoring programmes by MPI to ensure they are safe to eat.

USA – E. coli at San Diego State University

Food Poison Journal

On Sept. 6, Student Health Services notified the SDSU community of two cases of Shiga Toxin-Producing E. coli (STEC) in the student community in one residential and one non-residential student.  These students began experiencing symptoms on Aug. 27 and 29, respectively.

At this time, a specific food source has not been identified for either of these cases. SDSU’s Environmental Health and Safety team is working closely with the County of San Diego Health & Human Services Agency to investigate these cases and to identify and confirm the potential source. Additional information will be shared with the community as it becomes available.