Category Archives: Decontamination Microbial

Research – Underreported Human Exposure to Mycotoxins: The Case of South Africa

MDPI

South Africa (SA) is a leading exporter of maize in Africa. The commercial maize farming sector contributes to about 85% of the overall maize produced. More than 33% of South Africa’s population live in rural settlements, and their livelihoods depend entirely on subsistence farming. The subsistence farming system promotes fungal growth and mycotoxin production. This review aims to investigate the exposure levels of the rural population of South Africa to dietary mycotoxins contrary to several reports issued concerning the safety of South African maize. A systematic search was conducted using Google Scholar. Maize is a staple food in South Africa and consumption rates in rural and urban communities are different, for instance, intake may be 1–2 kg/person/day and 400 g/person/day, respectively. Commercial and subsistence maize farming techniques are different. There exist differences influencing the composition of mycotoxins in food commodities from both sectors. Depending on the levels of contamination, dietary exposure of South Africans to mycotoxins is evident in the high levels of fumonisins (FBs) that have been detected in SA home-grown maize. Other potential sources of exposure to mycotoxins, such as carryover effects from animal products and processed foods, were reviewed. The combined effects between FBs and aflatoxins (AFs) have been reported in humans/animals and should not be ignored, as sporadic breakouts of aflatoxicosis have been reported in South Africa. These reports are not a true representation of the entire country as reports from the subsistence-farming rural communities show high incidence of maize contaminated with both AFs and FBs. While commercial farmers and exporters have all the resources needed to perform laboratory analyses of maize products, the greater challenge in combatting mycotoxin exposure is encountered in rural communities with predominantly subsistence farming systems, where conventional food surveillance is lacking.

Research – Aflatoxins Contamination in Raw and Roasted Cashew nuts in Mtwara, Tanzania

AJMR

The aim of this work was to determine the contamination levels of raw and roasted cashew nuts sold in Masasi and Newala districts of Mtwara region in Tanzania. A total of 60 samples including 40 roasted (24 samples from Newala and 16 from Masasi) and 20 raw samples (12 from Newala and 8 from Masasi) were collected. Determination of total aflatoxins levels in raw and roasted cashew nuts samples was carried out by immune affinity high performance liquid chromatography (HPLC). The levels of contamination ranged from not detected (less than Limit of Quantification) to 3.29 µg/kg for both aflatoxin B1 and total aflatoxin in the cashew nuts samples. None of the samples had total aflatoxins contamination greater than the recommended maximum residues of 4 µg/kg set by European Commission (2010) or 10 µg/kg set by FAO and WHO (1995). About a quarter (38%) of the samples had total aflatoxins less than limit of quantification. All roasted cashew nut samples were found to have total aflatoxins less than 3 µg/kg while about 86% of raw cashew nut samples had total aflatoxins less than 3 µg/kg.

Research – Examining the Effect of Organic Acids on Inactivation of Hepatitis E Virus

Journal of Food Protection

Infection with hepatitis E virus genotype 3 (HEV-3) is an emerging cause of illness in developed countries. In North America and Europe, HEV-3 has been increasingly detected in swine, and exposure to pigs and pork products is considered the primary source of infection. We have previously demonstrated the prevalence of the HEV-3 genome in commercial pork products in Canada. In this study, we investigated the application of citric acid and acetic acid to inactivate HEV-3 on food and on food-contact surfaces. For this purpose, plastic, stainless steel and pork pâté surfaces were inoculated with HEV-3 and were treated with acetic acid or citric acid at 1%, 3%, or 5%. The infectivity of post treatment viral particles was determined by cell culture. A greater than 2-log reduction in viral infectivity was observed on plastic and stainless steel treated with the organic acids, but the treatment was much less effective on HEV infectivity on pork pâté (average reductions of 0.47 log citric acid, and 0.63 log acetic acid). Therefore, we conclude that citric acid and acetic acid have potential application to control HEV-3 on food contact surfaces, but are not suitable for food.

Research Paper Sunlight Parameters Influence the Survival and Decline of Salmonella and Escherichia coli in Water

Journal of Food Protection

The effect of variations in temperature, ultraviolet (UV) radiation, and sunlight intensity on generic Escherichia coli , E. coli O157:H7, Salmonella Newport and antibiotic resistant (ABR) variants of E. coli O157:H7 and S . Newport exposed to sunlight was evaluated. Bacterial strains suspended in sterile deionized water at a concentration of 8 log CFU/ml were exposed to sunlight on three different days for 180 min; control treatments were stored in the dark. The mean temperature of 30.08 and 26.57℃ on day 1 and 3 were significantly different (p<0.05). The UV intensity was significantly different on all three days and sunlight intensity significantly differed on day 3 (p<0.05). Bacterial population decline positively correlated with temperature, sunlight and UV intensity. Differences in bacterial population declines differed among specie, antibiotic resistance (ABR) profile and day of exposure. (p<0.05). On days 1 and 2, the populations of generic E. coli dropped below the limit of detection (1 log CFU/ml) while the % of live cells was 67% and 6.6% respectively. The artificial neural network model developed to predict bacterial survival under different environmental conditions suggested that Salmonella cells were more resistant than E. coli . The ABR strains had significantly higher viable cells after sunlight exposure (p<0.05). Sunlight exposed cells resuscitated in TSB varied in maximum population density and maximum growth rate based on bacterial species and presence of antibiotic resistance. Morphological changes such as viable but non-culturable (VBNC) state transition and filament formation was detected in sub-populations of sunlight exposed bacteria. Daily fluctuations in UV and sunlight intensity can result in significant variations in bacterial decline and recovery.

Ireland – Four Enforcement Orders served on food businesses in August

FSAI

The Food Safety Authority of Ireland (FSAI) today reported that three Closure Orders and one Prohibition Order were served on food businesses during the month of August for breaches of food safety legislation, pursuant to the European Union (Official Controls in Relation to Food Legislation) Regulations, 2020 and the FSAI Act, 1998. The Enforcement Orders were issued by environmental health officers (EHOs) in the Health Service Executive (HSE) and sea-fisheries protection officers in the Sea-Fisheries Protection Authority (SFPA).

Three Closure Orders were served under European Union (Official Controls in Relation to Food Legislation) Regulations, 2020 on:

  • Zing by Chaska (restaurant/café), 90-91 Marlborough Street, Dublin 1
  • Fredis Pizzeria, Market Square, Bailieborough, Cavan
  • New Victoria (take away), 51 Dorset Street Upper, Dublin 1

One Prohibition Order, which is under appeal, was served under the FSAI Act 1998 on:

  • MFV Nausicaa DA63 (under appeal) (fishing vessel), County Dublin

Some of the reasons for the Closure Orders in August include: frozen chicken was defrosted unsafely with the surface of the chicken warming to 12 degrees Celsius while the core of the chicken remained frozen; safe procedures for cooling hot food were not followed; temperature-sensitive ready-to-eat foods were consistently kept at temperatures likely to result in a risk to health e.g. pasta salad stored in chilled food display unit in the buffet had a temperature of 14.3 degrees Celsius; adequate procedures were not in place to control pests; a lack of evidence of proper hand-washing procedures; a broken water heater left the proprietor unable to adequately clean or disinfect working utensils and equipment; despite the presence of a copy of the FSAI’s Safe Catering Pack, there was no evidence to prove that procedures detailed within had been fully implemented and maintained.

USA – Leafy Greens STEC Action Plan

FDA

Leafy greens are among the most widely consumed vegetables and an important part of an overall healthy diet. However, while millions of servings are consumed safely every day, leafy greens have been repeatedly associated with illnesses caused by Shiga toxin-producing E. coli (STEC), the most common of which is E. coli O157:H7. FDA is committed to breaking this cycle of reoccurring outbreaks.

Over the last several years the FDA and partners in the public and private sectors have worked to enhance the safety of leafy greens through the development and implementation of the Leafy Greens STEC Action Plan (LGAP). This work includes prioritized inspections, focused sampling, stakeholder engagement and collaboration, data sharing, root cause investigations, and advancements in the science of detection and prevention.

Collectively, this work has expanded our body of knowledge about how and why outbreaks linked to leafy greens have occurred, which has guided and informed the evolution of the action plan over the years. Still, we know that we cannot fix the issue of leafy green contamination on our own. Industry leadership, along with collaboration among growers, processors, retailers, state partners, and the broader agricultural community, is critical to establishing needed prevention measures and preventing foodborne illness.

The following table provides the approaches for three priority areas: Prevention, Response, and Addressing Knowledge Gaps, as well as accomplishments that have been made since the action plan launched in March 2020.

USA – FDA Core Table – Investigations of Foodborne Illness Outbreaks

FDA

What’s New

  • For the Salmonella Mississippi outbreak (ref# 1097) in a not yet identified product, the case count has increased from 99 to 100 cases.
  • For the Salmonella Senftenberg outbreak (ref# 1087) in a not yet identified food, the case count has increased from 22 to 27 cases.
  • For the Salmonella Typhimurium outbreak (ref# 1095) in a not yet identified food, the case count has increased from 73 to 78 cases.
  • For the Cyclospora outbreak (ref# 1080) the case count has increased from 75 to 79 cases.
  • For the Salmonella Braenderup outbreak (ref# 1075) the FDA investigation has closed. A product linked to illnesses was not identified.
  • The investigation associated with Dry Cereal (ref # 1064) has ended and the FDA investigation has closed with no pathogen or cause of the self-reported illnesses identified, despite extensive testing for numerous potential microbial and chemical adulterants.

RASFF Alerts – Animal Feed – Salmonella – Raw Pet Food – Whole Egg Powder

RASFF

Enterobacertiaceae and Salmonella spp. in raw pet food for fish from Thailand in Germany

RASFF

Salmonella spp. in whole egg powder, processed into pet- food from Germany in Switzerland and Austria

Research – Transmission of Cryptosporidium by Fresh Vegetables

Journal of Food Protection

water contamination

Consumption of fresh fruits and vegetables is increasing thanks to the awareness to the benefits to human health. Vegetables may become contaminated by enteric pathogens (protozoan parasites, bacteria and viruses) by irrigation with contaminated water, fertilization with fresh animal manure or by infected food handlers. Cryptosporidium spp. are fecal-oral protozoan parasites, known to be highly persistent in the environment, which facilitate the transmission of the infectious oocysts. Efficient methods were developed for releasing and concentrating Cryptosporidium oocysts from leafy vegetables and sensitive and specific methods were applied for their enumeration. The aims of this review are to discuss the development and optimization of methods applied to release oocysts from leafy vegetables, the prevalence of Cryptosporidium oocysts on fresh leafy vegetables from various parts of the world and to discuss cryptosporidiosis outbreaks resulting from the consumption of leafy vegetables. Three solutions were used with comparable efficiency to release oocysts from leafy vegetables 1M glycine solution, 0.1% Alconox and filter elution buffer with an efficiency of 36.2%, 72.6% and 44%, respectively. The prevalence of Cryptosporidium oocysts was reported in developed as well as from developing countries, although simple detection methods were applied. Most of the cryptosporidiosis outbreaks were reported in developed countries, which can be related to their efficient surveillance system. Transmission of infectious pathogens, such as Cryptosporidium may be facilitated by fresh vegetables, which are imported and transferred from less developed to highly developed countries and consumed uncooked. Monitoring of Cryptosporidium oocysts by sensitive detection methods may enhance measures to prevent their transmission by freshly consumed vegetables.

Research – Influence of Different Stainless-Steel Finishes on Biofilm Formation by Listeria monocytogenes

Journal of Food Protection

Biofilm formation of L. monocytogenes on stainless steel, a widely used abiotic surface in the food processing industry was investigated, focusing on the attachment tendency and behavior of L. monocytogenes 08-5578 on eight different Stainless-steel surfaces: glass bead blasted (rough and fine), deburred (Timesaver), drum deburred, pickled, pickled and drum polished, electrolytic polished and cold rolled (untreated control). The aim was to see if there are finishes with significant lower bacterial attachment. Roughness properties (Ra, Rt, Rz, RSm; determined by interferometry) were also compared with number of adhering cells to detect possible correlations. Cultivation of L. monocytogenes biofilms was carried out using a CDC biofilm reactor (CBR) with 1% TSB set at 20°C for 4, 8, and 24 h. Additionally, a cultivation trial was run with continuous nutrient flow (1% TSB, 6.2 ml/min) for 24 h. Eight hour results showed significant difference ( P < 0.05) in biofilm cell counts in biofilms between the glass bead blasted surfaces (3.23 and 3.26 log CFU/cm 2 for the fine and rough, respectively) and deburred (Timesaver) surface (2.57 log CFU/cm 2 ); between drum deburred and deburred (Timesaver) surface (3.41 vs 2.57 log CFU/cm 2 ); between drum deburred and pickled surface (3.41 vs 2.77 log CFU/cm 2 ). Data gained after 4, 24 h and the additional 24 h continuous flow cultivation showed no significant difference in attachment among surfaces. No correlation between roughness data and attachment was found after all 4 incubation times, suggesting that roughness values, at these ranges, are insufficient in determining surfaces’ affinity to bacteria. This study suggests that roughness values cannot be used to predict the degree of L. monocytogenes attachment to a specific stainless steel surface.