Category Archives: Food Microbiology Research

Research – Open Access Bacillus cereus Cocktail Secondary Growth Model for the Food Industry

MDPI

Abstract

A cost-effective algorithm is presented, using a virtual dataset of growth rates from a cocktail of Bacillus cereus strains, for developing an open access, extended-range secondary growth model. Extended-range growth models can span the range of processing conditions typically used in food manufacturing and are therefore more relevant for industry. The open access extended-range secondary growth model for a cocktail of B. cereus strains was created using publicly available data, and the methodology can be adapted for modelling growth of other pathogens. An extended-range model can help manage B. cereus hazards in novel food categories with non-traditional formulations as estimations of B. cereus risks in these foods become more precise. This open access model, however, needs to be validated using data from B. cereus strain cocktails isolated from production facilities. Once validated, these independent factor models are valuable tools, in a pathogen decision support platform, which are tuned to local production environments. Such a platform can address the needs of current and future food product portfolios, effectively mitigating risks associated with B. cereus and other relevant pathogens.

Research – Vibrio parahaemolyticus Foodborne Illness Associated with Oysters, Australia, 2021–2022

CDC

Abstract

The bacterium Vibrio parahaemolyticus is ubiquitous in tropical and temperate waters throughout the world and causes infections in humans resulting from water exposure and from ingestion of contaminated raw or undercooked seafood, such as oysters. We describe a nationwide outbreak of enteric infections caused by Vibrio parahaemolyticus in Australia during September 2021–January 2022. A total of 268 persons were linked with the outbreak, 97% of whom reported consuming Australia-grown oysters. Cases were reported from all states and territories of Australia. The outbreak comprised 2 distinct strains of V. parahaemolyticus, sequence types 417 and 50. We traced oysters with V. parahaemolyticus proliferation back to a common growing region within the state of South Australia. The outbreak prompted a national recall of oysters and subsequent improvements in postharvest processing of the shellfish.

Research – Investigating the Potential of L(+)-Lactic Acid as a Green Inhibitor and Eradicator of a Dual-Species Campylobacter spp. Biofilm Formed on Food Processing Model Surfaces

MDPI

Abstract

Campylobacter spp. are prevalent foodborne bacterial enteric pathogens. Their inclusion in biofilms on abiotic surfaces is considered a strategy that facilitates their extraintestinal survival. Organic acid (OA) treatments could be used in a green approach to decontaminate various surfaces. This work aimed to evaluate the inhibitory and eradicative effects of L(+)-lactic acid (LA), a naturally occurring OA, on a dual-species biofilm formed on two food processing model surfaces (polystyrene and stainless steel) by three selected foodborne Campylobacter spp. isolates (two C. jejuni and one C. coli). The influence of aerobiosis conditions (microaerophilic, aerobic and CO2 enriched) on the resistance of the established biofilms to the acid was also tested. In parallel, the predominant metabolites contained in the planktonic media of biofilm monocultures and mixed-culture biofilm were comparatively analyzed by an untargeted metabolomics approach. Results revealed that LA inhibited mixed-culture biofilm formation by more than 2 logs (>99%) on both surfaces when this was applied at its highest tested concentration (4096 μg/mL; 0.34% v/v). However, all the preformed mixed-culture biofilms (ca. 106−7 CFU/cm2) could not be eradicated even when the acid was used at concentrations exceeding 5% v/v, denoting their extremely high recalcitrance which was still influenced by the abiotic substratum, and the biofilm-forming aerobiosis conditions. The metabolic analysis revealed a strain-specific metabolite production which might also be related to the strain-specific biofilm-forming and resistance behaviors and resulted in the distinct clustering of the different samples. Overall, the current findings provide important information on the effectiveness of LA against biofilm campylobacteria and may assist in mitigating their risk in the food chain.

Researchers pioneer nanotechnology to combat E. coli in rice, strengthen food safety

Food Safety News

Researchers at the University of Texas at El Paso (UTEP) have made a major breakthrough in agricultural biotechnology, focusing on the use of nanotechnology to combat E. coli contamination in rice crops. This discovery, led by Hamidreza Sharifan and his team, offers promising solutions for improving food safety and addressing bioterrorism threats.

The research centers on the development of advanced methods to detect and mitigate the effects of pathogens, particularly E. coli, which poses a significant threat to global food systems. The team, which includes Daisy Wilson, a Ph.D. student in environmental science and engineering, and Valeria Gonzalez, a senior undergraduate in forensic science, conducted groundbreaking work in biofortification and nanoparticle application to reduce microbial contamination.

“We got an internship with the Department of Homeland Security as a team,” Wilson told The Prospector, UTEP’s student newspaper. “It was led by Dr. Sharifan, and he mentored myself and Valeria for the summer.”

Research – Listeria in Pregnancy—The Forgotten Culprit

MDPI

Listeria monocytogenes is a Gram-positive bacterium that causes listeriosis, a severe foodborne illness that is particularly dangerous during pregnancy. It thrives in diverse environments, including refrigerated conditions and food production facilities, due to its adaptability to varying temperatures, pH levels, and salt concentrations. Its virulence stems from the ability to invade host cells, particularly macrophages and epithelial cells, and avoid, or at least postpone, immune detection by utilizing virulence factors such as internalins, listeriolysin O, and actin assembly-inducing protein. This intracellular motility and biofilm formation make LM a persistent pathogen in food safety and public health. Pregnant women are at a much higher risk of listeriosis, which can result in serious fetal complications such as miscarriage, stillbirth, and preterm labor due to LM’s affinity for placental tissues. The vertical transmission of LM from mother to fetus can lead to neonatal listeriosis, which can result in sepsis and meningitis, with high mortality rates if not promptly treated. Early diagnosis and treatment with antibiotics, such as ampicillin or gentamicin, are crucial for maternal and neonatal outcomes.

Research – Is it possible to reduce foodborne Campylobacter infections in humans through vaccination of animals?

Science Direct

Vaccination has been used successfully over the years to eradicate many serious diseases, but what about human foodborne pathogens, such as Campylobacter? Most human cases of Campylobacter infection are associated with consumption of poultry products. Vaccination of poultry to prevent early colonization or to reduce the Campylobacter colonization level may be a viable intervention strategy in the future; however, no commercial Campylobacter vaccine is currently available.

Research – Impact of Various Washing Protocols on the Mitigation of Escherichia coli Contamination in Raw Salad Vegetables

MDPI

Vegetables are an essential component of a balanced diet. The consumption of ready-to-eat foods may lead to the risk of infections and illnesses due to microbial contamination. To mitigate the potential of microbial contamination risks, it is critical to promote safe handling practices among consumers. In this study, our research evaluated the efficacy of different vegetable washing methods, specifically with lettuce, tomato, and cucumber, to establish optimal practices for reducing microbial contamination. This study consisted of two phases. Initially, a survey was distributed to 150 volunteers using snowball sampling to assess everyday vegetable handling and washing methods. The survey’s results identified four predominant methods: washing with a 5% vinegar solution for 3 min followed by tap water rinse (37.3% of participants), rinsing with tap water for 1 min (29.3%), washing with a 5% salt solution (vegetable soap) for 3 min followed by a tap water rinse (16.6%), and a 3 min tap water rinse (14%). A minor segment (3.33%) reported not washing their vegetables at all. The survey’s findings guided the second phase, which tested the aforementioned washing protocols’ effectiveness in reducing Escherichia coli (E. coli) levels on spiked contaminated salad vegetables. The tested vegetables were sterilized using UV light, inoculated with 0.5 McFarland E. coli, and then washed using the four identified methods. After that, E. coli enumeration after washing was performed using 3M™ Petrifilm and the comparison was analyzed via one-way ANOVA. During this study, it was revealed that the cucumbers had the highest E. coli contamination levels in comparison to the lettuce and tomato after washing. Interestingly, by comparing the three washing methods, it was found that washing the vegetables with vinegar proved to be the most effective solution for reducing microbial presence on both lettuce and cucumbers. Notably, the natural smoothness of tomato skin led to no significant differences in contamination levels across washing methods. In summary, vinegar washing effectively reduces microbial contamination from salad vegetables, highlighting the need for informed consumer practices to prevent foodborne outbreaks. This study emphasizes the importance of monitoring contamination sources and using safe washing techniques.

Research – E. coli in Food

MAST

In light of the news of the last few days, the Swedish Food Agency considers it appropriate to emphasize several points regarding the handling of food, especially with E. coli in mind.

What is E. coli ?

There are many types of coliform bacteria. They are found in the intestines of humans and animals. Some species can produce toxins and thus cause serious diseases in people, especially children, the elderly and other vulnerable individuals. These toxin-producing E. coli bacteria are called STEC (Shiga Toxin-producing Escherichia Coli ) and can cause serious illness in some cases.

Foodborne infections due to E. coli

The bacteria can get into meat during slaughter, if the contents of the animal’s intestines come into contact with the meat. Preventive measures that reduce the chance of meat becoming contaminated are therefore important, such as clean tools and hygiene during slaughter. The bacteria can also get into vegetables, fruits and other things that are grown in close contact with soil, organic waste or water that is contaminated with feces.

People can become infected with E. coli , through contaminated food (tdhakki and vegetables) or water, through direct contact with animals or environments contaminated with their feces. The bacterium thus gets through the mouth and down into the digestive tract.

It is common practice that beef, lamb and horse steaks are served without being deep-fried. On raw pieces of meat, bacteria are on the outer layer of the meat and not inside the muscle. They are therefore killed when the meat is fried or grilled at high temperatures. Everything else applies to hamburgers and other dishes made from minced meat. When meat is minced, microorganisms spread throughout the meat. Light frying therefore does not kill bacteria present in the meat. In order to kill E. coli and other disease-causing microorganisms, the hamburgers and other mincemeat dishes must be fried through or so that the core temperature is at least 75°C.

What can consumers do to avoid infection?

  • Fully fry round hamburgers and other minced meat
  • Maintain kitchen hygiene when handling raw and minced meat
  • Avoid cross contamination by keeping meat separate from other foods, especially from those that should not be cooked such as salad
  • Rinse all vegetables in clean water
  • Wash cutting boards, utensils, knives and the surrounding area after handling raw meat to prevent the transfer of bacteria to foods that are not to be heated
  • Do not wipe up blood with a cloth used on other surfaces, use paper towels instead
  • Good hand washing with soap and water after using the toilet, before handling food and after handling raw meat is an important rule to prevent infection
  • Prevent blood from leaking from meat in the fridge
  • Avoid consumption of unpasteurized dairy products

France – Dry sausages – Listeria monocytogenes

Gov France

Product Category
Food
Product subcategory
Meats
Product brand name
Without marks
Model names or references
Dry blue sausage Dry comté sausage Dry hazelnut sausage Chorizo ​​Plain troquet Hazelnut troquet Comté troquet Chorizo ​​troquet
Product identification
Batch
Fab02/08/204
Start/End of marketing date
From 08/27/2024 to 10/13/2024
Storage temperature
Product to be stored at room temperature
Health mark
FR01.202.002CE
Geographic area of ​​sale
Amberieu en Bugey. Saint Maurice of Gourdans
Distributors
Sylak coffee without pressure

Irish Seafood Agency Reveals Major Incidents in 2023

Food Safety News

An Irish agency responsible for seafood safety has published its annual report, revealing the number of food safety incidents investigated in 2023.

The Sea-Fisheries Protection Authority (SFPA) was involved in 25 reports of alleged illnesses following the consumption of fishery products or live bivalve mollusks.

Sea-Fisheries Protection Officers (SFPOs) carried out 2,297 food safety official controls across 2,325 premises. Of these checks, 535 were inspections of approved establishments, and 1,553 consisted of official controls, such as checks prior to certifying a consignment of food being exported to a non-EU country and temperature and labeling checks.