The purpose of this study was to evaluate the antimicrobial efficacy of an aqueous ozone (Bio-Safe) treatment andtech lactic acid solutions on natural microbiota and E. coli O157:H7 and Salmonella surrogates on beef carcasses and trim in a commercial beef processing plant. For every repetition, 40 carcass and 40 trim swabs (500 cm2) were collected. Samples were taken using EZ-ReachTM swabs, and plated into aerobic plate count (APC), coliform, and E. coli PetrifilmTM for enumeration. In addition, a five-strain cocktail (MP-26) of E. coli surrogates was inoculated onto trim. For every trim surrogate repetition, 30 trim pieces were sampled after attachment and after ozone intervention. Samples were diluted and counts were determined using the TEMPO® system for E. coli enumeration. Ozone and lactic acid interventions significantly reduced (p < 0.003) bacterial counts in carcasses and trim samples. Moreover, lactic acid further reduced APC and coliforms in trim samples compared to ozone intervention (p < 0.009). In the surrogate trials, ozone significantly reduced (p < 0.001) surrogate concentration. Historical data from the plant revealed a reduction (p < 0.001) of presumptive E. coli O157:H7 in trim after a full year of ozone intervention implementation. The novel technology for ozone generation and application as an antimicrobial can become an alternative option that may also act synergistically with existing interventions, minimizing the risk of pathogens such as Salmonella and E. coli O157:H7. View Full-Text
Traditionally, Salmonella isolates are separated into serotypes based on structural differences on the surface of the cells (O antigens) and thread‑like portions of the flagella (H antigens), using the Kauffman-White classification scheme. In this technique, antibodies are prepared against these specific antigens in a blood serum known as antiserum. Confirmed Salmonella sp. isolates are then tested with this antisera and are observed for agglutination reactions.
Through testing unknown samples against a series of antisera, the specific serotype of an isolate can be discerned. As previously discussed, there are a great number of serological variants of Salmonella and so this process can be very long and labour intensive, requiring highly experienced staff with a vast library of antisera at their disposal. Because of this, the Kauffman-White serotyping method is often only carried out by reference laboratories, with routine microbiology laboratories only stocking a small number of antisera.
As an example, at ALS Rotherham we stock the antisera for our in-house control strain, Salmonella enterica subsp. enterica ser. Nottingham, which enables us to distinguish our strain from others using the antisera O16, Henz15 and Hd. This serotype is recommended by the health protection agency in the UK for use as a control strain, due to being a very rare serotype and thus very unlikely to be isolated as a wild type. Historically, when further analysis was required for one of our samples, the isolates would be subcontracted to a reference laboratory capable of full serological testing. For a plethora of reasons, this type of analysis all too often had a lengthy turnaround time which, while accurate, was often too little too late and unhelpful in making a practical difference to our client, the FBO (food business operator).
Research has identified critical factors that enable dangerous bacteria to spread disease by surviving on surfaces in hospitals and kitchens.
The study into the mechanisms which enable the opportunistic human pathogen Pseudomonas aeruginosa to survive on surfaces, could lead to new ways of targeting harmful bacteria.
To survive outside their host, pathogenic bacteria must withstand various environmental stresses. One mechanism is the sugar molecule, trehalose, which is associated with a range of external stresses, particularly osmotic shock — sudden changes to the salt concentration surrounding cells.
Researchers at the John Innes Centre analysed how trehalose is metabolised by P. aeruginosa to define its role in protection against external stresses.
Combining analytical biochemistry and reverse genetics — using mutated bacteria lacking key functions — they show that trehalose metabolism in P. aeruginosa is connected to biosynthesis of the carbon storage molecule glycogen.
Experiments showed that disruption of either trehalose or glycogen pathways significantly reduced the ability of P. aeruginosa to survive on human-made surfaces such as kitchen or hospital counters.
The study found that while both trehalose and glycogen are important for stress tolerance in P. aeruginosa they counter distinct stresses: trehalose helps the bacteria to survive in conditions of elevated salt; glycogen contributes to survival in dry (desiccated) environments.
The findings raise the possibility of targeting the trehalose and glycogen pathways to limit pathogen survival on human-made surfaces.
“We have shown how a dangerous human pathogen Pseudomonas aeruginosa responds to environmental challenges, such as salt stress or drying out. Disrupting the production of certain stress-tolerance sugars in this bug significantly reduces its ability to survive on kitchen and hospital worksurfaces,” said corresponding author of the study Dr Jacob Malone.
An unexpected finding was how the bacteria operates different pathways for different stresses, said Dr Malone: “Conventional wisdom says that trehalose was responsible for both phenotypes, but we have shown that trehalose only protects against osmo-stress and glycogen is needed to protect against desiccation. We were also surprised to see such a marked drop in surface survival when we disrupted the pathways in the bugs.”
The next step for the research is to understand how trehalose and glycogen metabolic pathways are regulated in P. aeruginosa and closely related species. The group also wants to understand how glycogen accumulation allows the bacteria to survive in dry environments and provide more explanation of how and when different parts of the pathways are turned on and off.
P. aeruginosa is a significant pathogen in animals as well as humans. In humans it primarily affects immunocompromised individuals, where it is a major cause of pneumonia and hospital-acquired infections. Chronic P. aeruginosa infections occur in 80% of adult cystic fibrosis patients, where it is the primary cause of morbidity and mortality.
Stuart D. Woodcock, Karl Syson, Richard H. Little, Danny Ward, Despoina Sifouna, James K. M. Brown, Stephen Bornemann, Jacob G. Malone. Trehalose and α-glucan mediate distinct abiotic stress responses in Pseudomonas aeruginosa. PLOS Genetics, 2021; 17 (4): e1009524 DOI: 10.1371/journal.pgen.1009524
The present study was designed to investigate whether near infrared (NIR) spectroscopy with minimal sample processing could be a suitable technique to rapidly measure histamine levels in raw and processed tuna fish. Calibration models based on orthogonal partial least square regression (OPLSR) were built to predict histamine in the range 10–1000 mg kg−1 using the 1000–2500 nm NIR spectra of artificially-contaminated fish. The two models were then validated using a new set of naturally contaminated samples in which histamine content was determined by conventional high-performance liquid chromatography (HPLC) analysis. As for calibration results, coefficient of determination (r2) > 0.98, root mean square of estimation (RMSEE) ≤ 5 mg kg−1 and root mean square of cross-validation (RMSECV) ≤ 6 mg kg−1 were achieved. Both models were optimal also in the validation stage, showing r2 values > 0.97, root mean square errors of prediction (RMSEP) ≤ 10 mg kg−1 and relative range error (RER) ≥ 25, with better results showed by the model for processed fish. The promising results achieved suggest NIR spectroscopy as an implemental analytical solution in fish industries and markets to effectively determine histamine amounts. View Full-Text
The main pathogenic bacteria in food are Campylobacter and Salmonella. But Listeria in cheese and enterohemorrhagic Escherichia coli (ECEH) bacteria in young shoots have also made headlines in recent years.
Current
Smoked fish, what are the health risks?
04/16/2021 – Smoked fish are popular specialties in Switzerland. Consumed without cooking, they can become a food safety concern if hygiene rules are not respected during processing.
An assessment of the dietary risks associated with smoked fish was carried out as part of a pilot study in collaboration with the Office for Consumer Affairs of the canton of Vaud.
The study did not reveal any major risk, but follow-up should be ensured in order to maintain a high level of food safety and quality. The cantonal authorities concerned will keep this topic in their monitoring program and the FSVO plans to carry out a more detailed assessment.
Likewise, it is very important to wash your hands after coming into contact with animal products, as Campylobacter, Salmonella, Listeria and EHEC are transmitted from animals to humans. These diseases are called zoonoses.
Campylobacter
Infection with Campylobacter bacteria is the most common zoonosis in Switzerland, as in other European countries. It is the cause of gastrointestinal diseases in humans. The illness can last for about a week and in some circumstances may require hospitalization.
Campylobacter infection is characterized by abdominal pain, watery or bloody diarrhea, and an increase in temperature. Vomiting and high fever can also occur.
Infection is caused by contaminated food that has not been sufficiently cooked before consumption or that has come into direct contact with animals. In southern countries, contaminated water sources also represent a significant risk. The main source of infection, however, remains poultry meat.
According to data from the Federal Office of Public Health (OFSP), there are around 1,000 cases of Campylobacter infections each year. All patients do not consult their doctor, this figure is actually much higher. Overall, the number of cases has grown steadily over the past few years to reach around 7,500 during the year 2014.
Prevent Campylobacter infections
Campylobacter bacteria can survive in food, but cannot multiply there. Since contamination by Campylobacter does not affect foodstuffs, it is not possible to identify their presence by smell or appearance.
Campylobacter can be safely eliminated by thoroughly cooking the food at 70 ° C for at least 2 minutes by roasting, cooking or pasteurization. Freezing the food reduces the number of Campylobacter, without eliminating them completely.
Salmonella
Salmonella infection is most often manifested by inflammatory bowel disease with sudden onset of diarrhea, nausea, vomiting, fever, headache and abdominal pain. Salmonella infections are subject to notification .
They usually occur by ingesting contaminated food. The danger comes mainly from poultry, eggs, egg preparations, unpasteurized milk and meat products. Contamination through other animal products, utensils used, water, humans, etc. can occur throughout the food manufacturing process.
Prevent salmonellosis
Salmonella infections are fought on two levels:
the number of infected domestic animals should be reduced;
contamination of food with salmonella must be avoided and their multiplication stopped.
Listeria
In people without weakened immune systems, a Listeria infection is usually accompanied by mild symptoms or even no symptoms at all. People who are immunocompromised can experience a variety of serious symptoms, the outcome of which can be fatal. During pregnancy, a Listeria infection can lead to miscarriage or cause a child to have sepsis or meningitis when it is born.
Listeria transmission is caused by the ingestion of contaminated raw food, mainly of animal origin: meat, smoked fish, cold cuts, soft cheese. Transmission through contact with infected animals is rarer.
Prevent listeriosis
In the first place, the general rules of hygiene should be observed when in contact with food and animals. Pregnant women and people with weakened immune systems should in particular avoid raw vegetables, raw or undercooked meat as well as raw fish and seafood, soft cheese and cheese made from unpasteurized milk. .
Enterohemorrhagic Escherichia coli (EHEC)
The majority of people infected with EHEC have abdominal pain accompanied by cramping, a short-term fever followed by intestinal colic which becomes violent, and slightly bloody hemorrhagic diarrhea. In a minority of people, only watery diarrhea is observed. Cases of EHEC infections are very rare in Switzerland. The mortality rate reaches 3 to 5%.
Escherichia coli bacteria naturally belong to our intestinal flora. EHECs are a pathogenic line of these generally harmless bacteria. Infection occurs first by consuming contaminated animal foods, mainly undercooked ground beef and unpasteurized dairy products. Contaminated drinking water, young shoots, potatoes and unpasteurized apple juice can, for example, also contain EHEC. More rarely, cases of transmission of EHEC are observed through contact with animals or animal faeces.
Prevent EHEC infections
Since a very small number of infectious agents is enough to get sick, it is important to follow the general rules of hygiene. It is therefore strongly recommended to wash your hands thoroughly after having been in contact with animals and to cook the meat thoroughly when preparing meals. Raw food should always be stored in the refrigerator.
Spore-forming bacteria are a great concern for fruit juice processors as they can resist the thermal pasteurization and the high hydrostatic pressure treatments that fruit juices receive during their processing, thus reducing their microbiological quality and safety. In this context, our objective was to evaluate the efficacy of Ultraviolet-C (UV-C) light at 254 nm on reducing bacterial spores of Alicyclobacillus acidoterrestris, Bacillus coagulans and Bacillus cereus at two stages of orange juice production. To simulate fruit disinfection before processing, the orange peel was artificially inoculated with each of the bacterial spores and submitted to UV-C light (97.8–100.1 W/m2) with treatment times between 3 s and 10 min. The obtained product, the orange juice, was also tested by exposing the artificially inoculated juice to UV-C light (100.9–107.9 W/m2) between 5 and 60 min. A three-minute treatment (18.0 kJ/m2) reduced spore numbers on orange peel around 2 log units, while more than 45 min (278.8 kJ/m2) were needed to achieve the same reduction in orange juice for all evaluated bacterial spores. As raw fruits are the main source of bacterial spores in fruit juices, reducing bacterial spores on fruit peels could help fruit juice processors to enhance the microbiological quality and safety of fruit juices. View Full-Text
Bacillus cereus, which causes foodborne disease, is detected using selective media. However, competing flora is the most common factor preventing the correct enumeration of B. cereus on selective agars. In this study, we aimed to improve the selectivity of mannitol-yolk-polymyxin B agar (MYPA) and its modified version containing trimethoprim (mMYPA) developed in our previous study by supplementation with ceftazidime (16 μg/mL). Ceftazidime-supplemented MYPA (C-MYPA16) and mMYPA (C-mMYPA16) were evaluated for bacteria recoverability and selectivity using three types of ready-to-eat vegetables. Four B. cereus and one B. thuringiensis strains were mixed and artificially inoculated into vegetable salad, radish sprouts, and sprout mix, and then recovered using MYPA, mMYPA, C-MYPA16, and C-mMYPA16. In all tested vegetables, mMYPA, C-MYPA16, and C-mMYPA16 exhibited similar recoverability of B. cereus / thuringiensis ( p > 0.05), whereas MYPA showed undistinguishable colonies in case of radish sprouts and sprout mix. At the same time, C-mMYPA16 provided the best selectivity compared with the other agars because it eliminated most of competing flora in the tested vegetables, especially in sprouts, without negatively affecting the recovery of B. cereus / thuringiensis . Our results indicate that the supplementation of mMYPA with ceftazidime may improve medium selectivity for B. cereus / thuringiensis in food testing.
Dried parsley is regularly contaminated with foodborne pathogens, especially Salmonella (S.) spp. Application of contaminated ingredients in ready-to-eat dishes without further thermal treatment represents a considerable health risk. This study examines the suitability of pulsed light as a novel decontamination method of Salmonella spp. in dried parsley, the impact on selected quality parameters (chlorophyll content, phenolic compounds, color, odor) and product characters (temperature, aw-value). Samples were inoculated with one of three Salmonella isolates (S. Cerro or one of two isolates of S. Agona) at two contamination levels of 103 or 107 CFU/g and treated under various experimental factors, including distance to the light source and exposure time, resulting in fluences in the range of 1.8 – 19.9 J/cm2. At selected parameter settings (9.8 and 13.3 J/cm2), the effect of prolonged storage time (48 h) of inoculated samples prior to treatment on the reduction of S. Cerro was examined. Samples treated at the same fluences were also stored for 35 days at 22 – 25 °C. The three Salmonella isolates were significantly reduced by pulsed light (p < 0.05). Reduction factors ranged between 0.3 – 5.2 log CFU with varying sensitivities of the isolates. In general, increasing fluences (depending on exposure time and distance to the light source) resulted in increasing reductions of Salmonella spp. However, on closer examination, exposure time and distance to the light source in detail had a varying influence on the reduction of the different Salmonella isolates. Decreasing reduction factors were observed by increasing the contamination level and prolonging storage time of inoculated samples prior to treatment. No undesirable changes in quality parameters and sensory analysis were detectable at fluences of 9.8 and 13.3 J/cm2, indicating that pulsed light may be a suitable alternative for the decontamination of dried parsley.
Recently, ready-to-eat vegetable salads have gained popularity worldwide. However, the microbial safety of ready-to-eat salads is a health concern, primarily due to Salmonella enteritidis contamination during the growing, harvesting, processing, and handling of produce. This study aimed to develop a bacteriophage-based strategy to control S. enteritidis growth in mixed-ingredient salads. A lytic Salmonella-specific phage SapYZU01 was isolated from a soil sample from a suburban vegetable field in Yangzhou, China. SapYZU01 exhibited characteristics such as a short latent period, a large burst size, and a lytic effect against 13 S. enteritidis strains isolated from various sources (human, pork, deli, chicken, and chicken meat). The SapYZU01 genome did not contain virulence or antibiotic resistance genes. SapYZU01 significantly decreased the viability of S. enteritidis cells in iceberg lettuce, chicken meat, and mixed-ingredient (lettuce+chicken) salads at 37 and 25 °C. Furthermore, bacterial counts in the salad decreased significantly (by 4.0 log colony-forming units (CFU)/g) at 25 °C upon treatment of contaminated lettuce with SapYZU01 at an MOI of 100 prior to salad preparation. Bacterial counts were decreased by 3.8 log CFU/g at 25 °C in (lettuce+chicken) salads treated with SapYZU01 at an MOI of 100 after the salad preparation. In contrast, treating cooked chicken meat with SapYZU01 at an MOI of 100 before mixing it with contaminated lettuce decreased the bacterial count of the salad by 1.2 log CFU/g at 25 °C. These findings indicate the potential application of SapYZU01 as a natural biocontrol agent against S. enteritidis in mixed-ingredient salads. Furthermore, the application of lytic bacteriophage SapYZU01 in mix-ingredient salads should considered the bacteriophage treatment method in addition to the bacteriophage concentration.
People who may have this product are asked not to consume it and to return it to the point of sale where it was purchased.
People who have consumed this product and who present with fever, isolated or accompanied by headaches, are invited to consult their attending physician, notifying him of this consumption. Pregnant women should pay special attention to these symptoms, as well as immunocompromised people and the elderly. These symptoms may suggest listeriosis, a disease that can be serious and can take up to eight weeks to incubate.
FURTHER INFORMATION
▸ Mini Mont d’Or AOP Mini coin + ceramic • Barcode: 3564709172491 • Lot: 3053 • DLC: 01.04.21 – 02.04.21
▸ Mini Mont d’Or AOP Mini coin • Barcode: 3564709170732 • Lot: 3053 • DLC: 01.04.21 – 02.04.21
▸ Health stamp FR 25.041.001 CE
▸ Marketing These products were marketed in the Self-Service department from 02/26/21.
▸ Consumer service contact For more information, please contact the manufacturer on 0 800 87 41 87 (free service and call)
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