Category Archives: Decontamination Microbial

Research- Assessing the Prevalence and Potential Risks of Salmonella Infection Associated with Fresh Salad Vegetable Consumption in the United Arab Emirates

MDPI

Abstract

This study aimed to investigate the occurrence and characteristics of Salmonella isolates in salad vegetables in the United Arab Emirates (UAE). Out of 400 samples tested from retail, only 1.25% (95% confidence interval, 0.41–2.89) were found to be positive for Salmonella, all of which were from conventional local produce, presented at ambient temperature, and featured as loose items. The five Salmonella-positive samples were arugula (n = 3), dill (n = 1), and spinach (n = 1). The Salmonella isolates from the five samples were found to be pan-susceptible to a panel of 12 antimicrobials tested using a disc diffusion assay. Based on whole-genome sequencing (WGS) analysis, only two antimicrobial resistance genes were detected—one conferring resistance to aminoglycosides (aac(6′)-Iaa) and the other to fosfomycin (fosA7). WGS enabled the analysis of virulence determinants of the recovered Salmonella isolates from salad vegetables, revealing a range from 152 to 165 genes, collectively grouped under five categories, including secretion system, fimbrial adherence determinants, macrophage-inducible genes, magnesium uptake, and non-fimbrial adherence determinants. All isolates were found to possess genes associated with the type III secretion system (TTSS), encoded by Salmonella pathogenicity island-1 (SPI-1), but various genes associated with the second type III secretion system (TTSS-2), encoded by SPI-2, were absent in all isolates. Combining the mean prevalence of Salmonella with information regarding consumption in the UAE, an exposure of 0.0131 salmonellae consumed per person per day through transmission via salad vegetables was calculated. This exposure was used as an input in a beta-Poisson dose–response model, which estimated that there would be 10,584 cases of the Salmonella infection annually for the entire UAE population. In conclusion, salad vegetables sold in the UAE are generally safe for consumption regarding Salmonella occurrence, but occasional contamination is possible. The results of this study may be used for the future development of risk-based food safety surveillance systems in the UAE and to elaborate on the importance for producers, retailers, and consumers to follow good hygiene practices, particularly for raw food items such as leafy salad greens.

Research – Microbiological Assessment of White Button Mushrooms with an Edible Film Coating

MDPI

Abstract

The development of edible coatings incorporating bioextracts from mushrooms native to Portuguese forests aims to enhance the value of the endogenous forest and mycological resources by harnessing their potential as a source of antimicrobial and antioxidant compounds. Edible coatings represent an important pathway to decreasing food waste and contributing to implementing a circular bioeconomy. The coating should result in product valorization through improved preservation/conservation, increased shelf life, as well as enhancement of its antioxidant and enzymatic properties. To evaluate the effectiveness of an edible coating on fungal food matrices, a 14-day shelf-life study was conducted, wherein both coated and untreated mushrooms were examined under controlled storage temperatures of 4 °C and 9.3 °C. Agaricus bisporus was chosen as the food matrix for its bioeconomy significance, and Pleurotus eryngii was selected for the preparation of the food-based coating due to its profile of bioactive compounds. Microbiological analysis and physicochemical monitoring were conducted on the food matrices and the coating. Coated mushrooms had less mass loss and color change, and had better texture after 14 days. Microbiological analysis revealed that the coating had no antimicrobial activity. Overall, the coating improved the shelf life of the coated mushrooms but had less effect on the microbial community.

Research – Development and characterization of antibacterial packaging film based on poly (vinyl alcohol)/agarose enriched with cinnamon oil

Wiley Online

Abstract

The antibacterial packaging films were produced from poly (vinyl alcohol) (PVOH), agarose, and cinnamon (Cinnamon cassia) oil (CO). The mechanical, antibacterial, water- and UV-barrier properties of the resulting films were fully characterized. Our findings revealed that increasing amount of CO slightly affected the color of resulting film, while the dispersion of CO in polymeric matrix was influenced by CO concentration. UV-barrier property of PVOH/agarose was enhanced by adding a small amount of CO. Tensile strength of the resulting films insignificantly changed (8.94–10.23 MPa) with raising CO content while the flexibility remarkably dropped from 92.63% to 75.49%. Remarkably, the PVOH/agarose containing 1.5% (v/v) CO presented strong inhibition against Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus due to the presence of cinnamaldehyde in CO and this inhibitory efficiency was maintained for up to 7 days. Furthermore, the PVOH/agarose film enriched with 1% (v/v) CO was applied for enhancing the storability of bread slices during 50-day storage at room temperature.

UK – Risk of Campylobacteriosis from low-throughput Poultry Slaughterhouses

FSA

Executive Summary
Campylobacter is the most common cause of bacterial gastroenteritis in the UK. Every
year there are an estimated 300,000 foodborne cases in the UK, of which more than half
are related to poultry meat.
Poultry is the main reservoir for Campylobacter and undercooked poultry presents a risk
to the consumer of becoming infected with Campylobacter, while thorough cooking kills
Campylobacter. Infection may also result as a consequence of cross-contamination
during preparation or storage of chicken.
Slaughterhouses are classified as either low-throughput (≤7.5 million birds per year) or
high-throughput (>7.5 million birds per year). Campylobacter levels are routinely
monitored in chicken carcases that are processed in high-throughput slaughterhouses.
Established process hygiene criteria (PHC) state the samples submitted by
slaughterhouses currently should not exceed 1,000 CFU/g Campylobacter in more than
30% of samples submitted. The microbiological criteria regulation is the same for high-
throughput and low-throughput slaughterhouses, however, testing is not currently carried
out in all low-throughput slaughterhouses due to the financial burden of routine testing.
This work was commissioned to assist the FSA to make a risk-based decision on
whether a tailored-made sampling regime for small-throughput slaughterhouses would be
appropriate.
We considered the whole pathway of the chicken from farm to fork using scientific
literature, data from own survey of Campylobacter in slaughterhouses, in addition to
business data and information regarding UK levels of infection from Campylobacter.
Overall, there was no significant difference between the proportion of highly
contaminated samples (>1,000 CFU/g) gathered from low and high-throughput
slaughterhouses. Using the number of chickens per year that are processed by low and
high-throughput slaughterhouses, we estimated that high-throughput slaughterhouses
contribute a significantly larger number of Campylobacter cases due to their volume.
Currently, most chicken on sale in the UK is produced in high-throughput plants. All else
being equal, small improvements to large plants will have a bigger impact on the overall
risk to the UK consumer population than large changes to a far smaller plants.
A number of uncertainties and evidence gaps were identified during this risk assessment.
We had no information as to the method in which the poultry were reared prior to arriving
at the slaughterhouse and are aware that evidence suggests that this can directly affect
Campylobacter levels at slaughter. Data on low-throughput abattoirs were only available
for a limited period of three months and at the end of slaughter. There was no information
available as to the onward processing of meat handled by slaughterhouses, and we
therefore assumed that low and high-throughput slaughterhouses contribute equally to
retail and hospitality etc. In addition, we assumed that only UK slaughtered chicken is
consumed in the UK.
In conclusion, with currently available data it is not possible to identify any difference
between the current per portion risk of Campylobacteriosis to consumers for low and
high-throughput slaughterhouses. We also conclude that the frequency of occurrence
of campylobacteriosis in the total UK population from chicken produced in low-
throughput slaughterhouses is medium and for high-throughput slaughterhouses, this is
high. The uncertainty associated with this frequency is medium. The risk assessment
concludes that the severity of Campylobacter infection is low, with low uncertainty.
This assumes that the proportion of the total domestic consumption of chicken meat
originating from low-throughput slaughterhouses does not change.
The current sampling regime requires samples to be taken once a week. If more than 15
out of 50 samples have high levels of Campylobacter, this is considered a failure and
mitigations need to be put in place. We predicted that if samples are taken once every
two weeks or once every 4 weeks instead, that would still allow us to identify some
slaughterhouses failing to comply with the 15/50 exceedance rate (71% and 57%,
respectively). However, identifying issues will take longer and may not detect some
failing slaughterhouses, and may affect behaviours in the plant, i.e. less frequent
sampling may affect standards during processing.
There is a lack of consistency in the application of sampling requirements in low-
throughput slaughterhouses and a lack of information on the corrective actions taken in
the event of an exceedance. Therefore, it is not possible to differentiate the effect on per-
portion risk of changes to current sampling requirements. However, due to the small
proportion of total poultry meat consumed in the UK that is produced at low-throughput
slaughterhouses, changes to the official sampling requirements at low-throughput
slaughterhouses are unlikely to result in a large change in the total number of cases of
campylobacteriosis in the UK population.

Finland – Large outbreak linked to school meals in Finland; hundreds sickened

Food Safety News

More than 600 people have fallen ill in a suspected food poisoning outbreak at several schools in a Finnish city.

This past week, officials from the city of Mikkeli sent a questionnaire to parents of students and staff about symptoms that occurred during or after school meals on Aug. 16. As of Monday morning, answers had been received from nearly 3,800 parents and 350 employees.

All schools in Mikkeli have had at least a few patients. The incident is being investigated with the Finnish Food Authority (Ruokavirasto) and National Institute of Health and Welfare (THL).

Samples taken from different foods and raw materials are being examined to find out the cause of the epidemic. Results of laboratory tests are expected later this week.

Research – First Report of Aeromonas veronii as an Emerging Bacterial Pathogen of Farmed Nile Tilapia (Oreochromis niloticus) in Brazil

MDPI

Abstract

Brazil is one of the world’s leading producers of Nile tilapia, Oreochromis niloticus. However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. Aeromonas species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS). In late December 2022, an epidemic outbreak was reported in farmed Nile tilapia in the state of São Paulo, Brazil, characterized by clinical signs and gross pathology suggestive of MAS. The objective of this study was to isolate, identify, and characterize in vitro and in vivo the causative agent of this epidemic outbreak. The bacterial isolates were identified as Aeromonas veronii based on the homology of 16S rRNA (99.9%), gyrB (98.9%), and the rpoB gene (99.1%). A. veronii showed susceptibility only to florfenicol, while it was resistant to the other three antimicrobials tested, oxytetracycline, enrofloxacin, and amoxicillin. The lowest florfenicol concentration capable of inhibiting bacterial growth was ≤0.5 µg/mL. The phenotypic resistance of the A. veronii isolate observed for quinolones and tetracycline was genetically confirmed by the presence of the qnrS2 (colE plasmid) and tetA antibiotic-resistant genes, respectively. A. veronii isolate was highly pathogenic in juvenile Nile tilapia tested in vivo, showing a mortality rate ranging from 3 to 100% in the lowest (1.2 × 104) and highest (1.2 × 108) bacterial dose groups, respectively. To our knowledge, this study would constitute the first report of highly pathogenic and multidrug-resistant A. veronii associated with outbreaks and high mortality rates in tilapia farmed in commercial net cages in Brazil.

Research – Campylobacter Trends Show Decreasing Incidence, Rising Resistance Since 2012

Infectious Disease Advisor

Researchers conducted a study to estimate trends in the incidence of Campylobacter infection in the United States over time. Data on laboratory-confirmed Campylobacter diagnoses at 10 sites were collected from the Foodborne Diseases Active Surveillance Network between 1996 and 2019. Data on antimicrobial susceptibility were collected from the National Antimicrobial Resistance Monitoring System from 2005 to 2018. Campylobacter jejuni and C coli isolates were tested for antimicrobial susceptibility via broth microdilution. The incidence of Campylobacter infection was estimated after adjustments for sex, age, and the use of culture-independent diagnostic testing.

The researchers used a pooled chi-squared statistic to compare changes (2005-2016 vs 2017-2018) in the percentage of ciprofloxacin-, erythromycin-, and extensively drug-resistant isolates. They also used multivariable logistic regression to assess the association between AMR and clinical outcomes.

Research – Impact of climate change on foodborne infections and intoxications

Journal of Health Monitoring

Temperature, precipitation, humidity, and soil properties are important environmental factors that influence the spread and survival of zoonotic pathogens. Changes in these environmental factors as a result of climate change, such as permanently elevated ambient temperatures, in-creasing precipitation, but also water scarcity, may contribute to the spread and survival of pathogens.

Climate change may thus exert an increasing influence on more than half of all infectious diseases. This is not only true for already existing, i. e. endemic, infectious agents; climatic changes also favour the establishment of novel infectious agents (emergence) as well as the return of pathogens sup-pressed in the past (re-emergence). For example, in the
future, agriculture may have to rely more frequently on treated wastewater due to water scarcity, which will be ex- acerbated by climate change. This poses a number of risks
to food safety, including contamination of irrigated produce by various types of pathogens.

This review addresses hazards to human health posed by the most important foodborne bacteria, parasites and marine biotoxins in Germany and presents recommendations for reducing the risks. For example, the risk of all infections discussed here can be reduced by observing good hygiene during food preparation (kitchen hygiene) and adherence to cold chains.

Research – 12 Mistakes You Might Be Making When Defrosting Meat

The Daily Meal

Storing meat can be pretty tricky. As a perishable substance, meat doesn’t last long once you get it home from the store, and some types, like chicken pieces or ground beef, may only have a day or two in your refrigerator before they start to spoil. To take advantage of the affordability of buying meat in bulk, turn to your freezer

But handling meat — defrosted or otherwise — can be a tricky business. Meat can be a host for multiple different kinds of bacteria, including E. coli, Salmonella, and Bacillus cereus, all of which can cause food poisoning.

Read More at the link above

Research -The Impacts of Acidophilic Lactic Acid Bacteria on Food and Human Health: A Review of the Current Knowledge

Gov france

Abstract

The need to improve the safety/quality of food and the health of the hosts has resulted in increasing worldwide interest in acidophilic lactic acid bacteria (LAB) for the food, livestock as well as health industries. In addition to the use of acidophilic LAB with probiotic potential for food fermentation and preservation, their application in the natural disposal of acidic wastes polluting the environment is also being investigated. Considering this new benefit that has been assigned to probiotic microorganisms in recent years, the acceleration in efforts to identify new, efficient, promising probiotic acidophilic LAB is not surprising. One of these effots is to determine both the beneficial and harmful compounds synthesized by acidophilic LAB. Moreover, microorganisms are of concern due to their possible hemolytic, DNase, gelatinase and mucinolytic activities, and the presence of virulence/antibiotic genes. Hence, it is argued that acidophilic LAB should be evaluated for these parameters before their use in the health/food/livestock industry. However, this issue has not yet been fully discussed in the literature. Thus, this review pays attention to the less-known aspects of acidophilic LAB and the compounds they release, clarifying critical unanswered questions, and discussing their health benefits and safety.