Author Archives: KSW

Research – Innovative Hurdle Strategies for Listeria Control on Food-Contact Surfaces: A Peroxyacetic Acid–Steam Approach

Posted on August 23, 2024 | Leave a comment

MDPI

Abstract

The persistence of Listeria monocytogenes biofilms on equipment surfaces poses a significant risk of cross-contamination, necessitating effective surface decontamination strategies. This study assessed the effectiveness of hurdle treatments combining peroxyacetic acid (PAA) and saturated steam against 7-day-old L. innocua (a non-pathogenic surrogate for L. monocytogenes) biofilms on stainless steel (SS), polyester (PET), and rubber surfaces. Results demonstrated >6 log10 CFU/coupon L. innocua reductions on SS and PET surfaces after PAA (40 ppm, 1 min) followed by steam treatment (100 °C, 6 s). On rubber surfaces, PAA (80 ppm, 1 min) followed by steam treatment (100 °C, 6 s) resulted in ~5 log10 CFU/coupon L. innocua reduction. The presence of apple juice soil reduced the efficacy of hurdle treatments, with PAA (40 ppm, 1 min) and steam exposure (6 s) resulting in 5.6, 5.8, and 4.2 log10 CFU/coupon reductions of L. innocua on SS, PET, and rubber, respectively. The efficacy of this antimicrobial combination was further reduced by surface defects, especially in the presence of organic matter. Nevertheless, the treatment still achieved >5 log10 CFU/coupon reductions of L. innocua on worn SS and PET soiled with apple juice and ~4.5 log10 CFU/coupon reduction on worn, soiled rubber surfaces. These findings highlight that PAA treatments followed by a brief steam exposure are effective strategies for controlling Listeria on food-contact surfaces.

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Posted in Biofilm, Food Microbiology Research, Food Technology, Hurdle Technology, Listeria, Listeria innocua, Listeria monocytogenes, Research, Technology

Research – Persistence of Salmonella and Campylobacter on Whole Chicken Carcasses under the Different Chlorine Concentrations Used in the Chill Tank of Processing Plants in Sri Lanka

Posted on August 22, 2024 | Leave a comment

MDPI

Abstract

The persistence of non-typhoidal Salmonella and Campylobacter in chicken meat is a considerable public health risk and a future challenge. This study aimed to determine the prevalence of Salmonella and Campylobacter in poultry processing lines where different chlorine concentrations were used in the chill tank. The samples were collected from four types of processing plants in Sri Lanka, considering the chlorine concentration used in the chill tank, which ranged from 2 ppm to 50 ppm. Salmonella and Campylobacter were isolated from whole carcass washings, neck skin, and cecal samples. Subsequently, an antimicrobial susceptibility test was performed for the isolates. The results revealed the overall prevalence of Salmonella and Campylobacter was 78.25% and 63.5%, respectively. Positive percentages of Salmonella and Campylobacter were high in the carcasses compared to the neck skin and ceca. The Campylobacter counts on the whole carcasses were significantly low (p < 0.001), at higher chlorine concentrations ranging from 20 to 30 ppm and 40 to 50 ppm. The pathogen prevalence in the whole carcasses was 84.7% Campylobacter coli, 39.1% Campylobacter jejuni, 71.1% Salmonella Typhimurium, and 28.8% Salmonella Infantis. The highest resistance was observed for tetracycline (63.8%) in Salmonella, while it was for gentamicin (87.8%) in Campylobacter. The prevalence percentage of multidrug-resistant Campylobacter was 51.2%, while it was 2.12% for Salmonella. The persistence of multidrug-resistant Salmonella and Campylobacter on the post-chill carcasses was highlighted in the present study as a significant public health threat that has to be addressed urgently.

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Posted in Antibacterial, Campylobacter, Food Microbiology Research, Food Technology, Research, Salmonella, Technology

Research – Cryptosporidium spp.

Posted on August 22, 2024 | Leave a comment

ACSA

crypto

When the European Food Safety Authority published a review of the public health risk of foodborne parasites in 2018, it focused on three, which it considers to be the most pressing today and in the future immediate, either for current production systems, the effectiveness of control measures, eating habits or because of their severity. The selection included Cryptosporidium spp., Toxoplasma gondii and Echinococcus ssp. These parasites are resistant in the environment, they do not have specific controls, and the food industry’s awareness of them is variable, in contrast to what happens with Trichinella spiralis and Anisakidae .

Cryptosporidiosis is generally associated with acute gastrointestinal conditions, has no specific treatment, and outbreaks have occurred related to the consumption of contaminated fresh produce.

EFSA

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Posted in Cryptosporidiosis, Cryptosporidium, Food Microbiology Research, Microbiological Risk Assessment, Microbiology Risk, Research, Uncategorized, Water, water microbiology, Water Safety

Research – Clostridium perfringens in the Intestine: Innocent Bystander or Serious Threat?

Posted on August 21, 2024 | Leave a comment

MDPI

Abstract

The Clostridium perfringens epidemic threatens biosecurity and causes significant economic losses. C. perfringens infections are linked to more than one hundred million cases of food poisoning annually, and 8–60% of susceptible animals are vulnerable to infection, resulting in an economic loss of more than 6 hundred million USD. The enzymes and toxins (>20 species) produced by C. perfringens play a role in intestinal colonization, immunological evasion, intestinal micro-ecosystem imbalance, and intestinal mucosal disruption, all influencing host health. In recent decades, there has been an increase in drug resistance in C. perfringens due to antibiotic misuse and bacterial evolution. At the same time, traditional control interventions have proven ineffective, highlighting the urgent need to develop and implement new strategies and approaches to improve intervention targeting. Therefore, an in-depth understanding of the spatial and temporal evolutionary characteristics, transmission routes, colonization dynamics, and pathogenic mechanisms of C. perfringens will aid in the development of optimal therapeutic strategies and vaccines for C. perfringens management. Here, we review the global epidemiology of C. perfringens, as well as the molecular features and roles of various virulence factors in C. perfringens pathogenicity. In addition, we emphasize measures to prevent and control this zoonotic disease to reduce the transmission and infection of C. perfringens.

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Posted in Clostridium, Clostridium perfringens, Food Microbiology Research, Research

Research – Microbial Diversity Across Tea Varieties and Ecological Niches: Correlating Tea Polyphenol Contents with Stress Resistance Microbial Community Differences among Different Tea Varieties and Ecological Niches

Posted on August 21, 2024 | Leave a comment

Frontiers In.org

Microorganisms exhibit intricate interconnections with tea trees plants; however, despite the well-established role of microorganisms in crop growth and development, research on microbes within the tea plant remains insufficient, particularly regarding endophytic microorganisms. In this study, we collected samples of leaves and rhizosphere soils were collected from ‘Zhuyeqi’, ‘Baojing Huangjincha#1Baojing Huangjinchayihao’, ‘Anjibaicha’Baiye#1’, and ‘Jinxuan’ varieties planted. Our analyses revealed significant variations in tea polyphenol contents among tea varieties, particularly with the ‘Zhuyeqi’ variety exhibiting higher levels of tea polyphenols (>20% contents). Microbiome studies have revealed that endophytic microbial community in tea plants exhibited higher host specificity compared to rhizospheric microbial community rhizosphere microbial community. Analyses of across-ecological niches of the microbial community associated with tea plants of the microbiota associated with tea plants revealed that soil bacteria serve as a significant reservoir for endophytic bacteria in tea plants, Balneola Bacillus may play a crucial role in shaping the bacterial community across-ecological niche within the tea plants with higher tea polyphenol levels. In the aforementioned analyses, the microbial community of ‘Zhuyeqi’ exhibited a higher degree of host specificity for leaf endophytic microorganisms, the topological structure of the co-occurrence network is also more intricate, harbouring a greater number of potential core microorganisms within its nodes. A closer examination was conducted on the microbial community. A more intricate examination was conducted on the microbial community of ‘Zhuyeqi’, further analyses of its endophytic bacteria indicated that its endophytic microbial community harbored a greater abundance of biomarkers, particularly among bacteria, and the enriched Methylobacterium and Sphingomonas in ‘Zhuyeqi’ may play distinct roles in disease resistance and drought resilience in tea plants. In summary, this study has shed light on the intricate relationships of tea plant varieties with their associated microbial communities, unveiling the importance of microorganisms and tea varieties with higher tea polyphenols, and offering valuable insights to the study of microorganisms and tea plants. this study shaded light on the intricate relationship between tea plant varieties and their associated microbial community and unveiled the importance of the tea varieties with higher tea polyphenols in microbial studies, offered valuable insights for the studies of microorganism-tea plants.

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Posted in Food Microbiology, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbial growth, Microbial Spoilage, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Research

Research – Evaluation of the safety of microorganisms (“probiotics”) used in food supplements

Posted on August 21, 2024 | Leave a comment

ACSA

The Food Safety Authority of Ireland (FSAI) Scientific Committee has published a scientific report on the safety assessment of micro-organisms (“probiotics”) used in food supplements which aims to help companies assess the safety of “probiotics” , in the absence of specific legal criteria.

“Probiotics” are defined by FAO/WHO* as “live micro-organisms which when administered in adequate amounts confer a health benefit on the host”. The term “probiotic”, however, is currently an unauthorized health claim under EU law. Applications for health claims on “probiotics” have been submitted for evaluation to the European Food Safety Authority (EFSA) and so far, no application has received a positive opinion and subsequent authorization. Although the term is not permitted on food product or dietary supplement labels, the term is used in this scientific report because it is widely used by industry and the scientific community.

The Committee found that reported adverse events associated with “probiotics” are few and tend to be ad hoc reports of infections, including bacteremia, sepsis, or endocarditis in people with belonging to different risk groups. 

The report makes recommendations on the criteria for safety assessment and the evidence that a producer of food supplements should use to demonstrate the micro-organism safety of their products.

FSAI

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Posted in Food Microbiology Research, Probiotic, Research

Research – Shopping at the Farmers Market with Food Safety in Mind

Posted on August 20, 2024 | Leave a comment

FSIS USDA

Going to the farmers market is a weekly staple for many, and markets are available across the country both seasonally and year-round. Farmers markets offer a wide variety of fresh local products like fruits, vegetables, meats, cheeses and beverages. When shopping at the farmers market, it’s important to keep food safety in mind to avoid foodborne illness from tagging along.

Read more at the link above.

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Posted in Food Safety, Food Safety Management, food safety training

Research – Bacterial Persister Cells in the Food Industry

Posted on August 20, 2024 | Leave a comment

Frontiers In.org

The food industry plays a crucial role in global health and economy, offering a wide range of products that sustain human populations. However, ensuring food safety and preventing foodborne illnesses remain significant challenges. A critical issue is the presence of bacterial persister cells – dormant cells within bacterial populations that exhibit remarkable tolerance to various stressors, including antibiotics and sanitizers. This dormancy state allows them to survive unfavorable conditions and potentially become active again if under favorable conditions.

Persister cells are implicated in recurrent contamination and outbreaks within food production environments. Unlike antibiotic resistance, which involves genetic changes, persistence is a phenotypic adaptation that poses unique challenges for detection and control. Understanding the mechanisms of persistence, its triggers, and implications in the food industry is essential for developing effective strategies to mitigate food safety risks.

This Research Topic aims to consolidate current knowledge on bacterial persister cells in the food industry, including the fundamental mechanisms that underlie bacterial persistence, their role in foodborne diseases, and innovative approaches for detection and management.

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Posted in Food Microbiology Research, Food Safety, Food Safety Management, food safety training, Research

Research – Prevalence and Characterization of Salmonella during Pork Sausage Manufacturing

Posted on August 19, 2024 | Leave a comment

MDPI

Abstract

Pork carcasses and meat may harbor Salmonella and may contaminate other products during harvest and fabrication. Sources of contamination include manure on hides, environmental contamination, ingredients from external sources, and lymph nodes. Swine lymph nodes are often incorporated into ground meat, as their anatomical location makes removal labor prohibitive. A sausage processing plant in the midwestern United States was sampled monthly (except for December) from May 2021 to April 2022 to enumerate Salmonella and Enterobacteriaceae (EB) throughout the sausage manufacturing process to determine high-risk stages and efficiency of existing in-plant interventions. Salmonella serotypes and antimicrobial susceptibility were evaluated on a subset of isolates recovered at the end phases of sausage production. In each collection, samples were taken from the carcasses of eight sows through 11 stages of sausage manufacturing. A total of 830 samples were cultured. Thirty-four Salmonella were isolated from the final three production stages; of these, there were eleven serotypes. Three isolates displayed resistance to ampicillin, whereas the remainder of the isolates were pan-susceptible to the antimicrobials tested. Salmonella and EB were significantly reduced (p < 0.001) by acid washes at different stages of production, and the results point to the beneficial effects of interventions to lessen Salmonella concentrations in retail products.

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Posted in Food Microbiology Research, Research, Salmonella

Research – Quantification of 700 mycotoxins and other secondary metabolites of fungi and plants in grain products

Posted on August 18, 2024 | Leave a comment

Nature

This work reports on the validation of a liquid chromatography–tandem mass spectrometric method for the simultaneous quantification of more than 700 mycotoxins and other secondary fungal metabolites and plant toxins in pasta, biscuits, crackers and musli. The “dilute and shoot” approach was found to be fully applicable to these complex matrices, as only 7–14% of the analytes exhibited significant matrix effects while recoveries of the extraction were outside the target range of 70–120% for only 26 compounds. Data on repeatability (based on 7 brands per matrix) and on intermediate precision was compliant to the related < 20% criterion for 95–98% and 99% of all analytes, respectively. The limits of quantification were much lower than the related regulatory limits set for mycotoxins in cereal products. Application of the method to 157 samples from the European market revealed the presence of enniatins and deoxynivalenol in the majority of the samples. No regulatory limits were exceeded except the sum of ergot alkaloids being higher in a few samples than the 50–150 µg/kg to be implemented as of July 2024.

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Posted in Food Microbiology Research, Mycotoxin, Research