Category Archives: 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 by | 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 by | 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 – Bacterial Persister Cells in the Food Industry

Posted on August 20, 2024 by | 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 by | 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 by | 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

USA – What is the Most Common Source of Food Poisoning in the United States of America?

Posted on August 17, 2024 by | Leave a comment

Food Poisoning News

According to salmonella lawyer Ron Simon, interviewed for this article, about one-in-six Americans will contract food poisoning this year alone. Simon notes that some of the victims will become sick for as little as a few days, while others will suffer catastrophic illness, including death. This is backed up by the CDC which admits that 48 million Americans get sick in an average year from food poisoning, and  about 128 thousand of those require hospitalization.  Of those, about 3000 die each year.  According to Simon, who represents one of those who died in the very recent Boar’s Head deli meat Listeria outbreak, food poisoning is a serious concern and one public health experts and food producers need to pay attention to.

Read more at the link above.

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Posted in food contamination, food death, food handler, Food Hazard, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Poisoning, Food Poisoning Death, Food Poisoning Illness, Food Quality, food recall, Food Safety, Research

The Use Of Predictive Models In Food Safety Through The Processing Chain

Posted on August 17, 2024 by | Leave a comment

Frontiers In.org

One of the food industry’s most pressing challenges is providing safe and nutritious food for all. Microbial growth in the food supply or processed food products can reduce shelf life. On the other hand, foods’ composition and physicochemical characteristics can allow the growth and distribution of foodborne pathogens. The response of microorganisms to food composition, processing, or storage conditions will determine their growth capacity. The development of microbial growth models in food product environments differs from traditional growth models used in fermentations or lab cultures due to restrictions or advantages provided by the food environment. In predictive microbiology, the growth of pathogenic or food-spoilage microorganisms is determined under controlled conditions and used to predict their behavior in food systems.

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

Research – Antibacterial Activity of Ethanol Extract from Australian Finger Lime

Posted on August 17, 2024 by | Leave a comment

MDPI

Abstract

Australian finger lime (Citrus australasica L.) has become increasingly popular due to its potent antioxidant capacity and health-promoting benefits. This study aimed to determine the chemical composition, antibacterial characteristics, and mechanism of finger lime extract. The finger lime extracts were obtained from the fruit of the Australian finger lime by the ethanol extraction method. The antibacterial activity of the extract was examined by detecting the minimum inhibitory concentration (MIC) for two Gram-positive and four Gram-negative bacterial strains in vitro, as well as by assessing variations in the number of bacteria for Candidatus Liberibacter asiaticus (CLas) in vivo. GC-MS analysis was used to identify the antibacterial compounds of the extract. The antibacterial mechanisms were investigated by assessing cell permeability and membrane integrity, and the bacterial morphology was examined using scanning electron microscopy. The extract demonstrated significant antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Gram-negative bacterial species, such as Escherichia coli, Agrobacterium tumefaciens, Xanthomonas campestris, Xanthomonas citri, and CLas. Among the six strains evaluated in vitro, B. subtilis showed the highest susceptibility to the antimicrobial effects of finger lime extract. The minimum inhibitory concentration (MIC) of the extract against the tested microorganisms varied between 500 and 1000 μg/mL. In addition, the extract was proven effective in suppressing CLas in vivo, as indicated by the lower CLas titers in the treated leaves compared to the control. A total of 360 compounds, including carbohydrates (31.159%), organic acid (30.909%), alcohols (13.380%), polyphenols (5.660%), esters (3.796%), and alkaloids (0.612%), were identified in the extract. We predicted that the primary bioactive compounds responsible for the antibacterial effects of the extract were quinic acid and other polyphenols, as well as alkaloids. The morphology of the tested microbes was altered and damaged, leading to lysis of the cell wall, cell content leakage, and cell death. Based on the results, ethanol extracts from finger lime may be a fitting substitute for synthetic bactericides in food and plant protection.

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Posted in Antibacterial, Antimicrobials, Bio-Preservative, Research

Research – Anti-Biofilm Effects of Z102-E of Lactiplantibacillus plantarum against Listeria monocytogenes and the Mechanism Revealed by Transcriptomic Analysis

Posted on August 17, 2024 by | Leave a comment

MDPI

Abstract

Lactic acid bacteria (LAB) are the most common probiotics, and they present excellent inhibitory effects on pathogenic bacteria. This study aimed to explore the anti-biofilm potential of the purified active substance of Lactiplantibacillus plantarum, named Z102-E. The effects of Z102-E on Listeria monocytogenes were investigated in detail, and a transcriptomic analysis was conducted to reveal the anti-biofilm mechanism. The results indicated that the sub-MIC of Z102-E (3.2, 1.6, and 0.8 mg/mL) decreased the bacterial growth and effectively reduced the self-aggregation, surface hydrophobicity, sugar utilization, motility, biofilm formation, AI-2 signal molecule, contents of extracellular polysaccharides, and extracellular protein of L. monocytogenes. Moreover, the inverted fluorescence microscopy observation confirmed the anti-biofilm effect of Z102-E. The transcriptomic analysis indicated that 117 genes were up-regulated and 214 were down-regulated. Z102-E regulated the expressions of genes related to L. monocytogenes quorum sensing, biofilm formation, etc. These findings suggested that Z102-E has great application potential as a natural bacteriostatic agent.

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Posted in Food Microbiology Research, lactic acid bacteria, Lactobacillus, Listeria, Listeria monocytogenes, Research

Research – Fighting Cronobacter will go far beyond infant formula

Posted on August 14, 2024 by | Leave a comment

Lex Blog

The 2022 infant formula crisis focused renewed attention on the dangers posed by Cronobacter infections to newborns, but recent research has made clear that reducing these risks may be significantly more complex than many of us anticipated.

This conclusion is based on a better understanding of the ecology of the pathogen and, in particular, the results of a recent study released by IEH Laboratories, which provides a further understanding of the bacterial pathogen itself by finding it in the home environment and other foods. It’s become evident that the link between Cronobacter sakazakii and powdered infant formula (PIF) might not be as straightforward as we originally thought. While the conventional narrative has pointed to the production environment as the source of the pathogen, this new research suggests that the home environment and foods also may play a role.

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Posted in Cronobacter sakazakii, Food Microbiology Research, Research