Category Archives: pathogenic

CPS – Funded Projects 2022 – Superheated Steam – Process Surface Decontamination

Posted on January 5, 2022 by | Leave a comment

CPS

Practical application of superheated steam to harvesting, processing, and produce packing tools and equipment

Pathogens can contaminate environmental surfaces in produce handling operations. The industry uses sanitation programs to clean these surfaces and prevent product contamination. Highly effective sanitation procedures reduce the likelihood that pathogens will cross-contaminate products. In facilities that do not use water in their sanitation programs, tools like brushes and rags are used to clean. No-rinse sanitizers are sometimes used as well, but they cannot be used in organic operations. Superheated steam is a novel surface sanitizer that can kill pathogens on environmental surfaces. It is sometimes referred to as “dry steam” because it does not leave moisture or condensation on surfaces, making it a viable option for dry produce facilities. This project is designed to evaluate superheated steam use under industry relevant conditions. We will not only determine how well it works, but we will assess other key performance indicators including cost, range of appropriate applications, and the effect of extended use on equipment wear-and-tear and change to ambient relative humidity. This project will provide industry with the tools to comprehensively assess tradeoffs in superheated steam implementation. These resources will help improve the design of sanitation programs and enhance control over pathogen cross-contamination.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research

Research – Best Practice for the Control of Human Pathogenic Microorganisms in Plant Production Systems

Posted on January 4, 2022 by | Leave a comment

Teagasc

There is an increased emphasis on and observance of food-borne diseases associated with fresh produce, due in part to changes in the processing, agronomy and distribution of fresh produce but also in the increasing trend for the consumption of minimally processed and raw, ready-to-eat crops. A recent meeting of European experts and commercial growers, assembled under the HuPlant Cost Action assessed the current European situation in relation to the safety of horticultural produce under the themes of
(1) protecting fresh produce from microbial pathogens,
(2) control strategies and sampling and
(3) risk assessment and risk based sampling.
The following report details the discussions and observations which emanated from that meeting, including a list of recommendations, aimed at
(1) Growers,
(2) Regulators and Advisors and
(3) Scientists.
For growers recommendations include reinforcement through clear communication on the need to prevent initial contamination of produce through the adoption of good microbiological safety practice, utilising on farm risk assessments and a focus on avoidance of initial contamination rather than a reliance on decontamination efforts.
This can be achieved through approaches such as the adoption and incorporation of good agricultural practice and good hygiene into standard operating procedures on farm. Recommendations to regulators and advisors include balancing communication messages to growers, indicating what is required of them, but also equally, clearly explaining why it is necessary.
Additionally it was felt that additional supports and materials could be made available to growers, particularly to smaller growers, to assist in the training of staff on the importance of biological safety practice, particularly in sectors where staff turnover may be high and differences in the native languages spoken.
Finally recommendations to scientists include a greater emphasis on knowledge transfer and also to, where possible focus knowledge transfer efforts into developing clear recommendations which growers can implement. The interaction between the plant microbiome, potential pathogens, environmental conditions and agricultural practices requires a greater level of attention and research to aid in predict the risk of human pathogen establishment.
Overall it was recognised that through increased interaction and information exchange between stakeholders will enable better understanding of the issues and opportunities faced by the horticultural sector and the co-creation of advice through participation of all stakeholders can assist in reducing the risk of contamination of horticultural produce.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research, Technology

Research – Detrimental Effect of Ozone on Pathogenic Bacteria

Posted on December 27, 2021 by | Leave a comment

MDPI

Background: Disinfection of medical devices designed for clinical use associated or not with the growing area of tissue engineering is an urgent need. However, traditional disinfection methods are not always suitable for some biomaterials, especially those sensitive to chemical, thermal, or radiation. Therefore, the objective of this study was to evaluate the minimal concentration of ozone gas (O3) necessary to control and kill a set of sensitive or multi-resistant Gram-positive and Gram-negative bacteria. The cell viability, membrane permeability, and the levels of reactive intracellular oxygen (ROS) species were also investigated;

Material and Methods: Four standard strains and a clinical MDR strain were exposed to low doses of ozone at different concentrations and times. Bacterial inactivation (cultivability, membrane damage) was investigated using colony counts, resazurin as a metabolic indicator, and propidium iodide (PI). A fluorescent probe (H2DCFDA) was used for the ROS analyses;

Results: No reduction in the count colony was detected after O3 exposure compared to the control group. However, the cell viability of E. coli (30%), P. aeruginosa (25%), and A. baumannii (15%) was reduced considerably. The bacterial membrane of all strains was not affected by O3 but presented a significant increase of ROS in E. coli (90 ± 14%), P. aeruginosa (62.5 ± 19%), and A. baumanni (52.6 ± 5%);

Conclusion: Low doses of ozone were able to interfere in the cell viability of most strains studied, and although it does not cause damage to the bacterial membrane, increased levels of reactive ROS are responsible for causing a detrimental effect in the lipids, proteins, and DNA metabolism. View Full-Text

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Posted in Decontamination Microbial, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Ozone, Pathogen, pathogenic, Pseudomonas, Pseudomonas aeruginosa, Pseudomonas fluorescens, Research, Technology

Research – Super bugs bedevil food safety

Posted on December 20, 2021 by | Leave a comment

Food Safety News

“Super bugs” and “food safety.” You can say the two in one breath simply because they are so closely connected.

“Super bugs” is a popularized term for “antibiotic resistance,” or “antimicrobial resistance.” They don’t go by that name for nothing. According to the federal Centers for Disease Control and Prevention, each year in the United States, at least 2.8 million people are infected with antibiotic-resistant bacteria or fungi. More than 35,000 people die as a result. Antibiotic resistant bacteria frequently show up in outbreak strains of pathogens such as E. Coli, Salmonella and Listeria monocytogenes.

When looking ahead, the picture only gets more daunting. Some medical experts predict that worldwide by 2050 the number of deaths attributed to antibiotic resistance could reach 10 million and cost trillions of dollars — unless collective action is taken on a global scale.

No wonder then that some human and animal health experts are referring to this as a “slow moving pandemic.”

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Posted in Antibiotic Resistance, antimicrobial resistance, E.coli, Food Microbiology Research, Food Pathogen, Listeria, Listeria monocytogenes, Pathogen, pathogenic, Research, Salmonella

Research – Differential Survival of Generic E. coli and Listeria spp. in Northeastern U.S. Soils Amended with Dairy Manure Compost, Poultry Litter Compost, and Heat-Treated Poultry Pellets and Fate in Raw Edible Radish Crops

Posted on December 11, 2021 by | Leave a comment

Journal of Food Protection

Composted or heat-treated Biological Soil Amendments of Animal Origin (BSAAO) can be added to soils to provide nutrients for fresh produce. These products lower the risk of pathogen contamination of fresh produce when compared with use of untreated BSAAO; however, meteorological conditions, geographic location, and soil properties can influence the presence of pathogenic bacteria, or their indicators (e.g., generic E. coli) and allow potential for produce contamination. Replicated field plots of loamy or sandy soils were tilled and amended with dairy manure compost (DMC), poultry litter compost (PLC), or no compost (NoC) over two different field seasons, and non-composted heat-treated poultry pellets (HTPP) during the second field season. Plots were inoculated with a three-strain cocktail of rifampicin-resistant E. coli (rE.coli) at levels of 8.7 log CFU/m2. Direct plating and most probable number (MPN) methods measured the persistence of rE.coli and Listeria spp. in plots through 104 days post-inoculation. Greater survival of rE. coli was observed in PLC plots in comparison to DMC plots and NoC plots during year 1 (P < 0.05). Similar trends were observed for year 2, where rE. coli survival was also greater in HTPP amended plots (P < 0.05). Survival of rE. coli was dependent on soil type, where water potential and temperature were significant covariables. Listeria spp. were found in NoC plots, but not in plots amended with HTPP, PLC or DMC. Radish data demonstrate that PLC treatment promoted the greatest level of rE.coli translocation when compared to DMC and NoC treatments (P  < 0.05). These results are consistent with findings from studies conducted in other regions of the US and informs Northeast produce growers that composted and non-composted poultry-based BSAAO supports greater survival of rE. coli in field soils. This result has the potential to impact the food safety risk of edible produce grown in BSAAO amended soils as a result of pathogen contamination.

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Posted in Decontamination Microbial, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research, Technology

Research – How Safe to Eat Are Raw Bivalves? Host Pathogenic and Public Health Concern Microbes within Mussels, Oysters, and Clams in Greek Markets

Posted on November 20, 2021 by | Leave a comment

MDPI

Raw-bivalves consumption is a wide trend in Mediterranean countries. Despite the unambiguous nutritional value of seafood, raw consumption of bivalves may involve risks that could pose a significant threat to consumers’ health. Their filter-feeding behavior is responsible for the potential hosting of a wide variety of microorganisms, either pathogenic for the bivalves or public health threats. Under this prism, the current study was conducted in an effort to evaluate the risk of eating raw bivalves originating from the two biggest seafood markets in Thessaloniki, the largest production area of bivalves in Greece. Both microbiological and molecular methodologies were applied in order to assess the presence of various harmful microbes, including noroviruses, Bonamia, Marteilia, Esherichia coli, Salmonella, and Vibrio. Results indicated the presence of several Vibrio strains in the analyzed samples, of which the halophilic Vibrio harveyi was verified by 16S rRNA sequencing; other than this, no enteropathogenic Vibrio spp. was detected. Furthermore, although Esherichia coli was detected in several samples, it was mostly below the European Union (EU) legislation thresholds. Interestingly, the non-target Photobacterium damselae was also detected, which is associated with both wound infections in human and aquatic animals. Regarding host pathogenic microorganisms, apart from Vibrio harveyi, the protozoan parasite Marteilia refrigens was identified in oysters, highlighting the continuous infection of this bivalve in Greece. In conclusion, bivalves can be generally characterized as a safe-to-eat raw food, hosting more bivalve pathogenic microbes than those of public health concern.

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Posted in E.coli, Food Microbiology Research, Food Pathogen, Norovirus, Pathogen, pathogenic, Research, Salmonella, Vibrio

Research – The Persistence of Bacterial Pathogens in Surface Water and Its Impact on Global Food Safety

Posted on October 27, 2021 by | Leave a comment

MDPI

Water is vital to agriculture. It is essential that the water used for the production of fresh produce commodities be safe. Microbial pathogens are able to survive for extended periods of time in water. It is critical to understand their biology and ecology in this ecosystem in order to develop better mitigation strategies for farmers who grow these food crops. In this review the prevalence, persistence and ecology of four major foodborne pathogens, Shiga toxin-producing Escherichia coli (STEC), Salmonella, Campylobacter and closely related Arcobacter, and Listeria monocytogenes, in water are discussed. These pathogens have been linked to fresh produce outbreaks, some with devastating consequences, where, in a few cases, the contamination event has been traced to water used for crop production or post-harvest activities. In addition, antimicrobial resistance, methods improvements, including the role of genomics in aiding in the understanding of these pathogens, are discussed. Finally, global initiatives to improve our knowledge base of these pathogens around the world are touched upon.

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Posted in Campylobacter, Food Micro Blog, Food Microbiology, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research, Salmonella, Shigatoxin, STEC, STEC E.coli

Research – Risk evaluation of E. coli ST 131 as a foodborne pathogen in Switzerland

Posted on October 20, 2021 by | Leave a comment

BLV

Within recent years, the topic of multidrug-resistant, uropathogenic Escherichia coli strains has seen a rise in occurrence as foodborne pathogens. At the core of this topic is the specific clonal group referred to as Escherichia coli O25b:H4 sequence type 131 (ST 131). It is an extended-spectrum β-lactamase (ESBL) producing E. coli strain, postulated to be responsible for the spread of ESBL-encoding genes world-wide.
This literature review aimed to evaluate ST 131 as a foodborne pathogen in Switzerland, in order to assess the risk it poses for food producers in Switzerland specifically. On a global scale, ST 131 has been identified on all continents. It is mostly associated with chicken and poultry meat, and has been isolated from retail products many times.
Not exclusive to chicken, it was rarely identified from fish guts and gills. In all other meat products, ST 131 was found only in faecal matter, not in the product itself. Besides meat, the pathogen was not identified from any sources such as dairy, fruit and vegetables.
The situation is similar in Switzerland, where it was isolated frequently from chicken, rarely from fish and a complete absence of the pathogen in all other food product groups. The risk, ST 131 poses towards Swiss food producers has been evaluated as a medium risk factor for both chicken and fish products, and a low risk factor for any other products. Despite ST 131 being evaluated as a medium-to-low risk factor, depending on the product, it is still recommended to perform further research on the topic. Especially looking towards prevalence in Swiss food, in chicken and poultry meat, but also in fish.
Specifically fish designated for raw consumption (Sushi, Sashimi). Moreover, the spread of afore-mentioned ESBL-encoding genes is hypothesized to occur also during infection of humans. This leads to the recommendation, that ST 131 should be considered a food-safety risk in all products, in order to eliminate said spread. Whether this consideration as a food-safety risk is feasible, cannot be said without further analysis of products and viable treatment options.

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Posted in E.coli, Enteropathogenic E. coli, ESBL, Food Microbiology Research, Food Pathogen, Pathogen, pathogenic, Research

Information – Preventive Controls – A novel approach to kill pathogens utilizing non-flammable alcohol spraying technology:

Posted on September 23, 2021 by | Leave a comment

Food Safety Tech

It is a common misconception that low numbers of Salmonella, Cronobacter and other pathogens are not a problem in low moisture foods because these products do not support growth. Certain organisms can persist for prolonged periods of time in low-moisture products, and heat resistance of Salmonella is greatly increased at reduced water activities in food matrices.

The low water activity level found in most dry ingredients and finished products usually results in severely dehydrated bacteria. It is only when there is adequate moisture, temperature and growing conditions that these stressed bacteria recover and multiply.

Physical cleaning should be followed by chemical or equivalent disinfection procedures and all contact surfaces should be dry before use. If disinfection measures are inadequate, bacteria may adapt to the stress conditions and become more resistant to control efforts. Clean breaks for in-shift sanitizing are becoming more common, so speed of application and drying time must be considered when evaluating new interventions.

Newer technology used in food and medical applications include concentrated alcohol products applied through inert gases to eliminate flammability. Biomist, Inc. has developed new high-grade sanitizing systems and automation for food manufacturers to bolster their sanitation programs by safely applying alcohol-based sanitizers to processing equipment, pneumatic pipes, electronics and other vectors of contamination.

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Posted in Cronobacter sakazakii, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Salmonella

Research – A Systematic Review on the Effectiveness of Pre-Harvest Meat Safety Interventions in Pig Herds to Control Salmonella and Other Foodborne Pathogens

Posted on September 5, 2021 by | Leave a comment

MDPI

myco

This systematic review aimed to assess the effectiveness of pre-harvest interventions to control the main foodborne pathogens in pork in the European Union. A total of 1180 studies were retrieved from PubMed® and Web of Science for 15 pathogens identified as relevant in EFSA’s scientific opinion on the public health hazards related to pork (2011). The study selection focused on controlled studies where a cause–effect could be attributed to the interventions tested, and their effectiveness could be inferred. Altogether, 52 studies published from 1983 to 2020 regarding Campylobacter spp., Clostridium perfringens, Methicillin-resistant Staphylococcus aureus, Mycobacterium avium, and Salmonella spp. were retained and analysed. Research was mostly focused on Salmonella (n = 43 studies). In-feed and/or water treatments, and vaccination were the most tested interventions and were, overall, successful. However, the previously agreed criteria for this systematic review excluded other effective interventions to control Salmonella and other pathogens, like Yersinia enterocolitica, which is one of the most relevant biological hazards in pork. Examples of such successful interventions are the Specific Pathogen Free herd principle, stamping out and repopulating with disease-free animals. Research on other pathogens (i.e., Hepatitis E, Trichinella spiralis and Toxoplasma gondii) was scarce, with publications focusing on epidemiology, risk factors and/or observational studies. Overall, high herd health coupled with good management and biosecurity were effective to control or prevent most foodborne pathogens in pork at the pre-harvest level. View Full-Text

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Posted in Campylobacter, Clostridium perfringens, Food Microbiology Research, MRSA, Mycobacterium, Pathogen, pathogenic, Research, Toxoplasma gondii, Toxoplasmosis, Yersinia