Category Archives: Food Microbiology Research

Norway Research – Outbreaks stable but illnesses down in 2021 

Posted on May 28, 2022 by | Leave a comment

Food Safety News

The number of foodborne outbreaks in Norway has remained steady but fewer people were sick in 2021 compared to the year before.

A total of 25 foodborne outbreaks were announced this past year, which is on a par with 23 in 2020 but down compared to 46 in 2019 and 52 in 2018.

Overall, 327 people fell sick in the 25 outbreaks in 2021 with a range of three to 30 patients per outbreak. The 23 outbreaks in 2020 affected 495 people.

Data comes from a report that gives an overview of outbreaks and related illnesses reported to the Norwegian Institute of Public Health (FHI) in 2021.

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Posted in Decontamination Microbial, food bourne outbreak, Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Foodborne Illness, Foodborne Illness Death, foodborne outbreak, foodbourne outbreak, Illness, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, outbreak, Research

Research – A Review of Essential Oils as Antimicrobials in Foods with Special Emphasis on Fresh Produce

Posted on May 28, 2022 by | Leave a comment

Journal of Food Protection

Consumer safety concerns over established fresh produce washing methods, combined with demand for organic and clean label food, has led to the exploration of novel methods of produce sanitization. Essential oils (EOs), extracted from commonly found plants have potential as clean label sanitizers, as they are naturally derived and act as antimicrobials as well as antioxidants. In this review, the antimicrobial abilities of EOs are explored in the following categories: individually and in-combination, as emulsions, combined with existing chemical and physical preservation methods, incorporated into films and coatings, and in vapor phase. We examine combining EOs with one another, with EO components, with surfactants, or with other preservatives or preservation methods to increase sanitizing efficacy.  Components of major EOs are also identified, chemical mechanisms are discussed, and potential for antibacterial resistance and effect on organoleptic properties is examined. Studies reveal that EOs can serve as equivalent or better sanitizing agents than chlorine; nevertheless, concentrations must be kept low to avoid adverse sensory effects. For this reason, it is crucial that future studies address the maximum permissible EO concentrations, which do not negatively affect sensory properties.  This review should be beneficial to food scientists or industry personnel interested in sanitization and preservation of foods, including fresh produce with EOs.

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Posted in antimicrobial resistance, Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – The Response and Survival Mechanisms of Staphylococcus aureus under High Salinity Stress in Salted Foods

Posted on May 28, 2022 by | Leave a comment

MDPI

Staphylococcus aureus (S. aureus) has a strong tolerance to high salt stress. It is a major reason as to why the contamination of S. aureus in salted food cannot be eradicated. To elucidate its response and survival mechanisms, changes in the morphology, biofilm formation, virulence, transcriptome, and metabolome of S. aureus were investigated. IsaA positively regulates and participates in the formation of biofilm. Virulence was downregulated to reduce the depletion of nonessential cellular functions. Inositol phosphate metabolism was downregulated to reduce the conversion of functional molecules. The MtsABC transport system was downregulated to reduce ion transport and signaling. Aminoacyl-tRNA biosynthesis was upregulated to improve cellular homeostasis. The betaine biosynthesis pathway was upregulated to protect the active structure of proteins and nucleic acids. Within a 10% NaCl concentration, the L-proline content was upregulated to increase osmotic stability. In addition, 20 hub genes were identified through an interaction analysis. The findings provide theoretical support for the prevention and control of salt-tolerant bacteria in salted foods. View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Staphylococcus aureus

Research – Multistate Outbreak of Listeria monocytogenes Infections Linked to Fresh, Soft Hispanic-Style Cheese — United States, 2021

Posted on May 27, 2022 by | Leave a comment

CDC

Summary

What is already known about this topic?

Listeriosis outbreaks are frequently associated with consumption of fresh, soft Hispanic-style cheeses.

What is added by this report?

In early 2021, a multistate outbreak of listeriosis involving 13 cases in four states occurred, resulting in 12 hospitalizations and one death. The outbreak was linked to Hispanic-style cheese within 19 days of cluster detection. Rapid food testing by regulatory agencies in response to the investigation identified the implicated cheese.

What are the implications for public health practice?

To prevent severe health outcomes among persons at increased risk for listeriosis, public health agencies should improve communications, including implementing new methods of dissemination to emphasize the risk from eating fresh, soft Hispanic-style cheeses, even those made with pasteurized milk. 

Listeriosis is a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. An estimated 1,600 persons become ill with listeriosis each year, among whom approximately 260 die. Persons at higher risk for listeriosis include pregnant persons and their newborns, adults aged ≥65 years, and persons with weakened immune systems. Persons with invasive listeriosis usually report symptoms starting 1–4 weeks after eating food contaminated with L. monocytogenes; however, some persons who become infected have reported symptoms starting as late as 70 days after exposure or as early as the same day of exposure (1). On January 29, 2021, PulseNet, the national molecular subtyping surveillance network coordinated by CDC, identified a multistate cluster of three L. monocytogenes infections: two from Maryland and one from Connecticut (2). CDC, the Food and Drug Administration (FDA), and state and local partners began an investigation on February 1, 2021. A total of 13 outbreak-related cases were eventually identified from four states. All patients reported Hispanic ethnicity; 12 patients were hospitalized, and one died. Rapid food testing and record collection by regulatory agencies enabled investigators to identify a brand of queso fresco made with pasteurized milk as the likely source of the outbreak, leading to an initial product recall on February 19, 2021. Fresh, soft Hispanic-style cheeses made with pasteurized milk are a well-documented source of listeriosis outbreaks. These cheeses can be contaminated with L. monocytogenes unless stringent hygienic controls are implemented, and the processing environment is monitored for contamination (3). U.S. public health agencies should establish or improve communications, including new methods of disseminating information that also effectively reach Hispanic populations, to emphasize the risk from eating fresh, soft Hispanic-style cheeses, even those made with pasteurized milk.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

USA – BEAM Dashboard

Posted on May 27, 2022 by | Leave a comment

CDC

The BEAM (Bacteria, Enterics, Amoeba, and Mycotics) Dashboard is an interactive tool to access and visualize data from the System for Enteric Disease Response, Investigation, and Coordination (SEDRIC). The BEAM Dashboard provides timely data on pathogen trends and serotype details to inform work to prevent illnesses from food and animal contact. Currently, the dashboard focuses on data for Salmonella bacteria, but it will eventually include additional pathogens, antimicrobial resistance data, and epidemiologic data from outbreak investigations.

Frequently Asked Questions (FAQ)

For additional questions, please contact simso@cdc.gov.

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

USA – FDA Core Outbreak Table

Posted on May 27, 2022 by | Leave a comment

FDA

Date
Posted		 Ref Pathogen



 Product Total
Case Count		 Outbreak
Status
5/25/

2022

 1067 Salmonella 
Senftenberg		 Peanut Butter See Outbreak Advisory Ongoing
See Advisory
4/20/

2022

 1064 Not Yet
Identified		 Dry Cereal 558 adverse
event reports		 Ongoing
See Advice
4/13/

2022

 1057 Listeria
monocytogenes		 Not Yet
Identified		 20 Ongoing
See Advice
3/30/

2022

 1060 Not Yet
Identified		 Meal Replacement
Drink		 6 adverse
event reports		 Ended
See Advice
3/16/

2022

 1055 Salmonella
Saintpaul		 Not Identified 60 Ended
See Advice
2/17/

2022

 1056 Cronobacter
sakazakii		 Powdered
Infant
Formula		 See
Advisory		 Ended
See
Advisory
2/9/

2022

 1040 Listeria
monocytogenes		 Not Identified 20 Ongoing
See Advice
2/2/

2022

 1054 Enteroinvasive
E. coli
O143:H26		 Not
Identified		 16 Ended
See Advice
1/10/

2022

 1050 E. coli
O121:H19		 Romaine 4 Ended
12/29/

2021

 1052 E. coli
O157:H7		 Packaged
Salad		 See Outbreak
Advisory		 Ended
See Outbreak
Advisory
12/20/

2021

 1039 Listeria
monocytogenes		 Packaged
Salad		 See Outbreak
Advisory		 Ended
See Outbreak
Advisory
12/15/

2021

 1048 Listeria
monocytogenes		 Packaged
Salad		 See Outbreak
Advisory		 Ended
See Outbreak
Advisory

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Posted in FDA, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations

Research – Application of ultra-fine bubble technology to reduce Listeria monocytogenes contamination of fresh produce

Posted on May 26, 2022 by | Leave a comment

Center for Produce Safety

Summary

Water used for washing or hydrocooling can act as a source of produce contamination with Listeria monocytogenes. Since this could lead to human infections, controlling L. monocytogenes in hydrocooling water and produce is critical for food safety. Commercial disinfectants (chlorine, quaternary ammonium compounds) are not completely effective in killing L. monocytogenes in wash water or on produce, especially in presence of organic load.

This proposal aims to investigate the potential of a new technology that employs water containing ultra-fine gas bubbles (size ~ 1 micrometer or less) for washing produce (celery, gala apples, romaine lettuce). We will generate ultra-fine ozone (UFO) bubbles in water using a high energy shear method and test the potential of resulting solution to rapidly kill (in 30 to 60 sec) L. monocytogenes in wash water and on produce surface. In addition, the efficacy of UFO bubble water to synergistically improve the Listeria killing potential of aforementioned commercial disinfectants will be tested. The anti-listerial efficacy of UFO bubble water will also be tested in presence of organic load. Successful completion of this project will provide the produce industry with novel antimicrobial treatment for disinfecting wash water and produce in single pass or re- circulated hydrocooling systems.

Technical Abstract

The widespread distribution of Listeria monocytogenes in agricultural environments such as soil, manure and water results in frequent contamination of food processing areas. Although good agricultural practices partially reduce contamination, however, due to the open nature of farming, it is extremely difficult to completely prevent pathogen influx. Water used for washing or hydrocooling can act as a source of equipment and produce contamination with L. monocytogenes. Since this could lead to human infections, controlling L. monocytogenes in hydrocooling water and on the surface of fresh produce is critical for food safety. Currently used commercial disinfectants (chlorine, peracetic acid, quaternary ammonium compounds) are not completely effective in killing L. monocytogenes in wash water or on the surface of produce, especially in presence of organic load. Moreover, the presence of chemical residues and the formation of harmful organochlorine compounds is an occupational concern due to associated health risks, including cancer. Therefore, there is a need for developing novel strategies that could be employed (either alone or in combination with currently used commercial disinfectants) to control L. monocytogenes in wash water and on surface of fresh produce, vegetables and fruits.

This proposal aims to investigate the potential of a new technology that employs water containing ultra-fine gas bubbles (size ~ 1 micrometer or less) for washing produce (celery, gala apples, romaine lettuce). We will generate ultra-fine ozone (UFO) bubbles in water using a high energy shear method and test the potential of resulting solution to rapidly kill (in 30 to 60 sec) L. monocytogenes in wash water and on produce surface. In addition, the efficacy of UFO bubble water to synergistically improve the Listeria killing potential of aforementioned commercial disinfectants will be tested. The anti-listerial efficacy of UFO bubble water will also be tested in presence of organic load.

Potential impact from anticipated outcomes: Successful completion of this project will provide the produce industry with novel antimicrobial treatment for disinfecting wash water and produce in dump tanks, and single pass or re-circulated hydrocooling systems. This intervention will translate into increased microbiological safety of fresh produce.

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

Research – Frozen Vegetable Processing Plants Can Harbour Diverse Listeria monocytogenes Populations: Identification of Critical Operations by WGS

Posted on May 26, 2022 by | Leave a comment

MDPI

Frozen vegetables have emerged as a concern due to their association with foodborne outbreaks such as the multi-country outbreak of Listeria monocytogenes serogroup IVb linked to frozen corn. The capacity of L. monocytogenes to colonize food-processing environments is well-known, making the bacteria a real problem for consumers. However, the significance of the processing environment in the contamination of frozen foods is not well established. This study aimed to identify potential contamination niches of L. monocytogenes in a frozen processing plant and characterize the recovered isolates. A frozen vegetable processing plant was monitored before cleaning activities. A total of 78 points were sampled, including frozen vegetables. Environmental samples belonged to food-contact surfaces (FCS); and non-food-contact surfaces (n-FCS). Positive L. monocytogenes samples were found in FCS (n = 4), n-FCS (n = 9), and the final product (n = 1). A whole-genome sequencing (WGS) analysis revealed two clusters belonging to serotypes 1/2a-3a and 1/2b-3b). The genetic characterization revealed the presence of four different sequence types previously detected in the food industry. The isolate obtained from the final product was the same as one isolate found in n-FCS. A multi-virulence-locus sequence typing (MVLST) analysis showed four different virulence types (VT). The results obtained highlight the relevant role that n-FCS such as floors and drains can play in spreading L. monocytogenes contamination to the final product. View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, WGS, Whole Genomic Sequencing

Research – Microbiome of Lettuce Might Hold Secret to Better Food Safety

Posted on May 26, 2022 by | Leave a comment

Growing Produce

Eurofins Food Testing UK

Researchers at the University of Georgia Center for Food Safety are preparing to launch a study on E. coli colonization from a new angle: the microbiome of lettuce.

By studying the interactions between EcO157 and the lettuce microbiome — the entire community of microorganisms like bacteria that live on the surface of lettuce — researchers hope to better understand how the microbiome may affect the pathogen’s fate during produce processing.

Center for Food Safety Professor Xiangyu Deng, lead researcher on the project, says, “We want to really figure out the interactions between the pathogen and potential biocontrol organisms indigenous to lettuce.”

In other words, how does E. coli interact with other microorganisms on lettuce, and how can we use those interactions to control foodborne outbreaks?

The focus of the research, to start this year, will be how the microbiome interacts with EcO157. The team will use a new microscopic approach to create a biogeographic map of the microbiome.

“Clearly the microbiome interacts with EcO157, and that interaction has an implication for food safety,” Deng adds. “We want to understand the mechanism behind this interaction.”

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Posted in Decontamination Microbial, E.coli, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiome, Research

Finland – Large Salmonella outbreak dominates Finnish figures

Posted on May 26, 2022 by | Leave a comment

Food Safety News

A Salmonella outbreak affected more than 700 people in Finland in 2021, according to new information from the Finnish Food Authority (Ruokavirasto).

The implicated food was a salad with iceberg lettuce, cucumber and peas served in several kindergartens. It was previously known that almost 450 people, mostly children, had been ill.

Officials in the city of Jyväskylä investigated the incident with the help of the National Institute for Health and Welfare (THL).

Overall, 46 foodborne outbreaks were recorded in Finland this past year affecting almost 1,400 people. In 2020, 34 outbreaks were reported involving 543 people.

Seven Salmonella outbreaks sickened 824 people compared to three outbreaks with 21 sick in 2020.

The most common pathogen was norovirus with nine outbreaks and 260 cases. One of the main factors that contributed to foodborne norovirus incidents was an infected kitchen worker.

Read More at the link above.

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Posted in Decontamination Microbial, food bourne outbreak, Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Norovirus, outbreak, Salmonella