Category Archives: Microbiology

USA – FDA says the hepatitis A virus in this year’s frozen strawberry outbreak is identical to one from 2022

Food Safety News

Federal officials have confirmed that the strain of hepatitis A virus found in frozen organic strawberries involved in a multi-state outbreak this year is the same strain that caused an outbreak in 2022.

The organic strawberries associated with both outbreaks were imported to the United States from the same growing area in Baja California, Mexico, according to an outbreak update from the U.S. Food and Drug Administration.

So far this year there have been seven people confirmed infected and all seven reported eating frozen organic strawberries. Two of the patients required hospitalization.

FDA’s traceback investigation identified a common supplier of frozen organic strawberries, but Tuesday’s update did not name the supplier. Both this year and in 2022 the implicated strawberries were sold at a variety of stores under several different brand names.

Research – Austria reports Salmonella and Yersinia data for 2022

Food Safety News

Submissions of human Salmonella isolates are approaching pre-COVID-19 pandemic levels in Austria after a decline in 2020 and 2021, according to the Federal Ministry of Labour, Social Affairs, Health and Consumer Protection (BMSGPK).

In 2022, the number of isolates sent to the National Reference Centre for Salmonella increased by 118. This past year, 1,166 Salmonella isolates were submitted to the reference center compared with 1,048 in 2021. It is still below the 1,872 sent in 2019.

In 2022, the Austrian National Reference Centre for Yersinia at the Austrian Agency for Health and Food Safety (AGES) received 201 human isolates.

Of these, 107 were pathogenic, and 94 were non-pathogenic. Among the pathogenic ones, 105 belonged to Yersinia enterocolitica including 88 serovar O:3; biovar 4, and two were Yersinia pseudotuberculosis.

A total of 130 cases of yersiniosis were reported to BMSGPK. This was about the same level as in 2021. Based on data from 38 patients, 22 cases reported diarrhea, 11 had cases of abdominal pain and three each mentioned vomiting and fever.

USA – FDA – Core Outbreak Table – Update

FDA

What’s New

  • On 4/11/2023, an updated outbreak advisory was issued for the outbreak of hepatitis A virus linked to frozen organic strawberries (reference #1143).
  • The outbreak of Listeria monocytogenes (ref #1127) linked to enoki mushrooms has ended and the FDA investigation is closed.
Date
Posted
Ref Pathogen
or
Cause of
Illness
Product(s)
Linked to
Illnesses

(if any)
Total
Case
Count

Status
3/29/2023 1141 Salmonella Infantis Raw Flour See
CDC
Investigation
Notice
Active
3/8/2023 1144 Salmonella Hartford Not Yet
Identified
53 Active
3/1/2023 1143 Hepatitis A Virus Frozen Organic
Strawberries
See
Outbreak
Advisory
Active
2/15/2023 1123 Listeria
monocytogenes
Not Yet
Identified
See
CDC
Investigation
Notice
Active

MasterChef cooks cause food poisoning in Spain

Food Safety News

More than 40 people are suspected to have been affected by food poisoning as part of a TV cooking show in Spain.

Health officials in Valencia confirmed to local media that 44 diners invited to a recording of the MasterChef program on Jan. 19 suffered food poisoning. The episode was aired earlier this week. Symptoms included vomiting and diarrhea.

MasterChef is a popular reality television cooking show broadcast in several countries where contestants make a range of dishes, which are judged by experts.

Reports first surfaced on Twitter with a woman reporting she was one of many people who had gotten sick after tasting food served outside an aquarium in Valencia for staff as part of the program. A range of items, including seafood, were prepared for about 120 people.

Analysis, traceability information, and documentation of the process and treatment of food used and cooked were shown to health authorities.

However, officials were unable to find the source of the infection because of the time that had passed since the event meaning there was no food left to test.

The producer of the program in Spain, Shine Iberia, apologized to the affected diners.

“This is an absolutely exceptional case in these 11 years of MasterChef in Spain, a program where it is an absolute priority to guarantee the nutritional care of the people involved.”

Traveling to Mexico? Here’s how to avoid food poisoning on vacation.

Food Poisoning News

The inexpensive food and delicious smells often tempt travelers to purchase food from the numerous street vendors. Before indulging, however, it is recommended to be vigilant of how ingredients are stored and how the raw meats are handled. Food that is cooked in front of the customer, rather than appearing to be pre-cooked, is a much safer option. When food, even if cooked, is left at room temperature too long, the dangers of cross-contamination and bacterial growth are much higher.

An easy rule to follow is also simply trusting your instincts and avoiding vendors whose food carts are untidy or produce rotten odors. Look for hand-sinks, access to water, or refrigeration units.

Ceviche is also a very common dish in Mexico. Raw fish is exponentially more likely to be contaminated than cooked fish, especially if it is not stored correctly. Travelers should be especially wary of eating ceviche in an area that is farther away from the coast where the fish have to be stored for longer periods of time.  In addition, all ceviche stands should have refrigeration units or copious amounts of ice.

Mexico also has a long history of unsafe drinking water – often the source of “traveler’s diarrhea.” It is generally recommended to not drink water straight from the tap or to use ice cubes made from tap water. Even if the water is purified at the source, the pipes that the water passes through may not be sanitary. Caution should also be exercised when purchasing fruit juices or horchata made with ap water.  Recommendation? Stay hydrated by drinking bottled drinks.

Travelers to Mexico will have a more enjoyable trip if they make wise and informed choices regarding the food they consume. But don’t leave home without anti-diarrheal medicine!

Research – How to deal with food poisoning while traveling—and how to avoid it altogether

National Geographic

Some countries have a reputation for putting travelers at a higher risk for gastrointestinal illnesses. But you can get sick from an improperly handled meal anywhere in the world.

Pad thai from a Bangkok street vendor or raw milk cheese from a bistro in France taste delicious in the moment. But for many travelers, the local dishes that make trips meaningful sometimes give them food poisoning—and the wrong sort of vacation memories.

By some metrics, gastrointestinal infections related to food or water affect 30 to 70 percent of all travelers during or immediately after their trips, according to a 2015 study in BMJ Clinical Evidence. Each year, one in six Americans and nearly one in 10 people worldwide suffer from such illnesses caused by bacteria (E. coli, salmonella, listeria), viruses (norovirus, hepatitis A), or parasites (giardiasis, roundworms, tapeworms).

Lower-income countries have a reputation for putting travelers at a higher risk for food poisoning, but people are just as likely to be sickened from an improperly handled meal in Italy or Australia—or from some sushi at their local supermarket.

Here’s why people get food poisoning, what to do if it strikes, and how to (maybe) prevent it, read at the link above.

USA – Outbreak Investigation of Listeria monocytogenes: Enoki Mushrooms (November 2022)

FDA

The US Food and Drug Administration (FDA), along with Centers for Disease Control and Prevention (CDC) as well as state and local partners, investigated an outbreak of Listeria monocytogenes infections linked to enoki mushrooms. FDA identified enoki mushrooms distributed by Utopia Foods, Inc. of Glendale, New York, and imported from China, and enoki mushrooms labeled as “Producer: Shandong Youhe Biotechnology, Co.,” with an address in China and “Distributed By: Sun Hong Foods, Inc.” as likely sources of illnesses in this outbreak. Enoki mushrooms are long thin white mushrooms, usually sold in clusters. They are especially popular in East Asian cuisine and are also known as enokitake, golden needle mushrooms, futu, seafood mushrooms, or lily mushrooms.

As of April 7, 2023, CDC reports this outbreak is over. Five people in four states (CA, MI, NJ, NV) were sickened with five people reporting hospitalization. There was one pregnancy-associated illness and no reported deaths.

During this investigation, FDA leveraged ongoing surveillance sampling efforts. Several import and retail samples were collected and tested by FDA and/or state and local partners. Laboratory results indicated that many enoki products sampled were contaminated with Listeria. On January 17, 2023, FDA reported a positive import sample of enoki mushrooms that matched both outbreak strains and resulted in a voluntary recall expansion from Utopia Foods, Inc.

Additional sample collection and analysis conducted by the Maryland Department of Health identified both outbreak strains of Listeria in two product samples of enoki mushrooms. The products that tested positive were sold in a 7.05-oz (200g) clear plastic package with a brown and green label and included a label on the back of the package that states: “Producer: Shandong Youhe Biotechnology Co.,” with an address in China, and “Distributed By: Sun Hong Foods, Inc.”

While the outbreak has ended, FDA continues to assess the risk of Listeria contamination in enoki mushrooms.

Further, FDA has added enoki mushrooms from China to a country wide import alert (Import Alert (IA) #25-21). As stated in the Import Alert, FDA Import Divisions may subject shipments of enoki mushrooms from Republic of Korea and China to Detention Without Physical Examination (DWPE). FDA import alerts inform the FDA’s field staff and the public that the agency has enough evidence to allow for DWPE of products that appear to be in violation of the FDA’s laws and regulations. DWPE helps to prevent potentially violative products from being distributed in the United States.

In addition, after the 2020 outbreak linked to enoki mushrooms, FDA began implementing a Strategy to Help Prevent Listeriosis and Salmonellosis Outbreaks Associated with Imported Enoki and Imported Wood Ear Mushrooms, to protect public health. This prevention strategy is an affirmative, deliberate approach undertaken by FDA and stakeholders to help limit or prevent future outbreaks linked to certain FDA-regulated foods.

Recommendation

Although this outbreak investigation has ended, FDA and CDC are working to better understand the risk of Listeria monocytogenes contamination in enoki mushrooms.

CDC and FDA advise people who are pregnant, aged 65 or older, or have a weakened immune system to cook enoki mushrooms thoroughly, and to: 

  • Avoid eating enoki mushrooms raw. 
  • Keep raw enoki mushrooms separate from foods that won’t be cooked.
  • Wash your hands, items, and surfaces that have touched raw enoki mushrooms.

Restaurants should cook enoki mushrooms thoroughly before serving to customers, follow FDA’s safe handling and cleaning advice, and use extra vigilance in cleaning and sanitizing any surfaces and containers that may have come in contact with these products.

This advice is based on the following information:

  • Two recent multistate Listeria outbreaks have been linked to enoki mushrooms: This outbreak, and the first known Listeria outbreak in the United States linked to enoki mushrooms in 2020.
  • During this investigation, FDA leveraged ongoing surveillance sampling efforts. Several import and retail samples were collected and tested by FDA and/or state and local partners and many were contaminated with Listeria. Some samples contained high levels of the bacteria.
  • More than 20 recalls of enoki mushrooms due to potential Listeria contamination have been conducted since 2020.

Research – Human and animal botulism surveillance in France from 2008 to 2019

Frontiers in Microbiology

Botulism is a human and animal neurological disease caused by the action of bacterial neurotoxins (botulinum toxins) produced by bacteria from the genus Clostridium. This disease induces flaccid paralysis that can result in respiratory paralysis and heart failure. Due to its serious potential impact on public health, botulism is a closely monitored notifiable disease in France through a case-based passive surveillance system. In humans, this disease is rare, with an average of 10 outbreaks reported each year, mainly due to the consumption of contaminated foods. Type B and to a lesser extend type A are responsible for the majority of cases of foodborne botulism. Each year, an average of 30 outbreaks are recorded on poultry farms, about 20 cases in wild birds and about 10 outbreaks in cattle, involving a large number of animals. Mosaic forms C/D and D/C in birds and cattle, respectively, are the predominant types in animals in France. Types C and D have also been observed to a lesser extent in animals. With the exception of botulinum toxin E, which was exceptionally detected throughout the period in wild birds, the types of botulism found in animal outbreaks are different from those identified in human outbreaks over the last ten years in France and no human botulism outbreaks investigated have been linked to animal botulism. In line with the One Health concept, we present the first integrative approach to the routine surveillance of botulism in humans and animals in France.

Research – Bacterial signaling across biofilm affected by surface structure

Science Daily

Bacteria are also able to communicate with each other through chemical signals, a behavior known as quorum signaling (QS). These chemical signals spread through a biofilm that colonies of bacteria form after they reach a certain density, and are used to help the colonies scavenge food, as well as defend against threats, like antibiotics. Researchers examined how different structures affects biofilm growth and QS by the bacteria in the presence of antibiotics. They found structure does have an effect on QS in some strains of the bacteria.

Research – Microbiological Risk Assessment in Foods: Background and Tools, with a Focus on Risk Ranger

MDPI

Risk assessment is an important phase of the food production path; it is strictly related to the processing chain as a necessary step for safe foods. This paper represents a contribution to understanding what is and how risk assessment could be conducted; it aims to provide some information on the structure of risk assessment, the tools for its identification and measurement and the importance of risk assessment for correct communication. In this context, after a focus on the background and on some commonly used tools (Risk Ranger, FDA-iRisk, decision tree, among others), the paper describes how to perform risk assessment through three case studies: lettuce (for Listeria monocytogenes), chicken salad (for Escherichia coli), and fresh egg pasta (for Staphylococcus aureus) in the first step, and then a comparison of risk for chicken salad contaminated by different pathogens (E. coli O157:H7, Campylobacter spp. and Salmonella sp.). As a final step, a critical evaluation of Risk Ranger was carried out, pointing out its pros and cons.