Category Archives: Research

Research – Climate Change Is Making Europe’s Shellfish Dangerous

Medscape

Climate change is putting Europeans at an increased risk of contracting Vibrio-related infections, according to an assessment recently released by the European Food Safety Authority (EFSA).

Warming sea temperatures are expecting to increase the prevalence of the bacteria in seafood, especially in low-salinity or brackish waters, with a rise in antimicrobial resistance among the species creating additional cause for concern.

Vibrio bacteria, traditionally a problem in tropical and subtropical regions, can cause a range of illnesses, from mild gastroenteritis and ear infections to life-threatening conditions like sepsis.

Experts in Europe are calling for proper surveillance, funded research, and public awareness campaigns.

Research – Breakthrough in Combating Campylobacter Infections

Food Poisoning News

Researchers at Osaka Metropolitan University have made a new discovery in the fight against Campylobacter infections.  These infections, which primarily cause enteritis and can lead to severe complications like sepsis, remain a pressing concern worldwide, particularly affecting children under 5 and the elderly, according to a recent article from Asia Research News.

Campylobacter jejuni, a pathogen notorious for causing gastroenteritis and occasionally more serious extra-intestinal infections, has long eluded effective prevention and treatment methods. The absence of a vaccine or targeted medication has made controlling these infections challenging. However, the recent findings from the Osaka-based research team offer a promising new direction.

Research – APHA reports role in E. coli and Cryptosporidium outbreaks

Food Safety News

The Animal and Plant Health Agency (APHA) has been involved in four E. coli outbreak investigations so far this year in the United Kingdom.

A Shiga toxin-producing E. coli (STEC) O145 outbreak was linked to unpasteurized milk cheese produced by Mrs. Kirkham’s in Lancashire. APHA contributed to the incident management team investigation, including an advisory visit and epidemiologically relevant sampling.

Patients fell ill between July and December 2023. In late July 2024, the UK Health Security Agency (UKHSA) notified the Food Standards Agency (FSA) of four cases between June and July, taking the number of sick people to 40, including two deaths. One death was part of the latest update. While there is a microbiological link between the latest patients and previous cases, investigations did not identify a food chain connection between them and Mrs. Kirkham’s products.

Research – Aerotolerancy of Campylobacter spp.: A Comprehensive Review

MDPI

Abstract

Campylobacter spp. constitute a group of microaerophilic bacteria that includes strains that are aerotolerant and capable of surviving in aerobic conditions. Recent studies have shown that aerotolerant strains are highly prevalent in meats, animals, and clinical settings. Changes in growth media and other environmental conditions can affect the aerotolerance of Campylobacter strains and must be considered when studying their aerotolerance in vitro. Polymicrobial interactions and biofilms also play a significant role in the ability of Campylobacter to survive oxygen exposure. Continuous subculturing may foster aerotolerance, and studies have demonstrated a positive correlation between aerotolerance and virulence and between aerotolerance and the ability to survive stressful environmental conditions. Various mechanisms and genetic origins for aerotolerance have been proposed; however, most of the potential genes involved in aerotolerance require further investigation, and many candidate genes remain unidentified. Research is also needed to investigate if there are any clinical implications for Campylobacter aerotolerance. Understanding the aerotolerance of Campylobacter remains an important target for further research, and it will be an important step towards identifying potential targets for intervention against this clinically important food-borne pathogen.A

Seven Listeria outbreaks hit England in 2023

Food Safety News

Data from the UK Health Security Agency (UKHSA) shows Listeria infections rose slightly in 2023 and seven outbreaks were investigated.

In 2023, 177 listeriosis cases were reported in England and Wales compared to 167 in 2022. This is the highest level since 180 infections were noted in 2016.

For non-pregnancy-associated cases, death was reported for 32 people, of whom 11 had listeriosis recorded as a cause of death on the death certificate.

Research – Dutch data shows decline in outbreaks for 2023

Food Safety News

The number of outbreaks and people sick in them in the Netherlands has gone down compared to the previous year, according to statistics recently reported.

In 2023, 911 outbreaks were reported, with 3,500 people falling ill. In 2022, there were 1,173 outbreaks and 4,505 sick people.

Norovirus, Salmonella, and Campylobacter were still the most commonly identified causes of outbreaks in 2023.

Research – Assessing Listeria monocytogenes Growth in Artificially Inoculated Sea-Farmed Product—Raw Sea Bass (Dicentrarchus labrax) Fillet, Produced in Greece

MDPI

Abstract

Listeria monocytogenes (Lm) is responsible for listeriosis, a serious foodborne disease, with high hospitalization and mortality rates worldwide. The main cause of listeriosis in humans is the consumption of ready-to-eat (RTE) foods; Commission Regulation (EC) No 2073/2005 establishes microbiological criteria for Lm in RTE foods. Raw fish products are widely consumed, e.g., in sushi and various seafood recipes (e.g., carpaccio, sashimi, maki, nigiri, tartare, etc.), but are not subjected to RTE food safety criteria. The aim of our study was to assess the growth potential of Lm in raw sea bass fillets obtained from a leading aquaculture company in Greece. In order to assess the growth of Lm in raw sea bass fillets, we applied the “challenge test”, a scientific experiment designed to assess the growth of Lm within a specific food product under controlled conditions. According to our results, and taking into consideration the health risk for the listeriosis-vulnerable population, raw fish products utilized in the preparation of RTE foods, including sushi and an array of seafood dishes, should be incorporated in the Category of Safety Criteria of Regulation (EC) No 2073/2005 “Ready-to-eat food able to support the growth of Listeria monocytogenes”.

Hong Kong – Do Not Eat Raw Freshwater Fish to Avoid Harmful Bacteria and Parasites

CFS

Consuming raw freshwater fish (Chinese Yu Sang) can be hazardous to health. Raw freshwater fish including grass carp, bighead carp or snakehead may carry parasites such as Chinese liver fluke, which can cause obstruction, inflammation and cancer of the biliary ducts in the liver. Chinese liver fluke contributes to the majority of local human cases of enteric parasites.

In addition to parasites, eating raw or undercooked freshwater fish can lead to foodborne infections. In the past, there were outbreaks of Group B streptococcus (GBS) infections in Singapore which were associated with raw freshwater fish consumption. GBS can cause infections in different parts of the body including the bloodstream, lungs, bones and joints. People, especially the elderly and people with weakened immunity (e.g. people with chronic diseases), may also contract GBS by exposure to seawater through an existing open wound or a puncture wound when handling raw aquatic products.

In order to protect public health, raw freshwater fish (Chinese Yu Sang) is a prohibited food under the Food Business Regulation (Cap 132X) in Hong Kong. Consumers are advised not to eat raw or undercooked freshwater fish while dining locally or travelling and eat freshwater fish only if it is adequately cooked, especially when having hot pot or congee.

To prevent foodborne diseases, the public should also pay attention to personal, food and environmental hygiene:

  • Always keep your hands clean
  • Cover all wounds when handling raw seafood, and wear protective gloves if possible
  • Store raw and cooked foods separately, and use different knives and cutting boards to handle them separately to avoid cross-contamination
  • Cook food thoroughly before eating

Research – Modelling Behaviour of Salmonella spp. and Listeria monocytogenes in Raw and Processed Vegetables

MDPI

Abstract

Given the persistent occurrence of foodborne illnesses linked to both raw and processed vegetables, understanding microbial behavior in these foods under distribution conditions is crucial. This study aimed to develop predictive growth models for Salmonella spp. and Listeria monocytogenes in raw (mung bean sprouts, onion, and cabbage) and processed vegetables (shredded cabbage salad, cabbage and onion juices) at various temperatures, ranging from 4 to 36 °C. Growth models were constructed and validated using isolated strains of Salmonella spp. (S. Bareilly, S. Enteritidis, S. Typhimurium) and L. monocytogenes (serotypes 1/2a and 1/2b) from diverse food sources. The minimum growth temperatures for Salmonella varied among different vegetable matrices: 8 °C for mung bean sprouts, 9 °C for both onion and cabbage, and 10 °C for ready-to-eat (RTE) shredded cabbage salad. Both pathogens grew in cabbage juice at temperatures above 17 °C, while neither demonstrated growth in onion juice, even at 36 °C. Notably, Salmonella spp. exhibited faster growth than L. monocytogenes in all tested samples. At 8 °C, the lag time (LT) and specific growth rate (SGR) for Salmonella spp. in mung bean sprouts were approximately tenfold longer and threefold slower, respectively, compared to those at 10 °C. A decrease in refrigerator storage temperature by 1 or 2 degrees significantly prevented the growth of Salmonella in raw vegetables. These findings offer valuable insights into assessing the risk of foodborne illness associated with the consumption of raw and processed vegetables and inform management strategies in mitigating these risks.

Research – In Vitro Utilization of Prebiotics by Listeria monocytogenes

MDPI

Listeria monocytogenes is an emerging pathogen responsible for the serious foodborne disease, listeriosis. The commensal gut microbiota is the first line of defense against pathogen internalization. The gut microbiome can be modified by prebiotic substrates, which are frequently added to food products and dietary supplements. Prebiotics should selectively support the growth of beneficial microbes and thus improve host health. Nevertheless, little is known about their effect on the growth of L. monocytogenes. The aim of this study was to evaluate the growth ability of four L. monocytogenes strains, representing the most common serotypes, on prebiotic oligosaccharides (beta-(1,3)-D-glucan, inulin, fructooligosaccharides, galactooligosaccharides, lactulose, raffinose, stachyose and 2′-fucosyllactose and a mixture of human milk oligosaccharides) as a sole carbon source. The results showed that only beta-(1,3)-D-glucan was metabolized by L. monocytogenes. These cell culture data suggest that beta-(1,3)-D-glucan may not be selectively utilized by healthy commensal bacteria, and its role in intestinal pathogen growth warrants further exploration in vivo.