Category Archives: Pathogen

Scotland mulls pathogen action levels

Food Safety News

Food Standards Scotland (FSS) is considering introducing thresholds for action for some pathogens based on either a UK or Scottish approach.

Using targets based on reported infections of key pathogens could help monitor trends and be used as a trigger to act. However, figures would need to be interpreted carefully because of underreporting, inability to separate food and non-food sources, changes in demographics, and impacts of year to year fluctuations in environmental factors, such as weather.

When reported cases breach the threshold, different steps would be considered including an investigation to identify reasons behind the increase; additional food sampling associated with the pathogen and risk communication to consumers using tailored messages.

FSS currently uses Public Health Scotland data on confirmed laboratory reports for five pathogens to monitor how foodborne illness is changing.

Research – Identification of genetic variations related to pathogenicity by whole genome sequencing of Listeria monocytogenes SMFM2019-FV16 isolated from enoki mushroom

Wiley Online

Abstract

In this study, the characteristics of Listeria monocytogenes isolated from enoki mushroom (Flammulina velutipes) collected from May to July 2019 were analyzed. The isolates were analyzed for strain characteristics, hemolysis, antibiotic resistance, heat resistance, and virulence genes (inlAinlBactAplcB, and hlyA) were analyzed, and whole genome sequencing (WGS) analysis was performed for the strain with the highest risk. Seven isolates were obtained from some enoki mushroom samples. All isolates were β-hemolytic and had virulence genes. Antibiotic resistance test showed multi-drug resistance in Lmonocytogenes strain SMFM2019-FV15 and SMFM2019-FV16. Lmonocytogenes SMFM2019-FV16 showed higher heat resistance than the other isolates. According to the results Lmonocytogenes SMFM2019-FV16 was selected as the strain with the highest risk. WGS for Lmonocytogenes SMFM2019-FV16 showed that it had 14 antibiotic resistance genes and 43 virulence genes, and 35 single nucleotide variants in the 43 virulence genes were observed. These results indicate that these genetic variations might be related to the high risk of Lmonocytogenes SMFM2019-FV16.

USA – Cronobacter infections in babies are now a reportable disease

Food Safety News

The CDC has announced it will begin tracking infections caused by cronobacter, which was behind an outbreak in 2021-22 among babies and caused an infant formula shortage that plagued the nation for months.

The council is the body that recommends what diseases are “reportable.” That list already includes illnesses from other foodborne pathogens, including E. coli, Salmonella, and Listeria. About 120 other illnesses are on the list of “nationally notifiable” pathogens. The council and the CDC manage the list.

When the recommendation becomes active, cronobacter infections identified in infants less than 1-year-old will be reported by doctors and laboratories to state health departments. Those departments will then notify the CDC.

France sees a rise in outbreaks in 2021

Food Safety News

The number of outbreaks in France went up in 2021 but was still below 2018 and 2019 levels.

Figures from Santé publique France show there were 1,309 outbreaks affecting 11,056 people in 2021. A total of 512 people went to hospitals and 16 died.

Reported outbreaks rose from 1,010 in 2020 when figures were strongly impacted by the COVID-19 pandemic, according to officials.

For 327 incidents in 2021, a pathogen could be microbiologically confirmed in food or in at least one sick person per outbreak. A pathogen was suspected without microbiological confirmation for 734 outbreaks.

16 deaths in outbreaks
The most frequently microbiologically confirmed pathogen was Salmonella 147 times. It was mostly Salmonella Enteritidis, followed by monophasic Salmonella Typhimurium but the type was not known in 92 incidents. Confirmed Salmonella outbreaks were responsible for 935 patients and 166 hospitalizations.

Campylobacter caused 52 outbreaks with 178 patients and Bacillus cereus had 46 with 665 patients. Nineteen norovirus outbreaks sickened 493 and 11 histamine outbreaks affected 35 people.

Seven outbreaks were due to E. coli, six to Yersinia enterocolitica, four to Shiga toxin-producing E. coli (STEC), and one each because of Listeria monocytogenes, Clostridium botulinum, and Shigella.

The pathogen was identified in patients for 208 outbreaks, of which 143 were confirmed with Salmonella. Identification of the agent took place in food samples for 89 epidemics with 67 confirmed as Bacillus cereus, Staphylococcus aureus and Clostridium perfringens.

The top suspected pathogens based on epidemiological and clinical information, but not microbiologically confirmed, were the toxins Bacillus cereus, Staphylococcus aureus and Clostridium perfringens. For these three pathogens, 3,787 patients and 169 hospital trips were recorded.

Research – Antibacterial Activity against Four Fish Pathogenic Bacteria of Twelve Microalgae Species Isolated from Lagoons in Western Greece

MDPI

Abstract

Microalgae may produce a range of high-value bioactive substances, making them a promising resource for various applications. In this study, the antibacterial activity of twelve microalgae species isolated from lagoons in western Greece was examined against four fish pathogenic bacteria (Vibrio anguillarumAeromonas veroniiVibrio alginolyticus, and Vibrio harveyi). Two experimental approaches were used to evaluate the inhibitory effect of microalgae on pathogenic bacteria. The first approach used bacteria-free microalgae cultures, whereas the second approach used filter-sterilized supernatant from centrifuged microalgae cultures. The results demonstrated that all microalgae had inhibitory effects against pathogenic bacteria in the first approach, particularly 4 days after inoculation, where Asteromonas gracilis and Tetraselmis sp. (red var., Pappas) exhibited the highest inhibitory activity, reducing bacterial growth by 1 to 3 log units. In the second approach, Tetraselmis sp. (red var., Pappas) showed significant inhibition against V. alginolyticus between 4 and 25 h after inoculation. Moreover, all tested cyanobacteria exhibited inhibitory activity against V. alginolyticus between 21 and 48 h after inoculation. Statistical analysis was performed using the independent samples t-test. These findings suggested that microalgae produce compounds with antibacterial activity, which could be useful in aquaculture.

USA – Foodborne Illness Outbreaks at Retail Food Establishments — National Environmental Assessment Reporting System, 25 State and Local Health Departments, 2017–2019

CDC

Abstract

Problem/Condition: Each year, state and local public health departments report hundreds of foodborne illness outbreaks associated with retail food establishments (e.g., restaurants or caterers) to CDC. Typically, investigations involve epidemiology, laboratory, and environmental health components. Health departments voluntarily report epidemiologic and laboratory data from their foodborne illness outbreak investigations to CDC through the National Outbreak Reporting System (NORS); however, minimal environmental health data from outbreak investigations are reported to NORS. This report summarizes environmental health data collected during outbreak investigations and reported to the National Environmental Assessment Reporting System (NEARS).

Period Covered: 2017–2019.

Description of System: In 2014, CDC launched NEARS to complement NORS surveillance and to use these data to enhance prevention efforts. State and local health departments voluntarily enter data from their foodborne illness outbreak investigations of retail food establishments into NEARS. These data include characteristics of foodborne illness outbreaks (e.g., etiologic agent and factors contributing to the outbreak), characteristics of establishments with outbreaks (e.g., number of meals served daily), and food safety policies in these establishments (e.g., ill worker policy requirements). NEARS is the only available data source that collects environmental characteristics of retail establishments with foodborne illness outbreaks.

Results: During 2017–2019, a total of 800 foodborne illness outbreaks associated with 875 retail food establishments were reported to NEARS by 25 state and local health departments. Among outbreaks with a confirmed or suspected agent (555 of 800 [69.4%]), the most common pathogens were norovirus and Salmonella, accounting for 47.0% and 18.6% of outbreaks, respectively. Contributing factors were identified in 62.5% of outbreaks. Approximately 40% of outbreaks with identified contributing factors had at least one reported factor associated with food contamination by an ill or infectious food worker. Investigators conducted an interview with an establishment manager in 679 (84.9%) outbreaks. Of the 725 managers interviewed, most (91.7%) said their establishment had a policy requiring food workers to notify their manager when they were ill, and 66.0% also said these policies were written. Only 23.0% said their policy listed all five illness symptoms workers needed to notify managers about (i.e., vomiting, diarrhea, jaundice, sore throat with fever, and lesion with pus). Most (85.5%) said that their establishment had a policy restricting or excluding ill workers from working, and 62.4% said these policies were written. Only 17.8% said their policy listed all five illness symptoms that would require restriction or exclusion from work. Only 16.1% of establishments with outbreaks had policies addressing all four components relating to ill or infectious workers (i.e., policy requires workers to notify a manager when they are ill, policy specifies all five illness symptoms workers need to notify managers about, policy restricts or excludes ill workers from working, and policy specifies all five illness symptoms requiring restriction or exclusion from work).

Interpretation: Norovirus was the most commonly identified cause of outbreaks reported to NEARS, and contamination of food by ill or infectious food workers contributed to approximately 40% of outbreaks with identified contributing factors. These findings are consistent with findings from other national outbreak data sets and highlight the role of ill workers in foodborne illness outbreaks. Although a majority of managers reported their establishment had an ill worker policy, often these policies were missing components intended to reduce foodborne illness risk. Contamination of food by ill or infectious food workers is an important cause of outbreaks; therefore, the content and enforcement of existing policies might need to be re-examined and refined.

Public Health Action: Retail food establishments can reduce viral foodborne illness outbreaks by protecting food from contamination through proper hand hygiene and excluding ill or infectious workers from working. Development and implementation of policies that prevent contamination of food by workers are important to foodborne outbreak reduction. NEARS data can help identify gaps in food safety policies and practices, particularly those concerning ill workers. Future analyses of stratified data linking specific outbreak agents and foods with outbreak contributing factors can help guide the development of effective prevention approaches by describing how establishments’ characteristics and food safety policies and practices relate to foodborne illness outbreaks.

Research – A Review of Modern Methods for the Detection of Foodborne Pathogens

MDPI

Abstract

Despite the recent advances in food preservation techniques and food safety, significant disease outbreaks linked to foodborne pathogens such as bacteria, fungi, and viruses still occur worldwide indicating that these pathogens still constitute significant risks to public health. Although extensive reviews of methods for foodborne pathogens detection exist, most are skewed towards bacteria despite the increasing relevance of other pathogens such as viruses. Therefore, this review of foodborne pathogen detection methods is holistic, focusing on pathogenic bacteria, fungi, and viruses. This review has shown that culture-based methods allied with new approaches are beneficial for the detection of foodborne pathogens. The current application of immunoassay methods, especially for bacterial and fungal toxins detection in foods, are reviewed. The use and benefits of nucleic acid-based PCR methods and next-generation sequencing-based methods for bacterial, fungal, and viral pathogens’ detection and their toxins in foods are also reviewed. This review has, therefore, shown that different modern methods exist for the detection of current and emerging foodborne bacterial, fungal, and viral pathogens. It provides further evidence that the full utilization of these tools can lead to early detection and control of foodborne diseases, enhancing public health and reducing the frequency of disease outbreaks.

Research – Human Salmonellosis: A Continuous Global Threat in the Farm-to-Fork Food Safety Continuum

MDPI

Abstract

Salmonella is one of the most common zoonotic foodborne pathogens and a worldwide public health threat. Salmonella enterica is the most pathogenic among Salmonella species, comprising over 2500 serovars. It causes typhoid fever and gastroenteritis, and the serovars responsible for the later disease are known as non-typhoidal Salmonella (NTS). Salmonella transmission to humans happens along the farm-to-fork continuum via contaminated animal- and plant-derived foods, including poultry, eggs, fish, pork, beef, vegetables, fruits, nuts, and flour. Several virulence factors have been recognized to play a vital role in attaching, invading, and evading the host defense system. These factors include capsule, adhesion proteins, flagella, plasmids, and type III secretion systems that are encoded on the Salmonella pathogenicity islands. The increased global prevalence of NTS serovars in recent years indicates that the control approaches centered on alleviating the food animals’ contamination along the food chain have been unsuccessful. Moreover, the emergence of antibiotic-resistant Salmonella variants suggests a potential food safety crisis. This review summarizes the current state of the knowledge on the nomenclature, microbiological features, virulence factors, and the mechanism of antimicrobial resistance of Salmonella. Furthermore, it provides insights into the pathogenesis and epidemiology of Salmonella infections. The recent outbreaks of salmonellosis reported in different clinical settings and geographical regions, including Africa, the Middle East and North Africa, Latin America, Europe, and the USA in the farm-to-fork continuum, are also highlighted.

USA – Food illnesses linked to Dave’s Sushi in Bozeman – a death possibly linked to mushrooms

Food Poison Journal

According to the Gallatin County Health Department, Dave’s Sushi in Bozeman is closed until further notice due to possible foodborne illnesses. The health department was notified of possible foodborne illness linked to eating at Dave’s Sushi on April 17. At this time, it is unclear what pathogen caused the illness.

On April 18, the health department performed an inspection and reportedly found Dave’s Sushi with four violations.

According to press reports, a man died after eating at the popular Bozeman restaurant, Dave’s Sushi, according to Broadwater County Sheriff Nick Rauser, who is also the county coroner. Sheriff Rauser says the 74-year-old man died at his home in Broadwater County. Sheriff Rauser says the call came in at 6:34 AM on the morning of April 18 and a relative told the responding officer that the man had eaten at Dave’s Sushi the night before, the same night the Gallatin County Health Department reported they received complaints of people becoming ill which led to the investigation and closure of the restaurant.

Dave’s Sushi will remain closed until further notice, pending a full investigation. According to a press release from the Gallatin City-County Health Department, the illnesses have been linked to eating at Dave’s Sushi on the afternoon of April 17, as well as April 1, April 8, April 9, and April 10.

Research – Deep ultraviolet fluorescence sensing with multispectral imaging to detect and monitor food-borne pathogens on the leafy green phyllosphere

Wiley Online

Demand for sustainable and safe raw agricultural commodities is growing rapidly worldwide. Reducing the risk of foodborne illnesses associated with fresh produce is a task which the industry and academic researchers have been struggling with for many years. There is an immediate need to devise a non-invasive optical detection system to monitor the food-borne pathogens on the leaf surface. The detection of foodborne pathogens on leafy produce is performed often too late because of the invasive techniques used to evaluate the pathogen colonization. Use of deep ultraviolet fluorescence (DUVF) sensing and visible–near infrared multispectral imaging (MSI) has previously been used to monitor plant interactions against both biotic and abiotic stress regimes. Using the patho-system that we developed to monitor Salmonella sp. and Listeria sp. ingression in leafy greens such as lettuce/spinach, we show that plant response in terms of fluctuation of chlorophyll pigments post-Salmonella/Listeria treatment is rapid. We also show that the mode of application of Salmonella/Listeria via foliar or root supplementation changes the ChlA response. Our data also reveals that the plant sentinel response in terms of early photosynthetic response may be critical to detect food-borne pathogens on leafy greens. MSI demonstrated that plant stress was detectable and proportional to the bacterial inoculation rate on plants. Our research may lead to implementation of better strategies and technology to increase yield and reduce risks associated with contamination of foodborne bacterial pathogens.