Category Archives: Food Microbiology Research

Research – Update and review of control options for Campylobacter in broilers at primary production

EFSA

 

The 2011 EFSA opinion on Campylobacter was updated using more recent scientific data. The relative risk reduction in EU human campylobacteriosis attributable to broiler meat was estimated for on‐farm control options using Population Attributable Fractions (PAF) for interventions that reduce Campylobacter flock prevalence, updating the modelling approach for interventions that reduce caecal concentrations and reviewing scientific literature. According to the PAF analyses calculated for six control options, the mean relative risk reductions that could be achieved by adoption of each of these six control options individually are estimated to be substantial but the width of the confidence intervals of all control options indicates a high degree of uncertainty in the specific risk reduction potentials. The updated model resulted in lower estimates of impact than the model used in the previous opinion. A 3‐log10 reduction in broiler caecal concentrations was estimated to reduce the relative EU risk of human campylobacteriosis attributable to broiler meat by 58% compared to an estimate larger than 90% in the previous opinion. Expert Knowledge Elicitation was used to rank control options, for weighting and integrating different evidence streams and assess uncertainties. Medians of the relative risk reductions of selected control options had largely overlapping probability intervals, so the rank order was uncertain: vaccination 27% (90% probability interval (PI) 4–74%); feed and water additives 24% (90% PI 4–60%); discontinued thinning 18% (90% PI 5–65%); employing few and well‐trained staff 16% (90% PI 5–45%); avoiding drinkers that allow standing water 15% (90% PI 4–53%); addition of disinfectants to drinking water 14% (90% PI 3–36%); hygienic anterooms 12% (90% PI 3–50%); designated tools per broiler house 7% (90% PI 1–18%). It is not possible to quantify the effects of combined control activities because the evidence‐derived estimates are inter‐dependent and there is a high level of uncertainty associated with each.

USA – Preliminary Incidence and Trends of Infections with Pathogens Transmitted Commonly Through Food — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2016–2019

CDC

Summary

What is already known about this topic?

The incidence of most infections transmitted commonly through food has not declined for many years.

What is added by this report?

Incidence of infections caused by ListeriaSalmonella, and Shigella remained unchanged, and those caused by all other pathogens reported to FoodNet increased during 2019. Infections caused by Salmonella serotype Enteritidis, did not decline; however, serotype Typhimurium infections continued to decline.

What are the implications for public health practice?

New strategies that target particular serotypes and more widespread implementation of known prevention measures are needed to reduce Salmonella illnesses. Reductions in Salmonella serotype Typhimurium suggest that targeted interventions (e.g., vaccinating chickens and other food animals) might decrease human infections. Isolates are needed to subtype bacteria so that sources of illnesses can be determined.

Research- Data shows connection between unpasteurized milk and infections

Food Safety News 

After reviewing details of brucellosis illnesses from recent years, including a 19-state outbreak, researchers are saying their findings show a link between raw milk and such infections.

Although the researchers did not name the dairy farm associated with the multistate  outbreak, the CDC and the FDA investigated the those illnesses, which occurred during the period reviewed by the research team and were connected to raw milk from Miller’s Biodiversity Farm in Pennsylvania.

Information about the researchers’ work was published recently in the Morbidity and Mortality Weekly Report, which is posted by the U.S. Centers for Disease Control and Prevention. The group of researchers, made up of people from the CDC and a number of states’ agencies, says additional study is needed regarding the emerging health dangers of consuming raw milk.

Infographics: Estimates of the global burden of foodborne diseases

WHO

   

Research – Offspring may inherit legacy of their father’s Toxoplasma infection

Science Daily Toxoplas

Australian researchers have revealed for the first time that males infected with the Toxoplasma parasite can impact their offspring’s brain health and behaviour.

Studying mice infected with the common parasite Toxoplasma, the team discovered that sperm of infected fathers carried an altered ‘epigenetic’ signature which impacted the brains of resulting offspring. Molecules in the sperm called ‘small RNA’ appeared to influence the offspring’s brain development and behaviour.

‘Intergenerational inheritance’ of similar epigenetic changes from men exposed to extreme trauma has been well documented. This latest research, published in Cell Reports, has raised the question of whether Toxoplasma infections — or even possibly other infections — in men before conception could impact the health of subsequent generations.

The research was led by Walter and Eliza Hall Institute researchers Dr Shiraz Tyebji and Associate Professor Chris Tonkin, in collaboration with Professor Anthony Hannan at the Florey Institute of Neuroscience and Mental Health

Research – Increased thermal tolerance in Cronobacter sakazakii strains in reconstituted milk powder due to cross protection by physiological stresses

Wiley Online 

Cronobacter sakazakii (C. sakazakii) is an opportunistic, neonatal, and food borne pathogen primarily associated with the contamination of powdered infant formula (PIF). The pathogen is reported to overcome the food safety barriers such as increased acidity, heat treatment, and so on. This study evaluates the thermal tolerance of C. sakazakii strains independently at 52, 55, and 58°C in reconstituted PIF after exposure to physiological stresses: refrigeration (4°C for 24 hr), starvation (37°C for 48 hr), and desiccation (25°C for 4 days). The Log10 CFU/ml and D‐values indicated that survival rate of all the strains decreased significantly (p < .05) after desiccation as compared to those of the control condition (without stress exposure). However, cold stress increased the thermal tolerance of all strains at all temperatures (52, 55, and 58°C) as indicated by increased D‐values. Among the tested strains, C. sakazakii strain N15 was found to be the most resistant to thermal treatment after each stress exposure as depicted by principal component analysis (PCA). No apparent correlation between thermal tolerance and starvation stress was observed. The findings indicate that prior exposure to stress conditions may induce cross protection to thermal treatment in C. sakazakii.

Research – Report says U.S. is failing food safety 101; incidence of illnesses still increasing

Food Safety News

Attempts to reduce food poisoning are failing as the U.S. incidence of foodborne illnesses continues to increase. Infections from five of eight pathogens tracked by the CDC are on the rise.

Initial analysis of data comparing the period from 2016-2018 with numbers for 2019 (see table below) shows that the federal government’s Healthy People 2020 targets for reducing foodborne illness will not be met, according to the Morbidity and Mortality Weekly Report (MMWR) published by the Centers for Disease Control and Prevention.

The bad news could be softened if businesses would adopt proven food safety measures, according to the research team.

“. . . progress in controlling major foodborne pathogens in the United States has stalled,” according to the report. “To better protect the public and achieve forthcoming Healthy People 2030 foodborne disease reduction goals, more widespread implementation of known prevention measures and new strategies that target particular pathogens and serotypes are needed.”

Research – New insight into bacterial structure to help fight against superbugs

Science Daily

Scientists from the University of Sheffield have produced the first high-resolution images of the structure of the cell wall of bacteria, in a study that could further understanding of antimicrobial resistance.

The research, published in Nature, revealed a new and unexpected structure of the outer bacterial layers of the bacterium Staphylococcus aureus.

The findings set a new framework for understanding how bacteria grow and how antibiotics work, overturning previous theories about the structure of the outer bacterial layers.

The images give unprecedented insight into the composition of the bacterial cell wall and will inform new approaches to developing antibiotics in order to combat antibiotic resistance. There are no other examples of studies of the cell wall in any organism at comparable resolution, down to the molecular scale.

Laia Pasquina Lemonche, a PhD Researcher from the University of Sheffield’s Department of Physics and Astronomy, said: “Many antibiotics work by inhibiting the bacteria’s production of a cell wall, a strong but permeable skin around the bacteria which is critical for its survival.

Europe – Shiga toxin/verocytotoxin-producing Escherichia coli (STEC/VTEC) infection – Annual Epidemiological Report for 2018

ECDC

Executive summary

  • For 2018, 30 EU/EEA countries reported 8 658 confirmed cases of infection with Shigatoxin/verocytotoxin-producing Escherichia coli (STEC/VTEC).
  • The overall notification rate was 2.4 cases per 100 000 population.
  • After a stable period from 2014 to 2017, the notification rate increased by 41% in 2018.
  • The highest notification rates were reported in Denmark, Ireland, Malta, Norway and Sweden.
  • The highest rate of confirmed cases was observed in 0–4-year-old children (11.5 cases per 100 000 population).

Research – Slovenian study reveals low levels of C. difficile in food

Food Safety News Clost

Researchers in Slovenia have described results from a long-term, national Clostridioides difficile food surveillance project. Positive results were found in meat, fresh produce and poultry.

The three-year period of testing revealed a low proportion of Clostridioides — formerly Clostridium — difficile contaminated food and high genotype variability. As the risk of infection associated with Clostridioides difficile contaminated food is unknown, no measures were recommended for positive results.

Because of an increasing association between Clostridioides difficile and food, in 2015, the Administration of the Republic of Slovenia for Food Safety, Veterinary Sector and Plant Protection (UVHVVR) included it in national food surveillance. In Slovenia, the number of cases increased from 316 in 2013 to 665 in 2017.

Retail minced meat and meat preparations such as beef, pork and poultry were sampled from 2015 to 2017. They were collected at food markets and grocery stores in all Slovenian regions. Selected raw retail vegetables, leaf salads and root vegetables, and ready-to-eat salads were sampled during 2016 and 2017 and seafood only in 2017.