Category Archives: Research

Research – Epidemiological and microbiological investigation of a large increase in vibriosis, northern Europe, 2018

Eurosurveillance

Food Illness

The habitat of  spp. bacteria is fresh and brackish water with moderate salinity. Non-toxigenic , as well as several human pathogenic non-cholera  species, including  and , cause vibriosis after seawater exposure or consumption of contaminated seafood [1]. Clinical manifestations range from mild gastroenteritis and otitis to wound infections that may lead to severe necrotising fasciitis and septicaemia with a potentially fatal outcome [25].

The Baltic Sea region is one of the areas where increasing numbers of cases related to  species causing vibriosis (VCV) have been reported in the last decades [6]. Several studies have shown how the occurrence of heatwaves, which lead to an increase in sea surface temperature, are linked with an increase in the number of reported vibriosis cases [4,712]. For instance, the years with an especially warm summer in the Baltic Sea region, 2006, 2010 and particularly 2014 (the warmest year in historical records at the time), were also the years with the largest number of vibriosis cases reported [6,11].

However, there is a notable gap in surveillance data for vibriosis since it is not a notifiable disease in the majority of European countries [1,6]. Therefore, the aim of this multi-country study was to describe the epidemiology of vibriosis cases in countries bordering the North and Baltic Seas area during the exceptionally warm year of 2018 [13,14], in order to investigate the extent of these infections in the study countries, map their genetic diversity, understand the predictors for developing severe vibriosis, and propose recommendations for public health measures.

Finland – Food Safety in Finland 2021

This report presents the 2021 results of regulatory control related to food safety, official controls and monitoring programmes on food and feed, as well as research and risk assessments.
The report also assesses, based on the results, the status of food safety and future needs for regulatory activities in Finland.
The report extends the annual report referred to in the EU Control Regulation (EU) No. 2017/625 on official control with respect to food safety; the annual report describes the results of the control in the various sectors of the food supply chain as a whole.
The results of official controls and investigations from 2021 indicate that the control works well and the level of food safety is good. The investigation of epidemics has developed, and the number of epidemics caused by unknown reasons was the smallest in years.
The export controls required by export countries were continued in accordance with the programmes. The number of food recalls has continued to increase dramatically. In 2021, more than 19,000 Oiva reports were published, which is an increase of 19 per cent from the previous year. Control was carried out through prioritised work. The new Food Act and the decrees issued under it entered into force in April 2021.

Research – WHO Seeks Experts on Microbial Hazards

Food Safety News

The World Health Organization (WHO) is looking for people with experience on risk assessment of microbiological hazards.

The call comes as the Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment (JEMRA) is renewing its expert roster for January 2023 to December 2027.

JEMRA is an international scientific expert group run by the Food and Agriculture Organization of the United Nations (FAO) and WHO. Meetings are convened on an ad-hoc basis, depending on requests from Codex.

One of the main aims is to provide a review of scientific advice on the state of microbiological risk assessment, and to develop the means of achieving risk assessments for specific pathogen -commodity combinations. Work often includes an evaluation of the impacts of different risk management options in the reduction or control of microbiological risks in food based on an analysis of the available knowledge.

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Research – Collective food poisoning (TIAC) ​​with E. coli O157 producing Shiga toxins, associated with the consumption of raw cucumbers

Sante Publique

On September 9, 2021, the Regional Health Agency (ARS) of Hauts-de-France was informed of a suspicion of collective food poisoning (TIAC) ​​affecting half-board students, educated in several schools in a municipality. of the Lille metropolis. 

On September 13, 2021, two cases of haemolytic and uremic syndrome (HUS) were diagnosed in two hospitalized children attending school in this town. Public Health France Hauts-de-France was asked by the Hauts-de-France ARS to provide support for the investigations and management of this TIAC. A total of 35 cases of gastroenteritis, with bloody diarrhea and fever (>38°C) in half of the cases, were identified. Ten cases were hospitalized and two children developed HUS. 

The cases identified were half-board students in four school groups (29 cases), a parent of a student and elderly people benefiting from the municipality’s home meal delivery service (5 cases). The case canteens were all supplied by the central municipal kitchen. 

The shape of the epidemic curve was in favour of a common and point source of contamination during meals on September 2 or 3, 2021. The case-control survey, carried out in schools, concluded that only the consumption of cucumbers in salad, served with the meal on September 2, was statistically and significantly associated with the occurrence of the disease.

A strain of E. highly pathogenic Shiga toxin-producing (STEC) O157 coli was isolated from the stool cultures of eight cases, including the two children who developed HUS and in the offending cucumber salad. Genomic analysis of the strains confirmed the genetic clustering of clinical and food strains that belonged to the same genomic cluster. The veterinary investigation revealed that a failure in the decontamination process, associated with incomplete peeling of the contaminated cucumbers, contributed to the occurrence of this TIAC. 

The cucumbers in question came from Belgium and the Belgian health authorities were informed via the dedicated European alert circuits. No other episodes of clusters of STEC infection related to this TIAC have been reported to the ARS over the period while cucumbers from the same batch had been widely distributed in communities and commercial catering services in the Hauts-de-France region. The food vehicle, incriminated in this TIAC, is part of the plants at risk because of its raw mode of consumption. It is important to remind vulnerable populations and collective catering services that preventing the risk of STEC infection, linked to the consumption of raw vegetables, requires washing, disinfection and peeling.

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Research – Risk factors for campylobacteriosis in Australia: outcomes of a 2018–2019 case–control study

BMC

Campylobacter kswfoodworld

Background

We aimed to identify risk factors for sporadic campylobacteriosis in Australia, and to compare these for Campylobacter jejuni and Campylobacter coli infections.

Methods

In a multi-jurisdictional case–control study, we recruited culture-confirmed cases of campylobacteriosis reported to state and territory health departments from February 2018 through October 2019. We recruited controls from notified influenza cases in the previous 12 months that were frequency matched to cases by age group, sex, and location. Campylobacter isolates were confirmed to species level by public health laboratories using molecular methods. We conducted backward stepwise multivariable logistic regression to identify significant risk factors.

Results

We recruited 571 cases of campylobacteriosis (422 C. jejuni and 84 C. coli) and 586 controls. Important risk factors for campylobacteriosis included eating undercooked chicken (adjusted odds ratio [aOR] 70, 95% CI 13–1296) or cooked chicken (aOR 1.7, 95% CI 1.1–2.8), owning a pet dog aged < 6 months (aOR 6.4, 95% CI 3.4–12), and the regular use of proton-pump inhibitors in the 4 weeks prior to illness (aOR 2.8, 95% CI 1.9–4.3). Risk factors remained similar when analysed specifically for C. jejuni infection. Unique risks for C. coli infection included eating chicken pâté (aOR 6.1, 95% CI 1.5–25) and delicatessen meats (aOR 1.8, 95% CI 1.0–3.3). Eating any chicken carried a high population attributable fraction for campylobacteriosis of 42% (95% CI 13–68), while the attributable fraction for proton-pump inhibitors was 13% (95% CI 8.3–18) and owning a pet dog aged < 6 months was 9.6% (95% CI 6.5–13). The population attributable fractions for these variables were similar when analysed by campylobacter species. Eating delicatessen meats was attributed to 31% (95% CI 0.0–54) of cases for C. coli and eating chicken pâté was attributed to 6.0% (95% CI 0.0–11).

Conclusions

The main risk factor for campylobacteriosis in Australia is consumption of chicken meat. However, contact with young pet dogs may also be an important source of infection. Proton-pump inhibitors are likely to increase vulnerability to infection.

Research – Genomic analysis of Listeria monocytogenes from US food processing environments reveals a high prevalence of QAC efflux genes but limited evidence of their contribution to environmental persistence

Researchgate

Background Quaternary ammonium compound (QAC) efflux genes increase the minimum inhibitory concentration of Listeria monocytogenes ( Lm ) to benzalkonium chloride sanitizer, but the contribution of these genes to persistence in food processing environments is unclear.

The goal of this study was to leverage genomic data and associated metadata for 4969 Lm isolates collected between 1999 and 2019 to: (1) evaluate the prevalence of QAC efflux genes among Lm isolates from diverse US food processors, (2) use comparative genomic analyses to assess confounding factors, such as clonal complex identity and stress tolerance genotypes, and (3) identify patterns in QAC efflux gene gain and loss among persistent clones within specific facilities over time.

Results The QAC efflux gene cassette bcrABC was present in nearly half (46%) of all isolates. QAC efflux gene prevalence among isolates was associated with clonal complex (𝛘 ² < 0.001) and clonal complex was associated with the facility type (𝛘 ² < 0.001). Consequently, changes in the prevalence of QAC efflux genes within individual facilities were generally attributable to changes in the prevalence of specific clonal complexes. Additionally, a GWAS and targeted BLAST search revealed that clonal complexes with a high prevalence of QAC efflux genes commonly possessed other stress tolerance genes. For example, a high prevalence of bcrABC in a clonal complex was significantly associated with the presence of the SSI-1 gene cluster ( p < 0.05). QAC efflux gene gain and loss were both observed among persistent populations of Lm in individual facilities, suggesting a limited direct role for QAC efflux genes as predictors of persistence.

Conclusion This study suggests that although there is evidence that QAC efflux genes are part of a suite of adaptations common among Lm isolated from some food production environments, these genes may be neither sufficient nor necessary to enhance persistence. This is a crucial distinction for decision making in the food industry. For example, changes to sanitizer regimen targeting QAC tolerance would not address other contributing genetic or non-genetic factors, such as equipment hygienic design which physically mediates sanitizer exposure.

Research – Effect of citral on the thermal inactivation of Escherichia coli O104:H4 in ground beef

Journal of Food Protection

The objective of the present study was to analyze the combined effect of heat treatment (55 to 62.5 °C) and citral (0 to 3%) on the heat resistance of Escherichia coli O104:H4 inoculated in ground beef. Inoculated meat packages were immersed in a circulating water bath stabilized at 55, 57.5, 60 and 62.5 °C for different times. The surviving microbial cells were counted in tryptic soy agar. A factorial design (4 x 4) was used to analyze the effect and interaction of heat treatment and citral. The results showed that heat and citral promoted E. coli O104:H4 thermal inactivation, suggesting a synergistic effect. At 55 °C, the incorporation of citral at 1, 2 and 3%, decreased D values (control: 42.75 min) by 85, 89, and 91%, respectively ( p < 0.05). Similarly, other evaluated temperatures exhibited a citral concentration-dependent effect ( P < 0.05). In conclusion, the findings could be a valuable tool for the food industry in designing a safe thermal process for inactivating E. coli O104:H4 in ground beef under similar thermal inactivation conditions.

Research – Microbiological quality of ready-to-eat salad products collected from retail and catering settings in England during 2020-21 

Journal of Food Protection

Salad and other fresh produce were collected in England from retail and catering during 2020-21 and  were tested for Salmonella, Shiga-toxin producing Escherichia coli (STEC), Listeria , Bacillus cereus , and generic E. coli. Of the 604 samples collected , 57% were from retail and 43% from catering: 61% were either salad leaves or salad leaves mixed with other products. Equal numbers of samples were prepacked or loose and 50% were refrigerated at the time of sampling. Combining results for all microbiological parameters, 84% were interpreted as satisfactory, 12% as borderline and 4% as unsatisfactory. One sample (prepacked  leaves, cucumber and tomato from a caterer) was categorised as unacceptable/potentially injurious due to detection of STEC O76, no STEC from human infections in the UK matched this isolate. No Salmonella enterica were detected but L. monocytogenes was recovered from 11 samples, one at 20 CFU/g the remainder at <20 CFU/g. B. cereus was detected at borderline levels (10 3 – <10 5 CFU/g) in 9% of samples and at an unsatisfactory level (>10 5 CFU/g) in one. E. coli were detected in 3% of samples at borderline (20 – <10 2 CFU/g) and in 4% at unsatisfactory (>10 2 CFU/g) levels. There was a significant association between the detection of L. monocytogenes and borderline/unsatisfactory levels of E. coli . There were no generic risks detected in association with the higher levels of B. cereus, STEC or Listeria but elevated levels of E. coli were predominantly confined to loose products from the UK and collected from caterers in the summer or autumn of 2021. Amongst the L. monocytogenes isolates, only one matched that from human cases and was recovered from a prepacked mixed salad from a catering business in 2021. This isolate was the same strain as that responsible for a multi country outbreak (2015-18) associated with Hungarian-produced frozen sweetcorn: no link to the outbreak food-chain was established.

Research – Antimicrobial Susceptibility and Molecular Characterization of Escherichia coli Recovered from Milk and Related Samples

MDPI

There is a rising concern about illnesses resulting from milk consumption due to contamination by pathogenic microorganisms including Escherichia coli. This study examined the occurrence and antimicrobial susceptibility of E. coli isolated from cow milk and related samples. Furthermore, partial sequencing was done to ascertain the genetic relatedness and possible cross contamination among the samples. In all, 250 samples, that is, 50 each of raw milk, cow teat, milkers’ hands, milking utensils, and fecal matter of cows, were cultured for the identification of E. coli. E. coli was detected in 101/250 samples (40.4%). Milk and fecal samples recorded the highest percentages of 68.0% and 66.0%, respectively. Forty-two (42) E. coli strains examined for antimicrobial resistance showed an overall 25.5% resistance, 15.0% intermediate resistance, and 59.5% susceptibility. The isolates had a high level of resistance to teicoplanin (100.0%), but were susceptible to chloramphenicol (95.2%) and azithromycin (92.9%). The Multiple Antibiotic Resistance (MAR) index pattern ranged from 0.1 to 0.5, and 40.5% exhibited multiple drug resistance. The E. coli strains formed 11 haplotypes, and a phylogenic tree analysis showed relatedness among the isolates in other African countries. This observation is an indication of cross contamination among the milk and its related samples. View Full-Text

Research – Efficacy of 405 nm Light-Emitting Diode Illumination and Citral Used Alone and in Combination for Inactivation of Vibrio parahaemolyticus on Shrimp

MDPI

Vibrio parahaemolyticus is a widely distributed pathogen, which is frequently the lead cause of infections related to seafood consumption. The objective of the present study was to investigate the antimicrobial effect of the combination of 405 nm light-emitting diode (LED) and citral on V. parahaemolyticus. The antimicrobial effect of LED illumination and citral was evaluated on V. parahaemolyticus not only in phosphate-buffered saline (PBS) but also on shrimp. Quality changes of shrimp were determined by sensory evaluation. Changes in bacteria cell membrane morphology, cell membrane permeability, cell lipid oxidation level, and DNA degradation were examined to provide insights into the antimicrobial mechanism. The combination of LED treatments and citral had better antimicrobial effects than either treatment alone. LED combined with 0.1 mg/mL of citral effectively reduced V. parahaemolyticus from 6.5 log CFU/mL to below the detection limit in PBS. Combined treatment caused a 3.5 log reduction of the pathogen on shrimp within 20 min and a 6 log reduction within 2 h without significant changes in the sensory score. Furthermore, combined LED and citral treatment affected V. parahaemolyticus cellular morphology and outer membrane integrity. The profile of the comet assay and DNA fragmentation analysis revealed that combination treatment did not cause a breakdown of bacterial genomic DNA. In conclusion, LED may act synergistically with citral. They have the potential to be developed as novel microbial intervention strategies. View Full-Text