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

Selective depletion of Campylobacter jejuni via T6SS dependent functionality: an approach for improving chickens gut health

The targeted depletion of potential gut pathogens is often challenging because of their intrinsic ability to thrive in harsh gut environments. Earlier, we showed that Campylobacter jejuni (C. jejuni) exclusively uses the Type-VI Secretion System (T6SS) to target its prey such as Escherichia coli (E. coli), and phenotypic differences between T6SS-negative and T6SS-positive C. jejuni isolates toward bile salt sensitivity. However, it remains unclear how the target-driven T6SS functionality prevails in a polymicrobial gut environment. Here, we investigated the fate of microbial competition in an altered gut environment via bacterial T6SS using a T6SS-negative and -positive C. jejuni or its isogenic mutant of the hemolysin-coregulated protein (hcp). We showed that in the presence of bile salt and prey bacteria (E. coli), T6SS-positive C. jejuni experiences enhanced intracellular stress leading to cell death. Intracellular tracking of fluorophore-conjugated bile salts confirmed that T6SS-mediated bile salt influx into C. jejuni can enhance intracellular oxidative stress, affecting C. jejuni viability. We further investigated whether the T6SS activity in the presence of prey (E. coli) perturbs the in vivo colonization of C. jejuni. Using chickens as primary hosts of C. jejuni and non-pathogenic E. coli as prey, we showed a marked reduction of C. jejuni load in chickens cecum when bile salt solution was administered orally. Analysis of local antibody responses and pro-inflammatory gene expression showed a reduced risk of tissue damage, indicating that T6SS activity in the complex gut environment can be exploited as a possible measure to clear the persistent colonization of C. jejuni in chickens.

No colonization resistance to Campylobacter jejuni in broilers fed brown algal extract-supplemented diets

Introduction

Campylobacter jejuni gastroenteritis is the most commonly reported zoonosis within the EU, with poultry products regarded as the primary source of transmission to humans. Therefore, finding strategies to reduce Campylobacter colonization in broilers holds importance for public health. Recent studies suggest that supplementation of broiler feed with brown algal extracts, particularly laminarin, can provide beneficial effects on broiler gut health, growth performance, and gut microbiota. However, its effect on gut microbiota development and subsequent reduction of Campylobacter loads in broiler caeca during the later stages of the birds' lives remains unclear.

Methods

Experimental colonization of Ross 308 broilers with two different strains of C. jejuni was conducted, with groups fed either a basal diet or the same basal diet supplemented with 725 ppm algal extract from Saccharina latissima to provide 290 ppm laminarin. Fecal samples were collected for bacterial enumeration, and caecal samples were obtained before and after the C. jejuni challenge for the determination of microbiota development.

Results and discussion

No significant differences in fecal C. jejuni concentrations between the groups fed different diets or exposed to different C. jejuni strains were observed. This suggests that both strains colonized the birds equally well and that the laminarin rich algal extract did not have any inhibitory effect on C. jejuni colonization. Notably, 16S rRNA amplicon sequencing revealed detailed data on the caecal microbiota development, likely influenced by both bird age and C. jejuni colonization, which can be valuable for further development of broiler feed formulations aimed at promoting gut health.

The In Vitro Antibacterial Activity of Phytogenic and Acid-Based Eubiotics against Major Foodborne Zoonotic Poultry Pathogens

The aim of the study was to investigate in vitro the antibacterial activity of 8 commercial drinking water additives against major zoonotic poultry pathogens (Campylobacter spp., Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Listeria spp.). We tested two essential oil-based phytogenics (Phyto CSC Liquide B, AEN 350 B Liquid), two acid-based eubiotics (Salgard® liquid, Intesti-Flora), and four blends of essential oils and organic acids (ProPhorceTM SA Exclusive, Herbal acid, Rigosol-N and Eubisan 3000). The antibacterial activity was determined by estimating the minimum inhibitory concentration (MIC) using a microdilution method. The MICs of the products against Campylobacter spp. ranged from 0.071% to 0.568% v/v, in which Herbal acid, a blend rich in lactic and phosphoric acids, also containing thyme and oregano oils, exhibited the highest efficacy (MIC: 0.071% v/v) against all the tested strains. The MICs of the tested products against Escherichia coli ranged between 0.071% and 1.894% v/v. Specifically, the MIC of Rigosol-N, a blend of high concentrations of lactic and acetic acid, was 0.142% v/v for both tested strains, whereas the MICs of Intesti-Flora, a mixture rich in lactic and propionic acid, ranged from 0.284% to 0.568% v/v. The MICs of the products against Salmonella Typhimurium were between 0.095% and 1.894% v/v. Specifically, the MIC of Eubisan 3000, a blend rich in oregano oil, was 0.284% v/v. The MICs against Staphylococcus aureus were between 0.142% and 9.090% v/v. The MICs of Phyto CSC Liquide B, which is rich in trans-cinnamaldehyde, were between 3.030% and 9.090% v/v, showing the highest MIC values of all tested products. Finally, the MIC values of the tested commercial products against Listeria spp. were 0.095% to 3.030% v/v. The MICs of ProPhorceTM SA Exclusive, a highly concentrated blend of formic acid and its salts, were 0.095-0.142% v/v against Listeria spp., while the MICs of AEN 350 B Liquid were between 0.284% and 1.894% exhibiting high Listeria spp. strain variability. In conclusion, all the selected commercial products exhibited more or less antibacterial activity against pathogenic bacteria and, thus, can be promising alternatives to antibiotics for the control of zoonotic poultry pathogens and the restriction of antimicrobial-resistant bacteria.

Bacteriological Survey of Insect Products in Japan

A microbiological study was conducted on 41 insect product samples (29 raw frozen [21 domestic and 8 imported], 10 powdered, and 2 processed), which were commercially available in Japan. The total aerobic count for raw frozen insects was 5.61 log cfu/g (range: 2.52-8.40), whereas the powdered insect count was 2.89 log cfu/g (range: 1.00-4.57). The bacterial count was significantly higher in raw frozen insects (p < 0.05). The coliform count for the raw frozen insects ranged from <1 to 6.90 log cfu/g, and that for the powdered insects ranged from <1 to 1.00 log cfu/g. The number of samples with values above the detection limit was significantly higher in raw frozen insects (p < 0.05). The detection frequencies of aerobic spores (<1-4.63 log cfu/g), anaerobic spores (<0-4.40 log cfu/g), and Bacillus cereus (<1.7-3.83 log cfu/g) showed no sample type-related significant difference. Listeria spp. was isolated from four samples of raw frozen insects, one of which was Listeria monocytogenes. We did not detect any of the following: Salmonella spp., Shiga toxin-producing E. coli (STEC), Campylobacter jejuni/coli, or pathogenic Yersinia. We isolated insect products retailed in Japan harboring food poisoning bacteria, including L. monocytogenes and B. cereus. In particular, raw frozen products displayed high levels of hygienic indicator bacteria.

Investigation of Potential Gut Health Biomarkers in Broiler Chicks Challenged by Campylobacter jejuni and Submitted to a Continuous Water Disinfection Program

The exploration of novel biomarkers to assess poultry health is of paramount importance, not only to enhance our understanding of the pathogenicity of zoonotic agents but also to evaluate the efficacy of novel treatments as alternatives to antibiotics. The present study aimed to investigate potential gut health biomarkers in broiler chicks challenged by Campylobacter jejuni and subjected to a continuous water disinfection program. A total of 144 one-day-old hatched broiler chicks were randomly allocated to four treatment groups with four replicates each, according to the following experimental design: Group A received untreated drinking water; Group B received drinking water treated with 0.01-0.05% v/v Cid 2000™ (hydrogen peroxide, acetic acid and paracetic acid); Group C was challenged by C. jejuni and received untreated drinking water; and Group D was challenged by C. jejuni and received drinking water treated with 0.01-0.05% v/v Cid 2000™. The use of Cid 2000™ started on day 1 and was applied in intervals until the end of the experiment at 36 days, while the C. jejuni challenge was applied on day 18. Potential biomarkers were investigated in serum, feces, intestinal tissue, intestinal content, and liver samples of broilers. Statistical analysis revealed significant increases (p < 0.001) in serum cortisol levels in C. jejuni-challenged broilers. Serum fluorescein isothiocyanate dextran (FITC-d) increased significantly (p = 0.004) in broilers challenged by C. jejuni and treated with drinking water disinfectant, while fecal ovotransferrin concentration also increased significantly (p < 0.001) in broilers that received the drinking water disinfectant alone. The gene expression levels of occludin (p = 0.003) and mucin-2 (p < 0.001) were significantly upregulated in broilers challenged by C. jejuni, while mucin-2 significantly increased in birds that were challenged and received the drinking water disinfectant (p < 0.001). TLR-4 expression levels were significantly (p = 0.013) decreased in both groups that received the drinking water disinfectant, compared to the negative control group. Finally, the C. jejuni challenge significantly increased (p = 0.032) the crypt depth and decreased (p = 0.021) the villus height-to-crypt-depth ratio in the ileum of birds, while the tested disinfectant product increased (p = 0.033) the villus height in the jejunum of birds. Furthermore, the counts of C. jejuni in the ceca of birds (p = 0.01), as well as its translocation rate to the liver of broilers (p = 0.001), were significantly reduced by the addition of the water disinfectant. This research contributes to novel insights into the intricate interplay of water disinfection and/or C. jejuni challenge with potential intestinal biomarkers. In addition, it emphasizes the need for continued research to unveil the underlying mechanisms, expands our understanding of broiler responses to these challenges and identifies breakpoints for further investigations.

Combined application of bacteriophages with a competitive exclusion culture and carvacrol with organic acids can reduce Campylobacter in primary broiler production

For reducing Campylobacter (C.) in the food production chain and thus the risk to the consumer, the combined application of different measures as a multiple-hurdle approach is currently under discussion. This is the first study to investigate possible synergistic activities in vivo, aiming at reducing intestinal C. jejuni counts by administering (i) bacteriophages (phages) in combination with a competitive exclusion (CE) product and (ii) carvacrol combined with organic acids. The combined application of the two selected phages (Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1) and the CE product significantly reduced C. jejuni loads by 1.0 log10 in cecal and colonic contents as well as in cloacal swabs at the end of the trial (33 and 34 days post hatch). The proportion of bacterial isolates showing reduced phage susceptibility ranged from 10.9% (isolates from cecal content) to 47.8% (isolates from cloacal swabs 32 days post hatch) for the Fletchervirus phage, while all tested isolates remained susceptible to the Firehammervirus phage. The use of carvacrol combined with an organic acid blend (sorbic acid, benzoic acid, propionic acid, and acetic acid) significantly reduced Campylobacter counts by 1.0 log10 in cloacal swabs on day 30 only.

Identification of novel small molecule inhibitors of twin arginine translocation (Tat) pathway and their effect on the control of Campylobacter jejuni in chickens

Introduction

Control of Campylobacter from farm to fork is challenging due to the frequent emergence of antimicrobial-resistant isolates. Furthermore, poultry production systems are known reservoirs of Campylobacter. The twin-arginine translocation (Tat) pathway is a crucial bacterial secretion system that allows Campylobacter to colonize the host intestinal tract by using formate as the main source of energy. However, Tat pathway is also a major contributing factor for resistance to copper sulfate (CuSO4).

Methods

Since mammals and chickens do not have proteins or receptors that are homologous to bacterial Tat proteins, identification of small molecule (SM) inhibitors targeting the Tat system would allow the development of safe and effective control methods to mitigate Campylobacter in infected or colonized hosts in both pre-harvest and post-harvest. In this study, we screened 11 commercial libraries (n = 50,917 SM) for increased susceptibility to CuSO4 (1 mM) in C. jejuni 81-176, a human isolate which is widely studied.

Results

Furthermore, we evaluated 177 SM hits (2.5 μg/mL and above) that increased the susceptibility to CuSO4 for the inhibition of formate dehydrogenase (Fdh) activity, a Tat-dependent substrate. Eight Tat-dependent inhibitors (T1-T8) were selected for further studies. These selected eight Tat inhibitors cleared all tested Campylobacter strains (n = 12) at >10 ng/mL in the presence of 0.5 mM CuSO4in vitro. These selected SMs were non-toxic to colon epithelial (Caco-2) cells when treated with 50 μg/mL for 24 h and completely cleared intracellular C. jejuni cells when treated with 0.63 μg/mL of SM for 24 h in the presence of 0.5 mM of CuSO4. Furthermore, 3 and 5-week-old chicks treated with SM candidates for 5 days had significantly decreased cecal colonization (up to 1.2 log; p < 0.01) with minimal disruption of microbiota. In silico analyses predicted that T7 has better drug-like properties than T2 inhibitor and might target a key amino acid residue (glutamine 165), which is located in the hydrophobic core of TatC protein.

Discussion

Thus, we have identified novel SM inhibitors of the Tat pathway, which represent a potential strategy to control C. jejuni spread on farms.

Quantitative assessment of food safety interventions for Campylobacter spp. and Salmonella spp. along the chicken meat supply chain in Burkina Faso and Ethiopia

Rural and small-scale chicken farming is a major source of income in most African countries, and chicken meat is an important source of nutrients. However, chicken meat can be contaminated with Campylobacter spp. and Salmonella spp., pathogens with a high reported burden of foodborne illnesses. Therefore, it is essential to control these pathogens in chicken meat. Quantitative microbial risk assessments (QMRA) can aid the development of effective food safety control measures and are currently lacking in chicken meat supply chains in the African context. In this study, we developed stochastic QMRA models for Salmonella spp. and Campylobacter spp. in the chicken meat supply chain in Burkina Faso and Ethiopia employing the modular process risk model in @Risk software. The study scope covered chicken farming, transport, slaughtering, consumer handling, and consumption. Effectiveness of candidate interventions was assessed against baseline models' outputs, which showed that the mean annual Campylobacter spp. risk estimates were 6482 cases of illness per 100,000 persons and 164 disability adjusted life years (DALYs) per 100,000 persons in Burkina Faso, and 12,145 cases and 272 DALYs per 100,000 persons in Ethiopia. For Salmonella spp., mean annual estimates were 2713 cases and 1212 DALYs per 100,000 persons in Burkina Faso, and 4745 cases and 432 DALYs per 100,000 persons in Ethiopia. Combining interventions (improved hand washing plus designated kitchen utensils plus improved cooking) resulted in 75 % risk reduction in Burkina Faso at restaurants and 93 to 94 % in Ethiopia at homes for both Salmonella spp. and Campylobacter spp. For Burkina Faso, adding good hygienic slaughter practices at the market to these combined interventions led to over 91 % microbial risk reduction. Interventions that involved multiple food safety actions in a particular step of the supply chain or combining different interventions from different steps of the supply chain resulted in more risk reduction than individual action interventions. Overall, this study demonstrates how diverse and scanty food supply chain information can be applied in QMRA to provide estimates that can be used to stimulate risk-based food safety action in African countries.

In-vitro selection of lactic acid bacteria to combat Salmonella enterica and Campylobacter jejuni in broiler chickens

Campylobacter and Salmonella are the two most prominent foodborne zoonotic pathogens reported in the European Union. As poultry is one of the major sources of these pathogens, it is imperative to mitigate the colonization of these pathogens in poultry. Many strains of lactic acid bacteria (LAB) have demonstrated anti-Salmonella and anti-Campylobacter characteristics to varying degrees and spectrums which are attributed to the production of various metabolites. However, the production of these compounds and consequent antimicrobial properties are highly strain dependent. Therefore, the current study was performed to select a potent LAB and determine its causal attribute in inhibiting Salmonella enterica and Campylobacter jejuni, in-vitro. Six LAB (Lactiplantibacillus plantarum (LP), Lacticaseibacillus casei (LC), Limosilactobacillus reuteri (LR), Lacticaseibacillus rhamnosus (LRh), Leuconostoc mesenteroides (LM) and Pediococcus pentosaceus (PP)) and three serovars of Salmonella enterica (Typhimurium, Enterica and Braenderup) and Campylobacter jejuni were used in the current study. Spot overlays, well diffusion, co-culture and co-aggregation assays against Salmonella and well diffusion assays against Campylobacter jejuni were performed. Organic acid profiling of culture supernatants was performed using HPLC. The results indicated that LRh, LM and PP had the most significant anti-Salmonella effects while LP, LC, LM and PP displayed the most significant anti-Campylobacter effects. Lactic acid and formic acid detected in the culture supernatants seem the most likely source of the anti-Salmonella and anti-Campylobacter effects exhibited by these LAB. In conclusion, Leuconostoc mesenteroides displayed the most significant overall anti-pathogenic effects when compared to the other LAB strains studied, indicating its potential application in-vivo.

Investigating bacteriophages as a novel multiple-hurdle measure against Campylobacter: field trials in commercial broiler plants

Campylobacter mitigation along the food production chain is considered effective for minimizing the public health burden of human campylobacteriosis. This study is the first combining different measures in a multiple-hurdle approach, using drinking water additives and feed additives in single and combined application schemes in commercial broiler plants. Broiler chickens in the study groups were naturally contaminated with Campylobacter. Application of an organic acid blend via drinking water, consisting of sodium propionate, potassium sorbate, and sodium diacetate, resulted in significant reductions of up to 4.9 log10 CFU/mL in fecal samples and in cecal samples at slaughter. The application of a phage mixture, consisting of Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1, resulted in reductions of up to 1.1 log10 CFU/mL in fecal samples 1 day after dosing. The sole administration of curcumin via feed resulted in small and inconsistent reductions. In the group receiving a combination of all tested measures, reductions of up to 1.1 log10 CFU/mL were observed. Based on the results of our field trials, it was shown that both the sole application and the combined application of mitigation measures in primary production can reduce the Campylobacter load in broiler chickens, while no synergism could be observed.

Broiler farming practices using new or re-used bedding, inclusive of free-range, have no impact on Campylobacter levels, species diversity, Campylobacter community profiles and Campylobacter bacteriophages

A multi-stage option to address food-safety can be produced by a clearer understanding of Campylobacter's persistence through the broiler production chain, its environmental niche and its interaction with bacteriophages. This study addressed Campylobacter levels, species, genotype, bacteriophage composition/ levels in caeca, litter, soil and carcasses across commercial broiler farming practices to inform on-farm management, including interventions. Broilers were sequentially collected as per company slaughter schedules over two-years from 17 farms, which represented four commercially adopted farming practices, prior to the final bird removal (days 39-53). The practices were conventional full clean-out, conventional litter re-use, free-range-full cleanout and free-range-litter re-use. Caeca, litter and soil collected on-farm, and representative carcases collected at the processing plant, were tested for Campylobacter levels, species dominance and Campylobacter bacteriophages. General community profiling via denaturing gradient gel electrophoresis of the flaA gene was used to establish the population relationships between various farming practices on representative Campylobacter isolates. The farming practice choices did not influence the high caeca Campylobacter levels (log 7.5 to log 8.5 CFU/g), the carcass levels (log 2.5 to log 3.2 CFU/carcass), the C. jejuni/C. coli dominance and the on-farm bacteriophage presence/levels. A principal coordinate analysis of the flaA distribution for farm and litter practices showed strong separation but no obvious farming practice related grouping of Campylobacter. Bacteriophages originated from select farms, were not practice-dependent, and were detected in the environment (litter) only if present in the birds (caeca). This multifaceted study showed no influence of farming practices on on-farm Campylobacter dynamics. The significance of this study means that a unified on-farm risk-management could be adopted irrespective of commercial practice choices to collectively address caeca Campylobacter levels, as well as the potential to include Campylobacter bacteriophage biocontrol. The impact of this study means that there are no constraints in re-using bedding or adopting free-range farming, thus contributing to environmentally sustainable (re-use) and emerging (free-range) broiler farming choices.

Evaluation of Two Recombinant Protein-Based Vaccine Regimens against Campylobacter jejuni: Impact on Protection, Humoral Immune Responses and Gut Microbiota in Broilers

Campylobacter infections in humans are traced mainly to poultry products. While vaccinating poultry against Campylobacter could reduce the incidence of human infections, no vaccine is yet available on the market. In our previous study using a plasmid DNA prime/recombinant protein boost vaccine regimen, vaccine candidate YP437 induced partial protective immune responses against Campylobacter in broilers. In order to optimise vaccine efficacy, the vaccination protocol was modified using a protein prime/protein boost regimen with a different number of boosters. Broilers were given two or four intramuscular protein vaccinations (with the YP437 vaccine antigen) before an oral challenge by C. jejuni during a 42-day trial. The caecal Campylobacter load, specific systemic and mucosal antibody levels and caecal microbiota in the vaccinated groups were compared with their respective placebo groups and a challenge group (Campylobacter infection only). Specific humoral immune responses were induced, but no reduction in Campylobacter caecal load was observed in any of the groups (p > 0.05). Microbiota beta diversity analysis revealed that the bacterial composition of the groups was significantly different (p ≤ 0.001), but that vaccination did not alter the relative abundance of the main bacterial taxa residing in the caeca. The candidate vaccine was ineffective in inducing a humoral immune response and therefore did not provide protection against Campylobacter spp. infection in broilers. More studies are required to find new candidates.

The European Union One Health 2022 Zoonoses Report

This report by the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of the zoonoses monitoring and surveillance activities carried out in 2022 in 27 Member States (MSs), the United Kingdom (Northern Ireland) and 11 non-MSs. Key statistics on zoonoses and zoonotic agents in humans, food, animals and feed are provided and interpreted historically. In 2022, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. The number of cases of campylobacteriosis and salmonellosis remained stable in comparison with 2021. Nineteen MSs and the United Kingdom (Northern Ireland) achieved all the established targets in poultry populations for the reduction of Salmonella prevalence for the relevant serovars. Salmonella samples from carcases of various animal species, and samples for Campylobacter quantification from broiler carcases, were more frequently positive when performed by the competent authorities than when own checks were conducted. Yersiniosis was the third most reported zoonosis in humans, followed by Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes infections. L. monocytogenes and West Nile virus infections were the most severe zoonotic diseases, with the most hospitalisations and highest case fatality rates. In 2022, reporting showed an increase of more than 600% compared with 2021 in locally acquired cases of human West Nile virus infection, which is a mosquito-borne disease. In the EU, the number of reported foodborne outbreaks and cases, hospitalisations and deaths was higher in 2022 than in 2021. The number of deaths from outbreaks was the highest ever reported in the EU in the last 10 years, mainly caused by L. monocytogenes and to a lesser degree by Salmonella. Salmonella and in particular S. Enteritidis remained the most frequently reported causative agent for foodborne outbreaks. Norovirus (and other calicivirus) was the agent associated with the highest number of outbreak human cases. This report also provides updates on brucellosis, Coxiella burnetii (Q fever), echinococcosis, rabies, toxoplasmosis, trichinellosis, infection with Mycobacterium tuberculosis complex (focusing on Mycobacterium bovis and Mycobacterium caprae) and tularaemia.

Fecal Microbiota Transplantation Reduces Campylobacter jejuni Colonization in Young Broiler Chickens Challenged by Oral Gavage but Not by Seeder Birds

Campylobacter spp., particularly C. jejuni and C. coli, are major food safety concerns, transmitted to humans mainly via contaminated poultry meat. In a previous study, we found that some commercial broiler farms consistently produced Campylobacter-free flocks while others consistently reared Campylobacter-colonized flocks, and significant differences in the gut microbiota compositions between the two types of farm categories were revealed. Therefore, we hypothesized that gut microbiota influences Campylobacter colonization in poultry and that the microbiota from Campylobacter-free flocks may confer colonization resistance to Campylobacter in the chicken intestine. In this study, two fecal microbiota transplantation (FMT) trials were performed to test the hypothesis. Newly hatched chicks were given FMT via oral gavage of the cecal content of Campylobacter-free adult chickens (treatment groups) or PBS (control groups) before the feed consumption. Approximately two weeks after the FMT, the birds were challenged with C. jejuni either by oral gavage (trial 1) or by co-mingling with Campylobacter-colonized seeder birds (trial 2) to evaluate the potential protective effect of the FMT. Cecal contents were collected (3 times, 5 days apart) to determine the Campylobacter colonization levels via culture and microbiota compositions via 16S rRNA gene sequencing. FMT reduced cecal Campylobacter colonization significantly (log10 1.2-2.54 CFU/g) in trial 1 but not in trial 2, although FMT significantly impacted the diversity and compositions of the gut microbiota in both trials. Several genera, such as Butyricimonas, Parabacteroides, Parasutterella, Bilophila, Fournierella, Phascolarctobacterium, and Helicobacter, had increased abundance in the FMT-treated groups in both trials. Furthermore, Campylobacter abundance was found to be negatively correlated with the Escherichia and Ruminococcus_torques_group genera. These findings indicate that even though FMT with adult cecal microbiota can positively affect the subsequent development of the gut microbiota in young broilers, its inhibitory effect on Campylobacter colonization varies and appears to be influenced by the challenge models.

Genetic characteristics, antimicrobial susceptibility, and virulence genes distribution of Campylobacter isolated from local dual-purpose chickens in central China

Food-borne antibiotic-resistant Campylobacter poses a serious threat to public health. To understand the prevalence and genetic characteristics of Campylobacter in Chinese local dual-purpose (meat and eggs) chickens, the genomes of 30 Campylobacter isolates, including 13 C. jejuni and 17 C. coli from Jianghan-chickens in central China, were sequenced and tested for antibiotic susceptibility. The results showed that CC-354 and CC-828 were the dominant clonal complexes of C. jejuni and C. coli, respectively, and a phylogenetic analysis showed that three unclassified multilocus sequence types of C. coli were more closely genetically related to C. jejuni than to other C. coli in this study. Of the six antibiotics tested, the highest resistance rates were to ciprofloxacin and tetracycline (100%), followed by lincomycin (63.3%), erythromycin (30.0%), amikacin (26.7%), and cefotaxime (20.0%). The antibiotic resistance rate of C. coli was higher than that of C. jejuni. The GyrA T86I mutation and 15 acquired resistance genes were detected with whole-genome sequencing (WGS). Among those, the GyrA T86I mutation and tet(O) were most prevalent (both 96.7%), followed by the blaOXA-type gene (90.0%), ant(6)-Ia (26.7%), aac(6')-aph(3'') (23.3%), erm(B) (13.3%), and other genes (3.3%). The ciprofloxacin and tetracycline resistance phenotypes correlated strongly with the GyrA T86I mutation and tet(O)/tet(L), respectively, but for other antibiotics, the correlation between genes and resistance phenotypes were weak, indicating that there may be resistance mechanisms other than the resistance genes detected in this study. Virulence gene analysis showed that several genes related to adhesion, colonization, and invasion (including cadF, porA, ciaB, and jlpA) and cytolethal distending toxin (cdtABC) were only present in C. jejuni. Overall, this study extends our knowledge of the epidemiology and antibiotic resistance of Campylobacter in local Chinese dual-purpose chickens.

UK-wide risk factor study of broiler carcases highly contaminated with Campylobacter

Campylobacter is a major cause of food poisoning and is typically the most common cause of gastroenteritis in the UK. Data collected at broiler farm and abattoir level, for slaughter batches that were sampled for UK-wide monitoring, were used to generate two epidemiological risk factor models. A total of 483 batches slaughtered between January 2016 and March 2017 were used in the analysis, coming from 19 abattoirs representing more than 85% of UK broiler production. For each selected slaughter batch, one carcase was sampled after primary chilling and 10 randomly sampled birds had caecal samples collected at the evisceration point. Samples were used for Campylobacter identification and quantification. Two multivariable mixed-effects models were designed, one with the binary outcome for the detection of a highly contaminated (>1000 colony forming units (CFU)/g) Campylobacter-positive carcase, whereas the other used the Campylobacter colony count (CFU/g) carcase outcome. The results suggest that caecal colonization within the batch was a key factor for the occurrence of Campylobacter on carcases, and many factors that were identified in the model were also likely to be related to colonization or related to the risk of introduction of Campylobacter from partial depopulation (referred to as thinning) of ~30% of the flock approximately 1 week before full flock depopulation events. The amount of neck skin in the sample was another key factor identified and was included in both models as a risk factor. The models have also identified other factors which may be related to the general health and husbandry on-farm (use of prebiotics or vaccines, and identification of the product used for drinking line cleaning), whereas the other factors may identify control points related to transmission within a farm. The identification of these variables could help focus control efforts on-farm, especially for relatively easy improvements, such as improving the provision of house-specific bird-weighing buckets/cages in houses.

Combining a parsimonious mathematical model with infection data from tailor-made experiments to understand environmental transmission

Although most infections are transmitted through the environment, the processes underlying the environmental stage of transmission are still poorly understood for most systems. Improved understanding of the environmental transmission dynamics is important for effective non-pharmaceutical intervention strategies. To study the mechanisms underlying environmental transmission we formulated a parsimonious modelling framework including hypothesised mechanisms of pathogen dispersion and decay. To calibrate and validate the model, we conducted a series of experiments studying distance-dependent transmission of Campylobacter jejuni in broilers. We obtained informative simultaneous estimates for all three model parameters: the parameter of C. jejuni inactivation, the diffusion coefficient describing pathogen dispersion, and the transmission rate parameter. The time and distance dependence of transmission in the fitted model is quantitatively consistent with marked spatiotemporal patterns in the experimental observations. These results, for C. jejuni in broilers, show that the application of our modelling framework to suitable transmission data can provide mechanistic insight in environmental pathogen transmission.

Use of Algerian Type Ras El-Hanout Spices Mixture with Marination to Increase the Sensorial Quality, Shelf Life, and Safety of Whole Rabbit Carcasses under Low-O2 Modified Atmosphere Packaging

This study aimed to evaluate the effect of combined treatments with Ras El-Hanout spices mixture and marinade solution containing extra virgin olive oil, onion, garlic, and concentrated lemon juice on sensorial quality, shelf life, and safety of whole rabbit carcasses under low-O2 modified atmosphere packaging (MAP). The values of pH, water holding capacity, shear force, thiobarbituric acid reactive substances, total volatile basic nitrogen, color (CIE L*a*b*), sensorial tests, and spoilage microorganisms were determined in rabbit meat at 0, 5, 10, 15, and 20 days during a retail display at 7 ± 1 °C. The results indicated that the marination process using the Ras El-Hanout blend of spices improved the water-holding capacity of meat maintaining optimum pH values. This combined treatment delayed the growth of major spoilage microorganisms, lipid oxidation, protein degradation, and undesirable color changes compared to unmarinated samples from the fifth to the twentieth day of retail exposure. The shelf life of rabbit carcasses under low-O2 MAP could be extended to 20 days of retail display, while rabbit carcasses under aerobic display presented a shorter shelf life of 5 to 10 days. Instrumental and sensorial tests showed that low-O2 MAP enhanced the tenderness of whole rabbit carcasses, with those marinated with Ras El-Hanout being the most positively perceived by the panelists. Marination also inhibited the pathogen Campylobacter jejuni, thus increasing the microbiological safety of the packaged product. The overall results indicated that low-O2 MAP combined with the Ras El-Hanout spice blend and marinade solution may represent a promising strategy for retail establishments to improve the quality, shelf life, and safety of rabbit carcasses.

Genomic and Antimicrobial Surveillance of Campylobacter Population in Italian Poultry

Campylobacter is one of the most common foodborne diseases worldwide with increasing rates of antibiotic resistance. Most cases of campylobacteriosis can be traced back to the consumption of poultry meat. Despite many efforts to reduce contamination in farms and in slaughterhouses, the persistence of this pathogen in poultry products remains a problem. This study aimed to evaluate the genetic diversity and antibiotic resistance of 542 C. jejuni and C. coli in Italian poultry, in the framework of two National Monitoring Programs. Genomes were screened for antibiotic resistance, virulence determinants and contextualized within a global collection of C. jejuni. ST2116, ST2863 and ST 832 were the most prevalent and significantly associated with Italian poultry. A worrying increase in resistance to quinolones, fluoroquinolones and tetracycline was observed in C. jejuni, while an increased occurrence of multidrug resistant (MDR) strains and strains resistant to macrolides was detected in C. coli. Low resistance rates were found for aminoglycosides. Molecular resistance determinants were consistent with the phenotypic resistance for tetracycline and quinolones. In silico analysis revealed 119 genes associated with virulence factors, with a notably higher prevalence of some genes in ST2863 genomes. This study highlights the increased resistance to macrolides and the emergence of MDR strains for C. coli, the genetic basis of AMR and the predominance of two genotypes among Campylobacter strains isolated from the Italian poultry farms.

Intestinal colonization with Campylobacter jejuni affects broiler gut microbiota composition but is not inhibited by daily intake of Lactiplantibacillus plantarum

Introduction

Lactobacilli may prevent broilers from colonization with Campylobacter spp. and other gram-negative zoonotic bacteria through lactic acid production and modulation of the intestinal microbiota. This study evaluated the effects of daily intake of Lactiplantibacillus plantarum 256 (LP256) on Campylobacter jejuni (C. jejuni) loads in ceca and feces of C. jejuni challenged broilers, together with the changes in the gut microbiota.

Methods

Two experiments were conducted using the broilers Ross 308 (R-308; Experiment 1) for 42 days and Rowan Ranger broilers (RR; Experiment 2) for 63 days. The LP256 strain was administered either via silage inoculated with LP256 or direct supplementation in the drinking water. Concurrently, haylage as a forage similar to silage but without any inoculum was tested. C. jejuni loads in fecal matter and cecal content were determined by plate counts and qPCR, respectively. The cecal microbiota, in response to treatments and the challenge, were assessed by 16S rRNA sequencing.

Results and Discussion

Culturing results displayed a significant reduction in C. jejuni colonization (2.01 log) in the silage treatment in comparison to the control at 1 dpi (day post-infection) in Experiment 1. However, no treatment effect on C. jejuni was observed at the end of the experiment. In Experiment 2, no treatment effects on C. jejuni colonization were found to be statistically significant. Colonization load comparison at the peak of infection (3 dpi) to that at the end of the trial (32 dpi) revealed a significant reduction in C. jejuni in all groups, regardless of treatment. Colonization dynamics of C. jejuni in the cecal samples analyzed by qPCR showed no difference between any of the treatments in Experiment 1 or 2. In both experiments, no treatment effects on the cecal microbiota were observed. However, proportional changes in the bacterial composition were observed after the C. jejuni challenge, suggesting that colonization affected the gut microbiota. Overall, the daily intake of LP256 was not effective in reducing C. jejuni colonization in either broiler type at the end of the rearing period and did not cause any significant changes in the birds' cecal microbiota composition.

An Integrated Paper Microfluidic Device Based on Isothermal Amplification for Simple Sample-to-Answer Detection of Campylobacter jejuni

Campylobacter jejuni is recognized as the most common species in the genus Campylobacter that causes foodborne diseases. The main reservoirs harboring C. jejuni are poultry products, which are associated with most illnesses, creating a demand for effective detection methods to achieve point-of-need diagnostics. We developed an easy-to-use, hybrid paper/polymer-based microfluidic device that integrates paper-based DNA extraction, isothermal nucleic acid amplification, and lateral flow detection. Overall, the recombinase polymerase amplification (RPA) reaction was completed in 20 min and demonstrated 100% specificity to C. jejuni, including 2 reference strains and 6 wild strains isolated from the agroecosystem, 9 other Campylobacter subspecies strains, and 11 non-Campylobacter strains. The limit of detection (LOD) was 46 CFU/mL with DNA extracted on the cellulose paper. The sensitivity was reduced to 460 CFU/mL on the integrated hybrid paper/polymer-based microfluidic device. This device could detect C. jejuni spiked at concentrations ranging from 101 to 102 CFU/g in chicken meat after an enrichment of 5 to 10 h. For C. jejuni levels of >102 CFU/g, it managed to confirm positive results immediately, without bacterial enrichment. RPA reagents and primers remained stable on the paper platform at 22°C for 12 h. After lyophilization and storage on paper, the RPA reaction showed consistent sensitivity for 3 days, and the LOD was reduced to 103 CFU/mL when storage was extended to 25 days. The use of this hybrid paper/polymer-based microfluidic device enabled detection of Campylobacter in foods with high specificity and sensitivity, demonstrating its potential as a reliable point-of-need diagnostic platform for on-site conditions due to its low cost, portability, and simplicity. IMPORTANCE The global health and economic burden of Campylobacter prompts the development of novel detection techniques that can be implemented in resource-limited and on-site settings. This study described point-of-need identification of C. jejuni using a hybrid paper/polymer-based microfluidic device that is easy to operate. This device had high specificity and sensitivity toward C. jejuni and significantly reduced the total analysis time compared to conventional culture-based methods. Nucleic acid extraction was simplified from intensive pipetting to a paper dipstick, making it more convenient for use in the field as a promising tool for future routine surveillance and outbreak investigation.

Investigation of the Effect of Three Commercial Water Acidifiers on the Performance, Gut Health, and Campylobacter jejuni Colonization in Experimentally Challenged Broiler Chicks

This study investigated the effect of three commercial water acidifiers on the performance, gut health, and C. jejuni colonization in experimentally challenged broiler chicks. A total of 192 one-day-old broiler chicks (Ross 308^®) were randomly allocated into 6 treatment groups with 4 replicates according to the following experimental design: group A, birds were not challenged and received tap water; group B, birds were challenged and received tap water; groups C, D, E, and F, birds were challenged and received tap water treated with 0.1% v/v SPECTRON^®, with 0.1-0.2% v/v ProPhorce™ SA Exclusive, with 0.1-0.2% v/v Premium acid, and with 0.1-0.2% v/v Salgard^® Liquid, respectively. The continuous water acidification evoked undesirable effects on broilers' performance and to an increased number of birds with ulcers and erosions in the oral cavity and the upper esophageal area. ProPhorce™ SA Exclusive and Premium acid significantly reduced the C. jejuni counts in the crop, whereas Salgard^® Liquid significantly reduced the C. jejuni counts in the ceca of birds. At slaughter age, only Premium acid significantly reduced C. jejuni counts in the ceca of birds. All the tested products ameliorated the changes induced by C. jejuni infection in the pH in the ceca of birds. It can be concluded that besides the effectiveness of the tested products in controlling C. jejuni in broilers, their continuous application evoked undesirable effects on broilers' performance, leading to the need to modify the dosage scheme in future investigations.

Plasmid DNA Prime/Protein Boost Vaccination against Campylobacter jejuni in Broilers: Impact of Vaccine Candidates on Immune Responses and Gut Microbiota

Campylobacter infections, traced to poultry products, are major bacterial foodborne zoonoses, and vaccination is a potential solution to reduce these infections. In a previous experimental trial using a plasmid DNA prime/recombinant protein boost vaccine regimen, two vaccine candidates (YP437 and YP9817) induced a partially protective immune response against Campylobacter in broilers, and an impact of the protein batch on vaccine efficacy was suspected. This new study was designed to evaluate different batches of the previously studied recombinant proteins (called YP437A, YP437P and YP9817P) and to enhance the immune responses and gut microbiota studies after a C. jejuni challenge. Throughout the 42-day trial in broilers, caecal Campylobacter load, specific antibodies in serum and bile, the relative expression of cytokines and β-defensins, and caecal microbiota were assessed. Despite there being no significant reduction in Campylobacter in the caecum of vaccinated groups, specific antibodies were detected in serum and bile, particularly for YP437A and YP9817P, whereas the production of cytokines and β-defensins was not significant. The immune responses differed according to the batch. A slight change in microbiota was demonstrated in response to vaccination against Campylobacter. The vaccine composition and/or regimen must be further optimised.

The European Union One Health 2021 Zoonoses Report

This report of the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring and surveillance activities carried out in 2021 in 27 MSs, the United Kingdom (Northern Ireland) and nine non-MSs. Key statistics on zoonoses and zoonotic agents in humans, food, animals and feed are provided and interpreted historically. In 2021, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. Cases of campylobacteriosis and salmonellosis increased in comparison with 2020, but decreased compared with previous years. In 2021, data collection and analysis at the EU level were still impacted by the COVID-19 pandemic and the control measures adopted in the MSs, including partial or total lockdowns. Sixteen MSs and the United Kingdom (Northern Ireland) achieved all the established targets in poultry populations for reduction in Salmonella prevalence for the relevant serovars. Salmonella samples from carcases of various animal species and samples for Campylobacter quantification from broiler carcases were more frequently positive when performed by the competent authorities than when own-checks were conducted. Yersiniosis was the third most reported zoonosis in humans, followed by Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes infections. L. monocytogenes and West Nile virus infections were the most severe zoonotic diseases, with the most hospitalisations and highest case fatality rates. Overall, MSs reported more foodborne outbreaks and cases in 2021 than in 2020. S. Enteritidis remained the most frequently reported causative agent for foodborne outbreaks. Salmonella in 'eggs and egg products' and in 'mixed foods' were the agent/food pairs of most concern. Outbreaks linked to 'vegetables and juices and products thereof' rose considerably compared with previous years. This report also provides updates on brucellosis, Coxiella burnetii (Q fever), echinococcosis, rabies, toxoplasmosis, trichinellosis, tuberculosis due to Mycobacterium bovis or M. caprae, and tularaemia.

Luminal and mucosa-associated caecal microbiota of chickens after experimental Campylobacter jejuni infection in the absence of Campylobacter-specific phages of group II and III

Campylobacteriosis is still the most commonly reported zoonosis in the European Union causing gastrointestinal disease in humans. One of the most common sources for these food-borne infections is broiler meat. Interactions between Campylobacter (C.) jejuni and the intestinal microbiota might influence Campylobacter colonization in chickens. The aim of the present study was to gain further knowledge about exclusive interactions of the host microbiota with C. jejuni in Campylobacter-specific phage-free chickens under standardized conditions and special biosafety precautions.Therefore, 12 artificially infected (C. jejuni inoculum with a challenge dose of 7.64 log₁₀ c.f.u.) and 12 control chickens of the breed Ross 308 were kept under special biosafety measures in an animal facility. At day 42 of life, microbiota studies were performed on samples of caecal digesta and mucus. No Campylobacter-specific phages were detected by real-time PCR analysis of caecal digesta of control or artificially infected chickens. Amplification of the 16S rRNA gene was performed within the hypervariable region V4 and subsequently sequenced with Illumina MiSeq platform. R (version 4.0.2) was used to compare the microbiota between C. jejuni-negative and C. jejuni-positive chickens. The factor chickens' infection status contributed significantly to the differences in microbial composition of mucosal samples, explaining 10.6 % of the microbiota variation (P=0.007) and in digesta samples, explaining 9.69 % of the microbiota variation (P=0.015). The strongest difference between C. jejuni-non-infected and C. jejuni-infected birds was observed for the family Peptococcaceae whose presence in C. jejuni-infected birds could not be demonstrated. Further, several genera of the family Ruminococcaceae appeared to be depressed in its abundance due to Campylobacter infection. A negative correlation was found between Christensenellaceae R-7 group and Campylobacter in C. jejuni-colonised chickens, both genera potentially competing for substrate. This makes Christensenellaceae R-7 group highly interesting for further studies that aim to find control options for Campylobacter infections and assess the relevance of this finding for chicken health and Campylobacter colonization.

Transmission of antimicrobial resistance (AMR) during animal transport

The transmission of antimicrobial resistance (AMR) between food-producing animals (poultry, cattle and pigs) during short journeys (< 8 h) and long journeys (> 8 h) directed to other farms or to the slaughterhouse lairage (directly or with intermediate stops at assembly centres or control posts, mainly transported by road) was assessed. Among the identified risk factors contributing to the probability of transmission of antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs), the ones considered more important are the resistance status (presence of ARB/ARGs) of the animals pre-transport, increased faecal shedding, hygiene of the areas and vehicles, exposure to other animals carrying and/or shedding ARB/ARGs (especially between animals of different AMR loads and/or ARB/ARG types), exposure to contaminated lairage areas and duration of transport. There are nevertheless no data whereby differences between journeys shorter or longer than 8 h can be assessed. Strategies that would reduce the probability of AMR transmission, for all animal categories include minimising the duration of transport, proper cleaning and disinfection, appropriate transport planning, organising the transport in relation to AMR criteria (transport logistics), improving animal health and welfare and/or biosecurity immediately prior to and during transport, ensuring the thermal comfort of the animals and animal segregation. Most of the aforementioned measures have similar validity if applied at lairage, assembly centres and control posts. Data gaps relating to the risk factors and the effectiveness of mitigation measures have been identified, with consequent research needs in both the short and longer term listed. Quantification of the impact of animal transportation compared to the contribution of other stages of the food-production chain, and the interplay of duration with all risk factors on the transmission of ARB/ARGs during transport and journey breaks, were identified as urgent research needs.

Quantification of Campylobacter contamination on chicken carcasses sold in retail markets in the United Arab Emirates

Background

Campylobacter is among the leading causes of foodborne zoonotic disease worldwide, with chicken meat accounting for the majority of human illnesses. This baseline study generates the first quantitative data for Campylobacter contamination in the United Arab Emirates chicken meat. Such data will help inform risk analysis and develop evidence-based food safety management.

Methods

For a year, chilled whole chicken carcasses (n = 315) belonging to seven different companies were collected from retail supermarkets. According to standard methods, Campylobacter enumeration was achieved by a direct plating in all chicken samples, and isolates were confirmed using multiplex PCR.

Results

Campylobacter spp. were recovered from 28.6% (90/315) of the samples. Campylobacter enumeration results indicated that 71.4% of the tested samples were contaminated with < 1 log10 CFU (colony-forming units)/g, and 7% were contaminated with ≥3 log10 CFU/g. The mean Campylobacter concentration was 2.70 log10 CFU/g, with a standard deviation of 0.41 log10 CFU/g. Campylobacter counts varied significantly in relation to the sourcing chicken processing companies. Six out of the seven surveyed companies provided Campylobacter positive samples. Moreover, significantly higher (p-value< 0.0001) counts were found to be associated with smaller size chicken carcasses (weighted 600–700 g; compared to the other categories, 800 g and 900–1000 g). Interestingly, C. coli was present in 83% of the positive samples, while C. jejuni was only detected in 6.4% of the samples. Compared with studies from other countries utilizing the same enumeration method, the UAE chicken appears to have a lower prevalence but a higher Campylobacter count per gram of carcasses. Higher Campylobacter counts were significantly associated with smaller carcasses, and C. coli was the dominant species detected in this study’s samples.

Conclusion

These results add to our understanding of the local, regional and global epidemiology of Campylobacter in chicken meat. Outputs of the current study may aid in developing a risk assessment of Campylobacter in the UAE, a country among the biggest per capita consumption markets for chicken meat worldwide.

Pulsed Light Application for Campylobacter Control on Poultry Meat and Its Effect on Colour and Volatile Profile

Campylobacter on poultry meat needs to be controlled to reduce the risk of infection caused by the consumption of chicken meat. Pulsed light (PL) application on poultry meat was studied to control Campylobacter spp. The effect of this technology was evaluated regarding poultry meat colour and volatile compound changes. Two breast sample groups were prepared: inoculated with Campylobacter (107 bacteria of Campylobacter jejuni strains) and not inoculated. Samples were submitted to PL, five pulses/s of 300 ms, 1 Hz, and 1 J/cm2 in the apparatus, PL Tecum unit (Claranor). A response surface experimental design was applied regarding the factors of voltage (1828 to 3000 W) and distance to the source UV lamp (2.6 to 5.4 cm). The binomial factorial treatment (voltage and distance) with PL induced different energy doses (fluence J/cm2) received by samples, 2.82 to 9.67 J/cm2. Poultry meat pulsed light treated had a significant decrease of Enterobacteriaceae counts. The treatments applied were unable to reduce 1 log Campylobacter cfu/g of poultry meat. The poultry meat PL treated became slightly light, redder, and yellower than those not treated. PL can decrease the proportion of aldehydes on total volatiles in meat, particularly on those associated with chicken-like, chicken skin-like, and sweet odour notes in fresh poultry meat. Further studies of PL with higher energy doses will be necessary to confirm if there are Campylobacter reductions and about poultry meat treated under storage to evaluate if volatile compounds can affect the flavour of PL-treated meat samples.

Systematic review of products with potential application for use in the control of Campylobacter spp. in organic and free-range broilers

Campylobacter spp. are some of the most important food-borne zoonoses in Europe and broiler meat is considered the main source of Campylobacter infections. Organic and free-range broilers have access to outdoor reservoirs of Campylobacter and are more frequently infected at slaughter than the conventional broiler flocks. Limitations to biosecurity and treatment options in these production types calls for additional solutions. This review examines intervention methods with sufficient strength and quality, which are able to reduce the load of Campylobacter safely and efficiently and discuss their applicability in organic and free-range broiler production. Four different products passed the inclusion criteria and their quality examined: ferric tyrosine chelate, a prebiotic fermentation product of Saccharomyces cerevisiae, short-chain fatty acid butyrate coated on microbeads added to feed, and a mix of organic acids added to the drinking water. Though potential candidates for reducing Campylobacter in broilers were identified, there is a lack of large scale intervention studies that demonstrate an effect under field conditions of a free-range broiler production.

Antimicrobial effect of a drinking water additive comprising four organic acids on Campylobacter load in broilers and monitoring of bacterial susceptibility

Application of organic acids via feed or drinking water is under discussion as a possible intervention strategy to reduce Campylobacter (C.) load in primary poultry production. A previous in vitro study showed that reduced concentrations of sorbic acid, benzoic acid, propionic acid, and acetic acid were required for antibacterial activity against Campylobacter when using a mixture of these 4 acids compared to when using the single acids. The present study aimed at determining the antibacterial efficiency of this combination in vivo as a drinking water additive for reducing shedding and intestinal C. jejuni colonization in broilers. Furthermore, we assessed whether the inoculated C. jejuni strain BfR-CA-14430 adapted in vivo to the applied organic acids. Results of this study showed that adding the organic acids consistently reduced Campylobacter loads in cloacal swabs. While significant reductions were observed within the entire study period, a maximum 2 log reduction occurred at an age of 18 d. However, after dissection at the end of the trial, no significant differences were detected in Campylobacter loads of cecal and colon contents compared to the control group. Susceptibility testing of re-isolates from cloacal swabs and cecal content revealed equal minimum inhibitory concentration (MIC) values compared to the inoculated test strain, suggesting that C. jejuni remained susceptible throughout the trial.

Impact of Bacillus subtilis Antibiotic Bacilysin and Campylobacter jejuni Efflux Pumps on Pathogen Survival in Mixed Biofilms

The foodborne pathogen Campylobacter jejuni is typically found in an agricultural environment; in animals, such as birds, as an intestinal commensal; and also in food products, especially fresh poultry meat. Campylobacter interactions within mixed species biofilms are poorly understood, especially at the microscale. We have recently shown that the beneficial bacterium Bacillus subtilis reduces C. jejuni survival and biofilm formation in coculture by secreting the antibiotic bacillaene. We extend these studies here by providing evidence that besides bacillaene, the antagonistic effect of B. subtilis involves a nonribosomal peptide bacilysin and that the fully functional antagonism depends on the quorum-sensing transcriptional regulator ComA. Using confocal laser scanning microscopy, we also show that secreted antibiotics influence the distribution of C. jejuni and B. subtilis cells in the submerged biofilm and decrease the thickness of the pathogen's biofilm. Furthermore, we demonstrate that genes encoding structural or regulatory proteins of the efflux apparatus system (cmeF and cmeR), respectively, contribute to the survival of C. jejuni during interaction with B. subtilis PS-216. In conclusion, this study demonstrates a strong potential of B. subtilis PS-216 to reduce C. jejuni biofilm growth, which supports the application of the PS-216 strain to pathogen biofilm control. IMPORTANCE Campylobacter jejuni is a prevalent cause of foodborne infections worldwide, while Bacillus subtilis as a potential probiotic represents an alternative strategy to control this alimentary infection. However, only limited literature exists on the specific mechanisms that shape interactions between B. subtilis and C. jejuni in biofilms. This study shows that in the two species biofilms, B. subtilis produces two antibiotics, bacillaene and bacilysin, that inhibit C. jejuni growth. In addition, we provide the first evidence that specific pathogen efflux pumps contribute to the defense against B. subtilis attack. Specifically, the CmeDEF pump acts during the defense against bacilysin, while CmeR-dependent overexpression of CmeABC nullifies the bacillaene attack. The role of specific B. subtilis antibiotics and these polyspecific pumps, known for providing resistance against medically relevant antibiotics, has not been studied during bacterial competition in biofilms before. Hence, this work broadens our understanding of mechanisms that shape antagonisms and defense during probiotic-pathogen interactions.

Monitoring of Campylobacter jejuni in a chicken infection model by measuring specific volatile organic compounds and by qPCR

Campylobacter is one of the leading bacterial foodborne pathogens worldwide. Poultry is the host species with this pathogen with the highest clinical impact. Flocks become colonised with Campylobacter, which leads to contamination of product entering the food-chain. Rapid and reliable Campylobacter detection methods could support controls to minimize the risks of contamination within the food-chain, which would easier enable the implementation of a logistical slaughter schedule or other control options. The present study evaluates current and emerging C. jejuni detection technologies on air samples in a unique study set-up of pre-defined C. jejuni prevalences. Both non-invasive detection technologies on air samples by subsequent measuring of volatile organic compounds (VOCs) or by qPCR detected the C. jejuni presence and could additionally distinguish between the number of present C. jejuni-positive birds in the study set-up. Nevertheless, electrostatic air samplers diagnosed fewer birds as C. jejuni-positive compared to the cultivation-based method. By measuring the VOCs, it was possible to detect the presence of two positive birds in the room. This apparent high sensitivity still needs to be verified in field studies. Techniques, such as these promising methods, that can facilitate C. jejuni surveillance in poultry flocks are desirable to reduce the risk of infection for humans.

Bacillus subtilis PS-216 Spores Supplemented in Broiler Chicken Drinking Water Reduce Campylobacter jejuni Colonization and Increases Weight Gain

Campylobacter jejuni is the leading cause of bacterial gastroenteritis, or campylobacteriosis, in humans worldwide, and poultry serves as a major source of infection. To reduce the risk associated with C. jejuni transmission via poultry meat, effective interventions during poultry production are needed, and the use of probiotics is a promising approach. In this study, 15 Bacillus subtilis strains were initially screened for their anti-Campylobacter activities. B. subtilis PS-216 strain demonstrated the best anti-Campylobacter activity against 15 C. jejuni isolates when examined using in vitro co-cultures. To evaluate the suitability of B. subtilis PS-216 for probiotic use, its susceptibility to eight clinically important antimicrobials and simulated gastric conditions was investigated. B. subtilis PS-216 was sensitive to all of the tested antibiotics. Although vegetative cells were sensitive to gastric conditions, B. subtilis PS-216 spores were highly resistant. We further evaluated the use of a B. subtilis PS-216 spore preparation (2.5 × 106 CFU/mL water) to prevent and/or reduce C. jejuni colonization in broiler chickens in vivo. Compared to the untreated group, significantly lower Campylobacter counts were detected in caeca of broilers continuously treated with B. subtilis PS-216 spores in their drinking water. Furthermore, broilers continuously treated with B. subtilis PS-216 spores showed improved weight gain, compared to the control group. Together, these results demonstrate the potential of B. subtilis PS-216 for use in poultry to reduce C. jejuni colonization and improve weight gain.

Impact of DNA Prime/Protein Boost Vaccination against Campylobacter jejuni on Immune Responses and Gut Microbiota in Chickens

Campylobacteriosis is reported to be the leading zoonosis in Europe, and poultry is the main reservoir of Campylobacter. Despite all the efforts made, there is still no efficient vaccine to fight this bacterium directly in poultry. Recent studies have reported interactions between the chicken immune system and gut microbiota in response to Campylobacter colonisation. The present study was designed to analyse in more depth the immune responses and caecal microbiota following vaccination with a DNA prime/protein boost flagellin-based vaccine that induces some protection in specific-pathogen-free White Leghorn chickens, as shown previously. These data may help to improve future vaccination protocols against Campylobacter in poultry. Here a vaccinated and a placebo group were challenged by C. jejuni at the age of 19 days. A partial reduction in Campylobacter loads was observed in the vaccinated group. This was accompanied by the production of specific systemic and mucosal antibodies. Transient relatively higher levels of Interleukin-10 and antimicrobial peptide avian β-defensin 10 gene expressions were observed in the vaccinated and placebo groups respectively. The analysis of caecal microbiota revealed the vaccination's impact on its structure and composition. Specifically, levels of operational taxonomic units classified as Ruminococcaceae and Bacillaceae increased on day 40.

Campylobacter Bacteriophage Cocktail Design Based on an Advanced Selection Scheme

Campylobacteriosis is a worldwide-occurring disease and has been the most commonly reported zoonotic gastrointestinal infection in the European Union in recent years. The development of successful phage-based intervention strategies will require a better understanding of phage–bacteria interactions to facilitate advances in phage cocktail design. Therefore, this study aimed to investigate the effects of newly isolated group II and group III phages and their combinations on current Campylobacter field strains. A continuous workflow for host range and efficiency of plating (EOP) value determination was combined with a qPCR-based phage group identification and a liquid-based planktonic killing assay (PKA). An advanced analysis scheme allowed us to evaluate phage cocktails by their efficacy in inhibiting bacterial population growth and the resulting phage concentrations. The results of this study indicate that data obtained from PKAs are more accurate than host range data based on plaque formation (EOP). Planktonic killing assays with Campylobacter appear to be a useful tool for a straightforward cocktail design. Results show that a group II phage vB_CcM-LmqsCP218-2c2 and group III phage vB_CjM-LmqsCP1-1 mixture would be most promising for practical applications against Campylobacter coli and Campylobacter jejuni.

Bacillus subtilis PS-216 Antagonistic Activities against Campylobacter jejuni NCTC 11168 Are Modulated by Temperature, Oxygen, and Growth Medium

As the incidence of Campylobacter jejuni and campylobacteriosis grows, so does the need for a better understanding and control of this pathogen. We studied the interactions of C. jejuni NCTC 11168 and a potential probiotic, Bacillus subtilis PS-216, in cocultures at different starting ratios and temperatures (20 °C, 37 °C, 42 °C), under different atmospheres (aerobic, microaerobic), and in different growth media (Mueller–Hinton, chicken litter medium, chicken intestinal-content medium). Under microaerobic conditions, B. subtilis effectively inhibited the growth of C. jejuni at 42 °C (log reduction, 4.19), even when C. jejuni counts surpassed B. subtilis by 1000-fold in the starting inoculum. This inhibition was weaker at 37 °C (log reduction, 1.63), while no impact on CFUs was noted at 20 °C, which is a temperature nonpermissive of C. jejuni growth. Under aerobic conditions, B. subtilis supported C. jejuni survival. B. subtilis PS-216 inhibited the growth of C. jejuni in sterile chicken litter (4.07 log reduction) and in sterile intestinal content (2.26 log reduction). In nonsterile intestinal content, B. subtilis PS-216 was able to grow, to a lesser extent, compared to Mueller–Hinton media, still showing potential as a chicken probiotic that could be integrated into the chicken intestinal microbiota. This study showed the strong influence of environmental parameters on the variability of C. jejuni and B. subtilis interactions. Furthermore, B. subtilis PS-216 antagonism was strongest against C. jejuni NCTC 11168 under conditions that might represent conditions in the chicken environment (42 °C, microaerobic atmosphere, chicken litter medium).

Application of Bacteriophages to Limit Campylobacter in Poultry Production

Campylobacter is a major foodborne pathogen with over a million United States cases a year and is typically acquired through the consumption of poultry products. The common occurrence of Campylobacter as a member of the poultry gastrointestinal tract microbial community remains a challenge for optimizing intervention strategies. Simultaneously, increasing demand for antibiotic-free products has led to the development of several alternative control measures both at the farm and in processing operations. Bacteriophages administered to reduce foodborne pathogens are one of the alternatives that have received renewed interest. Campylobacter phages have been isolated from both conventionally and organically raised poultry. Isolated and cultivated Campylobacter bacteriophages have been used as an intervention in live birds to target colonized Campylobacter in the gastrointestinal tract. Application of Campylobacter phages to poultry carcasses has also been explored as a strategy to reduce Campylobacter levels during poultry processing. This review will focus on the biology and ecology of Campylobacter bacteriophages in poultry production followed by discussion on current and potential applications as an intervention strategy to reduce Campylobacter occurrence in poultry production.

Isolation and Characterization of Group III Campylobacter jejuni-Specific Bacteriophages From Germany and Their Suitability for Use in Food Production

Campylobacter spp. are a major cause of bacterial foodborne diarrhea worldwide. While thermophilic Campylobacter species asymptomatically colonize the intestines of chickens, most human infections in industrial countries have been attributed to consumption of chicken meat or cross-contaminated products. Bacteriophages (phages) are natural predators of bacteria and their use at different stages of the food production chain has been shown to reduce the public health burden of human campylobacteriosis. However, regarding regulatory issues, the use of lytic phages in food is still under discussion and evaluation. This study aims to identify lytic phages suitable for reducing Campylobacter bacteria along the food production chain. Therefore, four of 19 recently recovered phages were further characterized in detail for their lytic efficacy against different Campylobacter field strains and their suitability under food production settings at different temperatures and pH values. Based on the results of this study, the phages vB_CjM-LmqsCP1-4 and vB_CjM-LmqsCP1-5 appear to be promising candidates for the reduction of Campylobacter jejuni in food production settings.

Improving Chicken Responses to Glycoconjugate Vaccination Against Campylobacter jejuni

Campylobacter jejuni is a common cause of diarrheal disease worldwide. Human infection typically occurs through the ingestion of contaminated poultry products. We previously demonstrated that an attenuated Escherichia coli live vaccine strain expressing the C. jejuni N-glycan on its surface reduced the Campylobacter load in more than 50% of vaccinated leghorn and broiler birds to undetectable levels (responder birds), whereas the remainder of the animals was still colonized (non-responders). To understand the underlying mechanism, we conducted three vaccination and challenge studies using 135 broiler birds and found a similar responder/non-responder effect. Subsequent genome-wide association studies (GWAS), analyses of bird sex and levels of vaccine-induced IgY responses did not correlate with the responder versus non-responder phenotype. In contrast, antibodies isolated from responder birds displayed a higher Campylobacter-opsonophagocytic activity when compared to antisera from non-responder birds. No differences in the N-glycome of the sera could be detected, although minor changes in IgY glycosylation warrant further investigation. As reported before, the composition of the microbiota, particularly levels of OTU classified as Clostridium spp., Ruminococcaceae and Lachnospiraceae are associated with the response. Transplantation of the cecal microbiota of responder birds into new birds in combination with vaccination resulted in further increases in vaccine-induced antigen-specific IgY responses when compared to birds that did not receive microbiota transplants. Our work suggests that the IgY effector function and microbiota contribute to the efficacy of the E. coli live vaccine, information that could form the basis for the development of improved vaccines targeted at the elimination of C. jejuni from poultry.

The European Union One Health 2020 Zoonoses Report

This report of the EFSA and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring activities carried out in 2020 in 27 EU Member States (MS) and nine non-MS. Key statistics on zoonoses and zoonotic agents in humans, food, animals and feed are provided and interpreted historically. Two events impacted 2020 MS data collection and related statistics: the Coronavirus Disease 2019 (COVID-19) pandemic and the withdrawal of the United Kingdom from the EU. In 2020, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. The EU trend for confirmed human cases of these two diseases was stable (flat) from 2016 to 2020. Fourteen of the 26 MS reporting data on Salmonella control programmes in poultry met the reduction targets for all poultry categories. Salmonella results for carcases of various species performed by competent authorities were more frequently positive than own-checks conducted by food business operators. This was also the case for Campylobacter quantification results from broiler carcases for the MS group that submitted data from both samplers, whereas overall at EU level, those percentages were comparable. Yersiniosis was the third most reported zoonosis in humans, with 10-fold less cases reported than salmonellosis, followed by Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes infections. Illnesses caused by L. monocytogenes and West Nile virus infections were the most severe zoonotic diseases with the highest case fatality. In 2020, 27 MS reported 3,086 foodborne outbreaks (a 47.0% decrease from 2019) and 20,017 human cases (a 61.3% decrease). Salmonella remained the most frequently reported causative agent for foodborne outbreaks. Salmonella in 'eggs and egg products', norovirus in 'crustaceans, shellfish, molluscs and products containing them' and L. monocytogenes in 'fish and fish products' were the agent/food pairs of most concern. This report also provides updates on tuberculosis due to Mycobacterium bovis or Mycobacterium caprae, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, Coxiella burnetii (Q fever) and tularaemia.

Parallel Sequencing Reveals Campylobacter spp. in Commercial Meat Chickens Less than 8 Days Old

Campylobacter from contaminated poultry meat is a major source of human gastroenteritis worldwide. To date, attempts to control this zoonotic infection with on-farm biosecurity measures have been inconsistent in outcome. A cornerstone of these efforts has been the detection of chicken infection with microbiological culture, where Campylobacter is generally not detectable until birds are at least 21 days old. Using parallel sequence-based bacterial 16S profiling analysis and targeted sequencing of the porA gene, Campylobacter was identified at very low levels in all commercial flocks at less than 8 days old that were tested from the United Kingdom, Switzerland, and France. These young chicks exhibited a much greater diversity of porA types than older birds testing positive for Campylobacter by culture or quantitative PCR (qPCR). This suggests that as the bacteria multiply sufficiently to be detected by culture methods, one or two variants, as indicated by porA type, dominate the infection. The findings that (i) most young chicks carry some Campylobacter and (ii) not all flocks become Campylobacter positive by culture suggest that efforts to control infection, and therefore avoid contamination of poultry meat, should concentrate on how to limit Campylobacter to low levels by the prevention of the overgrowth of single strains. IMPORTANCE Our results demonstrate the presence of Campylobacter DNA among fecal samples from a range of commercially reared meat chicks that are less than 8 days of age, consistent across 3 European countries. The recently developed, sensitive detection method indicates that infection occurs on commercial farms much earlier and more widely than previously thought, which opens up new opportunities to control Campylobacter contamination at the start of the food chain and reduce the unacceptably high levels of human disease.

Transcriptomic analysis of caecal tissue in inbred chicken lines that exhibit heritable differences in resistance to Campylobacter jejuni

BACKGROUND

Campylobacter jejuni is the leading cause of bacterial gastroenteritis in humans and the handling or consumption of contaminated poultry meat is a key source of infection. Selective breeding of poultry that exhibit elevated resistance to Campylobacter is an attractive control strategy. Here we studied the global transcriptional response of inbred chicken lines that differ in resistance to C. jejuni colonisation at a key site of bacterial persistence.

RESULTS

Three-week-old chickens of line 6₁ and N were inoculated orally with C. jejuni strain M1 and caecal contents and tonsils were sampled at 1 and 5 days post-infection. Caecal colonisation was significantly lower in line 6₁ compared to line N at 1 day post-infection, but not 5 days post-infection. RNA-Seq analysis of caecal tonsils of both lines revealed a limited response to C. jejuni infection compared to age-matched uninfected controls. In line N at days 1 and 5 post-infection, just 8 and 3 differentially expressed genes (DEGs) were detected (fold-change > 2 and false-discovery rate of < 0.05) relative to uninfected controls, respectively. In the relatively resistant line 6₁, a broader response to C. jejuni was observed, with 69 DEGs relating to immune regulation, cell signalling and metabolism at 1 day post-infection. However, by day 5 post-infection, no DEGs were detected. By far, the greatest number of DEGs were between uninfected birds of the two lines implying that differential resistance to C. jejuni is intrinsic. Of these genes, several Major Histocompatibility Complex class I-related genes (MHCIA1, MHCBL2 and MHCIY) and antimicrobial peptides (MUC2, AvBD10 and GZMA) were expressed to a greater extent in line N. Two genes within quantitative trait loci associated with C. jejuni colonisation were also more highly expressed in line N (ASIC4 and BZFP2). Quantitative reverse-transcriptase PCR analysis of a subset of transcripts confirmed the RNA-Seq results.

CONCLUSIONS

Our data indicate a limited transcriptional response in the caecal tonsils of inbred chickens to intestinal colonisation by Campylobacter but identify a large number of differentially transcribed genes between lines 6₁ and N that may underlie variation in heritable resistance to C. jejuni.

Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain

The role of food-producing environments in the emergence and spread of antimicrobial resistance (AMR) in EU plant-based food production, terrestrial animals (poultry, cattle and pigs) and aquaculture was assessed. Among the various sources and transmission routes identified, fertilisers of faecal origin, irrigation and surface water for plant-based food and water for aquaculture were considered of major importance. For terrestrial animal production, potential sources consist of feed, humans, water, air/dust, soil, wildlife, rodents, arthropods and equipment. Among those, evidence was found for introduction with feed and humans, for the other sources, the importance could not be assessed. Several ARB of highest priority for public health, such as carbapenem or extended-spectrum cephalosporin and/or fluoroquinolone-resistant Enterobacterales (including Salmonella enterica), fluoroquinolone-resistant Campylobacter spp., methicillin-resistant Staphylococcus aureus and glycopeptide-resistant Enterococcus faecium and E. faecalis were identified. Among highest priority ARGs bla CTX -M, bla VIM, bla NDM, bla OXA -48-like, bla OXA -23, mcr, armA, vanA, cfr and optrA were reported. These highest priority bacteria and genes were identified in different sources, at primary and post-harvest level, particularly faeces/manure, soil and water. For all sectors, reducing the occurrence of faecal microbial contamination of fertilisers, water, feed and the production environment and minimising persistence/recycling of ARB within animal production facilities is a priority. Proper implementation of good hygiene practices, biosecurity and food safety management systems is very important. Potential AMR-specific interventions are in the early stages of development. Many data gaps relating to sources and relevance of transmission routes, diversity of ARB and ARGs, effectiveness of mitigation measures were identified. Representative epidemiological and attribution studies on AMR and its effective control in food production environments at EU level, linked to One Health and environmental initiatives, are urgently required.

Bacillaene Mediates the Inhibitory Effect of Bacillus subtilis on Campylobacter jejuni Biofilms

Biofilms are the predominant bacterial lifestyle and can protect microorganisms from environmental stresses. Multispecies biofilms can affect the survival of enteric pathogens that contaminate food products, and thus, investigating the underlying mechanisms of multispecies biofilms is essential for food safety and human health. In this study, we investigated the ability of the natural isolate Bacillus subtilis PS-216 to restrain Campylobacter jejuni biofilm formation and adhesion to abiotic surfaces as well as to disrupt preestablished C. jejuni biofilms. Using confocal laser scanning microscopy and colony counts, we demonstrate that the presence of B. subtilis PS-216 prevents C. jejuni biofilm formation, decreases growth of the pathogen by 4.2 log₁₀, and disperses 26-h-old preestablished C. jejuni biofilms. Furthermore, the coinoculation of B. subtilis and C. jejuni interferes with the adhesion of C. jejuni to abiotic surfaces, reducing it by 2.4 log₁₀. We also show that contact-independent mechanisms contribute to the inhibitory effect of B. subtilis PS-216 on C. jejuni biofilm. Using B. subtilis mutants in genes coding for nonribosomal peptides and polyketides revealed that bacillaene significantly contributes to the inhibitory effect of B. subtilis PS-216. In summary, we show a strong potential for the use of B. subtilis PS-216 against C. jejuni biofilm formation and adhesion to abiotic surfaces. Our research could bring forward novel applications of B. subtilis in animal production and thus contribute to food safety. IMPORTANCE Campylobacter jejuni is an intestinal commensal in animals (including broiler chickens) but also the most frequent cause of bacterial foodborne infection in humans. This pathogen forms biofilms which enhance survival of C. jejuni in food processing and thus threaten human health. Probiotic bacteria represent a potential alternative in the prevention and control of foodborne infections. The beneficial bacterium Bacillus subtilis has an excellent probiotic potential to reduce C. jejuni in the animal gastrointestinal tract. However, data on the effect of B. subtilis on C. jejuni biofilms are scarce. Our study shows that the B. subtilis natural isolate PS-216 prevents adhesion to the abiotic surfaces and the development of submerged C. jejuni biofilm during coculture and destroys the preestablished C. jejuni biofilm. These insights are important for development of novel applications of B. subtilis that will reduce the use of antibiotics in human and animal health and increase productivity in animal breeding.

The European Union One Health 2019 Zoonoses Report

This report of the EFSA and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring activities carried out in 2019 in 36 European countries (28 Member States (MS) and eight non-MS). The first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. The EU trend for confirmed human cases of these two diseases was stable (flat) during 2015-2019. The proportion of human salmonellosis cases due to Salmonella Enteritidis acquired in the EU was similar to that in 2017-2018. Of the 26 MS reporting on Salmonella control programmes in poultry, 18 met the reduction targets, whereas eight failed to meet at least one. The EU prevalence of Salmonella target serovar-positive flocks has been stable since 2015 for breeding hens, laying hens, broilers and fattening turkeys, with fluctuations for breeding turkey flocks. Salmonella results from competent authorities for pig carcases and for poultry tested through national control programmes were more frequently positive than those from food business operators. Shiga toxin-producing Escherichia coli (STEC) infection was the third most reported zoonosis in humans and increased from 2015 to 2019. Yersiniosis was the fourth most reported zoonosis in humans in 2019 with a stable trend in 2015-2019. The EU trend of confirmed listeriosis cases remained stable in 2015-2019 after a long period of increase. Listeria rarely exceeded the EU food safety limit tested in ready-to-eat food. In total, 5,175 food-borne outbreaks were reported. Salmonella remained the most detected agent but the number of outbreaks due to S. Enteritidis decreased. Norovirus in fish and fishery products was the agent/food pair causing the highest number of strong-evidence outbreaks. The report provides further updates on bovine tuberculosis, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, West Nile virus, Coxiella burnetii (Q fever) and tularaemia.

The Data Behind Risk Analysis of Campylobacter Jejuni and Campylobacter Coli Infections

Campylobacter jejuni and Campylobacter coli are major causes of food-borne enteritis in humans. Poultry meat is known to be responsible for a large proportion of cases of human campylobacteriosis. However, other food-borne, environmental and animal sources are frequently associated with the disease in humans as well. Human campylobacteriosis causes gastroenteritis that in most cases is self-limiting. Nevertheless, the burden of the disease is relatively large compared with other food-borne diseases, which is mostly due to rare but long-lasting symptoms related to immunological sequelae. In order to pave the way to improved surveillance and control of human campylobacteriosis, we review here the data that is typically used for risk analysis to quantify the risk and disease burden, identify specific surveillance strategies and assist in choosing the most effective control strategies. Such data are mostly collected from the literature, and their nature is discussed here, for each of the three processes that are essential for a complete risk analysis procedure: risk assessment, risk management and risk communication. Of these, the first, risk assessment, is most dependent on data, and this process is subdivided into the steps of hazard identification, hazard characterization, exposure assessment and risk characterization. For each of these steps of risk assessment, information from published material that is typically collected will be summarized here. In addition, surveillance data are highly valuable for risk assessments. Different surveillance systems are employed in different countries, which can make international comparison of data challenging. Risk analysis typically results in targeted control strategies, and these again differ between countries. The applied control strategies are as yet not sufficient to eradicate human campylobacteriosis. The surveillance tools of Campylobacter in humans and exposure sources in place in different countries are briefly reviewed to better understand the Campylobacter dynamics and guide control strategies. Finally, the available control measures on different risk factors and exposure sources are presented.

Management Strategies for Prevention of Campylobacter Infections Through the Poultry Food Chain: A European Perspective

Numerous studies point out that at present, a complete elimination of Campylobacter species in the poultry food chain is not feasible. Thus, the current aim should be to establish control measures and intervention strategies to minimize the occurrence of Campylobacter spp. in livestock (esp. poultry flocks) and to reduce the quantitative Campylobacter burden along the food chain in animals and subsequently in foods. The most effective measures to mitigate Campylobacter focus on the primary production stage. Nevertheless, measures applied during slaughter and processing complement the general meat hygiene approaches by reducing fecal contamination during slaughtering and processing and as a consequence help to reduce Campylobacter in poultry meat. Such intervention measures at slaughter and processing level would include general hygienic improvements, technological innovations and/or decontamination measures that are applied at single slaughter or processing steps. In particular, approaches that do not focus on a single intervention measure would need to be based on a thorough process of evaluation, and potential combinatory effects have to be modeled and tested. Finally, the education of all stakeholders (including retailers, food handlers and consumers) is required and will help to increase awareness for the presence of foodborne pathogens in raw meat and meat products and can thus aid in the development of the required good kitchen hygiene.