Scientific Opinion on the public health hazards to be covered by inspection of meat (bovine animals)

Species prevalence, virulence genes, and antibiotic resistance of enterococci from food-producing animals at a slaughterhouse in Turkey

Healthy cattle, sheep, and goats can be reservoirs for gastrointestinal pathogenic fecal enterococci, some of which could be multidrug-resistant to antimicrobials. The objective of this study was to determine the prevalence and diversity of Enterococcus species in healthy sheep, goat, and cattle carcasses, as well as to analyze the antimicrobial resistance phenotype/genotype and the virulence gene content. During 2019-2020, carcass surface samples were collected from 150 ruminants in a slaughterhouse. A total of 90 enterococci, comprising five species, were obtained. The overall prevalence of enterococci was found to be 60%, out of which 37.7% were identified as Enterococcus (E.) hirae, 33.3% as E. casseliflavus, 15.5% as E. faecium, 12.2% as E. faecalis, and 1.1% as E. gallinarum. Virulence-associated genes of efaA (12.2%) were commonly observed in the Enterococcus isolates, followed by gelE (3.3%), asaI (3.3%), and ace (2.2%). High resistance to quinupristin-dalfopristin (28.8%), tetracycline (21.1%), ampicillin (20%), and rifampin (15.5%) was found in two, four, four, and five of the Enterococcus species group, respectively. The resistance of Enterococcus isolates to 11 antibiotic groups was determined and multidrug resistant (MDR) strains were found in 18.8% of Enterococcus isolates. Characteristic resistance genes were identified by PCR with an incidence of 6.6%, 2.2%, 1.1%, 1.1%, 1.1%, and 1.1% for the tetM, ermB, ermA, aac(6')Ie-aph(2")-la, VanC1, and VanC2 genes in Enterococcus isolates, respectively. Efflux pump genes causing multidrug resistance were detected in Enterococcus isolates (34.4%). The results showed that there were enterococci in the slaughterhouse with a number of genes linked to virulence that could be harmful to human health.

The role of cattle in the transmission of cystic echinococcosis in a highly endemic area of the Peruvian Andes

Cystic echinococcosis (CE) causes significant losses in Andean livestock production and affects Andean food security. However, more studies are needed to understand the epidemiology of the disease. In addition, the potential contribution of Andean cattle to the transmission of Echinococcus granulosus sensu lato needs to be known. This study aimed to determine the CE-prevalence and its association with risk factors, such as age and sex of the animals, the parasite load (number of cysts/organ) of condemned organs, and the viability and fertility of Echinococcus cysts from cattle in the Andes. The prevalence was examined in 348 cattle from an authorized slaughterhouse of Huancayo at 3300 m altitude. Cyst burden was determined by extracting all cysts from the total of the CE-infected organs. Cyst fertility and protoscolices viability were analysed from 90 randomly selected CE-infected organs. The CE prevalence was 35.6% (124/348; 95% CI: 30.6%-40.6%). There was no significant effect of age and sex on CE prevalence. CE was significantly more prevalent (p < 0.05) in lungs than livers, 34.8% (121/348; 95% CI: 29.8%-39.8%) vs 8.9% (31/348; 95% CI: 5.9%-11.9%). Most (75%) infected organs had one to five cysts. The mean cyst burden was significantly (p = 0.018) higher in the lungs than livers, 6.4 ± 4.9 vs 3.7 ± 2.9. Cyst fertility was 1.6% (10/608; 95% CI: 0.6%-2.6%). Despite the high CE prevalence, infected organs from Andean cattle play a minor role in CE transmission to dogs in the central Peruvian Andes.

Bovine cysticercosis epidemiology and the economic impact of the triceps brachii incision in a South African export abattoir

Taenia saginata is a zoonotic tapeworm of humans with bovines as its intermediate host (bovine cysticercosis). Traditional meat inspection is the main measure to identify the larval stage in carcasses and prevent human infection, but has a notoriously low sensitivity, especially in low prevalence settings. The legislation in multiple African countries mandates an incision in both triceps brachii muscles to detect the parasite as part of the normal post-mortem inspection, but this has an economic cost and is not universally mandated in other countries. The primary aim of this study was to investigate the epidemiology of bovine cysticercosis at an export abattoir in South Africa and determine the validity and cost of the triceps incision. Risk factors were investigated, and the effect of additional heart incisions on the current inspection. Four incisions were made into the heart in addition to the normal post-mortem inspection in 3353 carcasses. The proportion of positive animals with and without the cardiac and triceps incisions were compared using McNemar's chi-square tests, while risk factors were assessed using binary logistic regression. The economic impact of the triceps incision was estimated using a stochastic economic cost model. Thirty-three positive carcasses were identified for an apparent prevalence of 0.98 % (95 %CI, 0.69-1.36 %), while the true prevalence was estimated at 6.6 % (95 %CI, 4.3-8.8 %). All cysts were confirmed as T. saginata on histopathology with 70 % (95 %CI, 53-83 %) located in the heart. The additional cardiac incisions resulted in the detection of significantly more cases compared to the normal inspection method prevalence of 0.72 % (95 %CI, 0.47-1.05 %; P < 0.001). The apparent prevalence of T. saginata when omitting the triceps incision was not significantly lower compared to the prevalence when included in the inspection (P = 0.480). External feedlots (OR= 4.17, 95 %CI: 2.04-8.54, P < 0.001) and older animals (OR=3.90, 95 %CI: 1.17-13.03, P = 0.027) were associated with a positive detection. The current median annual financial cost to the food business operator from the triceps incision was estimated at $30387 (95 %CI: $0-$130696), with the proportion of deboned meat exported identified as the most important factor affecting cost (Spearman's rho=0.853). The identification of risk factors could aid in the development of a more effective risk-based inspection system. The current inspection should be modified to increase exposure of the heart and remove the triceps incisions. The latter should especially be considered given the minimal contribution to cysticercosis detection, the unsupported requirement for its inclusion specifically in Africa, and its economic impact, especially as beef exports increase.

Anthrax revisited: how assessing the unpredictable can improve biosecurity

B. anthracis is one of the most often weaponized pathogens. States had it in their bioweapons programs and criminals and terrorists have used or attempted to use it. This study is motivated by the narrative that emerging and developing technologies today contribute to the amplification of danger through greater easiness, accessibility and affordability of steps in the making of an anthrax weapon. As states would have way better preconditions if they would decide for an offensive bioweapons program, we focus on bioterrorism. This paper analyzes and assesses the possible bioterrorism threat arising from advances in synthetic biology, genome editing, information availability, and other emerging, and converging sciences and enabling technologies. Methodologically we apply foresight methods to encourage the analysis of contemporary technological advances. We have developed a conceptual six-step foresight science framework approach. It represents a synthesis of various foresight methodologies including literature review, elements of horizon scanning, trend impact analysis, red team exercise, and free flow open-ended discussions. Our results show a significant shift in the threat landscape. Increasing affordability, widespread distribution, efficiency, as well as ease of use of DNA synthesis, and rapid advances in genome-editing and synthetic genomic technologies lead to an ever-growing number and types of actors who could potentially weaponize B. anthracis. Understanding the current and future capabilities of these technologies and their potential for misuse critically shapes the current and future threat landscape and underlines the necessary adaptation of biosecurity measures in the spheres of multi-level political decision making and in the science community.

A Review of Toxoplasma gondii in Animals in Greece: A FoodBorne Pathogen of Public Health Importance

Toxoplasma gondii is a zoonotic protozoon with a complex life cycle and the second most important foodborne pathogen in Europe. Surveillance of toxoplasmosis is based on national considerations since there are no mandatory controls along the food chain in the European Union, and underreporting of meat is still a problem in many countries like Greece. The current review provides an overview of T. gondii prevalence, associated risk factors, and surveillance in animals in Greece, focusing on the transmission role of meat and highlighting the control measures that should be adopted by consumers. Sows, wild boars, hares, equines, and cats had lower, while sheep and goats generally had higher seroprevalence than their respective pooled European and global values. Seroprevalence in chickens was similar between Greece and Europe, while there was high variation in cattle studies, with no data regarding dairy products. Though a comprehensive meat safety assurance system is the most effective approach to control the principal biological hazards associated with meat, such as T. gondii, the prerequisite risk categorisation of farms and abattoirs based on EFSA's proposed harmonised epidemiological indicators has not materialised as yet in Greece. Therefore, comprehensive control strategies are still required to ensure food safety and safeguard public health.

Prevalence of Escherichia coli generic and pathogenic in pork meat: systematic review and meta-analysis

This research aimed to analyze scientific information regarding the prevalence of generic and pathogenic E. coli in the production and supply chain of pork meat, considering different types of samples, places of sampling, and pathotypes using a systematic review and meta-analysis tools. The meta-analysis for the prevalence of generic and pathogenic E. coli was conducted by estimating the effects within subgroups. Data subsets were analyzed using the DerSimonian-Laird method for binary random effects. The average prevalence of generic E. coli in different types of pork meat samples was determined to be 35.6% (95% CI 19.3-51.8), with no significant differences observed between pork meat and carcasses. Conversely, the average prevalence of E. coli pathotypes in samples related to the supply chain of pork meat was found to be 4.7% (95% CI 3.7-5.7). In conclusion, these findings suggest the possibility of establishing an objective threshold for E. coli prevalence as a benchmark for comparison within the meat industry. By utilizing this data, it becomes possible to propose a standardized limit that can serve as a reference point for evaluating and improving processes in the industry.

Field evaluation of two commercial serological assays for detecting bovine tuberculosis

Diagnosis of bovine tuberculosis in cattle is challenging due to complex immune host response to infection that limit the performance of available diagnostic tests. In this study, performance of two commercial serological assays developed to detect bovine tuberculosis were evaluated: Enferplex Bovine TB antibody kit including 11 antigens (EnferGroup, Ireland) and IDEXX M. bovis Ab kit (IDEXX, USA). The specificity value obtained with the ELISA IDEXX M. bovis Ab test was 97.1%, whereas it was 97.1% and 95.1% for the high specificity and sensitivity settings, respectively, with the Enferplex Bovine TB antibody kit. The sensitivity of the multiplexed Enferplex Bovine TB antibody test for SICCT-positive animals was higher (N = 172; 51.7% and 58.7% with high specificity and sensitivity settings, respectively) compared to the ELISA IDEXX M. bovis Ab test (sensitivity of 36.6%). "Antigen profiles" generated by the multiplexed Enferplex method showed that five out of 11 antigens present in the test were mostly identified as positive sera in cattle originating from bTB-outbreaks. In comparison, unique profiles appeared to be correlated with false positive results. However additional studies are needed to confirm the observed antigen profiles, and their potential use as an additional diagnostic tool. Serial interpretation of the two serological tests produced higher diagnostic specificity (>99%), reducing false positive results, which is essential for a screening test when the prevalence of bovine tuberculosis is low.

The Environment, Farm Animals and Foods as Sources of Clostridioides difficile Infection in Humans

The recent discovery of the same Clostridioides difficile ribotypes associated with human infection in a broad range of environments, animals and foods, coupled with an ever-increasing rate of community-acquired infections, suggests this pathogen may be foodborne. The objective of this review was to examine the evidence supporting this hypothesis. A review of the literature found that forty-three different ribotypes, including six hypervirulent strains, have been detected in meat and vegetable food products, all of which carry the genes encoding pathogenesis. Of these, nine ribotypes (002, 003, 012, 014, 027, 029, 070, 078 and 126) have been isolated from patients with confirmed community-associated C. difficile infection (CDI). A meta-analysis of this data suggested there is a higher risk of exposure to all ribotypes when consuming shellfish or pork, with the latter being the main foodborne route for ribotypes 027 and 078, the hypervirulent strains that cause most human illnesses. Managing the risk of foodborne CDI is difficult as there are multiple routes of transmission from the farming and processing environment to humans. Moreover, the endospores are resistant to most physical and chemical treatments. The most effective current strategy is, therefore, to limit the use of broad-spectrum antibiotics while advising potentially vulnerable patients to avoid high-risk foods such as shellfish and pork.

Engine oil from agricultural machinery as a source of PCDD/Fs and PCBs in free-range hens

Free-range hens spend most of their lives outdoors, resulting in their heavy exposure to environmental pollutants such as polychlorinated dibenzo-p-dioxin, dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), and non-dioxin-like polychlorinated biphenyls (NDL-PCBs). We present a case of contamination of free-range eggs that is previously unreported in the literature. The aim of our study was a source investigation after finding a high level of PCDD/Fs in samples of eggs from one of the inspected farms. Samples of hens' eggs, muscles, and livers and the feeds and soils were analyzed. The results showed that the soil samples taken from the paddock contained high concentrations of PCDD/Fs and DL-PCBs expressed as toxic equivalents (TEQ) (72.9 ± 18.2 pg WHO-TEQ g^-1 dry mas (d.m.)) and a high concentration of NDL-PCBs (207 ± 46.9 ng g^-1 d.m.). The investigation found that the cause of the soil contamination was oil leaking from the farm's tractor engine. The oil contained very high concentrations of PCDD/F and DL-PCBs (1013 ± 253 pg WHO-TEQ g^-1 oil) and 5644 ng g^-1 of NDL-PCBs. The source of the contamination was confirmed by the similarity of the PCDD/F and PCB profiles in the hen eggs and the soil contaminated by engine oil. The dietary intake of toxins resulting from consumption of the eggs is provided. For children, the consumption of contaminated eggs would result in an intake of double the tolerable weekly intake (TWI), while for adults, it would be approx. 60-70% of TWI.

The Value of Current Ante Mortem Meat Inspection and Food Chain Information of Dairy Cows in Relation to Post Mortem Findings and the Protection of Public Health: A Case for a More Risk-Based Meat Inspection

In this study, the contribution of the ante mortem (AM) inspection and the food chain information (FCI) to ensuring meat safety and public health was investigated, by evaluating the slaughterhouse findings of 223,600 slaughtered dairy cows in the Netherlands. The outcome of this study was that the ante mortem (AM) and post mortem (PM) inspections have a substantial overlap, and that with regard to food safety and public health in over 99% of cases the PM could even be omitted on the basis of the AM. In this study, the data provided by the dairy farmers on the current FCI forms contributed little to nothing with regard to the outcomes of AM and PM inspection. It is concluded that current meat inspection procedures need an update and a more risk-based approach needs to be adopted. Regarding this, the AM inspection of dairy cattle should remain, because it plays an important role in ensuring food safety (e.g., by preventing contamination of the slaughter line by excessively dirty animals, or animals with abscesses), monitoring animal welfare and in detecting some important notifiable diseases. The PM inspection, however, could in many cases be omitted, provided there is a strict AM inspection complemented by a vastly improved (automated) way of obtaining reliable FCI.

Raw Animal Meats as Potential Sources of Clostridium difficile in Al-Jouf, Saudi Arabia

Clostridium difficile present in feces of food animals may contaminate their meats and act as a potential source of C. difficile infection (CDI) to humans. C. difficile resistance to antibiotics, its production of toxins and spores play major roles in the pathogenesis of CDI. This is the first study to evaluate C. difficile prevalence in retail raw animal meats, its antibiotics susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240 meat samples were tested. C. difficile was identified by standard microbiological and biochemical methods. Vitek-2 compact system confirmed C. difficile isolates were 15/240 (6.3%). Toxins A/B were not detected by Xpect C. difficile toxin A/B tests. Although all isolates were susceptible to vancomycin and metronidazole, variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or tetracycline antibiotics were detected by Epsilon tests. C. difficile strains with reduced susceptibility to antibiotics should be investigated. Variability between the worldwide reported C. difficile contamination levels could be due to absence of a gold standard procedure for its isolation. Establishment of a unified testing algorithm for C. difficile detection in food products is definitely essential to evaluate the inter-regional variation in its prevalence on national and international levels. Proper use of antimicrobials during animal husbandry is crucial to control the selective drug pressure on C. difficile strains associated with food animals. Investigating the protective or pathogenic potential of non-toxigenic C. difficile strains and the possibility of gene transfer from certain toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains, respectively, should be worthy of attention.

Evaluation of the Presence and Viability of Mycobacterium bovis in Wild Boar Meat and Meat-Based Preparations

The aim of the present study is to provide information about the ability of Mycobacterium bovis to survive within wild boar (Sus scrofae) meat and meat-based preparations and the duration of this survival, and to consider the preservation of its infectious potential toward humans and animals. Meat samples were artificially contaminated with an M. bovis field strain and then stored at −20 °C, while two sausages batches were contaminated with the same field strain at two different concentrations, 10⁵ CFU/g and 10³ CFU/g, before storing them in proper conditions to allow for their ripening. A third sausage batch was contaminated by adding 2 g of wild boar lymph nodal tissue with active tuberculous lesions to the meat mixture. Bacteriological and biomolecular (PCR) methods were used to test the meat and sausage samples every 60 days and every 7–10 days, respectively. M. bovis was detected as still alive and viable on the frozen meat for the last test on the 342nd day, while from the sausage samples, M. bovis was isolated until 23 days after contamination. Our results indicate that M. bovis can stay alive and be viable for 23 days within sausages prepared with contaminated meat from infected wild boars. These products are usually eaten as fresh food after grilling, often cooking at a temperature that does not ensure complete inactivation of the pathogenic microorganisms present, which can pose a risk for humans to develop zoonotic tuberculosis.

Beef abattoir interventions in a risk-based meat safety assurance system

In risk-based meat safety assurance system, the use of interventions is intended to accomplish the meat safety targets on chilled carcasses, particularly in situations when an abattoir is unable to sufficiently reduce risks arising from specific farms/animal batches by using process hygiene alone. Furthermore, interventions are considered whenever food safety authorities identify meat production processes associated with high risks for consumers. This paper overviews the role of beef interventions in a risk-based, meat safety assurance system. Cattle hide interventions (chemical hide washes and microbial immobilisation treatment with shellac) and beef carcass interventions (pasteurisation treatments with hot water and/or steam and organic (lactic) acid washes), show consistent reduction effects of aerobic bacteria and faecal indicators and reduced prevalences of naturally present VTEC and Salmonella. The review also identified interventions where there was a lack of data and further research was needed, and other contextual factors to inform the risk management decisions for further development of risk-based meat safety assurance system.

Edible Insects and Toxoplasma gondii: Is It Something We Need To Be Concerned About?

ABSTRACT

Novel foods, such as edible insects and food products on the basis of insects, could play an important role in both human and animal nutrition in the future. The identification of dangers associated with insect consumption is fundamental to guarantee consumer safety and adequate regulatory guidelines for operators of the food sector. Although former studies have focused on the microbiological contamination of fresh or processed edible insects, so far little information is available about the occurrence of foodborne parasites, such as Toxoplasma gondii, whose life cycles make them candidates for potential insect breeding substrate contamination. Hence, we investigated the presence of contaminating T. gondii in farmed edible insects to rule out this further hazard for consumers. Four species of insects most commonly used as food for human consumption were analyzed: mealworm; African migratory locust, house cricket, and silkworm. Samples included live specimens but also minimally (dehydrated) and highly processed edible insects. Traces of T. gondii DNA were detected in samples of dehydrated mealworm. These results highlight the need for implementing good farming and processing practices with particular care paid to safe storage and handling of feed and substrates used for edible insects to reduce the chance of T. gondii entering the human food chain.

HIGHLIGHTS

Evaluation of the performance of slaughterhouse surveillance for bovine tuberculosis detection in Castilla y Leon, Spain

Post-mortem inspection (PMI) of routinely slaughtered cattle in abattoirs is an extremely valuable tool for detecting bovine tuberculosis (bTB) infected herds that can supplement active surveillance activities. However, its true performance is difficult to assess due to the multiple factors that may affect it. Here, we determined relative efficiencies in the detection of bTB-compatible lesions and probabilities of subsequent laboratory confirmation of abattoirs located in Castilla y Leon, one of the regions with the largest cattle population in Spain, between 2010 and 2017. The slaughtered animal population was split based on the results of the ante-mortem tests (reactors or non-reactors), and two generalized linear multivariable mixed models were fitted to each subpopulation to calculate the risk of lesion detection and laboratory confirmation per abattoir while accounting for the effect of potential confounding variables. Throughout the 8-year period, ∼30,000 reactors and >2.8 million non-reactor animals in the ante-mortem tests were culled in the abattoirs under study. Bovine TB compatible lesions were detected in 4,710 (16%) reactors and 828 (0.03%) non-reactor animals, of which >95% were confirmed as infected through bacteriology. The probability of disclosure of bTB-like lesions was associated with the animal subpopulation, type of source unit, the herd size, the year of slaughter, the breed and age of the animal, and/or the season of slaughter. The probabilities of detection of bTB-like lesions varied largely depending on the abattoir in both subpopulations, ranging from 603 to 3,070 per 10,000 animals for the reactors and 0.2-16.1 per 10,000 animals for the non-reactor animals. Results obtained here will help to quantify the performance of PMI in abattoirs in Castilla y Leon and the between-abattoir variability, and to identify animals at increased risk of having bTB-like lesions detected during PMI based on animal- and farm-related factors.

Regucalcin expression profiles in veal calf testis: validation of histological and molecular tests to detect sex steroids illicit administration

Background

Sex steroids administration in meat producing animals is forbidden within the EU to preserve consumers’ safety, but continuous monitoring to identify resurgence of their misuse is needed. Among biomarkers related to sex steroids abuse in veal calves the regucalcin (RGN) mRNA perturbations in testis have been described in RNAlater samples. To setup novel diagnostic method, to update current tests available in National Residue Control Plans (NRCPs) and in legal dispute when illicit practices on farm animals are suspected, the reliability of RGN profiling was assessed by histological and molecular techniques.

Methods

Formalin fixed paraffin embedded (FFPE) testis samples, chosen being the most effective preservation strategy adopted by histological NRCPs and allowing easier retrospective analysis if required by legal disputes, were analyzed from veal calves treated with nandrolone, 17β-estradiol and a cocktail of the two hormones. RGN levels were determined by quantitative Real Time PCR and Immunohistochemistry assays. Test performances were assessed and compared by multiple ROC curves.

Results

Both tests resulted sensitive and specific, allowing to enrich, in future field investigation, novel integrated diagnostic protocols needed to unveil sex steroid abuse.

Discussion

Developed RT-qPCR and IHC methods confirmed RGN as a useful and robust biomarker to detect illegal administration of sex steroid hormones in veal calves. The developed methods, successfully applied to ten years old FFPE blocks, could allow both retrospective analysis, when supplementary investigations are requested by authorities, and future implementation of current NRCPs.

Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates

The potential effects of a 24 or 72-h delay in post-mortem inspection (PMI) of ungulates on public health and monitoring of animal health and welfare was evaluated. The assessment used a survey of meat inspectors, expert opinion, literature search and a stochastic model for Salmonella detection sensitivity. Disease detection sensitivity at a delayed PMI is expected to reduce detection sensitivity to a variable extent, depending on the hazard and on the signs/lesions and organs involved. No reduction is expected for Trichinella detection in meat from susceptible animal species and any decrease in detection of transmissible spongiform encephalopathies (TSEs) will not exceed the current tolerance for fallen stock. A 24-h delay in PMI could result in a small reduction in sensitivity of detection for tuberculosis, echinococcosis and cysticercosis. A greater reduction is expected for the detection of pyaemia and Rift valley fever. For the detection of Salmonella, the median model estimates are a reduction of sensitivity of 66.5% (90% probability interval (PI) 0.08-99.75%) after 24-h delay and 94% (90% PI 0.83-100%) after 72-h delay of PMI. Laboratory testing for tuberculosis following a sampling delay of 24-72 h could result in no, or a moderate, decrease in detection depending on the method of confirmation used (PCR, culture, histopathology). For chemical contaminants, a delay in meat inspection of 24 or 72 h is expected to have no impact on the effectiveness of detection of persistent organic pollutants and metals. However, for certain pharmacologically active substances, there will be a reduced effectiveness to detect some of these substances due to potential degradation in the available matrices (tissues and organs) and the non-availability of specific preferred matrices of choice.

Assessing the value of bacteriological examination as a diagnostic tool in relation to meat inspection in cattle

In Denmark, lesions indicating acute generalised infection identified at meat inspection will result in total condemnation. An official bacteriological examination (BU) protocol can be used for slaughtered animals with lesions such as endocarditis and endophlebitis as an assisting diagnostic tool to confirm whether the condition is local or generalised. If local, the carcass can be approved after condemnation of the relevant organs. The BU involves cultivating samples from the spleen and muscle. The aim of this study was to assess the value of the BU protocol. The study was conducted from February to May 2019 at a Danish cattle abattoir. Three groups of slaughtered cattle were included: 24 cases consisting of cattle with endocarditis and endophlebitis, 25 control animals consisting of cattle fully approved at inspection and 16 animals condemned at inspection due to endocarditis and endophlebitis with complications. Samples were taken from the heart, liver, kidney, lung, spleen and muscles of each animal. The BU protocol was used for cultivation. Different types of colonies were identified using MALDI-TOF-MS analysis. One or more samples with bacterial growth were found in all condemned animals - in 16 out of the 24 case animals and in two out of 25 control animals. In all three groups, Trueperella pyogenes was the most frequently isolated bacterium (60%) followed by Fusobacterium necrophorum (10%). For the case animals, the organ most commonly found with bacterial growth was the liver (46%), followed by the lung (38%) and the kidney (38%), while 96% of the muscle samples were negative. For the condemned group, bacterial growth was found in 75% of the spleen samples, 56% of liver and lung samples, and 50% of the muscle samples. A statistical analysis of the samples from cases and controls showed strong pair-wise associations for the presence of bacteria between organs, but no pair-wise associations between presence of bacteria in the muscle and any of the organs. Hence, if bacteria are found e.g. in the liver, they are likely to be found in other organs, but not in the muscle. In total, 20 of the 24 case animals were fully or partly approved in accordance with the current rules for judgement. It was concluded that the BU protocol using spleen and muscle samples would be suitable as a diagnostic tool for the judgement of slaughtered animals in cases where there is doubt about the stage of the lesions observed.

Zoonotic risks of pathogens from sheep and their milk borne transmission

Sheep were domesticated around 9000 BC in the Middle East, and since then milk from sheep gradually became very popular, not only for drinking but also for making cheeses and other dairy products. Nowadays, these dairy products are also important for people with an allergy to cow milk, and these products are an essential part of the local daily diet in regions of the world that are not suitable for cows and goats. Consumption of raw milk and raw milk products has a zoonotic risk, and with regard to sheep, the main pathogens associated with such dairy products are: Brucella melitensis, Campylobacter spp., Listeria spp., Salmonella spp., Shiga-toxin producing Escherichia coli, Staphylococcus aureus, tick borne encephalitis virus, and Toxoplasma gondii. Especially, young children, elderly people, pregnant women and immunocompromised (YOPI) persons, and those suffering from disease should be aware of the risk of consuming raw milk and raw milk products. This latter risk can be reduced by proper flock health management, prevention of contamination during milking, adequate milk processing, transport, and refrigerated storage. Only processes equaling pasteurization sufficiently reduce zoonotic risks from milk and milk products, but proper cooling is essential and recontamination must be prevented. Therefore, strict hygiene practices throughout the production process and supply chain especially for raw milk and raw dairy products, should be applied. Small scale production systems pose a greater risk compared to industrialized production systems because of a less protocolized and controlled production process. This manuscript describes zoonotic risks of pathogens from sheep and their milk borne transmission. Additionally, routes of contamination, possibilities for multiplication, and prevention measures thereof are described. We summarize some major human outbreaks caused by consumption of sheep milk and products made thereof, and finally discuss their implications.

Occurrence and characterization of Shiga toxin-producing Escherichia coli (STEC) isolated from Chinese beef processing plants

In order to investigate the prevalence, O serogroup, virulence genes and antibiotic resistance of Shiga toxin-producing Escherichia coli (STEC) in two beef plants in China, a total of 600 samples collected from 6 sites (feces, hide, pre-evisceration carcasses, post-washing carcasses, chilled carcasses and meat, 50 samples per site in each plant) were screened for the existence of Shiga toxin-encoding genes by PCR. STEC strains in positives were isolated and characterized for serogroup and antibiotic sensitivity. The PCR prevalence rate in each site was 45.0%, 31.0%, 14.0%, 13.0%, 9.0% and 18.0%, respectively. Sixteen O serogroups including O157, O146 and O76 which are associated with disease were identified. The existence of both stx₁ and stx₂ genes was the most common among the isolated strains (42.3%). Among the overall 26 isolates, seven and three were resistant to at least three and ten antibiotics, indicating a high antibiotic resistance in STEC strains isolated from the study.

One Health approach to Clostridioides difficile in Japan

Clostridioides difficile infections (CDIs) are predominantly a healthcare-associated illness in developed countries, with the majority of cases being elderly and hospitalize patients who used antibiotic therapy. Recently, the incidence of community-associated CDIs (CA-CDIs) in younger patients without a previous history of hospitalization or antibiotic treatment has been increasing globally. C. difficile is sometimes found in the intestine of many animals, such as pigs, calves, and dogs. Food products such as retail meat products and vegetables sometimes contain C. difficile. C. difficile has also been isolated from several environments such as compost manure, rivers, and soils. Yet, direct transmission of C. difficile from animals, food products, and environments to humans has not been proven, although these strains have similar molecular characteristics. Therefore, it has been suggested that there is a relationship between CA-CDIs and C. difficile from animals, food products, and the environment. To clarify the importance of the presence of C. difficile in several sources, characterization of C. difficile in these sources is required. However, the epidemiology of C. difficile in animals, food products, and the environment is not well studied in Japan. This review summarizes recent trends of CDIs and compares the molecular characteristics of C. difficile in Japanese animals, food products, and the environment. The prevalence trends of C. difficile in Japan are similar to those in the rest of the world. Therefore, I recommend using a One Health approach to CDI surveillance, monitoring, and control.

The British E. coli O157 in cattle study (BECS): factors associated with the occurrence of E. coli O157 from contemporaneous cross-sectional surveys

BACKGROUND

Escherichia coli O157 is a bacterial pathogen associated with severe disease in humans for which cattle are an important reservoir of infection. The identification of possible risk factors for infection in cattle could facilitate the development of control strategies and interventions to mitigate the risk to human health. The purpose of this study was to utilize data collected in 2014-2015 during the two contemporaneous cross-sectional surveys of the British E. coli O157 in Cattle Study (BECS) to investigate potential risk factors for E. coli O157 status in cattle destined for the food chain.

RESULTS

In the England & Wales survey only one variable, herd size, was associated with the outcome farm-level E. coli O157 positive status. The odds increased for each additional animal in the herd. In the Scotland survey, as well as a measure of herd size (the number of cattle aged 12-30 months), having brought breeding females on to the farm in the last year also increased the odds, whereas farms sampled in spring were less likely to be positive compared to those sampled in autumn. On the positive farms, in both surveys, an increase in the proportion of pats positive for E. coli O157 was associated with animals being housed at the time of sampling. However, the effect of housing on pat-level prevalence within positive groups was lower on farms from England & Wales than from Scotland (OR 0.45 (95% C.I. 0.24-0.86)).

CONCLUSION

For the first time, factors associated with farm-level E. coli O157 status have been investigated in two contemporaneous surveys with comparable study design. Although factors associated with farm-level E. coli O157 status differed between the two surveys, one consistent factor was an association with a measure of herd size. Factors associated with the proportion of E. coli O157 positive pats within a positive farm were similar in both surveys but differed from those associated with farm-level status. These findings raise the hypothesis that measures to protect public health by reducing the risk from cattle may need to be tailored, rather than by assuming that a GB-wide protocol is the best approach.

Effect of Specimen Type and Processing on the Detection of Clostridioides [Clostridium] difficile in Piglet Fecal Samples

Subclinical Clostridioides difficile colonization in piglets could be a potential source of this bacterium for community-acquired C. difficile infection. The purposes of this study were to assess the effect of specimen type and processing on C. difficile isolation, culture, and detection by polymerase chain reaction (PCR), and to determine the occurrence of C. difficile in piglets of different ages. We compared different culture procedures-direct plating, ethanol shock, and an enrichment step-to isolate C. difficile from swine feces and rectal swabs. DNA was isolated directly from feces, processed feces, and bacterial isolates to detect the triose phosphate isomerase (tpi) gene and identify the toxins A and B genes. The results show that ethanol shock increased the C. difficile isolation from feces, while it decreased it for rectal swabs, in comparison with direct plating. The use of the enrichment broth gave the highest C. difficile recovery from both types of specimen. Our findings show low sensitivity for tpi gene detection after the DNA extraction directly from feces and an increase in PCR-positive samples when feces were processed before the DNA extraction. The overall prevalence of C. difficile was 16.9% (22/130), of which 100% were found to be toxigenic as assessed by the enrichment culture of fecal samples. The rate of isolation of positive samples decreased with the animal age, regardless of the presence or absence of diarrhea. Our results demonstrate the persistent reservoir of toxigenic C. difficile in fecal samples of piglets and support the impact of specimen processing on its isolation.

Comparison of postmortem inspection procedures for detecting caseous lymphadenitis of Australian sheep and goats

Alternative postmortem inspection procedures for the detection of gross abnormalities due to Caseous Lymphadenitis (CLA) of sheep and goats were compared quantitatively against the current Australian Standard (AS4696). Studies on sheep and goats in Australia during 2016 addressed data gaps regarding current prevalence, combinations of multiple lesions within affected carcases and sensitivity of inspection procedures enabling a comparison of alternative with current procedures. Using these contemporary inspection data from 54 915 sheep and 48 577 goats a desktop study estimated the effect of implementing alternative procedures of reduced palpation from eleven carcase sites to the four sites most commonly affected. Under current procedures it was estimated that 86 sheep and 34 goat carcases with CLA lesions are missed per 10,000 carcases. Under alternative procedures it is estimated that an additional 48.4 sheep and 10.5 goat carcases with CLA lesions would be missed per 10 000 carcases. Of these, 38.2 sheep and 5.6 goat per 10 000 carcases would contain CLA only in routinely discarded, non-edible tissue sites. Hence, only an additional 10.2 sheep and 4.9 goat carcases per 10 000 inspected, with CLA in edible tissue sites are estimated to be missed. These alternative procedures have now been officially implemented in the Australian domestic standard.

The relationship between the presence of antibodies and direct detection of Toxoplasma gondii in slaughtered calves and cattle in four European countries

In cattle, antibodies to Toxoplasma gondii infection are frequently detected, but evidence for the presence of T. gondii tissue cysts in cattle is limited. To study the concordance between the presence of anti-T. gondii IgG and viable tissue cysts of T. gondii in cattle, serum, liver and diaphragm samples of 167 veal calves and 235 adult cattle were collected in Italy, the Netherlands, Romania and the United Kingdom. Serum samples were tested for anti-T. gondii IgG by the modified agglutination test and p30 immunoblot. Samples from liver were analyzed by mouse bioassay and PCR after trypsin digestion. In addition, all diaphragms of cattle that had tested T. gondii-positive (either in bioassay, by PCR on trypsin-digested liver or serologically by MAT) and a selection of diaphragms from cattle that had tested negative were analyzed by magnetic capture quantitative PCR (MC-PCR). Overall, 13 animals were considered positive by a direct detection method: seven out of 151 (4.6%) by MC-PCR and six out of 385 (1.6%) by bioassay, indicating the presence of viable parasites. As cattle that tested positive in the bioassay tested negative by MC-PCR and vice-versa, these results demonstrate a lack of concordance between the presence of viable parasites in liver and the detection of T. gondii DNA in diaphragm. In addition, the probability to detect T. gondii parasites or DNA in seropositive and seronegative cattle was comparable, demonstrating that serological testing by MAT or p30 immunoblot does not provide information about the presence of T. gondii parasites or DNA in cattle and therefore is not a reliable indicator of the risk for consumers.

Poultry eggs as a source of PCDD/Fs, PCBs, PBDEs and PBDD/Fs

Regardless of the country or region of the world, poultry eggs are one of the most important components of the human diet. Nutritional value is derived from them, but chicken eggs can be contaminated with POPs. The aim of the study was to compare the impact of different types of chicken husbandry system on bioaccumulation of selected POPs. The HRGC/HRMS method was used for determination of 58 congeners of chlorinated and brominated halogenated aromatic hydrocarbons. The influence of the farm rearing system on concentration and congener profile was seen for most groups of tested contaminants, of which the eggs were a source. Human exposure to dioxins and dioxin-like compounds as a result of consumption of contaminated eggs should be a subject of concern. The occurrence of PCDD/Fs, PCBs, PBDEs, and PBDD/Fs in commonly consumed foodstuffs such as eggs supports the need for further research on environmental pollutants and for determination of exposure as the result of their occurrence in different food categories.

Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Food Chain Information: Data Quality and Usefulness in Meat Inspection in Portugal

Food chain information (FCI) is a mandatory component of meat inspection in the European Union. In Portugal there has been no assessment of FCI regarding risk-based meat inspection. The goal of the present study was to assess the quality and the usefulness of data provided by farmers. A total of 1,694 reports (989 for bovine animals, 575 for swine, and 130 for small ruminants) submitted to nine red meat slaughterhouses between September 2015 and January 2017 were analyzed. These reports covered a total of 79,889 animals. Overall, information was provided for the majority of the general identification items. To assess the quality of the information on health status, medication, disease occurrence, diagnostic tests, and results of previous ante- and postmortem exams, responses were classified as plausible, "nothing to declare," invalid, and nonresponse. Plausible information was provided by farmers on health status, medication, tests, and diseases on 82.7, 24.6, 5.4, and 0.1% of the FCI forms, respectively. More than 70% of the responses in all categories except health status were "nothing to declare." In pigs, when comparing ante- and postmortem inspection results with the corresponding FCI, no relevant contribution of the FCI was observed. Inaccurate or irrelevant information was provided for the majority of the detailed questions, impeding the formulation of appropriate risk-based meat inspection decisions. Farmers seem to have difficulty providing specific information. Better forms and better training are needed. Information on the prevalence of biological hazards relevant to public health currently is not available. Our results support the need to improve the systems used to obtain and integrate relevant information from the farm to the slaughterhouse.

Epidemiology and economic impact of bovine cysticercosis and taeniosis caused by Taenia saginata in northeastern Spain (Catalonia)

BACKGROUND

In Catalonia (north-eastern Spain), Taenia saginata has been described in cattle but its occurrence in humans is unclear. Moreover, whether cattle acquired the infection in Catalonia or outside Catalonia and its economic impact have not been investigated. This study aimed to estimate the prevalence and spatial distribution of bovine cysticercosis in Catalonia (2008-2015), and the burden from T. saginata upon the animal and human sectors in Catalonia (2013-2015).

METHODS

Data on cattle diagnosed with cysticercosis at meat inspection were collected and analysed. Cattle movement history was used to identify the most likely place of bovine cysticercosis infection and to investigate its spatial distribution. Data on taeniosis treatment (niclosamide and praziquantel) costs and their supply in Catalonia as well as data on patients attending primary care with diagnosis of taeniosis were collected. The financial impact associated with T. saginata due to carcasses condemned and frozen, meat inspection and human taeniosis was estimated.

RESULTS

During 2008-2015, between 18 and 107 cattle were found positive for cysticercosis each year (prevalence at slaughter of 0.010%). Movement history was available for 44% of the infected cattle and in 53% of them Catalonia was identified as the place where the infection was acquired with highest probability. Two significant bovine cysticercosis clusters were detected. The number of patients diagnosed with taeniosis in primary care during the period 2013-2016 was 41-63/year. The overall economic impact of T. saginata (2013-2015) amounted to 154,903 €/year (95% CI: 113,075-196,762). Meat inspection accounted for 81.9% (95% CI: 75.8-86.2%) of the costs, followed by costs due to carcass condemnation and freezing (9.4%; 95% CI: 6.9-12.8%), and taeniosis-associated costs (8.7%; 95% CI: 6.7-11.6%). Costs due to freezing and condemnation of carcasses reached 19,442 €/year (95% CI: 17,528-21,391) (509 €/lightly infected carcass and 1,140 €/heavily infected carcass). Taeniosis-associated costs were estimated at 12,848.5 €/year (237 €/patient).

CONCLUSIONS

The public health risk of T. saginata in the area seems to be low. The economic impact due to T. saginata was mainly attributed to meat inspection. The cost due to carcass condemnation and freezing was limited compared to the revenue of the beef sector. Developing and implementing risk-based surveillance is needed to lower the costs of meat inspection. Considering cattle movements might be useful in the development of such a strategy.

Risk-based inspection as a cost-effective strategy to reduce human exposure to cysticerci of Taenia saginata in low-prevalence settings

BACKGROUND

Taenia saginata cysticercus is the larval stage of the zoonotic parasite Taenia saginata, with a life-cycle involving both cattle and humans. The public health impact is considered low. The current surveillance system, based on post-mortem inspection of carcasses has low sensitivity and leads to considerable economic burden. Therefore, in the interests of public health and food production efficiency, this study aims to explore the potential of risk-based and cost-effective meat inspection activities for the detection and control of T. saginata cysticercus in low prevalence settings.

METHODS

Building on the findings of a study on risk factors for T. saginata cysticercus infection in cattle in Great Britain, we simulated scenarios using a stochastic scenario tree model, where animals are allocated to different risk categories based on their age, sex and movement history. These animals underwent different types of meat inspection (alternative or current) depending on their risk category. Expert elicitation was conducted to assess feasibility of scenarios and provide data for economic analysis. The cost-effectiveness of these scenarios was calculated as an incremental cost-effectiveness ratio, using the number of infected carcasses detected as the technical outcome.

RESULTS

Targeting the high-risk population with more incisions into the heart while abandoning incisions into the masseter muscles was found to reduce the total number of inspections and cost, while simultaneously increasing the number of infected carcasses found.

CONCLUSIONS

The results suggest that, under reasonable assumptions regarding potential improvements to current inspection methods, a more efficient and sensitive meat inspection system could be used on animals categorised according to their risk of harbouring T. saginata cysticercus at slaughter. Such a system could reduce associated cost to the beef industry and lower microbial contamination of beef products, improving public health outcomes.

Characterization of Shiga Toxin-Producing Escherichia coli O157 Isolates from Bovine Carcasses

The main purpose of this study was to determine the prevalence of Escherichia coli O157 on bovine carcasses before and after chilling at a large slaughterhouse located in the city of Barcelona, Spain, to assess the effectiveness of dry chilling on reducing E. coli O157 contamination of carcasses. In addition, the study characterized the E. coli O157 strains isolated in terms of virulence factors, antibiotic susceptibility, and their genetic diversity. Individual bovine carcasses were sampled before (n = 300) and after (n = 300) chilling over an 8-month period. Positive samples for E. coli O157 were subjected to virulence screening by PCR (stx1, stx2, and eaeA genes and the fliCH7 gene), antimicrobial susceptibility testing, and molecular typing by pulsed-field gel electrophoresis. A total of 9.7% (29 of 300) of the nonrefrigerated carcasses examined and 2.3% (7 of 300) of the refrigerated carcasses were positive for E. coli O157. All the isolates were serotype O157:H7, 92% (33 of 36) carried the stx1, stx2, and eaeA genes, and 8% (3 of 36) carried the stx2 and eaeA genes. Antimicrobial susceptibility testing showed a high degree of resistance: 29 strains (81%) were resistant to at least 1 antimicrobial of the 12 antimicrobials tested; 69% (25 of 36) were resistant to 4 or more antimicrobials. Molecular typing by pulsed-field gel electrophoresis found a high diversity of genetic types, implying little cross-contamination in the slaughterhouse. This study confirms that E. coli O157:H7 is present on the carcasses slaughtered in Spain, although its prevalence is reduced by the dry chilling process used. The recovered isolates showed potential pathogenesis and a high degree of multidrug resistance, confirming the importance of bovine meat monitoring.

Confirmation of the progesterone receptor as an efficient marker of treatment with 17β-estradiol in veal calves

Under current European Union legislation the use of anabolic steroids in food-producing livestock is banned because of their long-term adverse effects on human health. We examined the expression profile of the immunohistochemical marker progesterone receptor in veal calves' sex accessory glands following experimental administration of anabolic compounds. The aim was to confirm the accuracy of the immunohistochemical approach in the detection of the over-expression of the progesterone receptor induced by the administration of sexual steroids at low levels (17β-estradiol and nandrolone alone or in combination). A total of 217 male veal calves were randomly divided into four groups: group A (104 calves) treated with 17β-estradiol (5 mg/head; 4 weekly injections); group B (20 calves) treated with nandrolone (50 mg/head; 4 weekly injections); group C (20 calves) treated with the association of the two steroids (5 mg estradiol + 50 mg nandrolone; 4 weekly injections); and group K (73 calves) kept as a control. All the sexual accessory glands were collected at the slaughterhouse (15 days after the last administration) and subjected to immunohistochemical staining with anti-progesterone receptor antibody. All the calves treated with 17β-estradiol alone or in association with nandrolone (groups A and C) showed strong positivity, while nandrolone-treated calves and controls (groups B and K) gave negative results to the immunohistochemical investigation. The statistical analysis showed that the progesterone receptor is a significant predictor of 17β-estradiol treatment alone or in association with nandrolone (p < 0.001): the immunohistochemical study resulted in 100% sensitivity (CI = 95%: 97.1-100%) and specificity (CI = 95%: 95.1-100%) for prostate and 99% sensitivity (CI = 95%: 95.6-100%) and 100% specificity (CI = 95%: 95.1-100%) for bulbo-urethral glands. The data confirm that this innovative biological approach offers a reliable tool to enhance the efficacy of the histological test to detect illegal treatments with estrogens alone or in association with androgens.