Inspection of chicken wings and legs for animal welfare monitoring using X-ray computed tomography, visual examination, and histopathology.

In broiler chickens, fractures of wings and legs are recorded at poultry slaughterhouses based on the time of occurrence. Prekilling (PRE) fractures occur before the death of animal, so the chicken was still able to experience pain and distress associated with the injury (an animal welfare issue). Postkilling (POST) fractures occur when the chickens are deceased and fully bled-out and consequently unable to feel pain (not an animal welfare issue). Current practice dictates that fractures are recognized visually and recorded by the animal welfare officers as mandated by European Union and/or national regulations. However, new potential monitoring solutions are desired since human inspection suffers from some significant limitations including subjectivism and fatigue. One possible solution in detecting injuries is X-ray computed tomography (CT) scanning and in this study we aim to evaluate the potential of CT scanning and visual inspection in detecting limb fractures and their causes. Eighty-three chicken wings and 60 chicken legs (n = 143) were collected from a single slaughterhouse and classified by an animal welfare officer as PRE, POST or healthy (HEAL). Samples were photographed and CT scanned at a veterinary hospital. The interpretation of CT scans along with photographs took place in 3 rounds (1. CT scans only, 2. CT scans + photographs, 3. photographs only) and was performed independently by 3 veterinarians. The consistency of the interpretation in 3 rounds was compared with the animal welfare officer's classification. Furthermore, selected samples were also analyzed by histopathological examination due to questionability of their classification (PRE/POST). In questionable samples, presence of hemorrhages was confirmed, thus they fit better as PRE. The highest consistency between raters was obtained in the 2nd round, indicating that interpretation accuracy was the highest when CT scans were combined with photographs. These results indicate that CT scanning in combination with visual inspection can be used in detecting limbs fracture and potentially applied as a tool to monitor animal welfare in poultry slaughterhouses in the future.

Small Contaminations on Broiler Carcasses Are More a Quality Matter than a Food Safety Issue.

Depending on the interpretation of the European Union (EU) regulations, even marginally visibly contaminated poultry carcasses could be rejected for human consumption due to food safety concerns. However, it is not clear if small contaminations actually increase the already present bacterial load of carcasses to such an extent that the risk for the consumers is seriously elevated. Therefore, the additional contribution to the total microbial load on carcasses by a small but still visible contamination with feces, grains from the crop, and drops of bile and grease from the slaughter line was determined using a Monte Carlo simulation. The bacterial counts (total aerobic plate count, Enterobacteriaceae, Escherichia coli, and Campylobacter spp.) were obtained from the literature and used as input for the Monte Carlo model with 50,000 iterations for each simulation. The Monte Carlo simulation revealed that the presence of minute spots of feces, bile, crop content, and slaughter line grease do not lead to a substantial increase of the already existing biological hazards present on the carcasses and should thus be considered a matter of quality rather than food safety.

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.

A One Health Perspective on the Human-Companion Animal Relationship with Emphasis on Zoonotic Aspects.

Over time the human-animal bond has been changed. For instance, the role of pets has changed from work animals (protecting houses, catching mice) to animals with a social function, giving companionship. Pets can be important for the physical and mental health of their owners but may also transmit zoonotic infections. The One Health initiative is a worldwide strategy for expanding collaborations in all aspects of health care for humans, animals, and the environment. However, in One Health communications the role of particularly dogs and cats is often underestimated. OBJECTIVE: Evaluation of positive and negative One Health issues of the human-companion animal relationship with a focus on zoonotic aspects of cats and dogs in industrialized countries. METHOD: Literature review. RESULTS: Pets undoubtedly have a positive effect on human health, while owners are increasing aware of pet's health and welfare. The changing attitude of humans with regard to pets and their environment can also lead to negative effects such as changes in feeding practices, extreme breeding, and behavioral problems, and anthropozoonoses. For the human, there may be a higher risk of the transmission of zoonotic infections due to trends such as sleeping with pets, allowing pets to lick the face or wounds, bite accidents, keeping exotic animals, the importation of rescue dogs, and soil contact. CONCLUSIONS: One Health issues need frequently re-evaluated as the close human-animal relationship with pet animals can totally differ compared to decennia ago. Because of the changed human-companion animal bond, recommendations regarding responsible pet-ownership, including normal hygienic practices, responsible breeding, feeding, housing, and mental and physical challenges conforming the biology of the animal are required. Education can be performed by vets and physicians as part of the One Health concept.

Zoonotic bacteria and parasites found in raw meat-based diets for cats and dogs.

Feeding raw meat-based diets (RMBDs) to companion animals has become increasingly popular. Since these diets may be contaminated with bacteria and parasites, they may pose a risk to both animal and human health. The purpose of this study was to test for the presence of zoonotic bacterial and parasitic pathogens in Dutch commercial RMBDs. We analysed 35 commercial frozen RMBDs from eight different brands. Escherichia coli serotype O157:H7 was isolated from eight products (23 per cent) and extended-spectrum beta-lactamases-producing E coli was found in 28 products (80 per cent). Listeria monocytogenes was present in 19 products (54 per cent), other Listeria species in 15 products (43 per cent) and Salmonella species in seven products (20 per cent). Concerning parasites, four products (11 per cent) contained Sarcocystis cruzi and another four (11 per cent) S tenella In two products (6 per cent) Toxoplasma gondii was found. The results of this study demonstrate the presence of potential zoonotic pathogens in frozen RMBDs that may be a possible source of bacterial infections in pet animals and if transmitted pose a risk for human beings. If non-frozen meat is fed, parasitic infections are also possible. Pet owners should therefore be informed about the risks associated with feeding their animals RMBDs.

Farmers' knowledge and expectations of antimicrobial use and resistance are strongly related to usage in Dutch livestock sectors.

Comprehensive strategies to improve on-farm antimicrobial use (AMU) are needed to contain antimicrobial resistance (AMR). Little is known about farmers' motivating and enabling factors, and about their influence on AMU. In a cross-sectional online survey, Dutch dairy, veal and pig farmers (n=457) reported their on-farm AMU as "Defined Daily Dose Animal" per year (DDDAF) and completed a detailed questionnaire on their view, knowledge and behavior towards AMU and AMR. Exploratory factor analysis (EFA) on the questionnaire items identified four psychological factors labeled as 'referent beliefs', 'perceived risk', 'knowledge', and 'undesired attitude to regulations'. Linear regression was done to explore the relationship between the obtained factors and on-farm AMU across the three animal sectors. Dairy farmers showed the highest factor scores for 'knowledge' and the lowest for 'perceived risk'. 'Knowledge' scores were significantly and inversely related to AMU (P=0.0004). Borderline significant associations with AMU were found for 'perceived risk' and 'undesired attitude to regulations' (negative and positive relationships respectively). There were no apparent differences for these relationships between the three livestock sectors. Behavioral interventions in farmers such as educational campaigns or increased support by veterinarians could empower farmers with more prudent and rational practices, eventually reducing AMU in food animals.

Pre-scald brushing for removal of solids and associated broiler carcass bacterial contamination.

The aim of the study was to investigate the effect of brushing prior to scalding on reducing the E. coli and Enterobacteriaceae concentrations on carcasses. Three visits were arranged to a commercial slaughterhouse in which carcasses were cleaned in a separate line. Ten batches were sampled to compare the E. coli and Enterobacteriaceae concentrations on carcasses before and after a stand-alone brushing unit. Per batch, 8 carcasses before and 8 after brushing were sampled by the whole-carcass rinse method. Furthermore, the dry matter content and the pH were determined in these samples, as these parameters indirectly (dry matter) or directly (pH) influence the scalding lethality. Results revealed a small but statistically significant reduction (P < 0.001) in E. coli and Enterobacteriaceae concentrations on the brushed carcasses. The concentrations on whole carcasses were reduced on average by 0.3 log for both E. coli and Enterobacteriaceae. Rinse samples from treated carcasses had significantly less dry matter on average by 2.5 g (P < 0.001) and significantly higher pH by 0.08 units (P < 0.001). Although these differences are statistically significant, they might have rather low biological relevance; thus, further optimization of brushes is needed for more relevant results. This study confirms that brushing reduces bacterial concentrations on carcasses, which may be increased potentially by enlarging the brushed surface of the carcass. Further in-line investigations are needed to observe the effect of brushing on bacterial concentrations in scalding water and on carcasses after scalding and at the end of processing.

Explanatory Variables Associated with Campylobacter and Escherichia coli Concentrations on Broiler Chicken Carcasses during Processing in Two Slaughterhouses.

This study aimed at identifying explanatory variables that were associated with Campylobacter and Escherichia coli concentrations throughout processing in two commercial broiler slaughterhouses. Quantative data on Campylobacter and E. coli along the processing line were collected. Moreover, information on batch characteristics, slaughterhouse practices, process performance, and environmental variables was collected through questionnaires, observations, and measurements, resulting in data on 19 potential explanatory variables. Analysis was conducted separately in each slaughterhouse to identify which variables were related to changes in concentrations of Campylobacter and E. coli during the processing steps: scalding, defeathering, evisceration, and chilling. Associations with explanatory variables were different in the slaughterhouses studied. In the first slaughterhouse, there was only one significant association: poorer uniformity of the weight of carcasses within a batch with less decrease in E. coli concentrations after defeathering. In the second slaughterhouse, significant statistical associations were found with variables, including age, uniformity, average weight of carcasses, Campylobacter concentrations in excreta and ceca, and E. coli concentrations in excreta. Bacterial concentrations in excreta and ceca were found to be the most prominent variables, because they were associated with concentration on carcasses at various processing points. Although the slaughterhouses produced specific products and had different batch characteristics and processing parameters, the effect of the significant variables was not always the same for each slaughterhouse. Therefore, each slaughterhouse needs to determine its particular relevant measures for hygiene control and process management. This identification could be supported by monitoring changes in bacterial concentrations during processing in individual slaughterhouses. In addition, the possibility that management and food handling practices in slaughterhouses contribute to the differences in bacterial contamination between slaughterhouses needs further investigation.

A comparison of fluctuations of Campylobacter and Escherichia coli concentrations on broiler chicken carcasses during processing in two slaughterhouses.

The causes of differences in Campylobacter and Escherichia coli concentrations on broiler chicken carcasses after chilling between slaughterhouses are not fully identified. Therefore, it is a challenge for slaughterhouses to comply with Process Hygiene Criteria for broiler meat. The aim of the study was to identify which processing steps contribute to increases or decreases in Campylobacter and E. coli concentrations within and between two slaughterhouses. Identifying the processing steps with variable performance could explain the differences in bacterial concentrations after chilling between slaughterhouses. Thermotolerant Campylobacter and E. coli concentrations on carcasses during broiler processing were measured during the summer period in 21 trials after bleeding, scalding, defeathering, evisceration and chilling. In two slaughterhouses with comparable Campylobacter and E. coli concentrations in the incoming batches (after bleeding), the mean log10 concentrations are found to be significantly different after chilling. Campylobacter concentrations decreased by 1.40 log10 in Slaughterhouse 1 and by 1.86 log10 in Slaughterhouse 2, whereas E. coli decreased by 2.19 log10 in Slaughterhouse 1 and by 2.84 log10 in Slaughterhouse 2. Higher concentrations of Campylobacter and E. coli on carcasses after chilling were observed in Slaughterhouse 1 in which an increase in concentrations was observed after evisceration. The effect of processing on Campylobacter and E. coli concentrations in Slaughterhouse 1 did not differ between batches. In Slaughterhouse 2, the effect of processing on the concentrations of both bacteria varied over batches. Changes in E. coli concentration levels during processing were similar to Campylobacter except for defeathering. E. coli concentration significantly decreased after defeathering in both slaughterhouses, whereas Campylobacter increased in Slaughterhouse 2 and in Slaughterhouse 1 no significant changes were observed. The patterns of increases and decreases in bacterial concentrations during processing are specific for each slaughterhouse. Inhomogeneous patterns potentially explain the differences in concentrations after chilling between slaughterhouses. Critical processing steps should be validated in each slaughterhouse by longitudinal studies and potentially based on E. coli. E. coli has a potential to be used as an indicator of processing hygiene, because the impact of most of the studied processing steps was similar as for Campylobacter.

Propidium monoazide does not fully inhibit the detection of dead Campylobacter on broiler chicken carcasses by qPCR.

A real time quantitative PCR combined with propidium monoazide (PMA) treatment of samples was implemented to quantify live C. jejuni, C. coli and C. lari on broiler chicken carcasses at selected processing steps in the slaughterhouse. The samples were enumerated by culture for comparison. The Campylobacter counts determined with the PMA-qPCR and the culture method were not concordant. We conclude that the qPCR combined with PMA treatment of the samples did not fully reduce the signal from dead cells.

Antimicrobial susceptibility profiles of human and piglet Clostridium difficile PCR-ribotype 078.

In the last decade, outbreaks of nosocomial Clostridium difficile infections (CDI) occurred worldwide. A new emerging type, PCR-ribotype 027, was the associated pathogen. Antimicrobial susceptibility profiles of this type were extensively investigated and used to partly explain its spread. In Europe, the incidence of C. difficile PCR-ribotype 078 recently increased in humans and piglets. Using recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI) we studied the antimicrobial susceptibility to eight antimicrobials, mechanisms of resistance and the relation with previously prescribed antimicrobials in human (n=49) and porcine (n=50) type 078 isolates. Human and porcine type 078 isolates showed similar antimicrobial susceptibility patterns for the antimicrobials tested. In total, 37% of the isolates were resistant to four or more antimicrobial agents. The majority of the human and porcine isolates were susceptible to amoxicillin (100%), tetracycline (100%) and clindamycin (96%) and resistant to ciprofloxacin (96%). More variation was found for resistance patterns to erythromycin (76% in human and 59% in porcine isolates), imipenem (29% in human and 50% in porcine isolates) and moxifloxacin (16% for both human and porcine isolates). MIC values of cefuroxim were high (MICs >256 mg/L) in 96% of the isolates. Resistance to moxifloxacin and clindamycin was associated with a gyr(A) mutation and the presence of the erm(B) gene, respectively. A large proportion (96%) of the erythromycin resistant isolates did not carry the erm(B) gene. The use of ciprofloxacin (humans) and enrofloxacin (pigs) was significantly associated with isolation of moxifloxacin resistant isolates. Increased fluoroquinolone use could have contributed to the spread of C. difficile type 078.

Analysis of a Clostridium difficile PCR ribotype 078 100 kilobase island reveals the presence of a novel transposon, Tn6164.

BACKGROUND: Clostridium difficile is the main cause of antibiotic associated diarrhea. In the past decade, the number of C. difficile patients has increased dramatically, coinciding with the emergence of two PCR ribotypes 027 and 078. PCR ribotype 078 is also frequently found during C. difficile outbreaks in pigfarms. Previously, the genome of the PCR ribotype 078 strain M120, a human isolate, was described to contain a unique insert of 100 kilobases. RESULTS: Analysis of this insert revealed over 90 open reading frames, encoding proteins originating from transposons, phages and plasmids. The insert was shown to be a transposon (Tn6164), as evidenced by the presence of an excised and circularised molecule, containing the ligated 5'and 3'ends of the insert. Transfer of the element could not be shown through filter-mating experiments. Whole genome sequencing of PCR ribotype 078 strain 31618, isolated from a diarrheic piglet, showed that Tn6164 was not present in this strain. To test the prevalence of Tn6164, a collection of 231 Clostridium difficile PCR ribotype 078 isolates from human (n = 173) and porcine (n = 58) origin was tested for the presence of this element by PCR. The transposon was present in 9 human, tetracycline resistant isolates, originating from various countries in Europe, and none of the pig strains. Nine other strains, also tetracycline resistant human isolates, contained half of the transposon, suggesting multiple insertion steps yielding the full Tn6164. Other PCR ribotypes (n = 66) were all negative for the presence of the transposon. Multi locus variable tandem repeat analysis revealed genetic relatedness among transposon containing isolates. Although the element contained several potential antibiotic resistance genes, it did not yield a readily distinguishable phenotype. CONCLUSIONS: Tn6164 is a newly described transposon, occurring sporadically in C. difficile PCR ribotype 078 strains. Although no transfer of the element could be shown, we hypothesize that the element could serve as a reservoir of antibiotic resistance genes for other bacteria. Further research is needed to investigate the transfer capabilities of the element and to substantiate the possible role of Tn6164 as a source of antibiotic resistance genes for other gut pathogens.

Allergy among veterinary medicine students in The Netherlands.

BACKGROUND: Veterinary medicine students who practice with animals are potentially exposed to many occupational agents, yet sensitisation and allergic symptoms among this group have not been studied extensively. OBJECTIVE: The objective of this study was to estimate the prevalence of sensitisation and allergic symptoms in veterinary medicine students in association with study specialisation over time. METHODS: A questionnaire-based cross-sectional study was conducted. Blood was collected and tested for total and specific serum IgE for 16 different common and study-specific allergens using enzyme immunoassay. RESULTS: New development of self-reported allergic symptoms to various allergens occurred in 8.7%, of which 44% was deducted against animals. Handling farm animals was strongly associated with self-reported allergies to various allergens (OR=6.9, 95% CI 1.9 to 25) and animal allergens (OR=12, 95% CI 1.4 to 103). Sensitisation to at least one allergen occurred in 33.1%. Sensitisation prevalence tended to be elevated in later years of the equine study program. In contrast to self-reported allergies, the prevalence of sensitisation to any allergen decreased with prolonged study duration for those specialising in farm animal health (years 3-5: OR=0.5, 95% CI 0.3 to 1.1; year 6: OR=0.2, 95% CI 0.1 to 0.5). This was independent of whether people were raised on a farm, which is in itself a protective factor for allergy and sensitisation. CONCLUSION: This study provides evidence of an elevated prevalence of allergic symptoms with increasing years of veterinary study, suggesting that contact with animals, more specifically contact to farm animals, is a risk factor for the development of symptoms.