Evaluatie van de opleiding in antibioticabeleid en antibioticaresistentie door studenten van twee Belgische Faculteiten Diergeneeskunde

Antibioticabeleid is een essentiële stap in de beperking van de selectie van antibioticaresistentie. In deze studie wordt de evaluatie van 122 laatstejaarsstudenten Diergeneeskunde van de Universiteit Gent (UGent) en de Universiteit Luik (ULuik) weergegeven met betrekking tot de perceptie van het voorbereid zijn, de kwaliteit van het onderwijs en de tevredenheid over het onderwijs van antibioticabeleid en -resistentie. UGent-studenten voelden zich beter voorbereid op het klinisch gebruik van antimicrobiële middelen dan ULuik-studenten (3,23 versus 2,98, p = 0,03). Er waren geen statistisch significante verschillen voor wat betreft de andere twee velden van perceptie van paraatheid (farmacologie en kennis van antibioticaresistentie). Het totale resultaat van de kennisscore was 4,68 (sd 1,26) op 8, en er was geen statistisch significant verschil tussen de resultaten van de twee faculteiten. Minder dan 50% van de studenten was tevreden over hun opleiding over antibioticabeleid en -resistentie. De meeste deelnemers erkenden de noodzaak van extra voorlichting over rationeel antibioticagebruik. UGent-studenten waren meer bekend met formularia voor antimicrobieel gebruik dan ULuik-studenten. De resultaten van dit voorliggende onderzoek kunnen de kwaliteit van het veterinair onderwijs van antibioticabeleid en -resistentie in België helpen verbeteren.

Technical and market substitutability of recycled materials: Calculating the environmental benefits of mechanical and chemical recycling of plastic packaging waste

Most plastics are today mechanically recycled (MR), whereas chemical recycling (CR) is an emerging technology. Substitutability of virgin material is vital for their environmental performance assessed through life cycle assessment (LCA). MR faces the reduction in the material's technical quality but also the potential market because legal safety requirements currently eliminate applications such as food packaging. This study presents a data-driven method for quantifying the overall substitutability (OS), composed of technical (TS) and market substitutability (MS). First, this is illustrated for six non-food contact material (non-FCM) applications and three hypothetical future FCM applications from mechanical recyclates, using mechanical property and market data. Then, OS results are used in a comparative LCA of MR and thermochemical recycling (TCR) of several plastic waste fractions in Belgium. For mechanical recyclates, TS results for the studied non-FCM and FCM applications were comparable, but OS results varied between 0.35 and 0.79 for non-FCM applications and between 0.78 and 1 for FCM applications, reflecting the lower MS results for the current situation. Out of nine application scenarios, MR obtained a worse resource consumption and terrestrial acidification impact than CR in six scenarios. MR maintained the lowest global warming impact for all scenarios. This study contributes to an improved understanding of the environmental benefits of MR and TCR. Inclusion of other criteria (e.g. processability, colour, odour) in the quantification of the overall substitutability for MR products should be further investigated, as well as the environmental performance of TCR at industrial scale.

Vraag & Antwoord

Waar komen afgestudeerde dierenartsen terecht? Detectie van glutenallergie bij het paard

Postoperatieve anorexie en ileus bij het konijn: een praktijkonderzoek bij electieve chirurgie

Anorexie en ileus zijn frequent voorkomende postoperatieve complicaties bij konijnen en zijn potentieel fataal. Risicofactoren, zoals stress en pijn, moeten zoveel mogelijk beperkt of vermeden worden. Om risicofactoren rondom het anesthesieprotocol bij orchidectomie en ovario(hyster)- ectomie (OV(H)X) beter in beeld te brengen, werd een enquête rondgestuurd naar dierenartsen in België en Nederland. Uit de 209 ingevulde enquêtes bleek het type operatie (orchidectomie versus OV(H)X) een significante invloed te hebben. Er werden nog twee andere significante verschillen opgemerkt: er was minder vaak ileus bij OV(H)X waarbij butorfanol werd gebruikt en er was vaker anorexie bij OV(H)X waarbij een antidotum werd toegediend. Dit moet echter met de nodige voorzichtigheid geïnterpreteerd worden, aangezien andere studiegerelateerde factoren hierbij een rol gespeeld kunnen hebben. Het is hierbij vermeldenswaardig dat bij het gebruik van buprenorfine – een opioïde waarover in de literatuur tegenstrijdige resultaten te vinden zijn betreffende het al dan niet induceren van gastro-intestinale stase bij konijnen – in de voorliggende studie niet significant vaker ileus werd opgemerkt. 

A field study on correlations between macroscopic gut health scoring, histological measurements and performance parameters in broilers

Optimal intestinal health is a prerequisite for sustainable poultry production. Intestinal health can be evaluated by scoring macroscopic intestinal abnormalities and by histological measurements. The aim of this study was to evaluate correlations between macroscopic gut appearance scoring (GAS), coccidiosis lesion scoring, histological measurements and performance parameters in broilers under field conditions. Therefore, a cross-sectional study was performed on 50 broiler farms where birds were sampled at 28 days of age. The GAS was determined by scoring the absence or presence of 10 macroscopically visible parameters of the gastrointestinal tract, yielding a GAS between 0 and 10, with 0 meaning no gut abnormalities. On individual bird level, when birds had a GAS score of 6 or higher, significantly shorter villi were found in the duodenum. Also, CD3+ T-lymphocyte area percentage in the duodenal mucosa was significantly negatively correlated to villus length. On farm level, the average feed conversion ratio (FCR) was 1.59 ± 0.04 [1.52-1.73]. However, no correlations were found between the GAS at the age of 28 days and the prevalence of coccidiosis, nor did coccidiosis lesion scoring correlate with the FCR. Also, a higher GAS could not be associated with a higher FCR. In conclusion, on all farms a certain degree of macroscopic visible gut and coccidiosis lesions were present in birds of 28 days of age, while this did not correlate with the FCR. This suggests that broilers are able to cope with a certain level of gut damage before it influences the overall performance.

The ADKAR® change management model for farmer profiling with regard to antimicrobial stewardship in livestock production

Antimicrobial stewardship in veterinary practice and animal production is important from a One Health perspective. The ADKAR® change management model is a well-known strategy to implement behavioral change in people and small businesses. The objective of this study was to adapt the existing ADKAR® change management model to enable herd veterinarians to profile farmers with regard to antimicrobial stewardship. Therefore, an antimicrobial stewardship related scoring scale was defined. Subsequently, ADKAR® profiles of 26 poultry and 28 pig farmers from Belgium and the Netherlands were determined. For 57% of the farmers, perception and/or motivation were expected to limit successful change. For 70% of the farmers, knowledge and for 52% of the farmers, a lack of ability were the limiting factor. The ADKAR® model proved useful for identifying the key elements that prevent successful behavioral change in farmers to reduce the use of antibiotics in farm animals.

Vraag & Antwoord

Gebruik van Lincomycine tegen rattenplaag?

A step forward in quantifying the substitutability of secondary materials in waste management life cycle assessment studies

Life Cycle Assessment (LCA) is a widespread tool used to guide decision-makers towards optimal strategic choices for sustainable growth. A key aspect of LCA studies of waste management systems where recycling activities are present is to account for resource recovery and the related substitution effects. Although multiple scientific papers assume a 1:1 substitution ratio between similar materials/products, this is often incorrect as the actual ratio is likely to vary. The focus of this paper is on the calculation of the substitutability coefficient for secondary materials based on technical characteristics. A state of the art literature review showed that many different calculation procedures were applied, which led to a wide variety of substitutability coefficients (sometimes provided under different terminology). In this perspective, the objective of this paper is to provide guidelines on the procedure to be followed to calculate the substitutability coefficient for secondary materials, based on technical characteristics. These guidelines are then applied to two waste management case studies, one dealing with bottom ashes from incineration and the other with plastic waste. In total, sixteen technical substitutability coefficients are given for ten secondary materials, based on state of the art and presented case studies. The paper thus represents a step forward in quantifying the substitutability of secondary materials in waste management LCA studies. The guidelines presented may allow other case studies to enrich the list of coefficients, useful for all LCA practitioners in a harmonized way allowing a more correct evaluation of the environmental impacts associated with recycling activities.

Effect of subinhibitory exposure to quaternary ammonium compounds on the ciprofloxacin susceptibility of Escherichia coli strains in animal husbandry

BACKGROUND

Quaternary ammonium compound based disinfectants are commonly used in pig and poultry husbandry to maintain farm hygiene. However, studies have shown that subinhibitory concentrations of these disinfectants may increase antibiotic resistance. Investigation of antibiotic susceptibility is usually assessed via the microbroth dilution method, although this conventional culture-based technique only provides information on the bacteriostatic activity of an antimicrobial agent. Therefore, experiments were performed to investigate the effect of prior benzalkonium chloride (BKC) exposure on the viability of subsequent ciprofloxacin (CIP) treated Escherichia coli.

RESULTS

Following CIP treatment, bacterial cell counts were significantly higher after exposure to a subinhibitory BKC concentration than without BKC exposure. The flow cytometric results suggested a BKC-dependent onset of membrane damage and loss of membrane potential.

CONCLUSION

Our results indicate a lower bactericidal effect of CIP treatment on BKC-exposed E. coli isolates compared to unexposed E. coli isolates.

Quantitative assessment of biosecurity in broiler farms using Biocheck.UGent in Central Luzon, Philippines

The biosecurity status of 397 broiler farms in Central Luzon, the highest poultry meat-producing region in the Philippines, was assessed using Biocheck.Ugent. This online biosecurity assessment tool quantifies biosecurity level or compliance of surveyed farms. The system generates scores that reflect the current biosecurity status of each farm in terms of the different external and internal biosecurity measures being implemented in each farm. It was initially developed for pigs and broilers but recently is available for layers, swine, and cattle (beef, dairy, and veal). The overall biosecurity score of broiler farms in Central Luzon was 71.2%, with average external and internal biosecurity scores of 68.5 and 77.2%, respectively. Bataan had the highest biosecurity scores (76.5%) compared with the other 6 provinces. This was also true for the external and internal biosecurity scores of the province, with mean scores of 72.1 and 80.1%, respectively. Of the 11 subcategories of external and internal biosecurity that were assessed, purchase of day-old chicks, feeds and water supply, supply of materials, cleaning and disinfection, and materials between compartments had scores higher than the global scores. Low scores were generated from transport of live animals and infrastructure and biological vectors. The mean biosecurity score of farms with traditional/conventional type of housing was 7.8% lower than that with tunnel vent housing. Every year as the farm gets older, there was a corresponding drop of 0.2% in the biosecurity score. Biosecurity measures are in place in broiler farms in the country. However, there were areas with low scores which need to be prioritized to improve and upgrade the farms' biosecurity status. To date, this is the first quantitative assessment of biosecurity in broiler farms in the Philippines. High biosecurity scores may entail greater protection from disease incursion.

Repeated disinfectant use in broiler houses and pig nursery units does not affect disinfectant and antibiotic susceptibility in Escherichia coli field isolates

BACKGROUND

Disinfectants are frequently used in animal production to reduce or eliminate the load of infectious agents and parasites in buildings and equipment associated with the housing or transportation of animals. There are growing concerns that the use of disinfectants would select for resistance to antibiotics and disinfectants. The aim of this study was to determine the effect of repeated use of different disinfectants on the disinfectant and antibiotic susceptibility under practical conditions in a broiler and pig pilot farm. Therefore, the susceptibility of Escherichia coli (E. coli) to 14 antibiotics and 4 disinfectants was monitored over a one-year period.

RESULTS

High (20-50%) to very high (> 50%) resistance levels for ampicillin, sulfamethoxazole, trimethoprim and tetracycline were observed in both animal production types. Disinfectant susceptibility did not change over time and did not depend on the used disinfection product. Compared to in-use concentrations of formaldehyde, benzalkoniumchloride and a peracetic acid - hydrogen peroxide formulation, all E. coli strains remained susceptible indicating that the use of disinfectants did not select for disinfectant resistance. Moreover, no association could be found between the use of disinfectants and antibiotic resistance.

CONCLUSIONS

These findings suggest that repeated use of disinfectants in agricultural environments does not select for antibiotic resistance nor does it reduce disinfectant susceptibility.

Antibioticumgebruik bij de niet-gecompliceerde keizersnede bij het rund in Vlaanderen

De keizersnede is een routine-ingreep voor dierenartsen in de Vlaamse rundveepraktijk. Alhoewel de ingreep wordt aangeleerd volgens een standaardprotocol, blijkt uit eerder onderzoek dat het antibioticumgebruik bij deze indicatie sterk varieert tussen dierenartsen. In deze studie werd door middel van een vragenlijst getracht een beeld te schetsen van wanneer welke antibiotica gebruikt worden en in welke mate dit overeenstemt met de aanbevelingen van het kenniscentrum “Antimicrobial Consumption and Resistance in Animals” (AMCRA). Uit de resultaten blijkt dat alle respondenten antibiotica gebruiken tijdens de ingreep. Negentien percent dient ook standaardantibiotica toe kort na de operatie. Penicilline wordt in 52% van de gevallen als eerste keuze ingezet, wat overeenstemt met de AMCRA-richtlijnen. Het overige deel van de respondenten (48%) opteert voor breedspectrumantibiotica, zoals penicillineneomycine, penicilline-dihydrostreptomycine, lincomycine-spectinomycine, die volgens AMCRA tweedekeuzemiddelen zijn. Voor wat betreft de intramusculaire behandelingen vóór en na de ingreep, behandelt slechts 35% overeenkomstig de referentiedosering voor een koe tussen de 600 en 800 kg. Er wordt vooral ondergedoseerd bij behandelingen na de ingreep en bij nabehandeling. Op basis van de evaluatie van het tijdstip van behandelen en de antibioticumkeuze blijkt dat slechts 23% van de respondenten handelt in overeenstemming met de voorschriften van het AMCRA-formularium. Uit deze resultaten kan besloten worden dat het gebruik van antibiotica tijdens een nietgecompliceerde keizersnede sterk varieert en slechts tot op zekere hoogte overeenkomt met wat door AMCRA wordt aanbevolen. Onvoldoende kennis van de richtlijnen kan hier aan de basis liggen. Een betere communicatie is dan ook een eerste en belangrijke stap om de bewustwording te verbeteren.

Evaluation of group vaccination of sows and gilts against Salmonella Typhimurium with an attenuated vaccine in subclinically infected pig herds

Subclinical Salmonella Typhimurium infections occur frequently in pigs and constitute a major risk for human salmonellosis. With the currently available control measures, Salmonella Typhimurium infections in pigs remain difficult to control. Vaccination has been proposed to be an effective tool to control infections at farm level. In the current study, the effect of group vaccination of sows and gilts against Salmonella Typhimurium is evaluated on Salmonella prevalence in fecal and overshoe samples and ileocecal lymph nodes, and on serology in the sows and their offspring in three subclinically infected pig farms. In each farm, all sows and gilts were vaccinated twice, three weeks apart, with an attenuated histidine-adenine auxotrophic vaccine (Salmoporc®, IDT Biologika). From three months after the group vaccination onwards, all sows were given a booster dose three weeks before every farrowing. The farms were monitored bacteriologically and serologically from 12 months before until 15 months after the group vaccination. After group vaccination, no significant effect was detected in the prevalence of Salmonella Typhimurium in the fecal and overshoe samples collected in the sows (before: 2 %, after: 0 %) and their offspring at 18 weeks (before: 17 %, after: 11 %) and at 26 weeks of age (before: 15 %, after: 7 %), and when combining the results of the offspring at 18 and 26 weeks of age (before: 16 %, after: 9 %). Also, no significant effect was detected in the prevalence of Salmonella Typhimurium positive lymph nodes of sows (before and after: 0 %) and their offspring (before: 4 %, after: 7 %). Regarding serology, the mean S/P-ratios of the sows were significantly higher after the group vaccination, compared to before group vaccination (before: 1.50, after: 2.32, p < 0.001). The mean S/P-ratios of the offspring at slaughter age were significantly lower after the group vaccination, compared to before group vaccination (before: 1.71, after: 1.04, p = 0.001). In conclusion, group vaccination of sows and gilts resulted in a more beneficial serological status of the offspring, but did not significantly decrease Salmonella Typhimurium excretion and lymph node contamination.

29 Time-lapse analysis of bovine embryos derived after invitro fertilization from vitrified and fresh oocytes

Oocyte vitrification enables the long-term conservation of female genetic resources. However, obtaining viable bovine embryos from vitrified oocytes has proven to be difficult. Embryo development is a dynamic process, and critical stages can go unnoticed with the use of traditional morphologic assessments. Therefore, the aim was to evaluate morphokinetic parameters in embryos derived from fresh versus vitrified oocytes. After 22h of IVM, oocytes were divided into (1) oocytes surrounded by multiple layers of cumulus cells (COCs; n=275) and (2) oocytes partially denuded, leaving only corona radiata (CR; n=178). Then, two-thirds of the CR oocytes were subjected to one of two vitrification protocols as follows: high concentration of cryoprotectants (CR-H; n=171; Ortiz-Escribano et al. 2016 Theriogenology 86, 635-641) and low concentration of cryoprotectants (CR-L; n=163; Ishii et al. 2018 J. Reprod. Develop. 6). After warming, vitrified oocytes were incubated ~2h in maturation medium. Invitro fertilization and culture were performed simultaneously for all groups. Four to eight zygotes from each group were assigned randomly to time lapse (Primo Vision; Vitrolife), and group culture was performed in leftovers as a control. Differences between groups in survival (intact zygotes after IVF), cleavage, and blastocyst rates were evaluated by logistic regression. Morphokinetic data (time to reach first (1-2 cells), second (3-4 cells), third (5-8), fourth (9-16 cells), fifth (&gt;16 cells), cleavage, and blastocyst stage, and time in lag phase) were investigated. Survival rates in COCs (98%) and CR (96%) groups were not different; CR-H (87%) showed lower survival than COCs but similar survival to that of CR. Group CR-L (82%) had a lower survival rate than the rest of the groups (P&lt;0.05). Higher cleavage rate (83%) was found in COCs compared with the rest of the groups. The CR and CR-H groups showed similar cleavage rate (65 and 55%, respectively), whereas CR-L had a lower cleavage rate (42%) than other groups (P&lt;0.05). As expected, both vitrified groups showed lower blastocyst rates (4% for CR-H and 10% for CR-L) than fresh COCs (44%; P&lt;0.05). Morphokinetics measures were affected by the treatments: time to reach first cleavage was similar for COCs (35.3h), CR (38.4h), and CR-L (34.8h), whereas CR-H was slower (42.4h). However, the fourth division was reached earlier by CR-H (51.7h), which was significantly faster than for CR-L (88.8 h; P&lt;0.05) but similar for COCs (71.3h) and CR (60.7h). In conclusion, more morphokinetic data are needed to compare different vitrification methods and confirm whether time-lapse analysis can be used to predict blastocyst outcome after oocyte vitrification.

Exposure of ciprofloxacin-resistant Escherichia coli broiler isolates to subinhibitory concentrations of a quaternary ammonium compound does not increase antibiotic resistance gene transfer

Resistance to antibiotics threatens to become a worldwide health problem. An important attributing phenomenon in this context is that pathogens can acquire antibiotic resistance genes through conjugative transfer of plasmids. To prevent bacterial infections in agricultural settings, the use of veterinary hygiene products, such as disinfectants, has gained popularity and questions have been raised about their contribution to such spreading of antibiotic resistance. Therefore, this study investigated the effect of subinhibitory concentrations of benzalkoniumchloride (BKC), a quaternary ammonium compound (QAC), on the conjugative transfer of antibiotic resistance genes. Five Escherichia coli field strains originating from broiler chickens and with known transferable plasmid-mediated ciprofloxacin resistance were exposed to subinhibitory BKC concentrations: 1/3, 1/10 and 1/30 of the minimum bactericidal concentration. Antibiotic resistance transfer was assessed by liquid mating for 4 h at 25°C using E. coli K12 MG1655 as recipient strain. The transfer ratio was calculated as the number of transconjugants divided by the number of recipients. Without exposure to BKC, the strains showed a ciprofloxacin resistance transfer ratio ranging from 10-4 to 10-7. No significant effect of exposure to subinhibitory concentrations of BKC was observed on this transfer ratio.

Quantitative risk model to estimate the level of antimicrobial residues that can be transferred to soil via manure, due to oral treatments of pigs

Veterinary antimicrobials can spread via manure onto agricultural fields, representing an emission of these products or their active metabolites into the environment. This causes concerns regarding the role of antimicrobial residues in the development, selection and spread of resistance. Aiming to approach this issue quantitatively, first a literature review was performed on the bioavailability and extent of in vivo biotransformation of twelve antimicrobials commonly used in pigs orally, and on the level of their persistence in manure. This information was then used in a model estimating the level of each of these administered antimicrobials that is present in manure at the end of common storage durations in pits and, thus, readily applied onto soil. From the studied antimicrobials, the highest level of residues in stored manure was estimated for doxycycline (55% of the initial amount of doxycycline administered orally to pigs after six months of manure storage), as a combining result of its high use in pigs, low bioavailability and high stability in manure. Other antimicrobials (e.g. amoxicillin) are readily degraded and therefore pose less threat. The results of this study highlight the importance of rational antimicrobial use and of further research on pharmacokinetics of antimicrobials and their degraded products in different environmental compartments, to efficiently control the spread of residues and/or resistance genes from manure to these matrices.

Association between antimicrobial usage, biosecurity measures as well as farm performance in German farrow-to-finish farms

Background

Antimicrobial usage in food producing animals is of major concern. A clear link between the extent of use and the development of antimicrobial resistance has already been demonstrated. To evaluate strategies that may reduce the antimicrobial usage while assuring pig health and welfare, it requires profound knowledge of factors that are associated with antimicrobial usage. Data on biosecurity and herd management practices are important parameters to identify risk factors which are related to a higher antimicrobial usage. To investigate between-farm variations of high and low usage the treatment incidence (TI) per age group in 60 German farrow-to-finish herds was qualitatively and quantitatively analysed and linked to biosecurity measures, and herd management characteristics.

Results

Weaned pigs received most of the treatments (median TI = 487.6), followed by suckling pigs (median TI = 138.9). Suckling pigs were treated with critically important antimicrobials (3rd and 4th generation cephalosporines) to a remarkable extent. The number of sows present at site (p < 0.01) and a low score for external biosecurity (p = 0.06) were associated with a higher antimicrobial usage in pigs from birth till slaughter. Herds with a higher treatment incidence in growing pigs (TI 200 days): i) were located in a region with a high pig density (p < 0.01), ii) had a less strict access check for visitors and personnel (p < 0.01) and iii) scored lower in the subcategory ‘cleaning and disinfection’ (internal biosecurity) (p < 0.01). Herds with a higher treatment incidence in breeding pigs weaned more piglets per sow and year and scored better in the internal biosecurity level (p = 0.02).

Conclusions

With the main focus on the treatment incidence in pigs from birth till slaughter and in breeding pigs risk factors for a high usage in these age groups were identified. The level of biosecurity of a herd was associated with the amount of antimicrobials used. Therefore, the findings in this study indicate possible points of action in the reduction and prudent use of antimicrobials in Germany. The active improvement of biosecurity measures could be a promising alternative to reduce antimicrobial usage on herd level.

Electronic supplementary material

The online version of this article (10.1186/s40813-018-0106-5) contains supplementary material, which is available to authorized users.

Risk factors for antimicrobial use in food-producing animals: disease prevention and socio-economic factors as the main drivers?

The European Union requests an urgent decrease in antimicrobial use (AMU) in food producinganimals to reduce antimicrobial resistance in animals and humans and safeguard the efficacy of antimicrobials for future generations. The identification of risk factors (RFs) for AMU is essential to obtain a rapid reduction. The aim of this review was to summarize the current knowledge of RFs for AMU in veal calves, pigs and poultry. Thirty-three observational studies were included. Well-identified RFs for an increased AMU are frequent purchase of animals, herd size (large or small depending on the animal species), and a lack of selected biosecurity measures. Also in beef breed calves, more antimicrobials are used than in Holstein calves. AMU is influenced by the farmer, the veterinarian and by the integration. In general, socio-economic RFs are largely unexplored. The causal factors for AMU are multiple and complex, with possible confounding factors and unidentified interactions. Additional knowledge of socio-economic drivers appears particularly urgent to create tailor-made guidelines and awareness campaigns for each sector.

Evaluation of the hygienogram scores and related data obtained after cleaning and disinfection of poultry houses in Flanders during the period 2007 to 2014

Cleaning and disinfection (C&D) of poultry houses is an essential aspect in farm hygiene management. Adequate performance of the different steps of a C&D protocol and the use of suitable products are key to prevent and control zoonoses and animal diseases. Hygiene monitoring on total aerobic flora through sampling with agar contact plates at different locations of the poultry house results in a hygienogram score that is used to evaluate the proper execution of C&D.This study analyzed the hygienogram scores of 19,739 poultry flocks in Flanders after C&D. Data relating to the C&D protocol, i.e., year, season, husbandry system, production type, cleaning product, sampler, active components of the disinfectant, disinfection time, disinfection temperature, and disinfection responsible, were collected.The average hygienogram score decreased significantly over time, suggesting a general improvement between 2007 and 2014. Differences in scores were found among the husbandry systems, with the barn/aviary system having a significantly better hygienogram score compared to the floor house, furnished cage, and battery. Significantly better scores also were found when a cleaning product was used in the C&D protocol. Disinfection with a peracetic acid and hydrogen peroxide combination or formaldehyde gave the best scores. In addition, C&D protocols using ≥2 different disinfectants showed improved results compared to the use of one single disinfectant. Finally, disinfection applied by a specialist contractor resulted in a better score compared to disinfection by the farmer.In conclusion, analysis of the hygienogram scores and related data allowed identifying several factors, resulting in an improvement, which may reduce the total bacterial load in poultry stables and, consequently, the number of zoonotic and pathogenic micro-organisms.

Scoring biosecurity in European conventional broiler production

Good biosecurity procedures are crucial for healthy animal production. The aim of this study was to quantify the level of biosecurity on conventional broiler farms in Europe, following a standardized procedure, thereby trying to identify factors that are amenable to improvement. The current study used a risk-based weighted scoring system (biocheck.ugent ®) to assess the level of biosecurity on 399 conventional broiler farms in 5 EU member states. The scoring system consisted of 2 main categories, namely external and internal biosecurity, which had 8 and 3 subcategories, respectively. Biosecurity was quantified by converting the answers to 97 questions into a score from 0 to 100. The minimum score, "0," represents total absence of any biosecurity measure on the broiler farm, whereas the maximum score, "100," means full application of all investigated biosecurity measures. A possible correlation between biosecurity and farm characteristics was investigated by multivariate linear regression analysis. The participating broiler farms scored better for internal biosecurity (mean score of 76.6) than for external biosecurity (mean 68.4). There was variation between the mean biosecurity scores for the different member states, ranging from 59.8 to 78.0 for external biosecurity and from 63.0 to 85.6 for internal biosecurity. Within the category of external biosecurity, the subcategory related to "infrastructure and vectors" had the highest mean score (82.4), while the subcategory with the lowest score related to biosecurity procedures for "visitors and staff" (mean 51.5). Within the category of internal biosecurity, the subcategory "disease management" had the highest mean score (65.8). In the multivariate regression model a significant negative correlation was found between internal biosecurity and the number of employees and farm size. These findings indicate that there is a lot of variation for external and internal biosecurity on the participating broiler farms, suggesting that improvements are possible. Since the subcategory "visitors and staff" scored the lowest, better education of broiler farmers and their staff may help to improve overall biosecurity on broiler farms in Europe.

Perception, motivators and obstacles of biosecurity in cattle production

Farm biosecurity includes the prevention of disease transmission within and between farms. Two studies were set up to investigate what motivates and withholds farmers to implement biosecurity measures. The first study aimed to assess the perception of cattle farmers towards biosecurity and to identify possible reasons for its low application. This study consisted of a focus group discussion, of which the trends were used to develop a questionnaire for Flemish cattle farmers. Although the 91 participating farmers were familiar with several measures, they associated them with disease prevention rather than biosecurity. Nearly all farmers (98%) identified their herd veterinarian as their main source of information. Twenty percent and 32% of the respondents were convinced that the implementation of biosecurity would cost them more money and time, respectively. Finally, 80% of the farmers saw room for improvement of their herd, but indicated a need for practical information. The second study aimed to identify the key elements of twenty preselected biosecurity measures, motivators and obstacles for their implementation. They were judged by twenty-two cattle stakeholders, such as farmers, veterinarians and advisors, on feasibility, efficacy and return on investment. A box for parturition, a plan for rodent control and cleaning and disinfection of the stables scored highest overall. The lowest scoring measures were showering before entering the stables and an animal-free period of 24 hours. Their return on investment scored very low, since high investments are required. For a farmer to understand why biosecurity is beneficial, he must understand all risks and costs of disease and how biosecurity may reduce these risks and costs.

Biosecurity practices in Belgian cattle farming: Level of implementation, constraints and weaknesses

Over the last few years, a shift from curative towards preventive medicine occurred in the livestock sector. This led to an increased importance of biosecurity to better control infectious diseases by preventing their introduction and/or reducing their spread. Farmers are the main responsible actors of biosecurity measures (BSM). Existing studies report a low implementation level of BSM by the cattle farmers. Barriers such as cost, usefulness, importance, workload and lack of knowledge were investigated but the decision-making process of farmers related to a given BSM is not yet clarified. The objectives of this study were to (i) assess the level of implementation of BSM in cattle farms, (ii) assess the correlation between the importance that farmers give to a BSM and its effective implementation and (iii) identify the main reasons of non-implementation. A randomized survey was implemented in Belgium from December 2016 up to April 2017 with face-to-face interviews conducted in 100 Belgian farms. A descriptive analysis of data was performed using Microsoft Excel^® and Stata14^® . Chi-square and Spearman's rank correlation tests, respectively, allowed comparing implementation levels in dairy herds vs. beef herds and investigating the correlation between the importance that farmers give to a BSM and its implementation level. Biosecurity measures were poorly implemented to prevent disease introduction through direct contact and almost not to avoid indirect transmission. Some measures showed a significant difference in terms of implementation level between beef and dairy herds. A positive correlation was highlighted between the importance that farmers give to a BSM and its actual effective implementation. Perceived lack of efficiency, feasibility and usefulness are the reasons most often mentioned for non-implementation. Other factors potentially influencing the decision-making process should be further investigated and clarified. Evidence-based studies would be useful to convince the farmers of the need of implementing BSM.

Voorkomen van resistentie tegen de ‘meest kritisch belangrijke antimicrobiële geneesmiddelen’ bij Escherichia coli-isolaten van hond en kat

Om een beter inzicht te krijgen in het voorkomen van antimicrobiële resistentie tegen ‘de meest kritisch belangrijke antibiotica met hoogste prioriteit voor humane geneeskunde’ bij kleine huisdieren werd een descriptieve retrospectieve analyse van 811 antibiogrammen bij hond en kat uitgevoerd. De antibiogrammen werden door een diergeneeskundig, diagnostisch laboratorium uitgevoerd op 811 Escherichia coli-isolaten afkomstig van klinische stalen van honden en katten genomen door dierenartsen uit Vlaanderen, waarbij de isolaten voornamelijk van fecale (62,5%) of urogenitale (30,5%) oorsprong waren. De antimicrobiële gevoeligheid werd bepaald aan de hand van de disk-diffusiemethode met breekpunten voorzien door de leverancier van de antibioticumschijfjes. Met deze testmethode was 9,5% van de Escherichia coli-isolaten resistent tegen of intermediair gevoelig voor marbofloxacine, 16,7% voor enrofloxacine en 15,7% voor cefovecin. Het enigszins onverwachte verschil in resistentie tussen marbofloxacine en enrofloxacine kan mogelijk ten minste deels verklaard worden door de verschillende klinische breekpunten die gebruikt worden om de resultaten van een gevoeligheidstest voor honden- en kattenisolaten bij beide agentia te interpreteren. Het is mogelijk dat de waargenomen resistentie in deze studie het gevolg is van het regelmatige gebruik van onder andere fluoroquinolonen en derdegeneratiecefalosporinen, zodat het gebruik van deze ‘meest kritisch belangrijke antibiotica met hoogste prioriteit voor humane geneeskunde’ een belangrijk aandachtspunt in de kleinehuisdierensector blijft.

Review of transmission routes of 24 infectious diseases preventable by biosecurity measures and comparison of the implementation of these measures in pig herds in six European countries

This study aimed to review the transmission routes of important infectious pig diseases and to translate these into biosecurity measures preventing or reducing the transmission between and within pig herds. Furthermore, it aimed to identify the level of implementation of these measures in different European countries and discuss the observed variations to identify potentials for improvement. First, a literature review was performed to show which direct and indirect transmission routes of 24 infectious pig diseases can be prevented through different biosecurity measures. Second, a quantitative analysis was performed using the Biocheck.UGent™, a risk-based scoring system to evaluate biosecurity in pig herds, to obtain an insight into the implementation of these biosecurity measures. The database contained farm-specific biosecurity data from 574 pig farms in Belgium, Denmark, France, Germany, the Netherlands and Sweden, entered between January 2014 and January 2016. Third, a qualitative analysis based on a review of literature and other relevant information resources was performed for every subcategory of internal and external biosecurity in the Biocheck.UGent™ questionnaire. The quantitative analysis indicated that at the level of internal, external and overall biosecurity, Denmark had a significantly distinct profile with higher external biosecurity scores and less variation than the rest of the countries. This is likely due to a widely used specific pathogen-free (SPF) system with extensive focus on biosecurity since 1971 in Denmark. However, the observed pattern may also be attributed to differences in data collection methods. The qualitative analysis identified differences in applied policies, legislation, disease status, pig farm density, farming culture and habits between countries that can be used for shaping country-specific biosecurity advice to attain improved prevention and control of important pig diseases in European pig farms.

Analyse van de arbeidssituatie en perceptie van de kwaliteit van de opleiding van dierenartsen afgestudeerd aan de Faculteit Diergeneeskunde van de Universiteit Gent

In een enquête werd gepeild naar de arbeidssituatie van dierenartsen afgestudeerd aan de Universiteit Gent en de perceptie van de kwaliteit van de opleiding. Hiervoor werden drie cohorten dierenartsen gecontacteerd die afgestudeerd zijn gedurende drie tijdsintervallen, met name tussen 2002 en 2004, 2009 en 2011 en tussen 2014 en 2016. Uit 488 ingevulde vragenlijsten (47% van de gecontacteerde respondenten) werd onder andere duidelijk dat dierenartsen in Vlaanderen gemiddeld 47 uur per week werken en relatief tevreden zijn over de invulling van hun job. Tachtig procent (meest recent afgestudeerde cohorte) en 68% (langst afgestudeerde cohorte) van de respondenten werkt als practicus en 81% van deze practici werkt in een groepspraktijk. Dierenartsen met de Belgische nationaliteit hebben voornamelijk het statuut van zelfstandige, terwijl dierenartsen met de Nederlandse nationaliteit voornamelijk in loondienst werken. De respondenten geven aan tevreden te zijn over het theoretische aandeel binnen de opleiding diergeneeskunde maar ervaren het praktisch onderricht als te beperkt. Tijdens de opleiding zou er volgens de respondenten meer nadruk gelegd moeten worden op eerstelijnsdiergeneeskunde, op het verwerven van communicatievaardigheden met klanten en collega’s en op praktijkmanagement.

The impact of antimicrobial use guidelines on prescription habits in fourteen Flemish small animal practices

A prospective study was performed to explore the prescription habits in fourteen first-line, small animal practices during first consultations of cats and dogs. Consultations one month prior to the implementation of antimicrobial use guidelines and at least 20 days thereafter were examined. Differences in the proportion of consultations during which antimicrobials were prescribed, were assessed. Additionally, changes in the choice of active substance were critically evaluated against the introduced antimicrobial use guidelines. The proportion of consultations where antimicrobials were prescribed decreased in cats and dogs (both –12%) after the introduction of the antimicrobial use guidelines. There was an increase of consultations of cats (+13%) and dogs (+10%) where veterinarians handled according to those guidelines. However, an increase in the prescription of third-choice antimicrobials and highest priority critically important antimicrobials was noticed both in cats (+8% and +12%, respectively) and dogs (both +5%). This unexpected increase invites to create extra awareness amongst prescribers.

Vraag & Antwoord

Waar blijven de afgestudeerde dierenartsen na hun studie?

A 10-day vacancy period after cleaning and disinfection has no effect on the bacterial load in pig nursery units

BACKGROUND

Biosecurity measures such as cleaning, disinfection and a vacancy period between production cycles on pig farms are essential to prevent disease outbreaks. No studies have tested the effect of a longer vacancy period on bacterial load in nursery units.

METHODS

The present study evaluated the effect of a 10-day vacancy period in pig nursery units on total aerobic flora, Enterococcus spp., Escherichia coli, faecal coliforms and methicillin resistant Staphylococcus aureus (MRSA). Three vacancy periods of 10 days were monitored, each time applied in 3 units. The microbiological load was measured before disinfection and at 1, 4, 7 and 10 days after disinfection.

RESULTS

No significant decrease or increase in E. coli, faecal coliforms, MRSA and Enterococcus spp. was noticed. Total aerobic flora counts were the lowest on day 4 after disinfection (i.e. 4.07 log CFU/625 cm2) (P < 0.05), but the difference with other sampling moments was limited (i.e. 0.6 log CFU/625 cm2) and therefore negligible. Furthermore, this observation on day 4 was not confirmed for the other microbiological parameters. After disinfection, drinking nipples were still mostly contaminated with total aerobic flora (i.e. 5.32 log CFU/625 cm2) and Enterococcus spp. (i.e. 95 % of the samples were positive) (P < 0.01); the feeding troughs were the cleanest location (total aerobic flora: 3.53 log CFU/625 cm2 and Enterococcus spp.: 50 % positive samples) (P < 0.01).

CONCLUSIONS

This study indicates that prolonging the vacancy period in nursery units to 10 days after disinfection with no extra biosecurity measures has no impact on the environmental load of total aerobic flora, E. coli, faecal coliforms, MRSA and Enterococcus spp..

Comparison of competitive exclusion with classical cleaning and disinfection on bacterial load in pig nursery units

Background

Colonisation of the environment of nursery units by pathogenic micro-organisms is an important factor in the persistence and spread of endemic diseases in pigs and zoonotic pathogens. These pathogens are generally controlled by the use of antibiotics and disinfectants. Since an increasing resistance against these measures has been reported in recent years, methods such as competitive exclusion (CE) are promoted as promising alternatives.

Results

This study showed that the infection pressure in CE units after microbial cleaning was not reduced to the same degree as in control units. Despite sufficient administration of probiotic-type spores, the analysed bacteria did not decrease in number after 3 production rounds in CE units, indicating no competitive exclusion. In addition, no differences in feed conversion were found between piglets raised in CE and control units in our study. Also, no differences in faecal consistency (indicator for enteric diseases) was noticed.

Conclusion

These results indicate that the CE protocol is not a valuable alternative for classical C&D.

Guidance on the Selection of Appropriate Indicators for Quantification of Antimicrobial Usage in Humans and Animals

An increasing variety of indicators of antimicrobial usage has become available in human and veterinary medicine, with no consensus on the most appropriate indicators to be used. The objective of this review is therefore to provide guidance on the selection of indicators, intended for those aiming to quantify antimicrobial usage based on sales, deliveries or reimbursement data. Depending on the study objective, different requirements apply to antimicrobial usage quantification in terms of resolution, comprehensiveness, stability over time, ability to assess exposure and comparability. If the aim is to monitor antimicrobial usage trends, it is crucial to use a robust quantification system that allows stability over time in terms of required data and provided output; to compare usage between different species or countries, comparability must be ensured between the different populations. If data are used for benchmarking, the system comprehensiveness is particularly crucial, while data collected to study the association between usage and resistance should express the exposure level and duration as a measurement of the exerted selection pressure. Antimicrobial usage is generally described as the number of technical units consumed normalized by the population at risk of being treated in a defined period. The technical units vary from number of packages to number of individuals treated daily by adding different levels of complexity such as daily dose or weight at treatment. These technical units are then related to a description of the population at risk, based either on biomass or number of individuals. Conventions and assumptions are needed for all of these calculation steps. However, there is a clear lack of standardization, resulting in poor transparency and comparability. By combining study requirements with available approaches to quantify antimicrobial usage, we provide suggestions on the most appropriate indicators and data sources to be used for a given study objective.

Reducing Antimicrobial Usage in Pig Production without Jeopardizing Production Parameters

Antimicrobial usage (AMU) has been described to be high in pig production. Although farmers are aware of the high usage, little is known about intervention to improve the situation. This study evaluated the extent to which AMU could be reduced in pig production by the optimization of herd management, biosecurity status, vaccination strategy, anthelmintic therapy and advice on prudent AMU. Furthermore, the effects of these interventions on the herd production results were explored. This intervention study was conducted on 61 Flemish pig herds and included three visits per herd. During the initial visit, information was gathered on herd management, biosecurity status (quantified by means of the Biocheck.UGent^™ risk-based scoring system), vaccination strategy, anthelmintic therapy and AMU. This info was then translated into a herd-specific action plan which was discussed with the farmer and herd veterinarian/other advisors during the second visit. In the final herd visit (±8 months later), comparable data were obtained to evaluate the progress. Overall, a significant improvement of 2.4 points external and 7 points internal biosecurity on the herds was obtained, combined with additional vaccination, anthelmintic therapy and prudent AMU. This was accompanied by a significant reduction in the AMU with a decrease of 52% for the pigs from birth till slaughter and 32% for breeding animals, based on treatment incidences (TIs) and included an important reduction in the use of critically important antimicrobials. More importantly, the increased biosecurity levels and decreased AMU were combined with significantly improved technical results such as the number of weaned piglets per sow per year (+1.1), daily weight gain (+5.9 g/day) and mortality in the finisher period (-0.6%). Guided interventions as a team effort of farmer and herd veterinarian/other advisors have shown to be a promising method in the reduction of AMU in pig production.

Opinions of veterinarians on antimicrobial use in farm animals in Flanders and the Netherlands

Veterinarians play an important role in the reduction of antimicrobial use in farm animals. This study aims to quantify opinions of veterinarians from the Netherlands and Flanders regarding antimicrobial use and resistance issues in farm animals. An online survey was sent out to 678 and 1100 farm animal veterinarians in Flanders and the Netherlands, of which 174 and 437 were returned respectively. Suboptimal climate conditions were regarded as the most important cause for high antimicrobial use in farm animals. Flemish veterinarians also regarded insufficient biosecurity measures and farmers' mentality as important determinants, while the Dutch respondents ranked insufficient immunity of young animals and economic considerations of farmers as major causes. The majority of Dutch respondents (63.8 per cent) supported the existing national policy, which aimed to halve veterinary antimicrobial use, while the Flemish (32.9 per cent) were less supportive of such a policy. Improvements in housing and climate conditions, biosecurity measures and strict control of specific infectious diseases were seen as important and promising measures to reduce antimicrobial use. To reduce antimicrobial use in farm animals, some shared approaches might be applicable in both countries. However, cultural, political and societal differences between Flanders and the Netherlands require differentiated approaches to reduce veterinary antimicrobial use.

Quantitative and qualitative antimicrobial usage patterns in farrow-to-finish pig herds in Belgium, France, Germany and Sweden

Data on sales of antimicrobials using a standardised methodology have shown that there are vast differences between countries in amounts of antimicrobials sold for food-producing animals, but these data do not provide insight on how sales are distributed by species and age groups. The aim of this study was to compare herd level antimicrobial usage for pigs by age category, antimicrobial class and administration route for farrow-to-finish herds in four EU countries. A cross-sectional study was conducted among 227 farrow-to-finish pig herds with at least 100 sows and 500 finishing pigs in Belgium (n=47), France (n=60), Germany (n=60) and Sweden (n=60). Detailed information about the antimicrobial consumption for breeding and growing pigs was collected. Antimicrobial usage was quantified as active substance expressed as mg and then converted to treatment incidence (TI) based on Defined Daily Doses Animal per 1000 pig-days at risk. TIs varied between and within countries, herds and age groups. The Swedish herds had the lowest and the German herds the highest overall use. Most treatments were applied to weaned piglets except in the Swedish herds where treatments of suckling piglets were most frequent. Antimicrobials were most often applied through feed or water except in the Swedish herds where parenteral treatments were most frequent. Aminopenicillins was the antimicrobial class most commonly used. Use of third and fourth generation cephalosporins constituted 11% of use for the Belgian herds, which was higher compared to the other countries. There was a significant (p<0.01) association between the within-herd antimicrobial use across different age categories. This study has shown that there were large differences in antimicrobial use for pigs between countries, herds and age groups in farrow-to-finish herds of similar size when actual consumption data were compared. Collecting detailed usage data can be used to efficiently target high users in order to reduce antimicrobial consumption.

Risico op colistineresistentie neemt toe

In een recent artikel uit China werd overdraagbare resistentie tegen colistine beschreven die gevonden werd bij Escherichia (E. coli) bekomen uit voedselproducerende dieren, vlees en ziekenhuispatiënten (Liu et al., 2015). Heel recent werd deze resistentie onder meer ook gevonden in Denemarken, Frankrijk, het Verenigd Koninkrijk en België. Colistine wordt beschouwd als een van de laatste behandelopties tegen multiresistente bacteriën in de humane gezondheidszorg, voornamelijk bij patiënten met mucoviscidose. Alertheid voor colistineresistentie is geboden en het nieuwe resistentiemechanisme dient zorgvuldig te worden opgespoord bij dier- en mensgerelateerde bacteriën.

Gill infection model for columnaris disease in common carp and rainbow trout

Challenge models generating gill lesions typical for columnaris disease were developed for the fry of both Common Carp Cyprinus carpio and Rainbow Trout Oncorhynchus mykiss by means of an immersion challenge and Flavobacterium columnare field isolates were characterized regarding virulence. Carp inoculated with highly virulent isolates revealed diffuse, whitish discoloration of the gills affecting all arches, while in trout mostly unilateral focal lesions, which were restricted to the first two gill arches, occurred. Light microscopic examination of the gills of carp exposed to highly virulent isolates revealed a diffuse loss of branchial structures and desquamation and necrosis of gill epithelium with fusion of filaments and lamellae. In severe cases, large parts of the filaments were replaced with necrotic debris entangled with massive clusters of F. columnare bacterial cells enwrapped in an eosinophilic matrix. In trout, histopathologic lesions were similar but less extensive and much more focal, and well delineated from apparently healthy tissue. Scanning and transmission electron microscopic observations of the affected gills showed long, slender bacterial cells contained in an extracellular matrix and in close contact with the destructed gill tissue. This is the first study to reveal gill lesions typical for columnaris disease at macroscopic, light microscopic, and ultrastructural levels in both Common Carp and Rainbow Trout following a challenge with F. columnare. The results provide a basis for research opportunities to examine pathogen-gill interactions.

Replacing serum in culture medium with albumin and insulin, transferrin and selenium is the key to successful bovine embryo development in individual culture

Individual culture of bovine embryos is usually associated with low blastocyst development. However, during preliminary experiments in our laboratory we observed high blastocyst development after individual embryo culture in a serum-free culture system. We therefore hypothesised that serum has a negative effect on embryos cultured individually whereas embryos in groups can counteract this. First, we determined whether the timing of removal of serum (during maturation or culture) had an influence on individual embryo development. The results clearly showed that removal of serum during embryo culture was the main contributing factor since high blastocyst development was observed after individual culture in synthetic oviductal fluid supplemented with bovine serum albumin (BSA) and insulin, transferrin and selenium (ITS), independent of the maturation medium. Second, we investigated whether an individual factor of the ITS supplement was essential for individual embryo development. We demonstrated that repeatable high blastocyst percentages were due to the synergistic effect of ITS. Finally, we investigated if a group-culture effect can still be observed under serum-free conditions. Group culture generated blastocysts with higher total cell numbers and less apoptosis. These data show that individual culture in serum-free conditions leads to high blastocyst development, but group culture still improves blastocyst quality.