Temporal patterns of bovine leukemia virus infection in dairy herds in Atlantic Canada.

Objective: The primary objective was to determine the youngest age group where bovine leukemia virus (BLV)-infected dairy animals were identified. The secondary objective was to investigate associations between age-specific management practices and BLV infection status of different age groups of dairy calves and heifers. Procedure: For enrolled herds, BLV status was determined using blood samples from pre-weaned calves, weaned calves, and breeding-age heifers; and bulk tank milk from the adult herd. A questionnaire investigating age-specific management factors was administered for each herd. Ordinal logistic regression was performed to identify management factors associated with the youngest age range in which BLV was identified. Results: Fifty-three dairy herds from the 4 provinces in Atlantic Canada were enrolled. Bovine leukemia virus was most commonly earliest identified in pre-weaned heifers (18 herds, 32.1%) and the adult herd (18 herds, 32.1%). Ordinal logistic regression revealed that BLV was first identified in older age groups more often than in younger age groups when herds regrouped weaned heifers at least once, when fly control was used for breeding-age heifers, when herds practiced foot trimming on breeding-age heifers, and when bred heifers were brought in. Conclusion: Producers can use results to identify the youngest age group(s) in which BLV is identified and to tailor management strategies to prevent new infections.

Tendances temporelles de l'infection par le virus de la leucémie bovine dans les troupeaux laitiers des provinces atlantiques canadiennes. Objectif: L'objectif principal était de déterminer le groupe d'âge le plus jeune dans lequel les animaux laitiers infectés par le virus de la leucémie bovine (BLV) ont été identifiés. L'objectif secondaire était d'étudier les associations entre les pratiques de gestion spécifiques à l'âge et le statut d'infection par le BLV de différents groupes d'âge de veaux et de génisses laitiers. Procédure: Pour les troupeaux inscrits, le statut BLV a été déterminé à l'aide d'échantillons de sang provenant de veaux présevrés, de veaux sevrés et de génisses en âge de se reproduire; et de lait de réservoir en vrac du troupeau adulte. Un questionnaire portant sur les facteurs de gestion spécifiques à l'âge a été administré pour chaque troupeau. Une régression logistique ordinale a été réalisée pour identifier les facteurs de gestion associés à la tranche d'âge la plus jeune dans laquelle le BLV a été identifié. Résultats: Cinquante-trois troupeaux laitiers des quatre provinces atlantiques canadiennes ont été inscrits. Le virus de la leucémie bovine a été le plus souvent identifié le plus tôt chez les génisses pré-sevrées (18 troupeaux, 32,1 %) et dans le troupeau adulte (18 troupeaux, 32,1 %). La régression logistique ordinale a révélé que le BLV a été identifié pour la première fois plus souvent dans les groupes d'âge plus âgés que dans les groupes d'âge plus jeunes lorsque les troupeaux regroupaient au moins une fois les génisses sevrées, lorsque le contrôle des mouches était utilisé pour les génisses en âge de se reproduire, lorsque les troupeaux pratiquaient le parage des pattes des génisses en âge de se reproduire., et quand les taures saillies étaient intégrées au troupeau. Conclusion: Les producteurs peuvent utiliser les résultats pour identifier le(s) groupe(s) d'âge le plus jeune dans lequel le BLV est identifié et pour adapter les stratégies de gestion afin de prévenir de nouvelles infections.(Traduit par Dr Serge Messier).

Frequency of isolation and phenotypic antimicrobial resistance of fecal Salmonella enterica recovered from dairy cattle in Canada.

Salmonellosis is one of the leading causes of gastrointestinal infections in humans. In Canada, it is estimated that approximately 87,500 cases of salmonellosis occur every year in humans, resulting in 17 deaths. In the United States, it is estimated that 26,500 hospitalizations and 420 deaths occur every year. In dairy cattle, infections caused by nontyphoidal Salmonella enterica can cause mild to severe disease, including enteritis, pneumonia, and septicemia. Our study objectives were to determine the proportion of fecal samples positive for Salmonella in dairy cattle in Canada and determine the resistance pattern of these isolates. We used data collected through the Canadian Dairy Network for Antimicrobial Stewardship and Resistance (CaDNetASR). Pooled fecal samples from preweaning calves, postweaning heifers, lactating cows, and manure storage were cultured for Salmonella, and the isolates were identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Antimicrobial susceptibilities were determined using the minimum inhibitory concentration test, and resistance interpretation was made according to the Clinical and Laboratory Standards Institute. A 2-level, multivariable logistic regression model was built to determine the probability of recovering Salmonella from a sample, accounting for province, year, and sample source. The proportion of farms with at least one positive sample were 12% (17/140), 19% (28/144), and 17% (24/144) for the sampling years 2019, 2020, and 2021, respectively. Out of the 113 Salmonella isolates, 23 different serovars were identified. The occurrence of Salmonella appeared to be clustered by farms and provinces. The most common serovars identified were Infantis (14%) and Typhimurium (14%). Overall, 21% (24/113) of the Salmonella isolates were resistant to at least one antimicrobial. Resistance to tetracycline was commonly observed (17%); however, very limited resistance to category I antimicrobials (categorization according to Health Canada that includes third-generation cephalosporins, fluoroquinolones, polymyxins, and carbapenems) was observed, with one isolate resistant to amoxicillin and clavulanic acid. The proportion of Salmonella isolates resistant to 2 and 3 antimicrobial classes was 3.5% and 8.8%, respectively. Our study provided valuable information on the proportion of fecal samples positive for Salmonella, the serovars identified, and the associated resistance patterns across CaDNetASR herds, at regional and national levels.

Long-read sequencing reveals the shell microbiome of apparently healthy American lobsters Homarus americanus from Atlantic Canada.

The shell microbial community of lobsters-a key factor in the development of epizootic shell disease (ESD)-is still insufficiently researched in Atlantic Canada and many knowledge gaps remain. This study aimed to establish a baseline description and analysis of the shell microbiome of apparently healthy lobsters from four locations in the region. More than 180 lobster shell swab samples were collected from New Brunswick, Nova Scotia and Prince Edward Island (PEI). PacBio long-read 16S rDNA sequencing and bioinformatic analyses in QIIME2 identified the shell-associated bacteria. The shell microbiome of healthy lobsters consisted mainly of the bacterial classes Gammaproteobacteria, Saprospiria, Verrucomicrobiae, Alphaproteobacteria, Flavobacteriia, Acidimicrobiia and Planctomycetia. The microbial composition differed regionally and seasonally, with some classes showing decreased or increased relative abundances in the PEI samples as well as in the winter and spring samples in Nova Scotia. The core shell microbiome included potentially pathogenic as well as beneficial bacterial taxa, of which some were present only in certain regions. Bacterial taxa that have previously been associated with ESD were present on healthy lobsters in Atlantic Canada, but their frequency differed by location, sampling time, and moult stage. This study indicated that geographical and seasonal factors influenced the shell microbiome of apparently healthy lobsters more than host factors such as sex, size, and moult stage. Our results provide valuable reference microbial data from lobsters in a disease-free state.

Relationship between quantitative real-time PCR cycle threshold and culture for detection of Streptococcus equi subspecies equi.

Objective: To compare PCR and culture results for the detection of Streptococcus equi subspecies equi (S. equi). Animals: Respiratory tract samples (N = 158) from horses being tested for S. equi. Procedure: Bacterial culture was carried out on samples from which S. equi was detected by quantitative real-time PCR. Results: S. equi was isolated from 12 (7.6%) samples: 4/9 (44%) samples when the PCR cycle threshold (CT) was ≤ 30, 7/30 (23%) when the CT was 30.1 to 35, and 1/119 (0.8%) when the CT was 35.1 to 40. The highest CT sample from a sample that yielded a positive culture was 36.9. The optimal Youden's J value was at a CT of 34.2, the same value as determined by number needed to misdiagnose when the cost of a false negative is deemed to be either 5 or 10 × that of a false positive. Conclusions: Viable S. equi was only detected in a minority of quantitative PCR (qPCR) positive samples. A qPCR CT of 34.2 was a reasonable breakpoint for likelihood of the presence of culturable S. equi. Clinical relevance: Evaluation of CT values may be useful as a proxy to indicate the likelihood of cultivable S. equi being present and could be useful as part of risk assessments.

Relation entre le seuil du cycle de PCR quantitatif en temps réel et la culture pour la détection de Streptococcus equi sous-espèce equi. Objectif: Comparer les résultats de PCR et de culture pour la détection de Streptococcus equi sous-espèce equi (S. equi). Animaux: Échantillons des voies respiratoires (N = 158) de chevaux testés pour S. equi. Procédure: La culture bactérienne a été réalisée sur des échantillons à partir desquels S. equi a été détecté par PCR quantitatif en temps réel. Résultats: S. equi a été isolé à partir de 12 échantillons (7,6 %) : 4/9 (44 %) échantillons lorsque le seuil du cycle de PCR (CT) était ≤ 30, 7/30 (23 %) lorsque le CT était de 30,1 à 35 et 1/119 (0,8 %) lorsque le CT était de 35,1 à 40. L'échantillon CT le plus élevé d'un échantillon ayant donné une culture positive était de 36,9. La valeur J optimale de Youden était à un CT de 34,2, la même valeur que celle déterminée par le nombre nécessaire pour un mauvais diagnostic lorsque le coût d'un faux négatif est estimé à 5 ou 10 × celui d'un faux positif. Conclusion: Du S. equi viable n'a été détecté que dans une minorité d'échantillons positifs pour le PCR quantitatif (qPCR). Un CT qPCR de 34,2 était un seuil raisonnable pour la probabilité de la présence de S. equi cultivable. Pertinence clinique: L'évaluation des valeurs CT peut être utile comme approximation pour indiquer la probabilité de présence de S. equi cultivable et pourrait être utile dans le cadre d'une évaluation des risques.(Traduit par Dr Serge Messier).

Intramammary and systemic use of antimicrobials and their association with resistance in generic Escherichia coli recovered from fecal samples from Canadian dairy herds: A cross-sectional study.

Antimicrobial resistance (AMR) in animals, including dairy cattle, is a significant concern for animal and public health worldwide. In this study, we used data collected through the Canadian Dairy Network for Antimicrobial Stewardship and Resistance (CaDNetASR) to: (1) describe the proportions of AMR in fecal E. coli, and (2) investigate the relationship between antimicrobial use (AMU) (intramammary and systemic routes, while accounting for confounding by other variables) and AMR/multidrug resistance (MDR - resistance to ≥ 3 antimicrobial classes) in fecal E. coli from Canadian dairy farms. We hypothesized that an increase of the AMU was associated with an increase in AMR in E. coli isolates. A total of 140 dairy farms across five provinces in Canada were included in the study. Fecal samples from pre-weaned calves, post-weaned heifers, lactating cows, and farm manure storage were cultured, and E. coli isolates were identified using MALDI-TOF MS. The minimum inhibitory concentrations (MIC) to 14 antimicrobials were evaluated using a microbroth dilution methodology. AMU was quantified in Defined Course Dose (DCD - the dose for a standardized complete treatment course on a standard size animal) and converted to a rate indicator - DCD/100 animal-years. Of 1134 fecal samples collected, the proportion of samples positive for E. coli in 2019 and 2020 was 97.1% (544/560) and 94.4% (542/574), respectively. Overall, 24.5% (266/1086) of the E. coli isolates were resistant to at least one antimicrobial. Resistance towards tetracycline was commonly observed (20.7%), whereas resistance to third-generation cephalosporins, fluoroquinolones, and carbapenems was found in 2.2%, 1.4%, and 0.1% of E. coli isolates, respectively. E. coli isolates resistant to two or ≥ 3 antimicrobial classes (MDR) was 2.7% and 15%, respectively. Two multilevel models were built to explore risk factors associated with AMR with AMU being the main exposure. Systemic AMU was associated with increased E. coli resistance. For an increase in systemic AMU equivalent to its IQR, the odds of resistance to any antimicrobial in the model increased by 18%. Fecal samples from calves had higher odds of being resistant to any antimicrobial when compared to other production ages and farm manure storage. The samples collected in 2020 were less likely to be resistant when compared to samples collected in 2019. Compared to previous studies in dairy cattle in North America, AMR in E. coli was lower.

Antimicrobial use and its association with the isolation of and antimicrobial resistance in Campylobacter spp. recovered from fecal samples from Canadian dairy herds: A cross-sectional study.

Campylobacteriosis is one of the most common zoonotic diseases in North America. As opposed to humans, animal infections caused by Campylobacter spp. are often asymptomatic. In this study, data collected through the Canadian Dairy Network for Antimicrobial Stewardship surveillance system were used to determine the proportion of Campylobacter spp. and antimicrobial resistant isolates recovered from dairy cattle herds. Additionally, the association of antimicrobial use (AMU) with fecal carriage and antimicrobial resistance (AMR) of Campylobacter spp. were investigated. Pooled fecal samples from 5 animals from each production phase (pre-weaned calves, post-weaned heifers, lactating cows), and a manure storage sample were collected from 140 dairy herds across Canada. Samples were cultured using selective media, and Campylobacter isolates were speciated using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Antimicrobial susceptibilities were determined using the minimum inhibitory concentration test, and interpretation was made according to the Clinical and Laboratory Standards Institute. Two multilevel logistic regression models were used to investigate the association between the AMU with the isolation and antimicrobial resistance in Campylobacter spp. Of 560 samples, 63.8% were positive for Campylobacter spp., and 96% of the participating farms had at least one sample source (i.e., calves, heifers, lactating cows, or manure storage) positive for Campylobacter spp. Overall, 54.3% of the Campylobacter spp. isolates were resistant to at least one antimicrobial. Resistance to tetracycline was observed in 49.7% of the Campylobacter spp. isolates, followed by ciprofloxacin (19.9%) and nalidixic acid (19.3%). The proportion of multi-drug resistant (≥3 antimicrobial classes) Campylobacter spp. isolates was low (0.3%); however, 15.6% were resistant to two different classes of antimicrobials. Samples collected from lactating cows, heifers, and manure storage were more likely to be positive for Campylobacter spp. compared to calves. Total AMU was associated with a decreased probability of recovering Campylobacter spp. In addition, AMR to either tetracycline or ciprofloxacin had an interaction with antimicrobial use. The probability of resistance to tetracycline increased for each unit increase in the total AMU (Defined Course Dose/100 animal-years), while the probability of resistance to ciprofloxacin decreased. Campylobacter coli isolates were more likely to be resistant to ciprofloxacin and tetracycline when compared to C. jejuni. Our study demonstrated that Campylobacter spp. is widespread among Canadian dairy farms, and a higher proportion of resistance to tetracycline was identified. The total AMU was associated with increased resistance to tetracycline in Campylobacter spp. isolates; however, for ciprofloxacin the AMU was associated with decreased resistance.

Comparison of chlorhexidine and alcohol-based antisepsis on the paralumbar fossa in cattle.

OBJECTIVE: To determine skin reaction, post-treatment reduction (immediate effect), and 1 hour post-treatment reduction (sustained effect) of aerobic bacterial colony forming units (CFU) following three antiseptic protocols in cattle. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: Eighteen cows. METHODS: Three sites in each paralumbar fossa were clipped and randomly assigned to one of three treatment groups: 5 minute 4% chlorhexidine gluconate scrub (CHG); 90 second 80% ethanol scrub (ET); 90 second 70% isopropyl alcohol scrub (IPA). All sites were monitored at all sampling time points and at 24 hours following treatment for adverse skin reaction. Samples were collected pre-, immediately post-, and 1 hour post-treatment and plated in duplicate. Bacterial counts were shifted to eliminate zeroes, log10 transformed, and averaged. ANOVA was used to compare differences in mean reduction in log10 CFU/ml between groups. RESULTS: Reduction in log10CFU/ml was more pronounced immediately after application of IPA (p = .001) and ET (p = .001) than CHG. This reduction was better sustained after preparation with CHG than ET (p = .005) but not IPA. Immediate and sustained reductions in bacterial loads did not differ after application of IPA or ET. No adverse skin reactions were noted. CONCLUSIONS: Skin preparation with alcohol-based antiseptics was well tolerated and improved immediate bacterial reduction compared to CHG. This reduction was better sustained 1 hour after application of CHG than ET, but no difference was detected between CHG and IPA. CLINICAL RELEVANCE: Lack of adverse skin reaction and performance provide evidence to support skin preparation with alcohol-based antiseptics in cattle.

Development of a predictive model for bovine leukemia virus proviral load.

BACKGROUND: There is currently no commercially available method in Canada to identify bovine leukemia virus (BLV)-positive cows with high proviral load (PVL). OBJECTIVES: First, develop a model to predict PVL using common, commercially available, cost-effective diagnostic tests. Second, investigate the relationship between lymphocyte count and PVL in BLV-positive cows. ANIMALS: A total of 339 BLV-positive and 62 BLV-seronegative cows on 15 dairy farms. METHODS: Cross-sectional study. Blood and milk samples were collected from all lactating BLV-positive cows on each farm and 5 to 10 BLV-seronegative cows depending on herd size. Blood and milk samples were tested for anti-BLV antibodies using enzyme-linked immunosorbent assay (ELISA). Complete blood counts were performed on blood samples, and standard components analyses were obtained for milk samples. Proviral load was determined by quantitative polymerase chain reaction for each cow. RESULTS: The inverse of lymphocyte count, the square of the inverse of lymphocyte count, and milk ELISA percent positivity were positively associated with increasing PVL in BLV-positive cows. For BLV-positive cows, lymphocyte count >5.2 × 109 /L predicted a high PVL (BLV:Bovine DNA of >1 in blood) with a sensitivity of 92.4% and a specificity of 79.8%. For BLV-positive cows, white blood cell count >10.8 × 109 /L predicted a high PVL, with a sensitivity of 85.5% and a specificity of 83.6%. CONCLUSIONS AND CLINICAL IMPORTANCE: Based on these results, producers can implement commonly available diagnostic tests to identify cows with high probability of having high PVL, which may help in designing effective disease control strategies for BLV-positive herds.

Knowledge, attitudes and influencers of cat owners in North America around antimicrobials and antimicrobial stewardship.

OBJECTIVES: The primary aims of this study were to determine preferences of North American cat owners when they are prescribed an antimicrobial for their cat with regard to cost, method of administration and the importance of antibiotics for treating infections in people, and to establish baseline knowledge, attitudes and influencers of cat owners on antimicrobial resistance and stewardship. METHODS: An online questionnaire was used for data collection from two cat-owner groups: US cat owners and Canadian cat owners. Participants were queried on antimicrobial resistance and stewardship, and their preferences for their own cat when prescribed an antimicrobial, with respect to cost, method of drug administration and the importance of a drug for treating infections in people. Responses were evaluated through conjoint analysis and Likert-type questions. Data were analyzed using descriptive and analytic statistics. RESULTS: A total of 630 complete responses were included in the final analysis. Cost (37%) and method of administration (38%) were of similar participant preference when assessed using conjoint analysis. The importance of a drug for treating infections in people was lower priority (21%). The majority of cat owners preferred an antimicrobial that was 'very important' in treating human infections. A low proportion (21%) of participants responded that antimicrobial use in pets posed a risk to humans. Participants with a university education were more likely to respond that antimicrobial use in pets was a concern for people (31%; P <0.001). CONCLUSIONS AND RELEVANCE: Cat owners prioritize antimicrobial cost and method of administration equally. Few cat owners recognized the human antimicrobial resistance risks associated with antimicrobial use in pets.

Comparison of chlorhexidine and alcohol-based antisepsis of the distal limbs of horses.

BACKGROUND: An alcohol-based rub has been confirmed effective at reducing bacterial counts on equine skin. Skin sites with expected high bacterial burden have not been tested or has a comparison to a common protocol been performed. OBJECTIVES: To determine if ethanol-based antisepsis reduces bacterial counts on the equine distal limb comparable to a current chlorhexidine scrub method and determine the most effective application technique for the product. STUDY DESIGN: Randomised trial. METHODS: Forty-one horses were used in the study. By horse, each limb was randomly assigned to a treatment group: 5min scrub using 4% chlorhexidine gluconate to a clipped site (CHG); 90s scrub using 80% ethanol to a clipped site (ETC); 90s contact with 80% ethanol applied as a spray to a clipped site (ETS) and 90s scrub using 80% ethanol to an unclipped site (ETUC). Samples were collected pre- and post-treatment and plated in duplicate. Bacterial counts were log10 transformed and averaged between duplicates. A linear mixed model was used to compare mean log10 CFU/mL reduction between groups. A cost-benefit analysis was performed. RESULTS: There was no significant difference in mean log10 CFU/mL reduction between CHG and ETC in either fore- or hindlimbs. In forelimbs, there was no significant difference in mean log10 CFU/mL reduction between any groups. In hindlimbs, CHG had significantly greater mean log10 CFU/mL reduction than ETUC and ETS. No significant difference in cost-benefit was found between CHG and ETC. Significant differences were noted between CHG and both ETUC and ETS. MAIN LIMITATIONS: Researchers were not blinded to treatment group during sample collection. CONCLUSIONS: This study showed no significant difference in reduction in bacterial counts on the distal limb of horses between CHG and ethonol (ET) when applied as a scrub to a clipped site and there was no significant difference in cost-benefit between these treatments.

Canadian Dairy Network for Antimicrobial Stewardship and Resistance (CaDNetASR): An On-Farm Surveillance System.

Canada has implemented on-farm antimicrobial resistance (AMR) surveillance systems for food-producing animals under the Canadian Integrated Program for Antimicrobial Resistance (CIPARS); however, dairy cattle have not been included in that program yet. The objective of this manuscript was to describe the development and implementation of the Canadian Dairy Network for Antimicrobial Stewardship and Resistance (CaDNetASR). An Expert Panel (EP) of researchers was created to lead the development of the dairy surveillance system. The EP initiated a draft document outlining the essential elements of the surveillance framework. This document was then circulated to a Steering Committee (SC), which provided recommendations used by the EP to finalize the framework. CaDNetASR has the following components: (1) a herd-level antimicrobial use quantification system; (2) annually administered risk factor questionnaires; and (3) methods for herd-level detection of AMR in three sentinel enteric pathogens (generic Escherichia coli, Campylobacter spp., and Salmonella spp.) recovered from pooled fecal samples collected from calves, heifers, cows, and the manure pit. A total of 144 dairy farms were recruited in five Canadian provinces (British-Columbia, Alberta, Ontario, Québec, and Nova-Scotia), with the help of local herd veterinarians and regional field workers, and in September 2019, the surveillance system was launched. 97.1 and 94.4% of samples were positive for E. coli, 63.8, and 49.1% of samples were positive for Campylobacter spp., and 5.0 and 7.7% of samples were positive for Salmonella spp., in 2019 and 2020, respectively. E. coli was equally distributed among all sample types. However, it was more likely that Campylobacter spp. were recovered from heifer and cow samples. On the other hand, it was more common to isolate Salmonella spp. from the manure pit compared to samples from calves, heifers, or cows. CaDNetASR will continue sampling until 2022 after which time this system will be integrated into CIPARS. CaDNetASR will provide online access to farmers and veterinarians interested in visualizing benchmarking metrics regarding AMU practices and their relationship to AMR and animal health in dairy herds. This will provide an opportunity to enhance antimicrobial stewardship practices on dairy farms in Canada.

Application of next generation sequencing for detection of protozoan pathogens in shellfish.

Food and waterborne protozoan pathogens can cause serious disease in people. Three common species Cryptosporidium parvum, Giardia enterica and Toxoplasma gondii can contaminate diverse shellfish species, including commercial oysters. Current methods of protozoan detection in shellfish are not standardized, and few are able to simultaneously identify multiple species. Here, we present a novel metabarcoding assay targeting the 18S rRNA gene followed by next generation sequencing (NGS) for simultaneous detection of Cryptosporidium spp., Giardia spp. and T. gondii spiked into oyster samples. We further developed a bioinformatic pipeline to process and analyze 18S rRNA data for protozoa classification. The ability of the NGS assay to detect protozoa was later compared with conventional PCR. Results demonstrated that background amplification of oyster and other eukaryotic DNA competed with that of protozoa for obtained sequence reads. Sequences of target protozoans were obtained across all spiking levels; however, low numbers of target sequences in negative controls imply that a threshold for true positives must be defined for assay interpretation. While this study focused on three target parasites, the ability of this approach to detect numerous known and potentially unknown protozoan pathogens make it a promising screening tool for monitoring protozoan contamination in food and water.

Compliance with the Code of Practice for the Care and Handling of Equines on 50 horse farms in Prince Edward Island.

The objective of this study was to determine the proportion of horse farms on Prince Edward Island, Canada that comply with the requirements of the Code of Practice for the Care and Handling of Equines (Code). An investigator performed on-farm assessments while administering a questionnaire to owners of 50 horse farms. The percentage of farms in compliance with specific requirements in the Code ranged from 20% to 100% per requirement. The largest areas of non-compliance regarding facilities and housing were the lack of the ability to segregate sick or injured animals and the lack of an emergency action plan. It was determined that 72% of farms were in compliance with body condition scores and 54% reported to have taken corrective action when required. Farm owners who were aware of the Code were more likely to have good quality air in their barns as well as an emergency action plan in place.

L'objectif de la présente étude était de déterminer la proportion de fermes équines sur l'Île-du-Prince-Édouard, Canada qui se conforme aux exigences du Code de pratiques pour les soins et la manipulation des chevaux (Code). Un enquêteur effectua des évaluations à la ferme tout en procédant à un questionnaire auprès des propriétaires de 50 fermes équines. Le pourcentage de fermes en conformité avec des exigences spécifiques du Code variait de 20 % à 100 % selon l'exigence. Les secteurs les plus importants de nonconformité en regard des facilités et de logement étaient l'absence de la capacité à isoler les animaux malades ou blessés et l'absence d'un plan d'action d'urgence. Il fut déterminé que 72 % des fermes étaient en conformité pour les pointages d'état de chair et 54 % rapportèrent d'avoir pris les actions correctives lorsque requises. Les propriétaires de ferme qui étaient au courant du Code étaient plus susceptibles d'avoir un air de bonne qualité dans leurs fermes ainsi qu'un plan d'action d'urgence en place.(Traduit par Dr Serge Messier).

Short communication: Whole-genome sequence analysis of 4 fecal blaCMY-2-producing Escherichia coli isolates from Holstein dairy calves.

This study was carried out to determine the antimicrobial resistance (AMR) genes and mobile genetic elements of 4 fecal blaCMY-2-producing Escherichia coli isolated from Holstein dairy calves on the same farm using whole-genome sequencing. Genomic analysis revealed that 3 of the 4 isolates shared similar genetic features, including sequence type (ST), serotype, plasmid characteristics, insertion ST, and virulence genes. In addition to genes encoding for complex multidrug resistance efflux systems, all 4 isolates were carriers of genes conferring resistance to ß-lactams (blaCMY-2, blaTEM-1B), tetracyclines (tetA, tetB, tetD), aminoglycosides [aadA1, aph(3")-lb, aph(6)-ld], sulfonamides (sul2), and trimethoprim (dfrA1). We also detected 4 incompatibility plasmid groups: Inc.F, Inc.N, Inc.I, and Inc.Q. A novel ST showing a new purA and mdh allelic combination was found. The 4 isolates were likely enterotoxigenic pathotypes of E. coli, based on serotype and presence of the plasmid Inc.FII(pCoo). This study provides information for comparative genomic analysis of AMR genes and mobile genetic elements. This analysis could give some explanation to the multidrug resistance characteristics of bacteria colonizing the intestinal tract of dairy calves in the first few weeks of life.

Equine Skin Antisepsis Using an Alcohol-Based Rub.

Alcohol-based antisepsis has been extensively studied in human health care, but only little information is available regarding efficacy and tolerance in other species. The purpose of this study was to determine if an alcohol-based antiseptic is effective at reducing bacterial counts on equine skin and the appropriate contact time to do so, without causing any adverse skin reactions. Samples were collected before and after preparation from clipped sites over both jugular veins of horses and were plated on 3M Petrifilm Aerobic Count Plates in duplicate. Trial 1 tested an alcohol-based product (ET-80% ethanol) against a control of sterile saline at a contact time of 180-second. Trial 2 tested two different contact times of ET-90 and 180 seconds. All samples were assessed for colony-forming unit counts using an automated 3M Petrifilm reader. Data were analyzed by Kruskal-Wallis test, and the significance was set at P < .05. The results determined that ET had a mean 2.95 log10 reduction from prepreparation to postpreparation colony-forming unit counts. A significant difference in log reduction between ET and control (P = .0033) was observed. There was no difference in log10 reduction between the two contact times (P = .75). Mild urticaria was the only skin reaction observed and was often present in both ET and control groups. These findings demonstrate that ET is effective at reducing bacterial counts on equine skin at a contact time of 90 seconds without producing significant adverse skin reaction.

Effect of passive transfer of immunity on growth performance of preweaned dairy calves.

The primary objective of this observational study was to examine the association between passive transfer of immunity and growth performance in preweaning calves. A secondary objective was to evaluate the utility of a heart girth tape (HGT) to estimate body weight (BW) in preweaning calves. A total of 142 Holstein calves were enrolled in this study. Blood samples were collected 24 to 48 hours after birth and serum immunoglobulin G (IgG) concentration for each calf was measured by radial immunodiffusion assay. Calf BW was determined at birth, at 21 days, and at weaning using an electronic scale (ES) and HGT. A significant positive association was detected between serum IgG and both BW at 21 days and average daily gain (ADG) from 0 to 21 days of life. Additionally, ADG from 0 to 42 days of life showed a trend toward an improved rate of gain as IgG concentration increased. The Pearson correlation coefficient between BW obtained from ES and HGT was 0.81 at birth, 0.86 at 21 days, and 0.83 at weaning. The mean differences between BW obtained from ES and HGT were -3.1 kg at birth, -3.2 kg at 21 days, and -7.7 kg at weaning. In conclusion, serum IgG concentration in neonatal calves is an important contributing factor for the variation in growth performance of preweaning calves. The HGT can be used to estimate the BW of preweaning calves but has a tendency to overestimate weight, especially at weaning compared to birth and 21 days of age.

L'objectif principal de cette étude observationnelle était d'examiner l'association entre le transfert passif d'immunité et les performances de croissance chez des veaux en période de pré-sevrage. Un second objectif était d'évaluer l'utilité d'un ruban pour mesurer la circonférence du tronc au niveau du coeur (HGT) pour évaluer le poids corporel (PC) chez des veaux en période de pré-sevrage. Un total de 142 veaux Holstein fut inclus dans l'étude. Des échantillons de sang furent obtenus 24 et 48 h après la naissance et la concentration en immunoglobine G (IgG) sérique de chaque veau fut mesurée par épreuve d'immunodiffusion radiale. Le PC des veaux fut déterminé à la naissance, à 21 j, et au moment du sevrage à l'aide d'une balance électronique (BÉ) et du HGT. Une association positive significative fut détectée entre la concentration sérique d'IgG et le PC à 21 j d'âge et le gain journalier moyen (GJM) entre les jours d'âge 0 à 21. De plus, le GJM des jours 0 à 42 montrait une tendance vers un taux de gain amélioré à mesure que les concentrations en IgG augmentaient. Le coefficient de corrélation de Pearson entre le PC obtenu via la BÉ et le HGT était de 0,81 à la naissance, 0,86 à 21 j, et 0,83 au moment du sevrage. Les différences moyennes des valeurs de PC obtenues par BÉ et HGT étaient de −3,1 kg à la naissance, −3,2 kg à 21 j, et −7,7 kg au sevrage. En conclusion, la concentration sérique en IgG chez les veaux nouveau-nés est un facteur contribuant important des variations des performances de croissance des veaux en période pré-sevrage. Le HGT peut être utilisé pour estimer le PC de veaux en période de pré-sevrage mais à tendance à surestimer le poids, et ce plus spécialement au moment du sevrage comparativement au moment de la naissance et à 21 j d'âge.(Traduit par Docteur Serge Messier).

Multi-locus genotyping and phylogenetic analyses of Giardia intestinalis isolates from indigenous goats in Ogun State, Nigeria.

Giardiasis is a common gastrointestinal disease of humans and various animal species worldwide. In this study, 302 stool samples were collected from West African Dwarf and Sokoto Red breeds of goats in Ogun State, Nigeria, and screened for Giardia intestinalis coproantigens using enzyme-linked immunosorbent assay (ELISA). The genotypes of G. intestinalis in faecal samples collected from 152 goats raised on selected farms were identified by polymerase chain reaction (PCR) amplification and sequence analyses of the small subunit ribosomal RNA (ssu rRNA), glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi) and ß-giardin (bg) genes. Based on ELISA, an overall prevalence of 45.7% was recorded with the infection rates in pre-weaned (60.2%) and post-weaned goat kids (51.5%) being significantly (p < 0.05) higher than in adults (28.2%). Giardia intestinalis DNA was amplified in 31.6% and 29.6% of goat faeces at the ssu rRNA and gdh loci respectively. These were genotyped at the ssu rRNA locus as assemblages B (n = 13) and E (n = 36). Similar results were observed at the gdh locus except that eight isolates contained assemblage E mixed with either assemblage A or B. Additionally, sub-assemblages BI (n = 7) and BIII (n = 2) were identified with up to four single nucleotide polymorphisms (SNPs) occurring in these isolates. Multilocus genotypes (MLG) of all assemblage E isolates were identified using the ssu rRNA and gdh loci while MLG of all isolates containing assemblage B and mixed assemblages were determined after further typing at the tpi and bg loci. Forty-two MLG isolates were identified and these comprised 32, 8 and 2 (sub)-assemblage E, BI and BIII respectively. All isolates with mixed assemblages at the gdh locus were consequently designated as assemblage E by MLG. The assemblage E isolates from goats were genetically related to isolates from cattle, sheep and goats while the assemblage B isolates were related to isolates of human, pig and lemur origin. This suggests that G. intestinalis isolated from goats bred in Ogun State, Nigeria may be capable of cross-species transmission and may be of zoonotic importance.

Detection of endotoxin in plasma of hospitalized diarrheic calves.

OBJECTIVES: To investigate whether lipopolysaccharide (LPS) is present in plasma of calves with naturally occurring diarrhea. The second objective was to determine whether plasma [LPS] correlates with clinical, hematological, biochemical, and acid-base variables, and whether [LPS] differs between surviving and nonsurviving diarrheic calves. DESIGN: Prospective observational study (January 2012-May 2014). SETTING: Veterinary teaching hospital. ANIMALS: Thirty-four calves <28 days old admitted for diagnosis and treatment of diarrhea and 30 healthy control calves. MEASUREMENTS AND MAIN RESULTS: Admission demographics, physical examination, blood gas, biochemistry analysis, and outcome data were recorded. Plasma concentration of LPS was determined using a bovine LPS ELISA assay. Plasma [LPS] was detected in both healthy and diarrheic calves. Plasma [LPS] was significantly higher in diarrheic than healthy calves (median: 0.99 ng/mL; Interquartile range (IQR): 0.068, vs 0.88 ng/mL; 0.065 ng/mL, respectively; P < 0.001). Plasma [LPS] was higher in nonsurviving (1.04 ng/mL; 0.07 ng/mL) than in surviving calves (0.98 ng/mL; 0.022 ng/mL; P < 0.001). Plasma [LPS] was higher in beef (1.07 ng/mL; 0.182 ng/mL) than in dairy diarrheic calves (0.99 ng/mL; 0.022 ng/mL; P < 0.001). In diarrheic calves, plasma [LPS] correlated with [l-lactate] (r2 = 0.496; P = 0.002); hypoglycemia (r2 = -0.453; P = 0.007); increased unmeasured strong ions (r2 = 0.332; P = 0.050), [Mg2+ ] (r2 = 0.475; P = 0.004), and [phosphate] (r2 = 0.468; P = 0.005), and increased aspartate aminotransferase activity (r2 = 0.348; P = 0.003). CONCLUSIONS: This study highlights a potential role of LPS in the pathogenesis of metabolic derangements such as hyperlactatemia, hypoglycemia, and increased concentration of unmeasured strong anions in diarrheic calves. Further investigation evaluating the effect of LPS on l-lactate and glucose metabolism in diarrheic calves is warranted.

Prevalence and multilocus genotypes of Giardia duodenalis infecting pigs in Ogun state, Nigeria.

Giardia duodenalis is an intestinal flagellated protozoan parasite that is infectious to humans and a wide range of animals worldwide. While varying prevalence rates have been reported in pigs worldwide, there are currently no published reports on the genotypes of Giardia infecting pigs in any African country. The present study is on the prevalence and genotypes of G. duodenalis in 209 pigs raised on four farms in Ogun State Nigeria. Using an enzyme-linked immunosorbent assay (ELISA) kit, Giardia duodenalis coproantigens were detected on all farms and in 25.4% (53/209) of pigs sampled. However, there was no significant influence (p > 0.05) of age, sex and stool consistencies of the pigs on the distribution of the infection. Genotyping of Giardia duodenalis in all ELISA-positive samples, achieved by the amplification of the small subunit ribosomal RNA (ssu rRNA), glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi) and beta giardin (bg) genes, identified 14 and 37 assemblage B and E isolates respectively while mixed infection by both assemblages was recorded in two isolates. Novel nucleotide substitutions were identified in four assemblage B isolates at the ssu rRNA locus. Genetic diversity was observed among the assemblage B isolates after multiple alignment analyses of the gdh, tpi and bg sequences whereby sub-assemblages BII (n = 2), BIII (n = 9) and BIV (n = 3) were identified. The assemblage B isolates from pigs in this study were phylogenetically related to isolates from humans, marmoset and cattle while the assemblage E isolates were related to isolates from sheep, goats and cattle. These findings suggest that pigs in southwest Nigeria predominantly harbour G. duodenalis isolates that could be infectious to other animal species and to a lesser extent, isolates that may be of zoonotic importance.

Diagnostic performance of direct and indirect methods for assessing failure of transfer of passive immunity in dairy calves using latent class analysis.

Accurate diagnosis of failure of transfer of passive immunity (FTPI) in newborn calves is an essential component of dairy farm management plan. Several methods (direct and indirect) are available for diagnosis of FTPI in dairy calves. However, the indirect methods offer an advantage over the direct methods in not requiring an experienced veterinarian, rapid, cost efficient and can be performed under field-setting. The objective of this study was to estimate the diagnostic performance of radial immunodiffusion (RID) assay, transmission infrared (TIR) spectroscopy and digital Brix refractometer for diagnosis of FTPI in dairy calves using latent class models at four cut-off values of digital Brix refractometer. Holstein calves (n = 691) from 40 commercial dairy farms in the four Atlantic Canada provinces were blood-sampled and tested for detection of FTPI. Results showed that the number of calves with FTPI was 253 (36.6%) by RID, 194 (28.1%) by TIR and 204 (29.5%) by Brix refractometer at cut-off value of 8.2%. Estimates of SeRID was higher than SeTIR and SeBrix, at all Brix refractometer cut-offs, but with increase of Brix refractometer cut-off from 8.2 to 8.5%, SeRID and SeTIR were decreased from 96.0% (95% PCI: 88.0-99.0) and 79.0% (95% PCI: 70.0-85.0), to 92.0% (95% PCI: 77.0-99.0) and 74.0% (95% PCI: 61.0-82.0), respectively. SpRID and SpTIR were always higher than SpBrix at all tested cut-offs and were above 92.0%, and 96.0%, respectively. With increasing the cut-off of Brix refractometer from 8.2 to 8.5%, SeBrix estimate has remarkably increased from 79.0% (95% PCI: 70.0-96.0) to 95.0% (95% PCI: 87.0-100.0), respectively. Whilst, SpBrix was decreased from 95.0% (95% PCI: 91.0-98.0) at cut-off 8.2% to 84.0% (95% PCI: 78.0-94.0) at cut-off 8.5%. In conclusion, RID has a higher Se than TIR and Brix, if the latter is used with cut-offs of 8.2% or 8.3%. However, the higher the cut-off, the more comparable sensitivities of RID and digital Brix refractometer. The median estimate of SpTIR was always higher than SpRID and SpBrix at all tested cut-offs. However, the 95% confidence interval estimates of the three tests were overlapping across the tested cut-offs of digital Brix refractometer reflecting the inability to prefer a test over the other based on the Sp estimate.