Comparison of annual and regional variation in multidrug resistance using various classification metrics for generic Escherichia coli isolated from chicken abattoir surveillance samples in Canada.

Antimicrobial resistance (AMR) and related multidrug resistance (MDR) are important global public health issues. The Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) conducts surveillance of AMR in enteric bacteria and monitors MDR. However, the analysis of MDR is complicated by the lack of consensus for MDR definitions. The objectives were to describe the most common resistance patterns in generic E. coli isolates from chicken cecal samples and determine the impact of using different MDR metrics for analysis of annual and regional variation in MDR. From 2006 to 2015, 1598 E. coli isolates were collected from chickens at slaughter for CIPARS. Three MDR classification metrics were used: MDR-drug (MDR if the isolate was resistant (R) to ≥3 of the 13 antimicrobials); MDR-cat (MDR if R to ≥3 of the 9 antimicrobials categories); and MDR-class (MDR if R to ≥3 of the 6 antimicrobial classes). The most frequent resistance patterns overall, and by year and region were extracted along with patterns that included resistance to quinolones, and third generation cephalosporins and/or ß-lactams with ß-lactamase inhibitors. For each MDR metric, mixed logistic regression models, which included random intercepts for abattoir, were fitted to analyze the association between prevalence of MDR, and year and region. Interaction effects between year and region were evaluated. Overall, and in all years and regions, non-resistant was the most common resistance pattern (24.9%, 95% CI 22.8-27.1%). Resistance patterns that included third generation cephalosporins and ß-lactams with ß-lactamase inhibitors were common. The prevalence of MDR was variable: MDR-class 38.5% (95% CI 36.1-41.0%); MDR-cat 49.4% (95% CI 46.9-51.9%); and MDR-drug 53.3% (95% CI 50.8-55.8%). Based on models fitted with individual fixed effects, significant annual variation in the prevalence of MDR was identified with MDR-drug and MDR-class models. Significant regional variation was identified for all three MDR metric models. Significant interaction effects between year and region were identified with the MDR-drug and MDR-cat multivariable mixed logistic regression models. The interpretation of the association between the prevalence of MDR, and year and region differed depending on the MDR metric used. These results are supportive of the previous concerns that caution must be taken when comparing MDR results between studies. Global consensus is needed for the optimal MDR classification metric for foodborne enteric bacteria AMR surveillance.

The effect of dystocia on physiological and behavioral characteristics related to vitality and passive transfer of immunoglobulins in newborn Holstein calves.

The objective of this study was to examine the effect of calving difficulty or dystocia on the vitality of newborn calves and its association with blood pH, the apparent efficiency of immunoglobulin G (IgG) absorption (AEA), and weight gain. A total of 45 calving events (N = 48 calves) were monitored from the first sight of fetal membranes. All calves were assessed at the time of first attaining sternal recumbency (SR), at 2 and 24 h, and at 7 and 14 d of age. Measurements included time to SR, rectal temperature, respiration and heart rate, analysis of blood gases and other blood measures, suckling response, time to standing, passive transfer of IgG, and weight gain. Calves were separated from their dam 2 h after birth and fed a commercial colostrum replacer containing 180 g of IgG by esophageal tube feeder. Calves born following dystocia had lower venous blood pH and took longer to attain SR and attempt to stand than those born unassisted. Duration of calving interacted with the number of people required to extract the calf by pulling as a significant predictor of pH at SR. No association was found between pH at SR and AEA. However, reduced AEA was found in calves that were female and in calves that did not achieve SR within 15 min of birth. A longer calving duration, being born in July or August rather than June, and a shorter time spent standing in the first 2 d of life were significantly associated with reduced weight gain to 14 d. It was concluded that factors at calving impact the physiology, vitality, and subsequent weight gain of newborn calves.

L'objectif de la présente étude était d'examiner les effets des difficultés au moment du vêlage ou dystocie sur la vitalité de veaux nouveaunés et l'association avec le pH sanguin, l'efficacité apparente d'absorption des immunoglobulines G (IgG) (EAA), et le gain de poids. Quarante-cinq vêlages (N = 48 veaux) furent surveillés à partir de la première visualisation des membranes foetales. Tous les veaux furent évalués au moment de la première fois qu'ils étaient en décubitus sternal (DS), à 2 et 24 h, et à 7 et 14 jours d'âge. Les données recueillies incluaient le délai pour atteindre le DS, la température rectale, les rythmes respiratoire et cardiaque, l'analyse des gaz sanguins et d'autres mesures sanguines, la réponse de tétée, le délai pour se tenir debout, le transfert passif d'IgG et le gain de poids. Les veaux furent séparés de leur mère 2 h après la naissance et nourris par tube oesophagien avec un substitut commercial du colostrum contenant 180 g d'IgG. Les veaux nés suivant une dystocie avaient un pH sanguin veineux plus bas et ont pris plus de temps pour atteindre le DS et tenter de se lever que ceux nés sans assistance. La durée du vêlage a interagit avec le nombre de personnes requis pour extraire le veau en tirant comme un prédicteur significatif du pH à DS. Aucune association ne fut trouvée entre le pH à DS et l'EAA. Toutefois, une EAA réduite fut notée chez les génisses et chez les veaux qui n'étaient pas en DS à l'intérieur d'un délai de 15 min suivant la naissance. Une durée plus longue du vêlage, une naissance en juillet ou août plutôt qu'en juin, et un temps plus court à se tenir debout pendant les deux premières journées de vie étaient associés significativement avec un gain de poids moindre après 14 j. Il a été conclu que des facteurs au moment du vêlage ont un impact sur la physiologie, la vitalité et le gain de poids à venir de veaux nouveau-nés.(Traduit par Docteur Serge Messier).

Surveillance of antimicrobial resistance in clinical isolates of Pasteurella multocida and Streptococcus suis from Ontario swine.

Susceptibility results for Pasteurella multocida and Streptococcus suis isolated from swine clinical samples were obtained from January 1998 to October 2010 from the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, and used to describe variation in antimicrobial resistance (AMR) to 4 drugs of importance in the Ontario swine industry: ampicillin, tetracycline, tiamulin, and trimethoprim-sulfamethoxazole. Four temporal data-analysis options were used: visualization of trends in 12-month rolling averages, logistic-regression modeling, temporal-scan statistics, and a scan with the "What's strange about recent events?" (WSARE) algorithm. The AMR trends varied among the antimicrobial drugs for a single pathogen and between pathogens for a single antimicrobial, suggesting that pathogen-specific AMR surveillance may be preferable to indicator data. The 4 methods provided complementary and, at times, redundant results. The most appropriate combination of analysis methods for surveillance using these data included temporal-scan statistics with a visualization method (rolling-average or predicted-probability plots following logistic-regression models). The WSARE algorithm provided interesting results for quality control and has the potential to detect new resistance patterns; however, missing data created problems for displaying the results in a way that would be meaningful to all surveillance stakeholders.

Les résultats de sensibilité pour des isolats de Pasteurella multocida et Streptococcus suis provenant d'échantillons cliniques de porcs furent obtenus du Animal Health Laboratory de l'Université de Guelph pour la période de janvier 1998 à octobre 2010, et utilisés pour décrire la variation dans la résistance antimicrobienne (AMR) à quatre antibiotiques d'importance dans l'industrie porcine en Ontario : l'ampicilline, la tétracycline, la tiamuline, et le trimethoprime-sulfaméthoxazole. Quatre options temporelles d'analyse des données ont été utilisées : visualisation des tendances des moyennes mobiles de 12 mois, modélisation de régression logistique, statistiques d'un scan temporel, et un scan avec l'algorithme «Qu'y a-t-il d'étrange avec des évènements récents?¼ (WSARE). Les tendances d'AMR variaient entre les antibiotiques pour un agent pathogène et entre les agents pathogènes pour un antibiotique unique, ce qui suggère que la surveillance AMR pour un agent pathogène spécifique serait préférable à des données indicatrices. Les quatre méthodes ont fourni des données complémentaires, et parfois des résultats redondants. La combinaison la plus appropriée de méthodes d'analyse pour la surveillance en utilisant ces données incluait les statistiques d'un scan temporel avec une méthode de visualisation (moyenne mobile ou graphes de probabilité prédite suite à des modèles de régression logistique). L'algorithme WSARE a fourni des résultats intéressants pour le contrôle de qualité et a le potentiel de détecter des nouveaux patrons de résistance; toutefois, des données manquantes ont causé des problèmes pour montrer les résultats d'une manière qui serait signifiante pour toutes les personnes concernées par la surveillance.(Traduit par Docteur Serge Messier).

Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD.

Assessment of diagnostic tools for identifying cattle shedding and super-shedding Escherichia coli O157:H7 in a longitudinal study of naturally infected feedlot steers in Ohio.

The objectives of this study were to compare the performance of different diagnostic protocols (rectoanal mucosal swabs and immunomagnetic separation [RAMS-IMS], fecal samples and IMS [fecal-IMS], and direct plating) to determine the prevalence of Escherichia coli O157:H7 and to evaluate the pattern of E. coli O157:H7 shedding and super-shedding (defined as having a direct plating count equal to or >10(4) colony forming units of E. coli O157:H7 per gram of feces) in a longitudinal study of naturally infected feedlot steers. RAMS and fecal grab samples were obtained at 14-day intervals from 168 Angus-cross beef steers over a period of 22 weeks. Fecal samples were assessed by direct plating and IMS, whereas RAMS were tested only by enrichment followed by IMS to recover E. coli O157:H7. The period prevalence for shedding was high (62%) among feedlot steers and super-shedding was higher (23%) than anticipated. Although direct plating was the least sensitive method to detect E. coli O157:H7-positive samples, over 20% of high bacterial load samples were not detected by RAMS-IMS and/or fecal-IMS. The sensitivity of RAMS-IMS, fecal-IMS, and direct plating protocols was estimated using simple and multilevel mixed-effects logistic regression models, in which the dependent variable was the dichotomous results of each test and gold standard (i.e., parallel interpretation of the three protocols)-positive individuals were included as an independent variable along with other factors such as dietary supplements, time of sampling, and being exposed to a super-shedding pen-mate. The associations between these factors and the sensitivity of the diagnostic protocols were not statistically significant. In conclusion, differences in the reported impact of diet and probiotics on the shedding of E. coli O157:H7 in previous studies using RAMS-IMS or fecal-IMS were unlikely due to their impact on test performance.

A province-level risk factor analysis of fluoroquinolone consumption patterns in Canada (2000-06).

OBJECTIVES: To assess potential risk factors among socioeconomic variables and the rate of influenza for the use of different fluoroquinolone antimicrobials in Canada, and to evaluate modelling fluoroquinolone-use data by two different outcome measures. METHODS: Fluoroquinolone use was described monthly from 2000 to 2006 by two outcome measurements: defined daily doses and prescription counts. Multivariable linear and negative binomial models were produced with socioeconomic and influenza rate data. RESULTS: Significant socioeconomic predictors varied among the individual fluoroquinolone models, which may reflect the range of infections that are treated with fluoroquinolones. However, socioeconomic variables within the ciprofloxacin and levofloxacin models were similar, and indicated that use was highest in advantaged populations, depending on the measures being assessed. The rate of influenza was a significant predictor within models describing levofloxacin use and the defined daily dose model for ciprofloxacin use, after accounting for season. Influenza significantly interacted with the education variable in the levofloxacin defined daily dose model. CONCLUSIONS: Significant associations between levofloxacin use and influenza rates, after accounting for season, may suggest that levofloxacin was used to treat secondary bacterial infections or was prescribed inappropriately for seasonal viral respiratory tract infections. Yearly patterns of ciprofloxacin use show that prescribing practices changed; more ciprofloxacin prescriptions were dispensed towards the end of the study period, but for smaller doses or shorter treatment times. Associations with socioeconomic variables suggest that the fluoroquinolones ciprofloxacin and levofloxacin were more likely to be used in advantaged populations, probably due to the high cost of fluoroquinolone antimicrobials in comparison to the penicillin and macrolide groups.

A randomized controlled trial to assess the impact of dietary energy sources, feed supplements, and the presence of super-shedders on the detection of Escherichia coli O157:H7 in feedlot cattle using different diagnostic procedures.

Alteration of the gastro-intestinal tract through manipulation of cattle diets has been proposed as a preharvest control measure to reduce fecal shedding of Escherichia coli O157:H7. The objective of this study was to examine the effects of the energy source's moisture content (high moisture corn and dry whole-shelled corn), two natural feed supplements (Saccaromyces cerevisiae boulardii CNCM 1079-Levucell and Aspergillus oryzae-Amaferm), and two levels of vitamin A (2200 IU/kg and no supplementation) on the fecal excretion of E. coli O157:H7 in naturally infected cattle. One hundred sixty-eight Angus-cross beef steers were randomly allocated to 24 pens, and each pen was assigned 1 of 12 dietary treatments in a randomized complete block design. E. coli O157:H7 was detected by rectoanal mucosal swab (RAMS) and fecal grab samples using immunomagnetic separation (IMS) and standard microbiological techniques. On the basis of multivariable multilevel logistic regression models, we found a statistically significant (p < 0.05) increase in the prevalence of E. coli O157:H7 in animals fed dry whole-shelled corn in models based on fecal-IMS, and this effect was increased if a super-shedding animal (shedding > 10(4) colony forming units of E. coli O157:H7 per gram of feces) was present in the pen at the time of testing relative to animals fed high moisture corn and nonexposed to super-shedders. However, in similar models based on RAMS-IMS testing, the effect of corn type on the prevalence of E. coli O157:H7 varied with the type of feed additive used. Being exposed to a super-shedding pen-mate also increased the odds of being positive to E. coli O157:H7 in the RAMS-IMS models. These models demonstrate that the impact of different supplements may vary with the diagnostic test used, and that further research into the biological significance of differences between RAMS- and fecal-IMS test results is warranted.