Évaluation et gestion du risque associé à la présence de Salmonella spp. chez le porc à l'abattoir

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Prevalence and-resistance patterns of Salmonella spp. serotypes from humans and production animals in Canada

The aim of the study was to compare the serotypes and antimicrobial resistance patterns of Salmonella from humans, pigs and poultry. Fecal samples were processed using conventional enrichment and culture procedures. Randomly selected isolates were tested against 12 different antimicrobial agents (ampicillin, amoxycillinlclavulamic acid, chloramphenicol, ceftiofur, enrofloxacin, gentamicin, neomycin, spectinocycin, streptomycin, sulfisoxazol, tetracyclin and sulfamethoxazol/trimetroprim) by the Kirby-Bauer technique. The prevalence of Salmonella was evaluated at 20,9% (18,9-23,0 %) in finishing pigs, 13,4% (12,0-14,9 %) in poultry and 2,9 (2,1-3,8 %) in humans. These isolates belonged to 22 different serotypes. Three serotypes were identified in all species, namely Typhimurium, Heidelberg and Agona. Multiple resistance was found in 26,7% of humans, 84,2 % of pigs and 71 ,4 % of poultry strains of S. Typhimurium. Antimicrobial resistance was thus commonly observed in humans, pigs and poultry isolates recovered in this study

Genotypic characterization of Salmonella Typhimurium isolates from humans, pigs and poultry in Canada

A total of 101 isolates of Salmonella enterica serovar Typhimurium were characterized in this study to evaluate the risk for human health associated with the presence of Salmonella isolates in pigs and poultry. Fifteen isolates recovered from human clinical specimens were compared to animal isolates. Isolates were recovered during the same period and in the same geographical area and characterized by establishing their genotypic and phenotypic profiles. All strains were characterized by phage-typing, antimicrobia l resistance patterns to various antimicrobial agents and pulsed-field gel electrophoresis (PFGE) of genomic DNA using Xba I and Spe I. The most frequently isolated phage type was phage type 104 in human (20,0 %), PT 104 in pig (40,2 %) and S. Typhimurium variant copenhagen I 04 in poultry (50,0 %). Spe I gave the highest index of discrimination among S. Typhimurium as evidenced by the variety of PFGE patterns obtained. The typing of the isolates showed that some animal and human strains were genetically related

TRIAD zoning in Quebec: Experiences and results after 5 years

The TRIAD approach to forest management involves dividing the forest into 3 zones, each with its own management\ud objectives, but with the overall goal of increasing the ecological and economic sustainability of the forest. For the past 5 years, we have been experimenting with TRIAD zoning in central Quebec, incorporating social interests into the original concept of TRIAD management. Results generally indicate that this approach is economically viable, socially acceptable, and preferable ecologically in this area. Although much remains to be done, thus far the consensus among the\ud various project participants is that this approach may be a good fit for the public forest of Canada

Genotypic characterization of Salmonella Typhimurium isolates from humans, pigs and poultry in Canada

A total of 101 isolates of Salmonella enterica serovar Typhimurium were characterized in this study to evaluate the risk for human health associated with the presence of Salmonella isolates in pigs and poultry. Fifteen isolates recovered from human clinical specimens were compared to animal isolates. Isolates were recovered during the same period and in the same geographical area and characterized by establishing their genotypic and phenotypic profiles. All strains were characterized by phage-typing, antimicrobia l resistance patterns to various antimicrobial agents and pulsed-field gel electrophoresis (PFGE) of genomic DNA using Xba I and Spe I. The most frequently isolated phage type was phage type 104 in human (20,0 %), PT 104 in pig (40,2 %) and S. Typhimurium variant copenhagen I 04 in poultry (50,0 %). Spe I gave the highest index of discrimination among S. Typhimurium as evidenced by the variety of PFGE patterns obtained. The typing of the isolates showed that some animal and human strains were genetically related.</p

Prevalence and-resistance patterns of Salmonella spp. serotypes from humans and production animals in Canada

The aim of the study was to compare the serotypes and antimicrobial resistance patterns of Salmonella from humans, pigs and poultry. Fecal samples were processed using conventional enrichment and culture procedures. Randomly selected isolates were tested against 12 different antimicrobial agents (ampicillin, amoxycillinlclavulamic acid, chloramphenicol, ceftiofur, enrofloxacin, gentamicin, neomycin, spectinocycin, streptomycin, sulfisoxazol, tetracyclin and sulfamethoxazol/trimetroprim) by the Kirby-Bauer technique. The prevalence of Salmonella was evaluated at 20,9% (18,9-23,0 %) in finishing pigs, 13,4% (12,0-14,9 %) in poultry and 2,9 (2,1-3,8 %) in humans. These isolates belonged to 22 different serotypes. Three serotypes were identified in all species, namely Typhimurium, Heidelberg and Agona. Multiple resistance was found in 26,7% of humans, 84,2 % of pigs and 71 ,4 % of poultry strains of S. Typhimurium. Antimicrobial resistance was thus commonly observed in humans, pigs and poultry isolates recovered in this study.</p

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used