Genotypic and phenotypic characterization of Staphylococcus aureus causing persistent and nonpersistent subclinical bovine intramammary infections during lactation or the dry period

KA Veh, RC Klein, C Ster, G Keefe, P Lacasse, D Scholl, J-P Roy, D Haine, S Dufour, BG Talbot, AOB Ribon, F Malouin

Staphylococcus aureus is a significant pathogen frequently causing persistent intramammary infections (IMI) in dairy cows. We compared some genotypic and phenotypic characteristics of 285 strains collected from quarter milk samples from cows with persistent and nonpersistent subclinical IMI across Canada. Variable number of tandem repeats typing was used to infer the persistence of the same S. aureus strain in 3 consecutive quarter milk samples collected at intervals of 3 wk during lactation or before and after dry-off. Read More

Zinc as an agent for the prevention of biofilm formation by pathogenic bacteria

C Wu, J Labrie, YDN Tremblay, D Haine, M Mourez, M Jacques

AIMS: Biofilm formation is important for the persistence of bacteria in hostile environments. Bacteria in a biofilm are usually more resistant to antibiotics and disinfectants than planktonic bacteria. Our laboratory previously reported that low concentrations of zinc inhibit biofilm formation of Actinobacillus pleuropneumoniae. The aim of this study is to evaluate the effect of zinc on growth and biofilm formation of other bacterial swine pathogens. METHODS AND RESULTS: To determine the effect of zinc on biofilm formation, biofilms were grown with or without zinc in 96-well plates and stained with crystal violet. Read More

Characterization of the ability of coagulase-negative staphylococci isolated from the milk of Canadian farms to form biofilms

YDN Tremblay, D Lamarche, P Chever, D Haine, S Messier, M Jacques

“Mastitis is the most common and detrimental infection of the mammary gland in dairy cows and has a major economic impact on the production of milk and dairy products. Bacterial mastitis is caused by several pathogens, and the most frequently isolated bacterial species are coagulase-negative staphylocci (CNS). Although CNS are considered minor mastitis pathogens, the importance of CNS has increased over the years. However, the mechanism and factors involved in CNS intramammary infection are poorly studied and defined. Read More

Bayesian estimation of the diagnostic accuracy of a multiplex real-time PCR assay and bacteriological culture for 4 common bovine intramammary pathogens

M-È Paradis, D Haine, B Gillespie, SP Oliver, S Messier, J Comeau, DT Scholl

Bacteriological culture (BC) is the traditional method for intramammary infection diagnosis but lacks sensitivity and is time consuming. Multiplex real-time PCR (mr-PCR) enables testing the presence of several bacteria and reduces diagnosis time. Our objective was to estimate bacterial species-specific sensitivity (Se) and specificity of both BC and mr-PCR tests for detecting bacteria in milk samples from clinical mastitis cases and from apparently normal quarters, using a Bayesian latent class model. Read More

Examining the effect of intramammary infections with minor mastitis pathogens on the acquisition of new intramammary infections with major mastitis pathogens - A systematic review and meta-analysis

KK Reyher, D Haine, IR Dohoo, CW Revie

Major mastitis pathogens such as Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, and the coliforms are usually considered more virulent and damaging to the udder than minor mastitis pathogens such as Corynebacterium bovis and coagulase-negative staphylococci (CNS). The current literature contains several studies detailing analyses with conflicting results as to whether intramammary infection (IMI) with the minor pathogens decreases, increases, or has no effect on the risk of a quarter acquiring a new intramammary infection (NIMI) with a major pathogen. Read More

Identification of coagulase-negative Staphylococcus species by gas chromatography

M-È Paradis, D Haine, S Messier, J Middleton, J Perry, AI Ramirez, DT Scholl

Researching the impact and epidemiology of coagulase-negative Staphylococcus species (CNS) causing intramammary infections (IMI) require their identification at the species level. Gene sequencing is the gold standard but faster and less expensive methods could be useful. The Sherlock Microbial Identification System is an automated gas chromatographic (MIS-GC) system able to speciate CNS isolates in human clinical medicine by identifying the unique cellular fatty acid patterns in bacteria cell walls. Our objective was to validate the MIS-GC method for speciating CNS responsible for IMI in dairy cows. Read More

Tolerability and effectiveness of preservative-free dorzolamide–timolol (preservative-free COSOPT®) in patients with open-angle glaucoma or ocular hypertension

C Hutnik, D Neima, F Ibrahim, R Scott, J Vaillancourt, D Haine, JS Sampalis, N Bastien, S Foucart

Purpose: To assess the effect of preservative-free dorzolamidetimolol on nonvisual symptoms and intraocular pressure (IOP) in newly diagnosed and untreated patients with open-angle glaucoma or ocular hypertension. Methods: This was a prospective, 8-week, open-label, Canadian multicenter study. All patients were treated with preservative-free dorzolamidetimolol formulation. The primary outcome was the change in the nonvisual symptom score of the Glaucoma Symptom Scale (GSS-SYMP-6) from baseline to 8 weeks. Secondary effectiveness outcome measures were absolute and percent changes in IOP from baseline to 4 and 8 weeks. Read More

Tramiprosate in mild-to-moderate Alzheimer's disease - a randomized, double-blind, placebo-controlled, multi-centre study (the Alphase Study)

PS Aisen, S Gauthier, SH Ferris, D Saumier, D Haine, D Garceau, A Duong, J Suhy, J Oh, WC Lau, J Sampalis

Introduction: The aim of the study was to assess the clinical efficacy, safety, and disease-modification effects of tramiprosate (homotaurine, ALZHEMED™) in mild-to-moderate Alzheimer’s disease (AD). Material and methods: Double-blind, placebo-controlled, randomized trial in 67 clinical centres across North America. Patients aged >= 50 years, with mild-to-moderate AD (Mini-Mental State Examination score between 16 and 26) and on stable doses of cholinesterase inhibitors, alone or with memantine. Intervention: 78-week treatment with placebo, tramiprosate 100 mg or tramiprosate 150 mg BID. Read More

Domain-specific cognitive effects of tramiprosate in patients with mild to moderate Alzheimer's disease: ADAS-cog subscale results from the Alphase Study

D Saumier, A Duong, D Haine, D Garceau, J Sampalis

OBJECTIVES: Tramiprosate (homotaurine, ALZHEMED™) was recently investigated for its efficacy, safety and disease-modification effects in a Phase III clinical study in mild to moderate Alzheimer’s disease (AD) patients (the Alphase study). The primary cognitive endpoint measure of that study was the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog). To characterize potential cognitive benefits of tramiprosate, the present study describes exploratory analyses performed on scores obtained from the specific ADAS-cog subscales in order to determine whether specific domains of cognition may be differentially affected by tramiprosate, which would not have been evident from the measure’s total score. Read More

Montelukast as add-on therapy to inhaled corticosteroids in the management of asthma (the SAS trial)

JM Fitzgerald, S Foucart, S Coyle, J Sampalis, D Haine, E Psaradellis, RA McIvor

AIM: To evaluate the effectiveness of montelukast as add-on therapy for asthmatic patients who remain uncontrolled with low, moderate or high doses of inhaled corticosteroid monotherapy. DESIGN: An eight-week, multicentre, open-label, observational study. RESULTS: Of 320 patients enrolled, 288 (90.0%) completed the study. Of patients who had uncontrolled asthma symptoms (Canadian Asthma Consensus Guidelines Update, 2003) but were controlled according to the Asthma Control Questionnaire (ACQ score of less than 1. Read More