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Objectives: To evaluate the spermicidal efficacy of non-hormonal vaginal gel in vitro and in a post-coital test, and to evaluate its contraceptive efficacy in Canadian women of childbearing age., Methods: We conducted single-centre trial to assess spermicidal and contraceptive efficacy of vaginal gel. Participants were healthy, sexually active women aged 18-49 years and their regular male sexual partners (30 couples). Measured outcomes included effect of vaginal gel on sperm motility in vitro, its effect on sperm in a post-coital test, and its effect on pregnancy prevention over 3 months., Results: For in vitro spermicidal effect, 98% and 67% of sperm were immotile in the presence of the gel with sodium lauryl sulfate (gel-SLS) and gel alone, respectively. For the post-coital test, 99% and 93% of sperm were immotile in the presence of gel-SLS and gel alone, respectively. In the second part of trial, a total of 410 instances of vaginal intercourse in 95 menstrual cycles were protected (during 3-month period of gel-SLS use before each sexual intercourse with probability of 24 conceptions prevented according to Wilcox's table). Four women became pregnant during the study period; 2 during unprotected vaginal intercourse around the time of ovulation, and 2 attributed to user failure., Conclusion: Based on our results, the vaginal gel demonstrated important spermicidal and contraceptive effect. A larger phase III contraceptive efficacy trial is warranted. The vaginal gel may represent a non-hormonal spermicide/contraceptive option for women., (Copyright © 2021 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

This work demonstrates the ability of a bacterial concentration and recovery procedure combined with three different PCR assays targeting the lacZ, wecG, and 16S rRNA genes, respectively, to detect the presence of total coliforms in 100-ml samples of potable water (presence/absence test). PCR assays were first compared to the culture-based Colilert and MI agar methods to determine their ability to detect 147 coliform strains representing 76 species of Enterobacteriaceae encountered in fecal and environmental settings. Results showed that 86 (58.5%) and 109 (74.1%) strains yielded a positive signal with Colilert and MI agar methods, respectively, whereas the lacZ, wecG, and 16S rRNA PCR assays detected 133 (90.5%), 111 (75.5%), and 146 (99.3%) of the 147 total coliform strains tested. These assays were then assessed by testing 122 well water samples collected in the Québec City region of Canada. Results showed that 97 (79.5%) of the samples tested by culture-based methods and 95 (77.9%), 82 (67.2%), and 98 (80.3%) of samples tested using PCR-based methods contained total coliforms, respectively. Consequently, despite the high genetic variability of the total coliform group, this study demonstrated that it is possible to use molecular assays to detect total coliforms in potable water: the 16S rRNA molecular assay was shown to be as efficient as recommended culture-based methods. This assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

To assess molecular evolution of the respiratory syncytial virus (RSV) fusion gene, we analyzed RSV-positive specimens from 123 children in Canada who did or did not receive RSV immunoprophylaxis (palivizumab) during 2006-2010. Resistance-conferring mutations within the palivizumab binding site occurred in 8.7% of palivizumab recipients and none of the nonrecipients.

Background: A new human coronavirus (HCoV), HCoV-NL, was recently reported for Dutch patients with acute respiratory tract infections (ARTI). Little information is available on the incidence, clinical manifestations and epidemiologic features of HCoV-NL infections., Methods: We performed a prospective study of symptomatic (case subjects with ARTI) and asymptomatic (control subjects undergoing elective surgery) children,

Objective: Cephalosporins, especially cefazolin, are widely used in the prevention of postoperative wound infections after cardiac operations. As more and more Staphylococcus aureus and Staphylococcus epidermidis strains are becoming resistant to cephalosporins and other antibiotics, alternative agents, such as glycopeptides, are often used as prophylaxis. We performed a multicenter double-blind randomized controlled trial comparing teicoplanin, a glycopeptide antibiotic, with cefazolin., Methods: A total of 3027 adult patients undergoing elective coronary artery bypass grafting, valve operations, or both were randomized to a single dose of teicoplanin (15 mg/kg) or a 2-day course of cefazolin (2 g initial dose, followed by 1 g every 8 hours for 6 more doses). Patients were followed up for a total of 6 months postoperatively. The primary objective was to compare, between groups, the incidence of surgical infections up to 30 days postoperatively. Secondary objectives were incidence of other infections, other complications, and death., Results: A total of 3027 patients were randomized to receive either teicoplanin (n = 1518) or cefazolin (n = 1509). Thirty days postoperatively, there was a trend to more deep sternotomy wound infections in the teicoplanin group (31 vs 18, P =. 087), which became significant by 6 months (36 vs 19, P =.032). One hundred percent of the gram-positive strains infecting patients were susceptible to teicoplanin, whereas 8.3% were resistant to cefazolin. Pneumonia and urinary tract infections were more common in the teicoplanin group. Deep wound infections of the leg were more common in the cefazolin group., Conclusions: Cefazolin was more effective prophylaxis than teicoplanin against postoperative wound infections after elective cardiac operations. Infection rates were low with either treatment.

Small-fragment restriction enzyme analysis and DNA-DNA hybridization were used to compare 60 strains of Moraxella catarrhalis isolated from various geographic locations. Restriction enzyme analysis with HaeIII resulted in 46 different patterns, 7 of which were shared by more than one isolate. Hybridizations with two DNA probes resulted in 18 different patterns, 11 of which were shared by more than one isolate. Strains with the same restriction enzyme pattern always had the same hybridization pattern. However, of the 50 strains that shared the 11 hybridization patterns, 39 could be further differentiated by restriction enzyme analysis. We found that hybridization is a method that is specific for the epidemiological typing of M. catarrhalis, but because of limited sensitivity, combination with small-fragment restriction enzyme analysis may be necessary to better determine the relatedness of strains.

The choice of antimicrobial therapy for the treatment of bacteremia is often empirical and based on the knowledge of antibiotic susceptibility profiles of the most common bacteria causing such infections. It therefore is crucial to survey the susceptibility of bacteria causing sepsis. This study examines the susceptibility profiles of 941 gram-negative bacteria, isolated from septic patients in 10 Canadian hospitals, to 28 antimicrobial agents. Among the isolates, 30 different species were represented; Escherichia coli dominated, representing 52.5% of isolates. More than 50% of all bacteria were resistant to ampicillin. Only 67% of the E. coli isolates were susceptible to ampicillin, while 30% of all strains were resistant to ticarcillin. Of the cephalosporins, ceftazidime and cefoperazone/sulbactam were the agents to which isolates were the most susceptible (90%). Only 51% of the E. coli strains were susceptible to cephalothin, while 91% were still susceptible to cefazolin. A total of 93% and 98% of the strains were susceptible to aztreonam and imipenem, respectively. Aminoglycosides were highly active against most isolates, in general in the following order: netilmicin greater than tobramycin greater than gentamicin greater than amikacin. Tobramycin was the most active against Pseudomonas aeruginosa. Nearly all isolates were susceptible to the quinolones. Tolerance (MBC/MIC ratio, greater than or equal to 32) was rarely observed. This survey of the susceptibility of gram-negative bacteria causing sepsis provides valuable information for implementing the chemotherapy for gram-negative septicemia and demonstrates that several older and newer agents, alone or in combination, can be used as adequate initial therapy for gram-negative sepsis in Canada.

A study recently conducted across Canada showed that 64 of 2,503 clinical isolates of Haemophilus influenzae were resistant to beta-lactams without production of a beta-lactamase (L. D. Tremblay, J. L'Ecuyer, P. Provencher, M. G. Bergeron, and Canadian Study Group, Can. Med. Assoc. J. 143:895-900, 1990). The beta-lactamase-negative strains formed three distinct groups, with ampicillin MICs of 0.5 to 1, 2 to 4, and greater than or equal to 8 micrograms/ml for groups I, II, and III, respectively. We have investigated the mechanisms of resistance for eight strains originating from different infections and geographic areas. These strains were representative of groups I to III. Five strains were nontypeable, two were type B, and one was non-B. Chromosomal DNA extracted from each strain was used to transform the laboratory strain Rd. Transformants were selected on beta-lactam-containing plates and showed the same level of resistance to ampicillin as the donor strains. Differences in outer membrane proteins, porins, and lipopolysaccharide profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) did not change with resistance. Functional analyses of purified porins in artificial lipid bilayer experiments did not explain resistance. Peptidoglycan synthesis was measured by incorporation of [14C]alanine into trichloroacetic acid-insoluble cell wall material in the presence of chloramphenicol. The growth rate and the rate of peptidoglycan synthesis observed for the transformants of the isogenic set did not correlate with resistance. Whole-cell labeling with 125I-penicillin revealed modifications in penicillin-binding proteins (PBPs) among the transformants. In particular, PBPs 3A and 3B (65 and 63 kDa, respectively) showed a decrease in affinity for beta-lactams in all transformants (groups I, II, and III) and correlated with an increased MIC except in the transformant of group III, which showed higher levels of resistance. Partial purification and proteolytic digestion of 125I-penicillin-labeled PBP 3B led to two types of CnBr peptide profiles on SDS-PAGE, the profiles of the transformed strains from groups I and II being different from those of the control group and group III. Finally, electron microscopy revealed a distinct cell filamentation for the group III transformants. These data clearly indicate that changes in PBPs are a common mechanism that results in a significant level of non-beta-lactamase-mediated beta-lactam resistance in H. influenzae despite serotype, origin of isolation, or geographic distribution.

The in vitro activity of clarithromycin alone and in combination with its primary human metabolite, 14-hydroxy-clarithromycin, was determined against 203 strains of Haemophilus influenzae. Microdilution broth MICs and MBCs of both clarithromycin and 14-hydroxy-clarithromycin were determined. The clarithromycin MIC50 was 4 mg/l and the MIC90 was 8 mg/l. The hydroxy metabolite was 2-4-fold more active with an MIC50 and MIC90 of 2 mg/l. The MBCs were equal to the MICs. The microbicidal effect of combinations of clarithromycin and 14-hydroxy-clarithromycin was tested using a microdilution checkerboard technique and the fractional inhibitory index was calculated. The combination was additive in 92% and synergistic in 8% of all strains of H. influenzae tested; no antagonism was found. The results were independent of the site of isolation of the strain or presence of beta-lactamase. These findings suggest the potential clinical utility of clarithromycin for the treatment of H. influenzae infections.

We evaluated the incidence of Haemophilus influenzae resistance to selected antimicrobials used in Canada. From 1985 to 1987, 2503 H. influenzae isolates obtained in 14 hospitals across Canada were sent to the Centre hospitalier de l'université Laval (CHUL) for identification, serotyping, biotyping and testing for beta-lactamase production. Susceptibility tests were done with the use of 12 antibiotics. Of the strains 424 (16.9%) produced beta-lactamase; the proportion varied from 12.8%, in Newfoundland, to 19.6%, in Ontario. Of the strains 18.3% were type b; 19.4% of those produced beta-lactamase. Almost 82% of the strains were not type b. The proportion of beta-lactamase-producing strains varied according to the isolation site, from 15.3% in the respiratory tract to 25.6% in the blood. The overall level of resistance was 19.3% to ampicillin, 24.2% to erythromycin, 3.8% to trimethoprim-sulfamethoxazole, 1.7% to amoxicillin-potassium clavulanate, 1.4% to cefaclor, 1.3% to tetracycline, 1.0% to rifampin, 0.7% to cefuroxime and 0.1% to cefamandole. Disc diffusion susceptibility testing revealed 64 strains (2.6%) that did not produce beta-lactamase but were resistant to ampicillin and 9 (0.4%) that produced beta-lactamase but were susceptible to ampicillin. The results of beta-lactamase production tests were identical regardless of whether the tests were done by the CHUL or by the other hospitals, but there was a marked difference in the susceptibility test results between the CHUL and the other centres. Our results suggest that the level of resistance of H. influenzae to antibiotics is increasing in Canada and that the initial choice of drug therapy may have to be modified.