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Anne-Marie Bourgault

Publications and source records attributed to Anne-Marie Bourgault.

6 recordsLinked to original sources
PubMed2006

A portrait of the geographic dissemination of the Clostridium difficile North American pulsed-field type 1 strain and the epidemiology of C. difficile-associated disease in Québec.

BACKGROUND: An increase in the incidence and severity of Clostridium difficile-associated disease in Québec and the United States has been associated with a hypervirulent strain referred to as North American pulsed-field type 1 (NAP1)/027. METHODS: In 2005, a prospective study was conducted in 88 Québec hospitals, and 478 consecutive nosocomial isolates of C. difficile were obtained. The isolates were subjected to pulsed-field gel electrophoresis (PFGE) typing, antimicrobial susceptibility testing, and detection of binary toxin genes and tcdC gene deletion. Data on patient age and occurrence of complications were collected. RESULTS: PFGE typing of 478 isolates of C. difficile yielded 61 PFGE profiles. Pulsovars A (57%), B (10%), and B1 (8%) were predominant. The PFGE profile of pulsovar A was identical to that of strain NAP1. It showed 67% relatedness with 15 other PFGE patterns, among which 11 had both binary toxin genes and a partial tcdC deletion but different antibiotic susceptibility profiles. Pulsovars B and B1 were identical to strain NAP2/ribotype 001. In hospitals showing a predominant clonal A or B-B1 PFGE pattern, incidence of C. difficile-associated disease was 2 and 1.3 times higher, respectively, than in hospitals without any predominant clonal PFGE pattern. Severe disease was twice as frequent among patients with strains possessing binary toxin genes and tcdC deletion than among patients with strains lacking these virulence factors. CONCLUSIONS: This study helped to quantify the impact of strain NAP1 on the incidence and severity of C. difficile-associated disease in Québec in 2005. The identification of the geographic dissemination of this predominant strain may help to focus regional infection-control efforts.

Anti-Bacterial Agents↗
PubMed2006

In vitro susceptibility of Clostridium difficile clinical isolates from a multi-institutional outbreak in Southern Québec, Canada.

Clostridium difficile isolates from a 2004 outbreak in Québec, Canada, were all found to be susceptible to metronidazole, vancomycin, rifampin, and meropenem but resistant to bacitracin, cefotaxime, ciprofloxacin, and levofloxacin, and most (>80%) were resistant to ceftriaxone, clarithromycin, gatifloxacin, and moxifloxacin. The predominant NAP1 isolates were susceptible to clindamycin, while the NAP2 isolates were resistant.

Anti-Bacterial Agents↗
PubMed2005

A predominantly clonal multi-institutional outbreak of Clostridium difficile-associated diarrhea with high morbidity and mortality.

BACKGROUND: In March 2003, several hospitals in Quebec, Canada, noted a marked increase in the incidence of Clostridium difficile-associated diarrhea. METHODS: In 2004 we conducted a prospective study at 12 Quebec hospitals to determine the incidence of nosocomial C. difficile-associated diarrhea and its complications and a case-control study to identify risk factors for the disease. Isolates of C. difficile were typed by pulsed-field gel electrophoresis and analyzed for binary toxin genes and partial deletions in the toxin A and B repressor gene tcdC. Antimicrobial susceptibility was evaluated in a subgroup of isolates. RESULTS: A total of 1703 patients with 1719 episodes of nosocomial C. difficile-associated diarrhea were identified. The incidence was 22.5 per 1000 admissions. The 30-day attributable mortality rate was 6.9 percent. Case patients were more likely than matched controls to have received fluoroquinolones (odds ratio, 3.9; 95 percent confidence interval, 2.3 to 6.6) or cephalosporins (odds ratio, 3.8; 95 percent confidence interval, 2.2 to 6.6). A predominant strain, resistant to fluoroquinolones, was found in 129 of 157 isolates (82.2 percent), and the binary toxin genes and partial deletions in the tcdC gene were present in 132 isolates (84.1 percent). CONCLUSIONS: A strain of C. difficile that was resistant to fluoroquinolones and had binary toxin and a partial deletion of the tcdC gene was responsible for this outbreak of C. difficile-associated diarrhea. Exposure to fluoroquinolones or cephalosporins was a risk factor.

Aged↗
PubMed2002

Characterization of 2 influenza A(H3N2) clinical isolates with reduced susceptibility to neuraminidase inhibitors due to mutations in the hemagglutinin gene.

Previous studies have shown that amino acid changes in the hemagglutinin (HA) gene of influenza viruses may result in decreased susceptibility to neuraminidase inhibitors (NAIs) in vitro. However, the emergence and characteristics of such HA variants in the clinical setting remain poorly studied. Herein, we report 2 influenza A(H3N2) isolates, from untreated patients, harboring an Arg229-->Ile substitution in the HA1 gene. The Ile229 variants were as sensitive as the Arg229 viruses to zanamivir and oseltamivir in neuroaminidase inhibition assays but were significantly less susceptible (by 60-140-fold) in cell-based assays. Although the Ile229 variants adsorbed less efficiently to Madin-Darby canine kidney (MDCK) cells in kinetic binding assays, they remained very sensitive to zanamivir in ferrets. Our study shows the importance of the HA1 229 residue in virus binding to MDCK cells and confirms the unreliability of cell-based assays in predicting the in vivo susceptibility of HA variants to NAIs.

Amino Acid Substitution↗
PubMed1999

Should all stool specimens be routinely tested for Clostridium difficile?

OBJECTIVE: To determine the frequency with which Clostridium difficile was detected in stool specimens from outpatients and patients hospitalized for less than 4 days to assess the usefulness of routine laboratory screening for detecting this enteric pathogen. METHODS: Seven hundred and forty-one specimens from 398 patients were cultured over a 6-month period for Salmonella, Shigella, Yersinia, Escherichia coli O157:H7, Campylobacter and Clostridium difficile. Clostridium difficile culture-positive samples were further tested for cytotoxin production. RESULTS: Campylobacter, Salmonella, Shigella and E. coli O157:H7 were isolated in 50 (6.7%) specimens from 35 (8.8%) patients. Clostridium difficile was cultured from 88 (11.9%) specimens from 35 (8.8%) patients and its cytotoxin detected in 35 (4.7%) specimens of 12 (3%) patients. Clostridium difficile was the second most frequent enteric pathogen after Campylobacter. Of 178 (24%) specimens submitted with a specific request for Clostridium difficile testing, 13 (7.3%) were cytotoxin positive (three patients); of 563 specimens for which Clostridium difficile was not requested, 22 (3.9%) were cytotoxin positive (nine patients). CONCLUSIONS: Nine of 12 patients with cytotoxin-positive specimens would have gone undiagnosed in the laboratory had all stool samples submitted not been tested. These results suggest that Clostridium difficile disease is under-recognized and that testing all stool samples for Clostridium difficile may be warranted in our community of patients.

Journal Article↗