RÉSUMÉ
Clostridioides difficile infection (CDI) among children remains a concerning cause of morbidity in hospital settings. We present epidemiological and molecular trends in healthcare- and community-associated CDI among children in Canadian inpatient and outpatient settings, including those who experienced recurrent infections.
Sujet(s)
Clostridioides difficile , Infections à Clostridium , Infection croisée , Humains , Enfant , Canada/épidémiologie , Infections à Clostridium/épidémiologie , Infections à Clostridium/étiologie , Établissements de santé , Prestations des soins de santé , Infection croisée/épidémiologieRÉSUMÉ
The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.
Sujet(s)
COVID-19 , Infections à Clostridium , Infection croisée , Humains , COVID-19/épidémiologie , Pandémies , Canada/épidémiologie , Infections à Clostridium/épidémiologie , Infection croisée/épidémiologie , HôpitauxRÉSUMÉ
We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015-2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015-2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control.
Sujet(s)
Clostridioides difficile , Infections à Clostridium , Infection croisée , Adulte , Canada/épidémiologie , Clostridioides difficile/génétique , Infections à Clostridium/traitement médicamenteux , Infections à Clostridium/épidémiologie , Infection croisée/épidémiologie , Prestations des soins de santé , Humains , Tests de sensibilité microbienne , RibotypageRÉSUMÉ
BACKGROUND: Clostridium difficile are gram-positive, spore forming anaerobic bacteria that are the leading cause of healthcare-associated diarrhea, usually associated with antibiotic usage. Metronidazole is currently the first-line treatment for mild to moderate C. difficile diarrhea however recurrence occurs at rates of 15-35%. There are few reports of C. difficile metronidazole resistance in the literature, and when observed, the phenotype has been transient and lost after storage or exposure of the bacteria to freeze/thaw cycles. Owing to the unstable nature of the resistance phenotype in the laboratory, clinical significance and understanding of the resistance mechanisms is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Genotypic and phenotypic characterization was performed on a metronidazole resistant clinical isolate of C. difficile. Whole-genome sequencing was used to identify potential genetic contributions to the phenotypic variation observed with molecular and bacteriological techniques. Phenotypic observations of the metronidazole resistant strain revealed aberrant growth in broth and elongated cell morphology relative to a metronidazole-susceptible, wild type NAP1 strain. Comparative genomic analysis revealed single nucleotide polymorphism (SNP) level variation within genes affecting core metabolic pathways such as electron transport, iron utilization and energy production. CONCLUSIONS/SIGNIFICANCE: This is the first characterization of stable, metronidazole resistance in a C. difficile isolate. The study provides an in-depth genomic and phenotypic analysis of this strain and provides a foundation for future studies to elucidate mechanisms conferring metronidazole resistance in C. difficile that have not been previously described.
Sujet(s)
Antibactériens/pharmacologie , Clostridioides difficile/effets des médicaments et des substances chimiques , Clostridioides difficile/isolement et purification , Résistance bactérienne aux médicaments/effets des médicaments et des substances chimiques , Métronidazole/pharmacologie , Clostridioides difficile/génétique , Clostridioides difficile/ultrastructure , Résistance bactérienne aux médicaments/génétique , Multirésistance aux médicaments/effets des médicaments et des substances chimiques , Génomique , Humains , Phénotype , Polymorphisme de nucléotide simpleRÉSUMÉ
BACKGROUND: Staphylococcus aureus may produce superantigens that can non-specifically activate CD4(+) cells to potentially target the myelin basic protein. OBJECTIVE: This study examined the association between individuals with multiple sclerosis (MS) and colonization with S. aureus harbouring superantigens. METHODS: Nasal swabs were collected from non-MS subjects and patients with MS who had not experienced a relapse in the past six months (MS stable group) and who had suffered a relapse within 30 days of study recruitment (MS exacerbation group). S. aureus was isolated from the anterior nares of participants following standard procedures and staphylococcal superantigen genes (sea, seb, and tsst-1) were detected using standard laboratory PCR techniques. RESULTS: The study enrolled 204 patients, 80 in the non-MS and MS stable groups and 44 patients in the MS exacerbation group. Overall, 27.0% of patients were colonized with S. aureus with no significant differences identified between study groups. Amongst individuals colonized with S. aureus, the prevalence of sea was significantly greater in the MS exacerbation versus non-MS study group (p < 0.05; odds ratio 7.9; 95% confidence interval 1.2-49.5). CONCLUSIONS: The ability to rapidly screen patients for the presence of S. aureus producing sea may serve as a useful marker of a potential MS exacerbation.
Sujet(s)
Entérotoxines/immunologie , Sclérose en plaques/microbiologie , Infections à staphylocoques/immunologie , Staphylococcus aureus/immunologie , Superantigènes/immunologie , Adulte , Femelle , Humains , Modèles logistiques , Mâle , Adulte d'âge moyen , Sclérose en plaques/immunologie , Fosse nasale/immunologie , Facteurs de risqueRÉSUMÉ
Reverse transcriptase polymerase chain reaction was used to determine the amount of overexpression of the ampC gene in 52 cefoxitin-resistant Escherichia coli clinical isolates that had previously characterized mutations in their ampC promoter/attenuator regions. The results showed that mutations that create a consensus -35 box (TTGACA) are the most important factor in strengthening the ampC promoter, followed by base pair insertions that increase the distance between the -35 and -10 boxes to 17 or 18 bp. Mutations in the -10 box are of lesser importance and those in the attenuator region appear to have little effect on ampC expression. Three strains overexpress ampC due to the effect of insertion elements located in the ampC promoter regions. Further, the data show that there is no correlation between ampC overexpression and the minimum inhibition concentration of cefoxitin in clinical isolates. Overall, the data indicate that a combination of ampC promoter mutations and other strain-specific factors combine to contribute to the magnitude of cefoxitin resistance in E. coli.
Sujet(s)
Céfoxitine/pharmacologie , Protéines Escherichia coli/génétique , Escherichia coli/génétique , Mutation , Régions promotrices (génétique)/génétique , bêta-Lactamases/génétique , Antibactériens/pharmacologie , Séquence nucléotidique , Résistance bactérienne aux médicaments/génétique , Escherichia coli/effets des médicaments et des substances chimiques , Escherichia coli/isolement et purification , Infections à Escherichia coli/microbiologie , Régulation de l'expression des gènes bactériens , Humains , Tests de sensibilité microbienne , Données de séquences moléculaires , RT-PCRRÉSUMÉ
Enterococcus faecalis G1-0247 (vancomycin MIC, 16 microg/ml) was found to harbor a vanG operon 99% identical to the vanG operon in E. faecalis BM4518. E. faecalis N03-0233 (vancomycin MIC, 16 microg/ml) was found to harbor a novel vanG operon, vanG2, on an element in a different chromosomal location than the vanG-harboring elements in G1-0247 and BM4518.
Sujet(s)
Antibactériens/pharmacologie , Enterococcus faecalis/effets des médicaments et des substances chimiques , Enterococcus faecalis/génétique , Résistance à la vancomycine/génétique , Vancomycine/pharmacologie , Séquence nucléotidique , Canada , Chromosomes de bactérie , Enterococcus faecalis/isolement et purification , Tests de sensibilité microbienne , Données de séquences moléculaires , Opéron , Régions promotrices (génétique)RÉSUMÉ
OBJECTIVES: To characterize the mechanism of cefoxitin resistance in clinical isolate Escherichia coli N99-0001. METHODS: Plasmid analysis, PCR for beta-lactamases, and sequencing of the ampC genes was carried out. An RT-PCR method was developed to determine relative ampC expression. RESULTS: Analysis of the ampC promoter region of E. coli N99-0001 revealed a T-->A mutation at -32, a C-->A mutation at -11, an insertion of a T between -20 and -21, and a 28 bp deletion including the entire attenuator. RT-PCR showed that ampC was expressed 140-fold higher in E. coli N99-0001 than in E. coli ATCC 25922. CONCLUSIONS: Cefoxitin resistance in E. coli N99-0001 was due to overexpression of ampC caused by an increase in promoter strength.