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1.
Microbiol Spectr ; 9(3): e0078521, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34878297

RESUMO

NG-Test CTX-M MULTI and NG-Test Carba 5 (NG Biotech) are two rapid in vitro immunochromatographic assays that are widely used for the detection of the most common extended spectrum beta-lactamases (ESBL) and carbapenemases in Enterobacterales. ESBL and carbapenemases are leading causes of morbidity and mortality worldwide and their rapid detection from positive blood cultures is crucial for early initiation of effective antimicrobial therapy in bloodstream infections (BSI) involving antibiotic-resistant organisms. In this study, we developed a rapid workflow for positive blood cultures for direct identification of Enterobacterales by MALDI-TOF mass-spectrometry, followed by detection of ESBL and carbapenemases using NG-Test CTX-M MULTI and NG-Test Carba 5 (NG Biotech). The workflow was evaluated using Enterobacterales isolates (n = 114), primarily Klebsiella species (n = 50) and Escherichia coli (n = 40). Compared to the standard testing approach in our institution using BD Phoenix, our new testing approach demonstrates 100% sensitivity and specificity for organism identification and detection of ESBL and carbapenemases. Implementation of a rapid workflow in diagnostic microbiology laboratories will enable more effective antimicrobial management of patients with BSI due to ESBL- and carbapenemase-producing Enterobacterales. IMPORTANCE The incidence of bloodstream infections (BSI) with extended spectrum beta-lactamase (ESBL) producing and carbapenemase producing Enterobacterales (CPE) is increasing at an alarming rate, for which only limited therapeutic options remain available. Rapid identification of these bacteria along with their antibiotic resistance mechanisms in positive blood cultures with Gram-negative bacteria will allow for early initiation of effective therapy and limit the overuse of broad-spectrum antibiotics in BSI (1). In this study we evaluated a combined approach of testing positive blood cultures directly, using MALDI-TOF MS followed by rapid immunochromatographic tests, for the detection of ESBLs and CPEs. Our approach demonstrates 100% sensitivity and specificity for the identification of Enterobacterales and detection of ESBLs and CPEs in positive blood culture with a turnaround time (TAT) of ≤60 min compared to a TAT of 48 h required by conventional culture and susceptibility testing methods.


Assuntos
Bacteriemia/microbiologia , Proteínas de Bactérias/análise , Enterobacteriáceas Resistentes a Carbapenêmicos/metabolismo , Imunoensaio/métodos , beta-Lactamases/análise , Antibacterianos/farmacologia , Hemocultura , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Humanos , Klebsiella/classificação , Klebsiella/efeitos dos fármacos , Klebsiella/isolamento & purificação , Testes de Sensibilidade Microbiana , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
2.
Microbiol Spectr ; 9(3): e0190521, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34937166

RESUMO

The performance and early therapeutic impact of direct identification by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF; DIMT) on pediatric blood culture bottles using in-house-developed methods to obtain microbial pellets for spectrometric analysis have seldom been studied. During a 2-year period (June 2018 to May 2020), DIMT was performed on broths from positive pediatric blood culture bottles using an in-house-developed method. Organism identifications with a score of ≥1.6 were notified to treating clinicians. Therapeutic modifications that occurred after the communication of DIMT were reviewed through the electronic medical records. DIMT was performed on 530 pediatric positive blood culture bottles. Among 505 monomicrobial bottles, identifications from 298 (97.7%) deemed as bloodstream infections (BSI) and 189 (94.5%) as contaminations had DIMT notified to clinicians. All identifications were correct except for one Streptococcus mitis incorrectly reported as Streptococcus pneumoniae. Therapy modifications resulting from DIMT occurred in 27 (8.3%) patients with BSI. Deescalation from effective or ineffective broad-spectrum regimens occurred mainly in Enterococcus faecalis bacteremia, whereas appropriate escalation from an ineffective regimen with narrower spectrum occurred mainly in bacteremia caused by AmpC-ß-lactamase-producing Enterobacterales. Escalation therapy was instituted significantly faster than deescalation therapy (median time, 0.75 versus 10.5 h [P = 0.01]). DIMT also enabled clinicians to confirm contamination in nearly one-half of patients with contaminated blood cultures. Our DIMT method applied to positive pediatric blood culture bottles demonstrated reliable performance for the rapid identification of pathogens. Our DIMT approach allowed therapeutic optimization in BSI, especially involving microorganisms with intrinsic antibiotic resistance, and was helpful in the early identification of likely contaminants. IMPORTANCE We demonstrate the performance and early impact on the antimicrobial management of bloodstream infections of an inexpensive, in-house preparation method for direct identification of bloodstream pathogens in pediatric blood culture bottles by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Espectrometria de Massas em Tandem/métodos , Adolescente , Bacteriemia/sangue , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bactérias/química , Bactérias/efeitos dos fármacos , Hemocultura , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
3.
Microbiol Spectr ; 9(3): e0112221, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756089

RESUMO

Whole-genome sequencing was used to characterize carbapenemase-producing Enterobacterales (CPE) strains recovered from rectal screening swab samples obtained from children at a tertiary-care pediatric hospital in Qatar during a 3-year period. A total of 72 CPE isolates recovered from 61 fecal carriers were characterized. Escherichia coli (47 isolates [65.3%]) and Klebsiella pneumoniae (22 isolates [30.6%]) were the most common species identified. High levels of genetic diversity were observed for both species. These 72 isolates produced 78 carbapenemases, characterized as either NDM-type (41 enzymes [52.6%]) or OXA-48-type (37 enzymes [47.4%]). NDM-5 (24 enzymes [30.8%]), NDM-1 (15 enzymes [19.2%]), and OXA-181 (15 enzymes [19.2%]) were the most common variants detected within each type. Twenty-three NDM producers exhibited difficult-to-treat resistance, compared with only 2 of the OXA-48 producers. Multiple comorbidities were identified in 88.5% of the patients, whereas recent travel history to countries in which CPE are endemic was documented for 57.4% of the patients. All 9 blaOXA-48-type-gene-containing E. coli sequence type 38 (ST38) strains were isolated from patients without international travel history. The mean quarterly incidence of fecal carriage decreased more than 6-fold after the implementation of coronavirus disease 2019 (COVID-19)-related international travel restrictions in Qatar in mid-March 2020. Our data suggest that NDM-type and OXA-48-type carbapenemases expressed by a large diversity of E. coli and K. pneumoniae genotypes are largely dominant in the pediatric population of Qatar. Although our data indicate successful local expansion of E. coli ST38 strains harboring blaOXA-244 genes, at least within health care settings, blaOXA-48-type and blaNDM-type genes appear to have been mainly introduced sporadically by asymptomatic carriers who visited or received health care in some nearby countries in which the genes are endemic. IMPORTANCE To the best of our knowledge, this is the first study addressing the molecular characteristics of CPE in a pediatric population in Qatar using whole-genome sequencing. Since several countries in the Arabian Peninsula share relatively similar demographic patterns and international links, it is plausible that the molecular characteristics of CPE in children, at least in the middle and eastern parts of the region, are similar to those observed in our study.


Assuntos
Proteínas de Bactérias/química , Enterobacteriaceae/enzimologia , Fezes/química , beta-Lactamases/química , Adolescente , Antibacterianos , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , COVID-19 , Criança , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Escherichia coli/enzimologia , Escherichia coli/genética , Genótipo , Humanos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Mutação , Catar , Estudos Retrospectivos , SARS-CoV-2 , Sequenciamento Completo do Genoma , beta-Lactamases/genética , beta-Lactamases/isolamento & purificação
4.
BMC Pediatr ; 21(1): 267, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103044

RESUMO

BACKGROUND: Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe complication of coronavirus disease 2019 (COVID-19) in children, which is increasingly being reported worldwide. Here we report the first case series of 7 children diagnosed with MIS-C in Qatar. METHODS: Clinical features and outcomes of COVID-19 positive patients admitted to Sidra Medicine, Qatar from June to October 2020, who met the WHO case definition for MIS-C were reviewed. RESULTS: The mean age in our case series was 5.6 years, of which 71.4% were males. All patients were previously healthy but had a history of COVID-19 infection. Fever, rash, vomiting and abdominal pain were the most common symptoms (70-100%). The average hospitalization was 12.9 days with no case fatalities. Laboratory findings included lymphopenia and thrombocytopenia in most patients, as well as evidence of coagulopathy and elevated inflammatory markers such as C-reactive protein, ferritin and procalcitonin. Many patients (71.4%) required inotropic support in intensive care, while only one required respiratory support. Although all patients had elevated cardiac biomarkers, cardiovascular involvement was observed in 42.9% of patients with one patient developing a giant coronary aneurysm. All patients received intravenous immunoglobulin (IVIG) and 86% of patients received corticosteroids, with two patients requiring treatment with IL-1 inhibitors. CONCLUSIONS: Our report is one of the first reports on MIS-C from Asia. Although clinical features and outcomes are not significantly different from those reported elsewhere, lack of case fatalities in our cohort may indicate that early recognition and prompt medical attention is necessary for a favorable outcome in MIS-C.


Assuntos
COVID-19 , Ásia , Criança , Pré-Escolar , Feminino , Hospitais Pediátricos , Humanos , Masculino , Catar/epidemiologia , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica , Atenção Terciária à Saúde
6.
BMC Infect Dis ; 20(1): 237, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32192451

RESUMO

BACKGROUND: Infections with multidrug-resistant organisms (MDRO) pose a serious threat to patients with dysregulated immunity such as in hemophagocytic lymphohistiocytosis (HLH), but such infections have rarely been comprehensively characterized. Here, we present a fatal case of HLH secondary to cytomegalovirus (CMV) infection complicated by both anti-viral drug resistance and sepsis from multiple MDROs including pandrug-resistant superbug bacteria. CASE PRESENTATION: A previously healthy, six-year-old boy presented with a 45-day history of fever prior to a diagnosis of hemophagocytic lymphohistiocytosis and hemorrhagic colitis, both associated with CMV. On hospital admission, the patient was found to be colonized with multiple, multidrug-resistant (MDR) bacteria including vancomycin-resistant enterococci (VRE) and carbapenamase-producing organisms (CPO). He eventually developed respiratory, urine and bloodstream infections with highly drug-resistant, including pandrug-resistant bacteria, which could not be controlled by antibiotic treatment. Antiviral therapy also failed to contain his CMV infection and the patient succumbed to overwhelming bacterial and viral infection. Whole genome sequencing (WGS) of the MDR bacteria and metagenomic analysis of his blood sample revealed an unusual accumulation of a wide range of antimicrobial resistance mechanisms in a single patient, including antiviral resistance to ganciclovir, and resistance mechanisms to all currently available antibiotics. CONCLUSIONS: The case highlights both the risk of acquiring MDR superbugs and the severity of these infections in HLH patients.


Assuntos
Infecções por Citomegalovirus/complicações , Citomegalovirus/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Farmacorresistência Viral Múltipla , Linfo-Histiocitose Hemofagocítica/virologia , Sepse/mortalidade , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Antivirais/efeitos adversos , Antivirais/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Criança , Citomegalovirus/genética , Citomegalovirus/imunologia , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Evolução Fatal , Ganciclovir/efeitos adversos , Ganciclovir/uso terapêutico , Genótipo , Humanos , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Masculino , Sepse/tratamento farmacológico , Sepse/microbiologia , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/genética
7.
Artigo em Inglês | MEDLINE | ID: mdl-36339013

RESUMO

Background: The Accelerate Pheno system (AXDX) provides rapid identification (ID; 90 minutes) and antimicrobial susceptibility testing (AST; approximately 7 hours) from positive blood culture (BC) bottles. We assessed the potential of AXDX results to influence more timely antibiotic interventions with a convenience sample of 158 positive BCs. Methods: BCs with a mono-microbial Gram stain likely to be on the AXDX panel were run in parallel with the standard of care (SOC). Using results from the SOC, the medical microbiologist on call (MMOC) noted interventions made at the time of BC Gram stain and when ID and AST results were available. The timing of MMOC intervention was noted and compared with fastest potential SOC time and AXDX time. Results: Of 158 specimens selected for analysis, 144 were evaluable. ID was available 11.9 hours and AST 27.7 hours faster than SOC. Correct ID was provided for 85.2% of specimens and AST for 59.0% of specimens, with 97.5% essential agreement compared with the SOC. One hundred and thirteen clinical interventions were made on 100 specimens: 54.9% were narrowing; 33.6%, escalation; 6.2%, consultation with ID; and 3.5%, further investigation. If AXDX data had been used immediately once available, interventions would have been possible 24 hours earlier for ID interventions and 39 hours earlier for AST results. Conclusions: Results from rapid diagnostic panels such as AXDX have the potential to support timely antimicrobial de-escalation and other decisions to benefit patients, especially if paired with stewardship interventions.


Historique: Le système Accelerate Pheno (AXDX) permet de procéder à une identification rapide (ID; 90 minutes) et à des tests de susceptibilité antimicrobienne (AST; environ sept heures) à partir de bouteilles d'hémoculture (BH) positives. À l'aide d'un échantillon de commodité de 158 BH positives, les auteurs ont évalué le potentiel de résultats du système AXDX pour favoriser des interventions antibiotiques plus opportunes. Méthodologie: Les auteurs ont comparé les BH présentant une coloration de Gram monomicrobienne susceptible de se trouver sur le panel AXDX avec la norme de soins (NdS). À l'aide des résultats de la NdS, le microbiologiste médical sur appel (MMSA) a consigné les interventions effectuées au moment de la coloration de Gram de la BH et lorsque les résultats de l'ID et de l'AST étaient disponibles. Le moment de l'intervention du MMSA était consigné et comparé avec la durée de la NdS au potentiel le plus rapide et la durée de l'AXDX. Résultats: Des 158 échantillons sélectionnés en vue d'être analysés, 144 étaient évaluables. L'ID était disponible 11,9 heures et l'AST, 27,7 heures plus rapidement que la NdS. L'ID exacte était fournie pour 85,2 % des échantillons et l'AST exacte, pour 59,0 % des échantillons, selon une entente essentielle de 97,5 % par rapport à la NdS. Cent treize interventions ont été effectuées sur 100 échantillons : 54,9 % visaient à réduire le spectre, 33,6 %, à accroître la médication, 6,2 %, à demander une consultation avec l'ID et 3,5 %, à obtenir des explorations plus approfondies. Si les données de l'AXDX avaient été utilisées dès l'obtention des résultats, il aurait été possible d'agir 24 heures plus rapidement pour les interventions d'ID et 39 heures plus rapidement pour les résultats de l'AST. Conclusions: Les résultats des panels diagnostiques rapides comme l'AXDX ont le potentiel de favoriser une désescalade antimicrobienne et d'autres décisions au profit des patients, surtout s'ils s'associent à des interventions de gestion.

8.
Diagn Microbiol Infect Dis ; 95(4): 114880, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31607515

RESUMO

The BioFire FilmArray Respiratory Panel (FA RP) is a rapid multiplexed molecular assay approved for detection of viral and atypical bacterial pathogens in nasopharyngeal specimens. This study aimed to evaluate the performance of the BioFire FilmArray Respiratory Panel v1.7 on bronchoscopy specimens. We tested 133 bronchial specimens (87 archived and 46 prospectively collected) with the FA RP and compared the results to the Luminex NxTAG Respiratory Pathogen Panel (NxTAG RPP). After discordant analysis, 123 specimens gave concordant results using the FA RP and the NxTAG RPP for an overall agreement of 93.9% (kappa = 0.88 [95% CI 0.80-0.96]), a positive percent agreement of 93.7% (95% CI 83.7-97.7) and a negative percent agreement of 94.1% (95% CI 84.9-98.1). In conclusion, the BioFire FilmArray RP performed reliably to detect a broad range of respiratory pathogens in bronchoscopy specimens.


Assuntos
Bactérias/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Infecções Respiratórias/diagnóstico , Vírus/isolamento & purificação , Bactérias/genética , Broncoscopia , Testes Diagnósticos de Rotina , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Estudos Prospectivos , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Estudos Retrospectivos , Vírus/genética
9.
J Antimicrob Chemother ; 74(2): 315-320, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30312401

RESUMO

Objectives: Globally there is an increased prevalence of carbapenem-resistant Acinetobacter spp. (CRAs) and carbapenemase-producing Acinetobacter spp. (CPAs) in the hospital setting. This increase prompted the Canadian Nosocomial Infection Surveillance Program (CNISP) to conduct surveillance of CRA colonizations and infections identified from patients in CNISP-participating hospitals between 2010 and 2016. Methods: Participating acute care facilities across Canada submitted CRAs from 1 January 2010 to 31 December 2016. Patient data were collected from medical records using a standardized questionnaire. WGS was conducted on all CRAs and data underwent single nucleotide variant analysis, resistance gene detection and MLST. Results: The 7 year incidence rate of CRA was 0.02 per 10 000 patient days and 0.015 per 1000 admissions, with no significant increase observed over the surveillance period (P > 0.73). Ninety-four CRA isolates were collected from 58 hospitals, of which 93 (98.9%) were CPA. Carbapenemase OXA-235 group (48.4%) was the most common due to two separate clusters, followed by the OXA-23 group (41.9%). Patients with a travel history were associated with 38.8% of CRA cases. The all-cause 30 day mortality rate for infected cases was 24.4 per 100 CRA cases. Colistin was the most active antimicrobial agent (95.8% susceptibility). Conclusions: CRA remains uncommon in Canadian hospitals and the incidence did not increase from 2010 to 2016. Almost half of the cases were from two clusters harbouring OXA-235-group enzymes. Previous medical treatment during travel outside of Canada was common.


Assuntos
Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/isolamento & purificação , Infecção Hospitalar/epidemiologia , Monitoramento Epidemiológico , Hospitais/estatística & dados numéricos , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/enzimologia , Adolescente , Adulto , Idoso , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Canadá/epidemiologia , Carbapenêmicos/farmacologia , Criança , Pré-Escolar , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana/genética , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Adulto Jovem , beta-Lactamases/genética
10.
J Med Microbiol ; 66(9): 1308-1315, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28869004

RESUMO

PURPOSE: Urine flow cytometry (UFC) is an automated method to quantify bacterial and white blood cell (WBC) counts. We aimed to determine whether a threshold for these parameters can be set to use UFC as a sensitive screen to predict which urine samples will subsequently grow in culture. METHODOLOGY: Urines submitted to our microbiology laboratory at a tertiary care centre from 22 July 2015-17 February 2016 underwent UFC (Sysmex UF-1000i) analysis, regular urinalysis and urine culture. Positive urine cultures were defined as growth ≥104 c.f.u. ml-1 of organisms associated with urinary tract infections. The correlation of UFC bacterial and WBC counts with urine culture was assessed using receiver operating characteristics curves. The sensitivity (SN), specificity (SP), negative predictive values (NPVs), positive predictive values (PPVs) and false negative rate (FNR) were calculated at various thresholds in immunocompetent and immunosuppressed patients. RESULTS: A total of 15 046 urine specimens were submitted, of which 14 908 were analysable in the study. The average time to UFC result from receipt in the laboratory was 0.76 h (+/-1.04). The test performance at a set threshold of UFC bacteria ≥20 or WBC >5 was: SN=96.0 %, SP=39.2 %, PPV=47.0 %, NPV=94.5 % and FNR=4.0 %. This threshold eliminates 26 % of urine cultures. Immunosuppressed hosts had a lower sensitivity of 90.6 % and a higher FNR of 9.4 %. CONCLUSIONS: UFC is a rapid and sensitive method to screen out urine samples that will subsequently be negative and to reflex urines to culture that will subsequently grow. UFC results are available within 1 h from receipt and enable the elimination of culture when the set threshold is not met.


Assuntos
Bacteriúria/diagnóstico , Citometria de Fluxo/métodos , Piúria/diagnóstico , Urinálise/métodos , Infecções Urinárias/diagnóstico , Bacteriúria/microbiologia , Feminino , Humanos , Contagem de Leucócitos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Curva ROC , Infecções Urinárias/microbiologia
11.
Artigo em Inglês | MEDLINE | ID: mdl-28223374

RESUMO

Carbapenem-resistant Enterobacter cloacae complex isolates submitted to a reference laboratory from 2010 to 2015 were screened by PCR for seven common carbapenemase gene groups, namely, KPC, NDM, OXA-48, VIM, IMP, GES, and NMC-A/IMI. Nineteen of the submitted isolates (1.7%) were found to harbor Ambler class A blaNMC-A or blaIMI-type carbapenemases. All 19 isolates were resistant to at least one carbapenem but susceptible to aminoglycosides, trimethoprim-sulfamethoxazole, tigecycline, and ciprofloxacin. Most isolates (17/19) gave positive results with the Carba-NP test for phenotypic carbapenemase detection. Isolates were genetically diverse by pulsed-field gel electrophoresis macrorestriction analysis, multilocus sequence typing, and hsp60 gene analysis. The genes were found in various Enterobacter cloacae complex species; however, blaNMC-A was highly associated with Enterobacter ludwigii Whole-genome sequencing and bioinformatics analysis revealed that all NMC-A (n = 10), IMI-1 (n = 5), and IMI-9 (n = 2) producers harbored the carbapenemase gene on EludIMEX-1-like integrative mobile elements (EcloIMEXs) located in the identical chromosomal locus. Two novel genes, blaIMI-5 and blaIMI-6, were harbored on different IncFII-type plasmids. Enterobacter cloacae complex isolates harboring blaNMC-A/IMI-type carbapenemases are relatively rare in Canada. Though mostly found integrated into the chromosome, some variants are located on plasmids that may enhance their mobility potential.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Elementos de DNA Transponíveis/genética , Enterobacter cloacae/genética , Plasmídeos/genética , beta-Lactamases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Tipagem Bacteriana , Canadá , Chaperonina 60/genética , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/isolamento & purificação , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Filogenia , Sequenciamento Completo do Genoma
12.
CMAJ Open ; 4(4): E641-E645, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28018876

RESUMO

BACKGROUND: Colistin is often used as an antimicrobial of last resort for the treatment of infections caused by multidrug-resistant gram-negative bacilli. In 2015, plasmid-mediated colistin resistance in Escherichia coli due to MCR-1 was described. The purpose of this study was to evaluate the frequency of colistin resistance among E. coli clinical isolates obtained from patients in Canadian hospitals as part of the Canadian Ward Surveillance Study (CANWARD) and to determine how often the mcr-1 gene is detected among the colistin-resistant subset. METHODS: From January 2008 to December 2015 (excluding 2011), 10 to 15 sentinel hospitals submitted consecutive clinical isolates (1 per patient per infection site) from blood (100-240), respiratory (100-150), urine (25-100) and wound (25-100) infections. We performed susceptibility testing using Clinical and Laboratory Standards Institute broth microdilution methods. Isolates that showed resistance to colistin as defined by European Committee on Antimicrobial Susceptibility Testing breakpoints (minimum inhibitory concentration ≥ 4 µg/mL) were evaluated for the mcr-1 gene by polymerase chain reaction. RESULTS: In total, 5571 E. coli clinical isolates were obtained over the study years. Twelve isolates (0.2%) were resistant to colistin. The proportion of colistin-resistant isolates varied from 0.0% to 0.5% depending on the study year, and there was no clear trend toward increasing resistance over time. Typically the colistin-resistant isolates remained susceptible to antimicrobials from several other classes. Two colistin-resistant isolates (0.04%) were found to harbour the mcr-1 gene. INTERPRETATION: The results suggest that colistin resistance among E. coli human clinical isolates, including resistance mediated by the mcr-1 gene, remains rare in Canada.

13.
Antimicrob Agents Chemother ; 60(11): 6787-6794, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27600052

RESUMO

Carbapenemase-producing Enterobacteriaceae (CPE) are increasing globally; here we report on the investigation of CPE in Canada over a 5-year period. Participating acute care facilities across Canada submitted carbapenem-nonsusceptible Enterobacteriaceae from 1 January 2010 to 31 December 2014 to the National Microbiology Laboratory. All CPE were characterized by antimicrobial susceptibilities, pulsed-field gel electrophoresis, multilocus sequence typing, and plasmid restriction fragment length polymorphism analysis and had patient data collected using a standard questionnaire. The 5-year incidence rate of CPE was 0.09 per 10,000 patient days and 0.07 per 1,000 admissions. There were a total of 261 CPE isolated from 238 patients in 58 hospitals during the study period. blaKPC-3 (64.8%) and blaNDM-1 (17.6%) represented the highest proportion of carbapenemase genes detected in Canadian isolates. Patients who had a history of medical attention during international travel accounted for 21% of CPE cases. The hospital 30-day all-cause mortality rate for the 5-year surveillance period was 17.1 per 100 CPE cases. No significant increase in the occurrence of CPE was observed from 2010 to 2014. Nosocomial transmission of CPE, as well as international health care, is driving its persistence within Canada.


Assuntos
Proteínas de Bactérias/genética , Infecção Hospitalar/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/efeitos dos fármacos , Plasmídeos/metabolismo , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , Adolescente , Adulto , Idoso , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Canadá/epidemiologia , Carbapenêmicos/farmacologia , Criança , Pré-Escolar , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Eletroforese em Gel de Campo Pulsado , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/mortalidade , Feminino , Expressão Gênica , Hospitais , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Plasmídeos/química , Polimorfismo de Fragmento de Restrição , Prevalência , Vigilância em Saúde Pública , Análise de Sobrevida , Viagem/estatística & dados numéricos , beta-Lactamases/metabolismo
14.
Br J Ophthalmol ; 100(12): 1714-1718, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27030278

RESUMO

OBJECTIVE: To report the clinical and microbiological profiles of paediatric patients with infectious keratitis in Vancouver, Canada. DESIGN: In this observational case series, the microbiology results and medical records of 17 eyes with microbial keratitis in 16 children aged 17 years or younger were retrospectively reviewed. These patients had undergone corneal scraping between May 2006 and April 2011 at BC Children's Hospital or Vancouver General Hospital Eye Care Centre in Vancouver, British Columbia, Canada. Demographic information, clinical features, predisposing factors, results of microbiology studies, antibiotic susceptibilities, treatment course and outcomes were analysed. RESULTS: The mean age of patients was 11±5.7 years (range 1-17 years) and the male:female ratio was 1.4:1. Major predisposing factors were contact lens wear (6/17; 35%), and pre-existing ocular surface conditions including blepharitis (3/17; 18%) and Stevens-Johnson syndrome (3/17; 18%). Four patients had a previous corneal ulcer. The most commonly isolated microorganisms were Staphylococcus epidermidis and Acanthamoeba. Acanthamoeba was isolated in 67% of contact lens-related corneal ulcers, while the remaining 33% of contact lens-related corneal ulcers were associated with infection with Pseudomonas aeruginosa. Final visual acuity was better than 20/60 in 9 out of 16 patients (56%). Three patients subsequently required surgical management with either penetrating keratoplasty or deep anterior lamellar keratoplasty for treatment of corneal scarring. CONCLUSIONS: Contact lens wear and pre-existing ocular surface conditions are significant risk factors for the development of infectious keratitis in our paediatric population. Knowledge of regional patterns of infection and susceptibility are essential in ensuring prompt treatment of this potentially sight-threatening condition.


Assuntos
Córnea/patologia , Infecções Oculares/epidemiologia , Ceratite/epidemiologia , Centros de Atenção Terciária/estatística & dados numéricos , População Urbana , Adolescente , Colúmbia Britânica/epidemiologia , Criança , Pré-Escolar , Infecções Oculares/diagnóstico , Feminino , Humanos , Incidência , Lactente , Ceratite/diagnóstico , Masculino , Estudos Retrospectivos , Fatores de Risco
15.
JAMA ; 315(2): 142-9, 2016 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-26757463

RESUMO

IMPORTANCE: Clostridium difficile infection (CDI) is a major burden in health care and community settings. CDI recurrence is of particular concern because of limited treatment options and associated clinical and infection control issues. Fecal microbiota transplantation (FMT) is a promising, but not readily available, intervention. OBJECTIVE: To determine whether frozen-and-thawed (frozen, experimental) FMT is noninferior to fresh (standard) FMT in terms of clinical efficacy among patients with recurrent or refractory CDI and to assess the safety of both types of FMT. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, noninferiority trial enrolling 232 adults with recurrent or refractory CDI, conducted between July 2012 and September 2014 at 6 academic medical centers in Canada. INTERVENTIONS: Patients were randomly allocated to receive frozen (n = 114) or fresh (n = 118) FMT via enema. MAIN OUTCOMES AND MEASURES: The primary outcome measures were clinical resolution of diarrhea without relapse at 13 weeks and adverse events. Noninferiority margin was set at 15%. RESULTS: A total of 219 patients (n = 108 in the frozen FMT group and n = 111 in the fresh FMT group) were included in the modified intention-to-treat (mITT) population and 178 (frozen FMT: n = 91, fresh FMT: n = 87) in the per-protocol population. In the per-protocol population, the proportion of patients with clinical resolution was 83.5% for the frozen FMT group and 85.1% for the fresh FMT group (difference, -1.6% [95% CI, -10.5% to ∞]; P = .01 for noninferiority). In the mITT population the clinical resolution was 75.0% for the frozen FMT group and 70.3% for the fresh FMT group (difference, 4.7% [95% CI, -5.2% to ∞]; P < .001 for noninferiority). There were no differences in the proportion of adverse or serious adverse events between the treatment groups. CONCLUSIONS AND RELEVANCE: Among adults with recurrent or refractory CDI, the use of frozen compared with fresh FMT did not result in worse proportion of clinical resolution of diarrhea. Given the potential advantages of providing frozen FMT, its use is a reasonable option in this setting. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT01398969.


Assuntos
Clostridioides difficile , Criopreservação , Diarreia/terapia , Enterocolite Pseudomembranosa/terapia , Transplante de Microbiota Fecal , Idoso , Idoso de 80 Anos ou mais , Diarreia/etiologia , Método Duplo-Cego , Enterocolite Pseudomembranosa/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Resultado do Tratamento
16.
Clin Infect Dis ; 60(9): 1368-76, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25632012

RESUMO

BACKGROUND: Cryptococcus gattii (Cg) infection emerged in British Columbia in 1999. A longitudinal, clinical description of patients has not been reported. METHODS: Medical records were reviewed for Cg patients identified through surveillance (1999-2007). Risk factors for Cg mortality were explored using multivariate Cox regression; longitudinal patterns in serum cryptococcal antigen (SCrAg) titers and the probability of chest cryptococcomas over time were estimated using cubic B-splines in mixed-effects regression models. RESULTS: Among 152 patients, 111 (73.0%) were culture confirmed. Isolated lung infection was present in 105 (69.1%) patients; 47 (30.9%) had central nervous system infection, with or without lung involvement. Malignancy was the provisional diagnosis in 64 (42.1%) patients. Underlying diseases were present in 91 (59.9%) patients; 23 (15.1%) were immunocompromised, and 23 (15.1%) had asymptomatic disease. There were only 2 (1.8%) culture positive relapses, both within 12 months of follow-up. The estimated median time to resolution of lung cryptococcomas and decline in SCrAg titer to <1:8 was 2.8 and 2.9 years, respectively. Cg-related and all-cause mortality among culture-confirmed cases at 12 months' follow-up was 23.3% and 27.2%, respectively. Cg-related mortality was associated with age >50 years (hazard ratio [HR], 15.6; 95% confidence interval [CI], 1.9-130.5) and immunocompromise (HR, 5.8; CI, 1.5-21.6). All Cg-related mortality occurred among culture-positive cases within 1 year of diagnosis. CONCLUSIONS: Cryptococcomas and serum antigenemia were slow to resolve. However, late onset of failed therapy or relapse was uncommon, suggesting that delayed resolution of these findings does not require prolongation of treatment beyond that recommended by guidelines.


Assuntos
Criptococose/epidemiologia , Cryptococcus gattii , Pulmão/parasitologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Fungos/sangue , Colúmbia Britânica/epidemiologia , Criança , Pré-Escolar , Criptococose/diagnóstico , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Criptococose/mortalidade , Cryptococcus gattii/isolamento & purificação , Cryptococcus gattii/patogenicidade , Feminino , Humanos , Hospedeiro Imunocomprometido , Estudos Longitudinais , Pulmão/diagnóstico por imagem , Pneumopatias Fúngicas/tratamento farmacológico , Pneumopatias Fúngicas/epidemiologia , Pneumopatias Fúngicas/microbiologia , Pneumopatias Fúngicas/mortalidade , Masculino , Pessoa de Meia-Idade , Radiografia , Recidiva , Análise de Regressão , Fatores de Risco , Fatores de Tempo , Adulto Jovem
17.
Am J Ophthalmol ; 159(1): 37-43.e1, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25244977

RESUMO

PURPOSE: To determine if a new, single-sample device (ESwab; Copan Diagnostics, Inc) can simplify the traditional multi-sample approach to specimen collection in infectious keratitis. DESIGN: Prospective, diagnostic test evaluation. METHODS: In this institutional study, patients with suspected infectious keratitis meeting traditional criteria for diagnostic corneal specimen collection and culture were randomized to the order of first specimen collection method: ESwab or a sample directly plated for growth on chocolate agar. This was followed by standard samples for blood agar, Gram stain, Sabouraud agar, thioglycolate broth, and brain heart infusion broth in all cases. The specimens collected using the 2 approaches were analyzed separately by the laboratory in a masked fashion. The main outcome measure was positive growth on cultured media. RESULTS: Eighty-one eyes from 80 consecutive patients were sampled. Culture positivity rate for the multi-sample method and ESwab was 70% and 69%, respectively, with a 75% agreement rate. ESwab sensitivity was 84% (95% confidence interval [CI]: 72%-93%), with a specificity of 67% (95% CI: 45%-84%). Positive and negative predictive values of the ESwab were 86% (95% CI: 74%-94%) and 64% (95% CI: 43%-82%), respectively. There was no difference in positive culture reports with respect to the order of specimen collection technique used. CONCLUSIONS: The single-sample ESwab method is a more accessible and less cumbersome approach to corneal culturing for ophthalmologists, particularly those in the community setting who do not have access to the full set of traditional culture materials. Culture results using this single-sample approach were comparable to the multi-sample method.


Assuntos
Bactérias/isolamento & purificação , Úlcera da Córnea/microbiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Fúngicas/microbiologia , Manejo de Espécimes/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas Bacteriológicas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
18.
Microb Drug Resist ; 21(3): 253-60, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25545311

RESUMO

The usefulness of carbapenems for gram-negative infections is becoming compromised by organisms harboring carbapenemases, enzymes which can hydrolyze the drug. Currently KPC (class A), NDM (class B), and OXA-48 types (class D) are the most globally widespread carbapenemases. However, among the GES-type class A extended-spectrum ß-lactamases (ESBLs) there are variants that hydrolyze carbapenems, with blaGES-5 being the most common. Two Escherichia coli and two Serratia marcescens harboring blaGES-5 on plasmids were isolated by the Canadian Nosocomial Infection Surveillance Program (CNISP) from four different patients in a single hospital over a 2-year period. Complete sequencing of the blaGES-5 plasmids indicated that all four had nearly identical backbones consisting of genes for replication, partitioning, and stability, but contained variant accessory regions consisting of mobile elements and antimicrobial resistance genes. The plasmids were of a novel replicon type, but belonged to the MOBQ1 group based on relaxase sequences, and appeared to be mobilizable, but not self-transmissible. Considering the time periods of bacterial isolation, it would appear the blaGES-5 plasmid has persisted in an environmental niche for at least 2 years in the hospital. This has implications for infection control and clinical care when it is transferred to clinically relevant gram-negative organisms.


Assuntos
Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Plasmídeos/metabolismo , Serratia marcescens/genética , beta-Lactamases/genética , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Canadá/epidemiologia , Carbapenêmicos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Escherichia coli/classificação , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Feminino , Hospitais , Humanos , Sequências Repetitivas Dispersas , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Plasmídeos/química , Replicon , Alinhamento de Sequência , Análise de Sequência de DNA , Infecções por Serratia/tratamento farmacológico , Infecções por Serratia/epidemiologia , Infecções por Serratia/microbiologia , Serratia marcescens/classificação , Serratia marcescens/enzimologia , Serratia marcescens/isolamento & purificação , beta-Lactamases/metabolismo
19.
BMC Infect Dis ; 14: 393, 2014 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-25308184

RESUMO

BACKGROUND: Increasing multidrug resistance in gram-negative bacilli (GNB) infections poses a serious threat to public health. Few studies have analyzed co-resistance rates, defined as an antimicrobial susceptibility profile in a subset already resistant to one specific antibiotic. The epidemiologic and clinical utility of determining co-resistance rates are analyzed and discussed. METHODS: A 10-year retrospective study from 2002-2011 of bloodstream infections with GNB were analyzed from three hospitals in Greater Vancouver, BC, Canada. Descriptive statistics were calculated for antimicrobial resistance and co-resistance. Statistical analysis further described temporal trends of antimicrobial resistance, correlations of resistance between combinations of antimicrobials, and temporal trends in co-resistance patterns. RESULTS: The total number of unique blood stream isolates of GNB was 3280. Increasing resistance to individual antimicrobials was observed for E. coli, K. pneumoniae, K. oxytoca, E. cloacae, and P. aeruginosa. Ciprofloxacin resistance in E. coli peaked in 2006 at 40% and subsequently stabilized at 29% in 2011, corresponding to decreasing ciprofloxacin usage after 2007, as assessed by defined daily dose utilization data. High co-resistance rates were observed for ceftriaxone-resistant E. coli with ciprofloxacin (73%), ceftriaxone-resistant K. pneumoniae with trimethoprim-sulfamethoxazole (83%), ciprofloxacin-resistant E. cloacae with ticarcillin-clavulanate (91%), and piperacillin-tazobactam-resistant P. aeruginosa with ceftazidime (83%). CONCLUSIONS: Increasing antimicrobial resistance was demonstrated over the study period, which may partially be associated with antimicrobial consumption. The study of co-resistance rates in multidrug resistant GNB provides insight into the epidemiology of resistance acquisition, and may be used as a clinical tool to aid prescribing empiric antimicrobial therapy.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana , Infecções por Bactérias Gram-Negativas/microbiologia , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Colúmbia Britânica/epidemiologia , Ciprofloxacina/uso terapêutico , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Humanos , Klebsiella oxytoca/efeitos dos fármacos , Klebsiella oxytoca/isolamento & purificação , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Estudos Longitudinais , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Estudos Retrospectivos , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
20.
J Antimicrob Chemother ; 68 Suppl 1: i47-55, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23587778

RESUMO

OBJECTIVES: To compare the demographics, antimicrobial susceptibilities and molecular epidemiology of community-associated (CA) and healthcare-associated (HA) methicillin-resistant Staphylococcus aureus (MRSA) in Canada. METHODS: Between 2007 and 2011, 1266 MRSA were collected from inpatients and outpatients attending tertiary-care medical centres across Canada. Susceptibility testing was performed using broth microdilution and isolates were characterized by spa typing and PCR to detect the Panton-Valentine leucocidin (PVL) gene. Detection of heterogeneous vancomycin-intermediate S. aureus (hVISA) was performed using the Etest macromethod and confirmed by population analysis profiling. RESULTS: The annual proportion of S. aureus that were methicillin resistant decreased from 26.1% in 2007 to 19.3% in 2011 (P= 0.0002). Of 1266 MRSA isolated, 366 (28.9%) were CA-MRSA genotypes and 868 (68.6%) were HA-MRSA genotypes. The proportion of MRSA represented by CA-MRSA genotypes increased from 19.7% to 36.4% between 2007 and 2011 (P < 0.0001). CMRSA10 (USA300) was the predominant CA-MRSA genotype (22.1%); the most common HA-MRSA genotype was CMRSA2 (USA100/800) (58.1%). PVL was detected in 328/366 (89.6%) of CA-MRSA genotypes and 6/868 (0.7%) of HA-MRSA genotypes. The hVISA phenotype was detected in 7/27 (25.9%) of MRSA with a vancomycin MIC of 2 mg/L. CONCLUSIONS: The most frequent CA-MRSA genotype was CMRSA10 (USA300), while CMRSA2 (USA100/800) was the predominant HA-MRSA genotype. Despite a decrease in the numbers of MRSA, the proportion of CMRSA10 (USA300) CA-MRSA has risen significantly between 2007 and 2011 in Canada.


Assuntos
Infecção Hospitalar , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Canadá/epidemiologia , Criança , Pré-Escolar , Feminino , Genótipo , História do Século XXI , Humanos , Lactente , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem Molecular , Fenótipo , Infecções Estafilocócicas/história , Adulto Jovem
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