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1.
Emerg Infect Dis ; 30(7): 1487-1490, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38916874

RESUMO

Using phylogenomic analysis, we provide genomic epidemiology analysis of a large blastomycosis outbreak in Ontario, Canada, caused by Blastomyces gilchristii. The outbreak occurred in a locale where blastomycosis is rarely diagnosed, signaling a possible shift in geographically associated incidence patterns. Results elucidated fungal population genetic structure, enhancing understanding of the outbreak.


Assuntos
Blastomyces , Blastomicose , Surtos de Doenças , Filogenia , Blastomicose/epidemiologia , Blastomicose/microbiologia , Ontário/epidemiologia , Humanos , Blastomyces/genética , Genômica/métodos , Epidemiologia Molecular , Masculino , Genoma Fúngico , Feminino , Pessoa de Meia-Idade
2.
J Clin Microbiol ; 62(1): e0116123, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-38112529

RESUMO

Candida parapsilosis is a common cause of non-albicans candidemia. It can be transmitted in healthcare settings resulting in serious healthcare-associated infections and can develop drug resistance to commonly used antifungal agents. Following a significant increase in the percentage of fluconazole (FLU)-nonsusceptible isolates from sterile site specimens of patients in two Ontario acute care hospital networks, we used whole genome sequence (WGS) analysis to retrospectively investigate the genetic relatedness of isolates and to assess potential in-hospital spread. Phylogenomic analysis was conducted on all 19 FLU-resistant and seven susceptible-dose dependent (SDD) isolates from the two hospital networks, as well as 13 FLU susceptible C. parapsilosis isolates from the same facilities and 20 isolates from patients not related to the investigation. Twenty-five of 26 FLU-nonsusceptible isolates (resistant or SDD) and two susceptible isolates from the two hospital networks formed a phylogenomic cluster that was highly similar genetically and distinct from other isolates. The results suggest the presence of a persistent strain of FLU-nonsusceptible C. parapsilosis causing infections over a 5.5-year period. Results from WGS were largely comparable to microsatellite typing. Twenty-seven of 28 cluster isolates had a K143R substitution in lanosterol 14-α-demethylase (ERG11) associated with azole resistance. As the first report of a healthcare-associated outbreak of FLU-nonsusceptible C. parapsilosis in Canada, this study underscores the importance of monitoring local antimicrobial resistance trends and demonstrates the value of WGS analysis to detect and characterize clusters and outbreaks. Timely access to genomic epidemiological information can inform targeted infection control measures.


Assuntos
Candida parapsilosis , Fluconazol , Humanos , Fluconazol/farmacologia , Estudos Retrospectivos , Testes de Sensibilidade Microbiana , Farmacorresistência Fúngica/genética , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Genômica , Hospitais , Ontário
3.
J Clin Microbiol ; 60(12): e0103222, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36326257

RESUMO

There is an increasing body of literature on the utility of MALDI-TOF MS in the identification of filamentous fungi. However, the process still lacks standardization. In this study, we attempted to establish a practical workflow for the identification of three clinically important molds: Aspergillus, Fusarium, and Mucorales using MALDI-TOF MS. We evaluated the performance of Bruker Filamentous Fungi database v3.0 for the identification of these fungi, highlighting when there would be a benefit of using an additional database, the MSI-2 for further identification. We also examined two other variables, namely, medium effect and incubation time on the accuracy of fungal identification. The Bruker database achieved correct species level identification in 85.7% of Aspergillus and 90% of Mucorales, and correct species-complex level in 94.4% of Fusarium. Analysis of spectra using the MSI-2 database would also offer additional value for species identification of Aspergillus species, especially when suspecting species with known identification limits within the Bruker database. This issue would only be of importance in selected cases where species-level identification would impact therapeutic options. Id-Fungi plates (IDFP) had almost equivalent performance to Sabouraud dextrose agar (SDA) for species-level identification of isolates and enabled an easier harvest of the isolates with occasional faster identification. Our study showed accurate identification at 24 h for Fusarium and Mucorales species, but not for Aspergillus species, which generally required 48 h.


Assuntos
Fusarium , Mucorales , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fluxo de Trabalho , Aspergillus , Fungos
4.
Infect Immun ; 89(5)2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33526558

RESUMO

We aimed to determine whether T cell-specific STAT3 deletion influences the immune response to Aspergillus in the immunosuppressed context in CD4 Stat3-/- mice. Immunosuppressed and nonimmunosuppressed CD4 Stat3-/- mice and littermate Stat3flox/flox (Stat3fl/fl) mice were infected with Aspergillus fumigatus in an aerosol chamber, and the weight, activity, appearance, and respiratory rate of the mice were monitored daily for 21 days to evaluate their survival. Aspergillus infection was confirmed by lung fungal culture counts, histology, and a galactomannan test. Cytokines were measured at 3 days postinfection in bronchoalveolar lavage (BAL) fluid and serum. Immunosuppressed CD4 Stat3-/- mice began succumbing to infection by day 4, and by day 7, only 30% of mice survived. Immunosuppressed Stat3fl/fl mice started to succumb to the disease on day 5, and 40% of mice remained by day 7. The nonimmunosuppressed control Stat3fl/fl and CD4 Stat3-/- mice maintained their weight over the study period, without any evidence of infection by A. fumigatus by histology. In the BAL fluid, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), interferon gamma (IFN-γ), IL-17A, and IL-22 levels were elevated in Stat3fl/fl immunosuppressed mice compared to immunosuppressed CD4 Stat3-/- mice at 3 days postinfection. STAT3 in CD4+ T cells modulates the production of cytokines in the IL-17 pathway in immunosuppressed mice. However, it has no meaningful effect on the clearance of Aspergillus or the concomitant increase in susceptibility to Aspergillus infection.


Assuntos
Aspergilose/etiologia , Aspergilose/metabolismo , Aspergillus fumigatus/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Interações Hospedeiro-Patógeno , Fator de Transcrição STAT3/metabolismo , Animais , Aspergilose/patologia , Líquido da Lavagem Broncoalveolar , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Interações Hospedeiro-Patógeno/imunologia , Mediadores da Inflamação , Camundongos , Camundongos Knockout , Transdução de Sinais
5.
Clin Infect Dis ; 73(7): e1560-e1569, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-32766820

RESUMO

BACKGROUND: Blastomycosis has been reported from countries in Africa and the Middle East, but a decades-long debate has persisted regarding whether this is the same disease known in North America and caused by Blastomyces dermatitidis and Blastomyces gilchristii. METHODS: We reviewed published cases of human and veterinary blastomycosis from Africa and the Middle East. We abstracted epidemiological and clinical features of cases, including sites of disease, diagnosis, management, outcomes, and, where available, genetic and antigenic typing of case isolates. In addition, we sequenced nucleic acids from 9 clinical isolates from Africa deposited in global collections as B. dermatitidis; for 5, we sequenced the internal transcribed spacer regions, and for the other 4 we sequenced the whole genomes. RESULTS: We identified 172 unique human patients with blastomycosis, including 159 patients from 25 African countries and 12 patients from 5 Middle Eastern countries, and also identified 7 reports of veterinary blastomycosis. In humans, cutaneous disease predominated (n = 100/137, 73%), followed by pulmonary (n = 73/129, 57%) and osteoarticular involvement (n = 61/128, 48%). Unusual direct microscopy/histopathological presentations included short hyphal fragments in tissues (n = 23/129, 18%). There were 34 genotyped case isolates that comprised 4 species: Blastomyces percursus (n = 22, 65%), from 8 countries throughout all regions; Blastomyces emzantsi (n = 9, 26%), from South Africa; B. dermatitidis (n = 1, 3%), from the Democratic Republic of Congo; and B. gilchristii (n = 2, 6%), from South Africa and Zimbabwe. CONCLUSIONS: Blastomycosis occurs throughout Africa and the Middle East and is caused predominantly by B. percursus and, at least in South Africa, B. emzantsi, resulting in distinct clinical and pathological patterns of disease.


Assuntos
Blastomicose , Blastomyces/genética , Blastomicose/epidemiologia , Humanos , Oriente Médio , África do Sul
6.
J Clin Microbiol ; 59(3)2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33298609

RESUMO

Blastomycosis due to Blastomyces dermatitidis and Blastomyces gilchristii is a significant cause of respiratory mycoses in North America with occasional reported outbreaks. We developed a highly sensitive, specific, and reproducible TaqMan duplex real-time PCR assay for the differentiation of B. dermatitidis and B. gilchristii The new assay permitted retrospective analysis of Blastomyces cultures (2005 to 2019) and primary clinical specimens from blastomycosis cases (2013 to 2019) from New York patients. We identified B. dermatitidis as the predominant pathogen in 38 cases of blastomycosis, while B. gilchristii was a minor pathogen involved in five cases; these findings expand understanding of blastomycosis in New York. The duplex real-time PCR assay could be implemented in reference and public health laboratories to further understand the ecology and epidemiology of blastomycosis due to B. dermatitidis and B. gilchristii.


Assuntos
Blastomyces , Blastomicose , Blastomyces/genética , Blastomicose/diagnóstico , Blastomicose/epidemiologia , Humanos , New York/epidemiologia , América do Norte , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos
7.
Med Mycol ; 59(7): 728-733, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-33418565

RESUMO

Azole resistance in Aspergillus fumigatus is increasing worldwide and can affect prognosis. It is mostly mediated by cytochrome P51 (CYP51) mutations. In lung transplant recipients (LTR), little is known regarding the prevalence and clinical impact of CYP51 mutations. One hundred thirty-one consecutive A. fumigatus isolates from 103 patients were subjected to CYP51A genotyping through PCR and sequencing. Antifungal susceptibility testing was performed using the Sensititre YeastOne YO-9© broth microdilution technique. Correlations between genotype, phenotype, clinical manifestations of Aspergillus infection, and clinical outcomes were made. Thirty-four (26%) isolates harbored mutations of CYP51A; N248K (n = 14) and A9T (n = 12) were the most frequent. Three isolates displayed multiple point mutations. No significant influences of mutational status were identified regarding azole MICs, the clinical presentation of Aspergillus disease, 1-year all-cause mortality, and clinical outcomes of invasive forms. In the specific context of lung transplant recipients, non-hotspot CYP51A-mutated isolates are regularly encountered; this does not result in major clinical consequences or therapeutic challenges. LAY SUMMARY: In 131 isolates of Aspergillus fumigatus isolates originating from 103 lung transplant recipients, the CYP51A polymorphism rate was 26%, mostly represented by N248K and A9T mutations. These mutations, however, did not significantly impact azoles minimal inhibitory concentrations or clinical outcomes.


Assuntos
Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/genética , Proteínas Fúngicas/genética , Transplante de Pulmão/estatística & dados numéricos , Fenótipo , Polimorfismo Genético , Transplantados/estatística & dados numéricos , Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Mutação Puntual/genética , Prevalência
8.
Artigo em Inglês | MEDLINE | ID: mdl-32571812

RESUMO

To understand the epidemiology and susceptibility patterns of yeast infections in Ontario, Canada, we examined 4,715 clinical yeast isolates submitted to our laboratory for antifungal susceptibility testing from 2014 to 2018. Candida albicans was the most frequently submitted species (43.0%), followed by C. glabrata (21.1%), C. parapsilosis (15.0%), and C. tropicalis (6.2%). Twenty-three other Candida spp. (11.6%) and 4 non-Candida species (3.1%) were also identified. Few changes in species distribution were observed from 2014 to 2018, but the total numbers of yeast isolates sent for testing increased, with an annual 7.4% change. According to CLSI clinical breakpoints, resistance rates remained low overall. Moderate fluconazole resistance was noted among C. glabrata (9%), C. parapsilosis (9%), and C. tropicalis (12%) isolates. Only 1% of C. glabrata isolates were resistant to caspofungin, micafungin, and anidulafungin. Whole-genome sequence analysis confirmed 11 cases of acquired resistance to azoles or echinocandins via in-host evolution. There were mutations in the gene for the catalytic subunit of 1,3-beta-glucan synthase-mediated echinocandin resistance in 3 of 3 C. albicans strains, 3 of 4 C. glabrata strains, and 1 strain of C. tropicalis Azole resistance was likely caused by a homozygous ERG3 mutation in 1 C. albicans strain and a previously undescribed chromosomal-duplication event involving ERG11 and TAC1 orthologs in 1 C. tropicalis strain. While antifungal resistance rates remain low among yeast isolates in Ontario, ongoing surveillance is necessary to inform empirical therapy for optimal patient management and to guide antifungal stewardship.


Assuntos
Antifúngicos , Candida/efeitos dos fármacos , Farmacorresistência Fúngica , Antifúngicos/farmacologia , Candida/genética , Farmacorresistência Fúngica/genética , Equinocandinas/farmacologia , Genoma Fúngico , Humanos , Laboratórios , Testes de Sensibilidade Microbiana , Ontário , Análise de Sequência , Sequenciamento Completo do Genoma
10.
Emerg Infect Dis ; 24(7): 1257-1266, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29912691

RESUMO

Endemic mycoses represent a growing public health challenge in North America. We describe the epidemiology of 1,392 microbiology laboratory-confirmed cases of blastomycosis, histoplasmosis, and coccidioidomycosis in Ontario during 1990-2015. Blastomycosis was the most common infection (1,092 cases; incidence of 0.41 cases/100,000 population), followed by histoplasmosis (211 cases) and coccidioidomycosis (89 cases). Incidence of blastomycosis increased from 1995 to 2001 and has remained elevated, especially in the northwest region, incorporating several localized hotspots where disease incidence (10.9 cases/100,000 population) is 12.6 times greater than in any other region of the province. This retrospective study substantially increases the number of known endemic fungal infections reported in Canada, confirms Ontario as an important region of endemicity for blastomycosis and histoplasmosis, and provides an epidemiologic baseline for future disease surveillance. Clinicians should include blastomycosis and histoplasmosis in the differential diagnosis of antibiotic-refractory pneumonia in patients traveling to or residing in Ontario.


Assuntos
Blastomicose/epidemiologia , Coccidioidomicose/epidemiologia , Histoplasmose/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Blastomicose/história , Blastomicose/microbiologia , Coccidioidomicose/história , Coccidioidomicose/microbiologia , Feminino , Geografia Médica , Histoplasmose/história , Histoplasmose/microbiologia , História do Século XX , História do Século XXI , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , Prevalência , Vigilância em Saúde Pública , Adulto Jovem
11.
J Clin Microbiol ; 55(7): 2030-2034, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28404678

RESUMO

Aspergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating A. fumigatus infections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20 Aspergillus spp. (including 2 isolates of Aspergillus ustus and 1 of Aspergillus calidoustus that were used as controls due their intrinsic low azole susceptibility with respect to the in vitro response to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detect A. fumigatus strains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Voriconazol/farmacologia , Humanos , Estudo de Prova de Conceito
12.
Antimicrob Agents Chemother ; 59(1): 269-75, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25348540

RESUMO

Antimicrobial susceptibility patterns of 112 clinical isolates, 28 type strains, and 9 reference strains of Nocardia were determined using the Sensititre Rapmyco microdilution panel (Thermo Fisher, Inc.). Isolates were identified by highly discriminatory multilocus sequence analysis and were chosen to represent the diversity of species recovered from clinical specimens in Ontario, Canada. Susceptibility to the most commonly used drug, trimethoprim-sulfamethoxazole, was observed in 97% of isolates. Linezolid and amikacin were also highly effective; 100% and 99% of all isolates demonstrated a susceptible phenotype. For the remaining antimicrobials, resistance was species specific with isolates of Nocardia otitidiscaviarum, N. brasiliensis, N. abscessus complex, N. nova complex, N. transvalensis complex, N. farcinica, and N. cyriacigeorgica displaying the traditional characteristic drug pattern types. In addition, the antimicrobial susceptibility profiles of a variety of rarely encountered species isolated from clinical specimens are reported for the first time and were categorized into four additional drug pattern types. Finally, MICs for the control strains N. nova ATCC BAA-2227, N. asteroides ATCC 19247(T), and N. farcinica ATCC 23826 were robustly determined to demonstrate method reproducibility and suitability of the commercial Sensititre Rapmyco panel for antimicrobial susceptibility testing of Nocardia spp. isolated from clinical specimens. The reported values will facilitate quality control and standardization among laboratories.


Assuntos
Antibacterianos/farmacologia , Nocardia/efeitos dos fármacos , Nocardia/genética , Técnicas de Tipagem Bacteriana , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Humanos , Testes de Sensibilidade Microbiana/métodos , Tipagem de Sequências Multilocus , Nocardia/classificação , Nocardia/isolamento & purificação , Ontário , Controle de Qualidade , Reprodutibilidade dos Testes
13.
Med Mycol ; 52(7): 766-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25049039

RESUMO

Manipulation of Blastomyces dermatitidis requires the use of containment level 3 (CL3) practices. However, access to CL3 laboratories is limited and working conditions are restrictive. We describe the validation of a "heat-killing" method to inactivate B. dermatitidis, thus allowing cellular material to be removed from the CL3 laboratory for subsequent DNA isolation that is suitable for genetic applications.


Assuntos
Blastomyces/efeitos da radiação , Desinfecção/métodos , Viabilidade Microbiana/efeitos da radiação , Gestão da Segurança/métodos , Animais , Blastomyces/genética , Contenção de Riscos Biológicos , Genética Microbiana/métodos , Temperatura Alta , Humanos , Biologia Molecular/métodos
14.
G3 (Bethesda) ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39163563

RESUMO

Blastomyces dermatitidis and Blastomyces gilchristii are cryptic species of fungi that cause blastomycosis, an often severe disease involving pulmonary infection capable of systemic dissemination. While these species appear morphologically identical, differences exist in the genetic makeup, geographical range, and possibly the clinical presentation of infection. Here, we show genetic divergence between the cryptic species through both a Blastomyces species tree constructed from orthologous protein sequences and whole genome single nucleotide variant phylogenomic analysis. Following linked-read sequencing and de novo genome assembly, we characterized and compared the genomes of 3 B. dermatitidis and 3 B. gilchristii isolates. The B. gilchristii genomes (73.25-75.4 Mb), were ∼8 Mb larger than the B. dermatitidis genomes (64.88-66.61 Mb). Average nucleotide identity was lower between genomes of different species than genomes of the same species, yet functional classification of genes suggested similar proteomes. The most striking difference involved long terminal repeat retrotransposons. Although the same retrotransposon elements were detected in the genomes, the quantity of elements differed between the two species. Gypsy retrotransposon content was significantly higher in B. gilchristii (38.04-39.26 Mb) than in B. dermatitidis (30.85-32.40 Mb), accounting for the majority of genome size difference between species. Age estimation and phylogenetic analysis of the reverse transcriptase domains suggested that these retrotransposons are relatively ancient, with genome insertion predating the speciation of B. dermatitidis and B. gilchristii. We postulate that different trajectories of genome contraction led to genetic incompatibility, reproductive isolation and speciation, highlighting the role of transposable elements in fungal evolution.

15.
J Clin Microbiol ; 50(6): 1856-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22422855

RESUMO

Pneumocystis jirovecii pneumonia is a significant cause of morbidity and mortality in AIDS patients as well as those with non-HIV immunosuppressive diseases. To aid diagnosis, the commercial MycAssay Pneumocystis real-time PCR assay (Myconostica, Ltd., Manchester, United Kingdom) targeting the mitochondrial ribosomal large subunit (mtLSU) has been developed to detect P. jirovecii in bronchoalveolar lavage (BAL) specimens. Here, we validated this assay against a laboratory standard of direct immunofluorescence microscopy, a cdc2 real-time PCR assay, or conventional PCR and sequencing of mtLSU. While more sensitive than any of these three assays analyzed individually, the MycAssay Pneumocystis assay demonstrated 100% sensitivity, 100% specificity, a 100% negative predictive value, and a 100% positive predictive value for detecting the presence of P. jirovecii in BAL specimens compared to the laboratory standard. Of note, two samples with positive cycle threshold (C(T)) values according to the MycAssay Pneumocystis assay lacked exponential amplification curves and thus were deemed negative. Also negative according to the laboratory standard, these samples highlight the importance of examining the amplification curves, in addition to noting the C(T) values, when interpreting positive results. Comparison of the MycAssay Pneumocystis assay to a laboratory standard establishes this assay to be a highly sensitive and specific method for the detection of P. jirovecii in bronchoalveolar lavage specimens. The approach may also be useful for the clinical laboratory validation of other sensitive real-time PCR assays.


Assuntos
Líquido da Lavagem Broncoalveolar/microbiologia , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Micologia/métodos , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/diagnóstico , Técnica Direta de Fluorescência para Anticorpo/métodos , Humanos , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Reino Unido
16.
Med Mycol ; 50(3): 324-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21859386

RESUMO

We compared the FXG™: RESP (Asp +) real-time PCR assay (Myconostica Ltd) with two microscopic staining methods (direct immunofluorescence [IFA] and calcofluor white) for the detection of Pneumocystis jirovecii in 411 respiratory specimens submitted for P. jirovecii examination. We considered the specimen to be microscopically positive if the organism could be visualized through the use of either IFA or calcofluor white. A second, published real-time PCR assay targeting the cdc2 gene of P. jirovecii was used to adjudicate those specimens that were microscopically negative but Myconostica PCR positive. The Myconostica PCR positive samples were deemed to be true positives if they were concordant with microscopically positive results or if they were positive by the second PCR assay. As a result, the Myconostica PCR assay was found to be more sensitive than the two microscopy methods in detecting P. jirovecii (10.5% true positivity rate by PCR, 8.0% by immunofluorescence, and 7.1% by calcofluor white). The Myconostica PCR assay showed 93.5% sensitivity, 95.1% specificity, 70.5% positive predictive value, and 99.1% negative predictive value. Its high negative predictive value suggests a role of the Myconostica PCR assay in ruling out Pneumocystis pneumonia.


Assuntos
Benzenossulfonatos/metabolismo , Técnica Direta de Fluorescência para Anticorpo/métodos , Técnicas Microbiológicas/métodos , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Coloração e Rotulagem/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Micologia/métodos , Pneumonia por Pneumocystis/microbiologia , Sensibilidade e Especificidade , Adulto Jovem
17.
J Clin Microbiol ; 49(7): 2522-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21593254

RESUMO

Rapid identification of Cryptococcus neoformans var. grubii, Cryptococcus neoformans var. neoformans, and Cryptococcus gattii is imperative for facilitation of prompt treatment of cryptococcosis and for understanding the epidemiology of the disease. Our purpose was to evaluate a test algorithm incorporating commercial rapid biochemical tests, differential media, and DNA sequence analysis that will allow us to differentiate these taxa rapidly and accurately. We assessed 147 type, reference, and clinical isolates, including 6 other Cryptococcus spp. (10 isolates) and 14 other yeast species (24 isolates), using a 4-hour urea broth test (Remel), a 24-hour urea broth test (Becton Dickinson), a 4-hour caffeic acid disk test (Hardy Diagnostics and Remel), 40- to 44-hour growth assessment on l-canavanine glycine bromothymol blue (CGB) agar, and intergenic spacer (IGS) sequence analysis. All 123 Cryptococcus isolates hydrolyzed urea, along with 7 isolates of Rhodotorula and Trichosporon. Eighty-five of 86 C. neoformans (99%) and 26 of 27 C. gattii (96%) isolates had positive caffeic acid results, unlike the other cryptococci (0/10) and yeast species (0/24). Together, these two tests positively identified virtually all C. neoformans/C. gattii isolates (98%) within 4 h. CGB agar or IGS sequencing further differentiated these isolates within 48 h. On CGB, 25 of 27 (93%) C. gattii strains induced a blue color change, in contrast to 0 of 86 C. neoformans isolates. Neighbor-joining cluster analysis of IGS sequences differentiated C. neoformans var. grubii, C. neoformans var. neoformans, and C. gattii. Based on these results, we describe a rapid identification algorithm for use in a microbiology laboratory to distinguish clinically relevant Cryptococcus spp.


Assuntos
Criptococose/diagnóstico , Cryptococcus neoformans/isolamento & purificação , Meios de Cultura/química , DNA Fúngico/genética , Tipagem Molecular , Técnicas de Tipagem Micológica , Criptococose/microbiologia , Cryptococcus neoformans/classificação , Cryptococcus neoformans/genética , Cryptococcus neoformans/metabolismo , DNA Fúngico/química , Humanos , Análise de Sequência de DNA , Fatores de Tempo
18.
J Clin Microbiol ; 49(8): 3050-3, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21653762

RESUMO

Compared to DNA sequence analysis, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) correctly identified 100% of Cryptococcus species, distinguishing the notable pathogens Cryptococcus neoformans and C. gattii. Identification was greatly enhanced by supplementing a commercial spectral library with additional entries to account for subspecies variability.


Assuntos
Cryptococcus gattii/química , Cryptococcus gattii/classificação , Cryptococcus neoformans/química , Cryptococcus neoformans/classificação , Técnicas Microbiológicas/métodos , Micologia/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , DNA Fúngico/química , DNA Fúngico/genética , Humanos , Sensibilidade e Especificidade , Análise de Sequência de DNA/métodos
19.
Microbiol Spectr ; 9(2): e0080321, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34612671

RESUMO

Haemophilus influenzae can cause serious invasive disease. We report the epidemiology and antimicrobial susceptibility of invasive H. influenzae in Ontario, Canada, from 2014 to 2018 from laboratory-based data. Blood was the most common specimen source (89.5%). Consistent with widespread vaccination against serotype b (Hib), the incidence of Hib in Ontario remained low (0.04 cases per 100,000 population). H. influenzae disease primarily afflicted those <1 and ≥65 years of age. From 2014 to 2018, cases of invasive H. influenzae increased 5.6%, from 1.67 to 2.06 cases per 100,000 population, the majority of which were attributed to a 7.6% increase in the incidence of H. influenzae in those ≥65 years old. H. influenzae disease was primarily caused by nontypeable H. influenzae (NTHi) (74.2%) and, to a much lesser extent, serotype a (Hia) (8.9%) and serotype f (Hif) (10.2%). Serotype-dependent trends in antimicrobial susceptibility were observed. Hia and Hif isolates were predominantly susceptible to all antibiotics tested, while 27.2% of NTHi isolates were nonsusceptible to ampicillin. Resistance to ceftriaxone and meropenem, first-line antibiotics for invasive disease treatment, was nonexistent. The incidence of invasive H. influenzae in Ontario is increasing. The incidence and antimicrobial susceptibility of all serotypes and nontypeable H. influenzae should be monitored. IMPORTANCE H. influenzae can cause serious invasive, life-threatening disease and is considered 1 of 12 priority pathogens by the World Health Organization. Widespread vaccination against H. influenzae serotype b (Hib) has resulted in very low incidence of Hib in Ontario and other regions that have vaccination programs. However, the epidemiology of non-Hib serotypes and nontypeable H. influenzae (NTHi) remains poorly understood. Here, we describe the epidemiology of all invasive H. influenzae isolates (N = 1,338) received by our laboratory over the 5-year period and report on the antimicrobial susceptibility patterns by serotype. Overall, we observed an increase in the incidence of invasive disease over the study period, primarily driven by NTHi. Serotype-dependent trends in antimicrobial susceptibility were also observed. This work contributes to the global understanding of H. influenzae epidemiology and antimicrobial resistance and is additionally important for further vaccine planning initiatives.


Assuntos
Infecções por Haemophilus/epidemiologia , Infecções por Haemophilus/microbiologia , Haemophilus influenzae/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Criança , Pré-Escolar , Feminino , Infecções por Haemophilus/tratamento farmacológico , Infecções por Haemophilus/prevenção & controle , Haemophilus influenzae/classificação , Haemophilus influenzae/efeitos dos fármacos , Humanos , Incidência , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Ontário/epidemiologia , Sorogrupo , Vacinação , Adulto Jovem
20.
J Clin Microbiol ; 48(12): 4677-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20881164

RESUMO

Candida bracarensis is a recently described Candida species which is phenotypically similar to Candida glabrata. A case of C. bracarensis bloodstream infection in a bone marrow transplant patient is described and confirms this organism as an opportunistic human pathogen. The organism can be distinguished from C. glabrata by its white color on CHROMagar and by DNA sequence analysis using D1/D2 and internal transcribed spacer (ITS) primers.


Assuntos
Candida/isolamento & purificação , Candidíase/diagnóstico , Fungemia/diagnóstico , Hospedeiro Imunocomprometido , Antifúngicos/farmacologia , Transplante de Medula Óssea/efeitos adversos , Candida/classificação , Candidíase/microbiologia , Análise por Conglomerados , Meios de Cultura/química , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fungemia/microbiologia , Genes de RNAr , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Micologia/métodos , Filogenia , RNA Fúngico/genética , RNA Ribossômico/genética , Análise de Sequência de DNA
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