Real-time polymerase chain reaction detection of Cryptococcus neoformans and Cryptococcus gattii in human samples

Véron, Vincent; Simon, Stéphane; Blanchet, Denis; Aznar, Christine

doi:10.1016/j.diagmicrobio.2009.05.005

Cited by 35 publications

(18 citation statements)

References 15 publications

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“…Using these tests, most cases of cryptococcal meningitis are able to be diagnosed with good sensitivity and specificity (24,25). More recently, molecular methods for detection of both C. neoformans and C. gattii have been reported that may improve laboratory diagnosis (26,27).…”

Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens

et al. 2016

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Rapid diagnosis and treatment of infectious meningitis and encephalitis are critical to minimize morbidity and mortality. Comprehensive testing of cerebrospinal fluid (CSF) often includes Gram stain, culture, antigen detection, and molecular methods, paired with chemical and cellular analyses. These methods may lack sensitivity or specificity, can take several days, and require significant volume for complete analysis. The FilmArray Meningitis/Encephalitis (ME) Panel is a multiplexed in vitro diagnostic test for the simultaneous, rapid (ϳ1-h) detection of 14 pathogens directly from CSF specimens: Escherichia coli K1, Haemophilus influenzae, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus agalactiae, cytomegalovirus, enterovirus, herpes simplex virus 1 and 2, human herpesvirus 6, human parechovirus, varicella-zoster virus, and Cryptococcus neoformans/Cryptococcus gattii. We describe a multicenter evaluation of 1,560 prospectively collected CSF specimens with performance compared to culture (bacterial analytes) and PCR (all other analytes). The FilmArray ME Panel demonstrated a sensitivity or positive percentage of agreement of 100% for 9 of 14 analytes. Enterovirus and human herpesvirus type 6 had agreements of 95.7% and 85.7%, and L. monocytogenes and N. meningitidis were not observed in the study. For S. agalactiae, there was a single false-positive and false-negative result each, for a sensitivity and specificity of 0 and 99.9%, respectively. The specificity or negative percentage of agreement was 99.2% or greater for all other analytes. The FilmArray ME Panel is a sensitive and specific test to aid in diagnosis of ME. With use of this comprehensive and rapid test, improved patient outcomes and antimicrobial stewardship are anticipated.

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Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens

et al. 2016

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“…gattii, H. capsulatum, and P. jirovecii separately have been widely described based on the amplification of different targets, with varied sensitivity and specificity. Most of the rt-PCR approaches for the diagnosis of cryptococcosis are based on the amplification of monocopy genes (43,58), which may decrease the sensitivity of the technique. Our technique allows detection of both C. neoformas spp.…”

Section: Discussionmentioning

confidence: 99%

“…Routine clinical diagnosis of cryptococcosis is based on culture and detection of a capsular antigen, with varied sensitivity and specificity (39,40). However, molecular methods based on PCR and new technologies for antigen detection also have been described in recent years, although validation of these methods is pending (41)(42)(43)(44).…”

mentioning

confidence: 99%

A Multiplex Real-Time PCR Assay for Identification of Pneumocystis jirovecii, Histoplasma capsulatum, and Cryptococcus neoformans/Cryptococcus gattii in Samples from AIDS Patients with Opportunistic Pneumonia

et al. 2014

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A molecular diagnostic technique based on real-time PCR was developed for the simultaneous detection of three of the most frequent causative agents of fungal opportunistic pneumonia in AIDS patients: Pneumocystis jirovecii, Histoplasma capsulatum, and Cryptococcus neoformans/Cryptococcus gattii. This technique was tested in cultured strains and in clinical samples from HIV-positive patients. The methodology used involved species-specific molecular beacon probes targeted to the internal transcribed spacer regions of the rDNA. An internal control was also included in each assay. The multiplex real-time PCR assay was tested in 24 clinical strains and 43 clinical samples from AIDS patients with proven fungal infection. The technique developed showed high reproducibility (r 2 of >0.98) and specificity (100%). For H. capsulatum and Cryptococcus spp., the detection limits of the method were 20 and 2 fg of genomic DNA/20 l reaction mixture, respectively, while for P. jirovecii the detection limit was 2.92 log 10 copies/20 l reaction mixture. The sensitivity in vitro was 100% for clinical strains and 90.7% for clinical samples. The assay was positive for 92.5% of the patients. For one of the patients with proven histoplasmosis, P. jirovecii was also detected in a bronchoalveolar lavage sample. No PCR inhibition was detected. This multiplex real-time PCR technique is fast, sensitive, and specific and may have clinical applications.

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“…Amplification of the 18S and 28S rRNA genes using real-time PCR has been successfully employed to detect C. neoformans directly from pericardial fluid (339). Using a TaqMan real-time assay, other investigators showed that seven clinical samples that were culture positive for C. neoformans and C. gattii were confirmed to be positive by the real-time assay, with no false-negative, or false-positive, results (340). The utility of panfungal, nested, and real-time assays to distinguish C. neoformans from C. gattii is uncertain, and where this is not possible, the organism should be identified as "C. neoformans complex.…”

Section: Microbiological Diagnosismentioning

confidence: 99%

Cryptococcus gattii Infections

2014

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SUMMARY Understanding of the taxonomy and phylogeny of Cryptococcus gattii has been advanced by modern molecular techniques. C. gattii probably diverged from Cryptococcus neoformans between 16 million and 160 million years ago, depending on the dating methods applied, and maintains diversity by recombining in nature. South America is the likely source of the virulent C. gattii VGII molecular types that have emerged in North America. C. gattii shares major virulence determinants with C. neoformans , although genomic and transcriptomic studies revealed that despite similar genomes, the VGIIa and VGIIb subtypes employ very different transcriptional circuits and manifest differences in virulence phenotypes. Preliminary evidence suggests that C. gattii VGII causes severe lung disease and death without dissemination, whereas C. neoformans disseminates readily to the central nervous system (CNS) and causes death from meningoencephalitis. Overall, currently available data indicate that the C. gattii VGI, VGII, and VGIII molecular types more commonly affect nonimmunocompromised hosts, in contrast to VGIV. New, rapid, cheap diagnostic tests and imaging modalities are assisting early diagnosis and enabling better outcomes of cerebral cryptococcosis. Complications of CNS infection include increased intracranial pressure, severe neurological sequelae, and development of immune reconstitution syndrome, although the mortality rate is low. C. gattii VGII isolates may exhibit higher fluconazole MICs than other genotypes. Optimal therapeutic regimens are yet to be determined; in most cases, initial therapy with amphotericin B and 5-flucytosine is recommended.

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Real-time polymerase chain reaction detection of Cryptococcus neoformans and Cryptococcus gattii in human samples

Cited by 35 publications

References 15 publications

Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens

Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens

A Multiplex Real-Time PCR Assay for Identification of Pneumocystis jirovecii, Histoplasma capsulatum, and Cryptococcus neoformans/Cryptococcus gattii in Samples from AIDS Patients with Opportunistic Pneumonia

Cryptococcus gattii Infections

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