Cryptococcus neoformans meningitis with negative cryptococcal antigen: Evaluation of a new immunochromatographic detection assay.
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ABSTRACT:
SUBMITTER: Opota O
PROVIDER: S-EPMC4337943 | biostudies-literature | 2015 Mar
REPOSITORIES: biostudies-literature
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Cryptococcus neoformans meningitis with negative cryptococcal antigen: Evaluation of a new immunochromatographic detection assay.
Opota O O Desgraz B B Kenfak A A Jaton K K Cavassini M M Greub G G Prod'hom G G Giulieri S S
New microbes and new infections 20141219
Detection of cryptococcal antigen in serum or cerebrospinal fluid allows cryptococcal meningitis diagnosis within few hours with >90% sensitivity. In an HIV-positive patient with Cryptococcus neoformans meningitis, initial antigen detection by immunoagglutination was negative. We thus evaluated a new immunochromatographic detection assay that exhibited a higher sensitivity. ...[more]
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Project description:BackgroundCryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples.MethodsThe 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains.Principal findingsThe 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF.ConclusionUse of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.
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Project description:Cryptococcus, an opportunistic yeast, known to afflict immune-compromised patients is often overlooked in immune-competent patients. This has led to increasing morbidity and mortality worldwide. We present a case of Cryptococcus causing sternal osteomyelitis in an immune-competent individual. Till date no case of Cryptococcus causing sternal osteomyelitis in an immune-competent patient has been reported in the English literature since 1946-2011. With the rising incidence of Cryptococcus infection it should be included among the list of infections causing osteomyelitis. Early detection and prompt treatment can decrease both morbidity and mortality.
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Project description:A singleplex PCR assay using a single primer pair targeting the putative sugar transporter gene was developed here to distinguish Cryptococcus neoformans var. grubii, Cryptococcus neoformans var. neoformans, and Cryptococcus gattii according to the distinct size of the amplicon. The interspecies and intravarietal hybrids were also characterized on the basis of distinct combined profiles of amplicons. This PCR assay is a rapid, simple, and reliable approach suitable for laboratory diagnoses and large-scale epidemiologic studies.
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