5,966 research outputs found

    Development of a SimpleProbe real-Time PCR Assay for rapid detection and identification of the US novel urethrotropic clade of Neisseria meningitidis ST-11 (US_NmUC)

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    Urethritis, or inflammation of the urethra, is one of the most common reasons men seek clinical care. Sexually transmitted pathogens including Neisseria gonorrhoeae are responsible for over half of the symptomatic urethritis cases in U.S. men. Recently, clinics in Indianapolis, Columbus, Atlanta, and other U.S. cities began to note increasing numbers of men presenting with urethritis and Gram-negative intracellular diplococci in their urethral smears who test negative for N. gonorrhoeae. Many of these discordant cases, which have periodically reached highs of more than 25% of presumed gonococcal cases in some sexually transmitted infection clinics in the U.S. Midwest, are infected with strains in a novel urethrotropic clade of Neisseria meningitidis ST-11 (US_NmUC). However, no cultivation-independent tests are available for the US_NmUC strains, and prior studies relied on microbial culture and genome sequencing to identify them. Here, we describe a PCR test that can identify the US_NmUC strains and distinguish them from commensal and invasive N. meningitidis strains as well as N. gonorrhoeae. Our SimpleProbe®-based real-time PCR assay targets a conserved nucleotide substitution in a horizontally acquired region of US_NmUC strain genomes. We applied the assay to 241 urine specimens whose microbial compositions had previously been determined by deep shotgun metagenomic sequencing. The assay detected the single US_NmUC positive case in this cohort, with no false positives. Overall, our simple and readily adaptable assay could facilitate investigation of the pathogenesis and epidemiology of the US_NmUC clade

    Comparison of immunoassay and real-time PCR methods for the detection of Jembrana disease virus infection in Bali cattle

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    A sensitive diagnostic assay for the detection of infections with the bovine lentivirus Jembrana disease virus (JDV) is required in Indonesia to control the spread of Jembrana disease. Immunoassays are used routinely but are compromised by cross-reactive epitopes in the capsid (CA) protein of JDV and the genetically related bovine immunodeficiency virus (BIV). JDV gag-specific primers were tested in a real-time PCR assay to detect proviral DNA in peripheral blood mononuclear cells from 165 cattle from the Tabanan district of Bali. JDV-specific amplicons were detected in 9% of the cattle and only 33% of the real-time PCR positive cattle were seropositive. The delayed seroconversion that occurs after infection with JDV could explain the low concordance between these assays but other factors may be responsible. BIV proviral DNA was not detected in any of the PBMC DNA samples. A high concordance value of 98.6% was found between the JDV plasma-derived antigen Western blot and the JDV p26-his recombinant protein ELISA. Only 21% of the seropositive cattle had detectable levels of proviral DNA suggesting that the proviral load in recovered cattle is low. A combination of real-time PCR and JDV p26-his ELISA is recommended for the detection of infection with JDV in Indonesia

    Rapid and Highly Informative Diagnostic Assay for H5N1 Influenza Viruses

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    A highly discriminative and information-rich diagnostic assay for H5N1 avian influenza would meet immediate patient care needs and provide valuable information for public health interventions, e.g., tracking of new and more dangerous variants by geographic area as well as avian-to-human or human-to-human transmission. In the present study, we have designed a rapid assay based on multilocus nucleic acid sequencing that focuses on the biologically significant regions of the H5N1 hemagglutinin gene. This allows the prediction of viral strain, clade, receptor binding properties, low- or high-pathogenicity cleavage site and glycosylation status. H5 HA genes were selected from nine known high-pathogenicity avian influenza subtype H5N1 viruses, based on their diversity in biologically significant regions of hemagglutinin and/or their ability to cause infection in humans. We devised a consensus pre-programmed pyrosequencing strategy, which may be used as a faster, more accurate alternative to de novo sequencing. The available data suggest that the assay described here is a reliable, rapid, information-rich and cost-effective approach for definitive diagnosis of H5N1 avian influenza. Knowledge of the predicted functional sequences of the HA will enhance H5N1 avian influenza surveillance efforts

    Rapid and Highly Informative Diagnostic Assay for H5N1 Influenza Viruses

    Get PDF
    A highly discriminative and information-rich diagnostic assay for H5N1 avian influenza would meet immediate patient care needs and provide valuable information for public health interventions, e.g., tracking of new and more dangerous variants by geographic area as well as avian-to-human or human-to-human transmission. In the present study, we have designed a rapid assay based on multilocus nucleic acid sequencing that focuses on the biologically significant regions of the H5N1 hemagglutinin gene. This allows the prediction of viral strain, clade, receptor binding properties, low- or high-pathogenicity cleavage site and glycosylation status. H5 HA genes were selected from nine known high-pathogenicity avian influenza subtype H5N1 viruses, based on their diversity in biologically significant regions of hemagglutinin and/or their ability to cause infection in humans. We devised a consensus pre-programmed pyrosequencing strategy, which may be used as a faster, more accurate alternative to de novo sequencing. The available data suggest that the assay described here is a reliable, rapid, information-rich and cost-effective approach for definitive diagnosis of H5N1 avian influenza. Knowledge of the predicted functional sequences of the HA will enhance H5N1 avian influenza surveillance efforts

    Seroepidemiological studies of herpesvirus-associated diseases of marine turtles: Fibropapillomatosis and lung-eye-trachea disease

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    We have developed immunological tests that can identify marine turtles in Florida (green and loggerhead) that have been exposed to the LETV herpesvirus. The seroepidemiological data collected provides critical evidence about the relationship between infection with the FP-associated herpesvirus and the LETV herpesvirus. The data supports the hypothesis that LETV and FPHV infections are independent infections of marine turtles. The data shows that wild green turtles in Florida are exposed to the LETD-associated herpesvirus, which is the first description ofLETV infection in free-ranging marine turtles. To our knowledge, the antigenic proteins identified in this study are not only the first proteins from a reptilian herpesvirus to be cloned and expressed, but they represent the first reptilian herpesvirus proteins to be identified as immunogenic in their host species. (16 page document
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