sybr-green-i and HIV-Infections

The most efficient method for HIV-1 genetic characterization involves full-genome sequencing, but the associated costs, technical features, and low throughput preclude it from being routinely used for the analysis of large numbers of viral strains. Multiregion hybridization assays (MHA) represent an alternative for a consistent genetic analysis of large numbers of viral strains. Classically, MHA rely on the amplification by real-time PCR of several regions scattered along the HIV-1 genome, and on their characterization with clade-specific TaqMan probes (also known as hydrolysis probes). In this context, the aim of our study was the development of a technical variant of an MHA (vMHA(B/G/02)) for genotyping the most prevalent genetic forms of HIV-1 circulating in Portugal. Different sets of primers were designed for universal and clade-specific amplifications of several sections of the viral genome: gag, pol(Pr), pol(RT), vpu, env(gp120), and env(gp41). vMHA(B/G/02) was implemented using a real-time PCR-based approach, with detection dependent on the use of SYBR Green I. As an alternative, a technically less demanding strategy based on conventional PCR and agarose gel analysis of the reaction products was also developed. This method performed with overall good sensitivity and specificity (>91%) when a convenience sample of 45 plasma-derived HIV-1 strains was analyzed. Apart from the detection of subtype B, G, CRF02_AG, and CRF14_BG viruses, several unique B/G recombinant were also detected. Curiously, recombinant viruses including CRF02_AG sequences were not detected in the group of samples analyzed.

Topics: Benzothiazoles; Diamines; DNA Primers; Electrophoresis, Agar Gel; Genotype; HIV Infections; HIV-1; Humans; Molecular Epidemiology; Molecular Sequence Data; Molecular Typing; Nucleic Acid Hybridization; Organic Chemicals; Polymerase Chain Reaction; Portugal; Quinolines; Sensitivity and Specificity; Sequence Analysis, DNA; Staining and Labeling; Viral Proteins; Virology

Dried blood spot (DBS) is a reliable method of blood collection used for the diagnosis of several human diseases. DBS is particularly useful for diagnosing children and for the screening of high-risk populations especially in countries where health facilities are not readily accessible. This report describes a qualitative SYBR Green-based real-time multiplex RT-PCR for the simultaneous detection of hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) genomes in DBS. Specific viral amplicons were identified in the same sample by their distinctive melting temperatures. The analysis of scalar concentrations of the reference samples indicated that this multiplex procedure detects at least 2500 copies/ml of HCV and 400 copies/ml of HIV-1. HIV-1 and HCV viral loads in 20 patients infected with HIV-1 and/or HCV and in 5 healthy blood donors were also tested, confirming the sensitivity and specificity of the assay. This method may represent a reliable alternative for the detection of HIV-1/HCV co-infection, in rapid and relatively inexpensive screening programmes.

Topics: Adult; Benzothiazoles; Blood; Desiccation; Diamines; Hepacivirus; Hepatitis C; HIV Infections; HIV-1; Humans; Organic Chemicals; Quinolines; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Staining and Labeling; Time Factors; Transition Temperature; Young Adult

Viral components of the human endogenous retroviruses type K (HERV-K) have been largely detected in plasma from HIV-1 infected individuals. A Sybr Green Real-Time RT-PCR approach was optimized for detection and quantitation of HERV-K RNA titers in plasma samples using the iCycler technology. The method detected 1000 HERV-K RNA copies/mL of plasma sample. The Intra- and Inter-assay performance revealed a coefficient of variations that ranged from 0.2 to 2.46%, demonstrating accuracy and reproducibility. We quantified the HERV-K RNA load in 20 HIV-1 patients receiving highly active antiretroviral therapy (HAART). We found increased HERV-K RNA titers in patients with non-suppressive HAART (patients who may develop drug-resistance and/or received suboptimal therapeutic doses), compared to suppressive regimens (p < 0.001). HERV-K RNA was not detected in HCV-1 positive or seronegative controls. Sequencing of Real-Time RT-PCR products revealed particular HERV-K subtypes activated in the HIV-1 infection. The application of this assay could expand the understanding of the role of HERV-K in the HIV-1 infection and others pathological conditions.

Topics: Analysis of Variance; Antiretroviral Therapy, Highly Active; Base Sequence; Benzothiazoles; Cloning, Molecular; Diamines; Endogenous Retroviruses; Fluorescence; HIV Infections; HIV-1; Humans; Molecular Sequence Data; Organic Chemicals; Quinolines; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Sensitivity and Specificity; Staining and Labeling; Viral Load

Herpes Simplex Virus (HSV) Genital Ulcer Disease (GUD) is an important public health problem, whose interaction with HIV results in mutually enhancing epidemics. Conventional methods for detecting HSV tend to be slow and insensitive. We designed a rapid PCR-based assay to quantify and type HSV in cervicovaginal lavage (CVL) fluid of subjects attending a Genito-Urinary Medicine (GUM) clinic. Vaginal swabs, CVL fluid and venous blood were collected. Quantitative detection of HSV was conducted using real time PCR with HSV specific primers and SYBR Green I. Fluorogenic TaqMan Minor Groove Binder (MGB) probes designed around a single base mismatch in the HSV DNA polymerase I gene were used to type HSV in a separate reaction. The Kalon test was used to detect anti-HSV-2 IgG antibodies in serum. Testing for HIV, other Sexually Transmitted Infections (STI) and related infections was based on standard clinical and laboratory methods.. Seventy consecutive GUM clinic attendees were studied. Twenty-seven subjects (39%) had detectable HSV DNA in CVL fluid; HSV-2 alone was detected in 19 (70%) subjects, HSV-1 alone was detected in 4 (15%) subjects and both HSV types were detected in 4 (15%) subjects. Eleven out of 27 subjects (41%) with anti-HSV-2 IgG had detectable HSV-2 DNA in CVL fluid. Seven subjects (10%) were HIV-positive. Three of seven (43%) HIV-infected subjects and two of five subjects with GUD (40%) were secreting HSV-2. None of the subjects in whom HSV-1 was detected had GUD.. Quantitative real-time PCR and Taqman MGB probes specific for HSV-1 or -2 were used to develop an assay for quantification and typing of HSV. The majority of subjects in which HSV was detected had low levels of CVL fluid HSV, with no detectable HSV-2 antibodies and were asymptomatic.

Topics: Antibodies, Viral; Benzothiazoles; Bodily Secretions; Cervix Uteri; Cross-Sectional Studies; Diamines; DNA Primers; DNA, Viral; Female; Herpes Genitalis; HIV Infections; Humans; Organic Chemicals; Polymerase Chain Reaction; Prospective Studies; Quinolines; Simplexvirus; Vagina; Vaginal Douching

The persistence of proviral human immunodeficiency virus type 1 (HIV-1) DNA reservoir represents one of the major drawbacks to the total eradication of HIV-1. The quantitative determination of proviral HIV-1 DNA load offers significant therapeutic information, especially when the HIV-1 RNA levels drop below the detectable limits during the highly active retroviral therapy (HAART) treatment. Moreover, the detection of HIV-1 proviral DNA is an important diagnostic marker in the evaluation of HIV-1 infection of newborns of HIV-1 seropositive women.. We evaluated a real-time PCR based on LightCycler technology revealed through SYBR green fluorochrome (SYBR green real-time PCR) to quantify the HIV-1 proviral DNA load in peripheral blood mononuclear cells (PBMC) of HIV-1 seropositive patients.. Firstly, we assessed the SYBR green real-time quantitative PCR for HIV-1 proviral DNA load detection determining the specificity and sensitivity of the assay using the LightCycler system. Secondly, we tested the performance of our SYBR green real-time PCR on 50 HIV-1 seropositive patients under HAART and 20 blood donors.. The results of this study showed that our SYBR green real-time PCR is able to detect five copies of the HIV-1 genome. Moreover, our method revealed HIV-1 proviral DNA in all the 50 HIV-1 seropositive patients ( 627 +/- 1068 HIV-1 proviral DNA copies per 10(6) PBMC, with a range of 30-6300 copies), whereas no positive signal was observed in any PBMC blood donors. Our SYBR green real-time PCR represents a sensitive and useful approach that could be applied both in HIV-1 proviral DNA reservoir determination and in HAART monitoring, particularly when the HIV-1 plasmatic RNA is undetectable.

Topics: Benzothiazoles; Blood Donors; CD4 Lymphocyte Count; Diamines; DNA, Viral; HIV Infections; HIV Seropositivity; HIV-1; Humans; Leukocytes, Mononuclear; Organic Chemicals; Polymerase Chain Reaction; Proviruses; Quinolines; RNA, Viral; Sensitivity and Specificity; Viral Load; Viremia