Browsing by Author "Jarvis, Joseph N."

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    HIV-1C env and gag variation in the cerebrospinal fluid and plasma of patients with HIV-associated cryptococcal meningitis in Botswana
    (MDPI, 2020-12-07) Kelentse, Nametso; Moyo, Sikhulile; Mogwele, Mompati L.; Ditshwanelo, Doreen; Mokaleng, Baitshepi; Moraka, Natasha O.; Lechiile, Kwana; Leeme, Tshepo B.; Lawrence, David S.; Musonda, Rosemary; Kasvosve, Ishmael; Harrison, Thomas S.; Jarvis, Joseph N.; Gaseitsiwe, Simani
    ENGLISH ABSTRACT: HIV-1 compartmentalization in reservoir sites remains a barrier to complete HIV eradication. It is unclear whether there is variation in HIV-1 env and gag between cerebrospinal fluid (CSF) and plasma of individuals with HIV-associated cryptococcal meningitis (CM). We compared HIV-1 env characteristics and the gag cytotoxic T-lymphocyte (CTL) escape mutations from CSF and plasma samples. Employing population-based Sanger sequencing, we sequenced HIV-1 env from CSF of 25 patients and plasma of 26 patients. For gag, 15 CSF and 21 plasma samples were successfully sequenced. Of these, 18 and 9 were paired env and gag CSF/plasma samples, respectively. There was no statistically significant difference in the proportion of CCR5-using strains in the CSF and plasma, (p = 0.50). Discordant CSF/plasma virus co-receptor use was found in 2/18 pairs (11.1%). The polymorphisms in the HIV-1 V3 loop were concordant between the two compartments. From the HIV-1 gag sequences, three pairs had discordant CTL escape mutations in three different epitopes of the nine analyzed. These findings suggest little variation in the HIV-1 env between plasma and CSF and that the CCR5-using strains predominate in both compartments. HIV-1 gag CTL escape mutations also displayed little variation in CSF and plasma suggesting similar CTL selective pressure.
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    Rapid diagnosis of cryptococcal meningitis by use of lateral flow assay on cerebrospinal fluid samples : influence of the high-dose “hook” effect
    (American Society for Microbiology, 2014) Lourens, Adre; Jarvis, Joseph N.; Meintjes, Graeme; Samuel, Catherine M.
    Cryptococcal meningitis is the most frequent cause of meningitis and a major cause of mortality in HIV-infected adults in Africa. This study evaluated the performance of the lateral flow assay (LFA) on cerebrospinal fluid (CSF) samples for the diagnosis of cryptococcal meningitis against that of existing diagnostic tests. LFA performed on 465 undiluted CSF samples had a sensitivity of 91%. When the LFA was paired with Gram staining, a sensitivity of 100% was achieved after implementation of a dilution step for samples with negative LFA results and the presence of yeasts on microscopy. Microscopy is essential for preventing the reporting of false-negative results due to the high-dose “hook” effect.