Browsing by Author "Perfect, John"

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    Complete genome sequences for two talaromyces marneffei clinical isolates from Northern and Southern Vietnam
    (Microbiology Resource Announcements, 2020-01-01) Cuomo, Christina A; Shea, Terrance; Nguyen, Thu; Ashton, Philip; Perfect, John; Le, Thuy
    © 2020 Cuomo et al. Talaromyces marneffei is a thermally dimorphic fungus endemic in China and Southeast Asia that causes fatal infections in immunocompromised individuals, particularly in patients with advanced HIV disease. Here, we report the complete genome sequences of two clinical isolates from northern and southern Vietnam.
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    ECMM/ISHAM recommendations for clinical management of COVID-19 associated mucormycosis in low- and middle-income countries.
    (Mycoses, 2021-09) Rudramurthy, Shivaprakash M; Hoenigl, Martin; Meis, Jacques F; Cornely, Oliver A; Muthu, Valliappan; Gangneux, Jean Pierre; Perfect, John; Chakrabarti, Arunaloke; ECMM and ISHAM
    Reports are increasing on the emergence of COVID-19-associated mucormycosis (CAM) globally, driven particularly by low- and middle-income countries. The recent unprecedented surge of CAM in India has drawn worldwide attention. More than 28,252 mucormycosis cases are counted and India is the first country where mucormycosis has been declared a notifiable disease. However, misconception of management, diagnosing and treating this infection continue to occur. Thus, European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology (ISHAM) felt the need to address clinical management of CAM in low- and middle-income countries. This article provides a comprehensive document to help clinicians in managing this infection. Uncontrolled diabetes mellitus and inappropriate (high dose or not indicated) corticosteroid use are the major predisposing factors for this surge. High counts of Mucorales spores in both the indoor and outdoor environments, and the immunosuppressive impact of COVID-19 patients as well as immunotherapy are possible additional factors. Furthermore, a hyperglycaemic state leads to an increased expression of glucose regulated protein (GRP- 78) in endothelial cells that may help the entry of Mucorales into tissues. Rhino-orbital mucormycosis is the most common presentation followed by pulmonary mucormycosis. Recommendations are focused on the early suspicion of the disease and confirmation of diagnosis. Regarding management, glycaemic control, elimination of corticosteroid therapy, extensive surgical debridement and antifungal therapy are the standards for proper care. Due to limited availability of amphotericin B formulations during the present epidemic, alternative antifungal therapies are also discussed.
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    Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies.
    (Cell, 2021-05-18) Williams, Wilton B; Meyerhoff, R Ryan; Edwards, RJ; Li, Hui; Manne, Kartik; Nicely, Nathan I; Henderson, Rory; Zhou, Ye; Janowska, Katarzyna; Mansouri, Katayoun; Gobeil, Sophie; Evangelous, Tyler; Hora, Bhavna; Berry, Madison; Abuahmad, A Yousef; Sprenz, Jordan; Deyton, Margaret; Stalls, Victoria; Kopp, Megan; Hsu, Allen L; Borgnia, Mario J; Stewart-Jones, Guillaume BE; Lee, Matthew S; Bronkema, Naomi; Moody, M Anthony; Wiehe, Kevin; Bradley, Todd; Alam, S Munir; Parks, Robert J; Foulger, Andrew; Oguin, Thomas; Sempowski, Gregory D; Bonsignori, Mattia; LaBranche, Celia C; Montefiori, David C; Seaman, Michael; Santra, Sampa; Perfect, John; Francica, Joseph R; Lynn, Geoffrey M; Aussedat, Baptiste; Walkowicz, William E; Laga, Richard; Kelsoe, Garnett; Saunders, Kevin O; Fera, Daniela; Kwong, Peter D; Seder, Robert A; Bartesaghi, Alberto; Shaw, George M; Acharya, Priyamvada; Haynes, Barton F
    Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
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    Occult Talaromyces marneffei Infection Unveiled by the Novel Mp1p Antigen Detection Assay.
    (Open forum infectious diseases, 2020-11) Ly, Vo Trieu; Thanh, Nguyen Tat; Thu, Nguyen Thi Mai; Chan, Jasper; Day, Jeremy N; Perfect, John; Nga, Cao Ngoc; Vinh Chau, Nguyen Van; Le, Thuy
    Talaromyces marneffei causes fatal invasive mycosis in Southeast Asia. Diagnosis by culture has limited sensitivity and can result in treatment delay. We describe the use of a novel Mp1p enzyme immunoassay (EIA) to identify blood culture-negative talaromycosis, subsequently confirmed by bone marrow cultures. This EIA has the potential to speed diagnosis, enabling early therapy initiation.
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    Population Pharmacodynamics of Amphotericin B Deoxycholate for Disseminated Infection Caused by Talaromyces marneffei.
    (Antimicrobial Agents and Chemotherapy, 2019-02) Le, Thuy; Ly, Vo Trieu; Thu, Nguyen Thi Mai; Nguyen, Ashley; Thanh, Nguyen Tat; Chau, Nguyen Van Vinh; Thwaites, Guy; Perfect, John; Kolamunnage-Dona, Ruwanthi; Hope, William
    Amphotericin B deoxycholate (DAmB) is a first-line agent for the initial treatment of talaromycosis. However, little is known about the population pharmacokinetics and pharmacodynamics of DAmB for talaromycosis. Pharmacokinetic data were obtained from 78 patients; among them, 55 patients had serial fungal CFU counts in blood also available for analysis. A population pharmacokinetic-pharmacodynamic model was fitted to the data. The relationships between the area under the concentration-time curve (AUC)/MIC and the time to blood culture sterilization and the time to death were investigated. There was only modest pharmacokinetic variability in the average AUC, with a mean ± standard deviation of 11.51 ± 3.39 mg·h/liter. The maximal rate of drug-induced kill was 0.133 log10 CFU/ml/h, and the plasma concentration of the DAmB that induced the half-maximal rate of kill was 0.02 mg/liter. Fifty percent of patients sterilized their bloodstreams by 83.16 h (range, 13 to 264 h). A higher initial fungal burden was associated with a longer time to sterilization (hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.36 to 0.70; P < 0.001). There was a weak relationship between AUC/MIC and the time to sterilization, although this did not reach statistical significance (HR, 1.03; 95% CI, 1.00 to 1.06, P = 0.091). Furthermore, there was no relationship between the AUC/MIC and time to death (HR, 0.97; 95% CI, 0.88 to 1.08; P = 0.607) or early fungicidal activity {slope = log[(0.500 - 0.003·(AUC/MIC)]; P = 0.319} adjusted for the initial fungal burden. The population pharmacokinetics of DAmB are surprisingly consistent. The time to sterilization of the bloodstream may be a useful pharmacodynamic endpoint for future studies. (This study has been registered at the ISRCTN registry under no. ISRCTN59144167.).
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    Superiority of a novel Mp1p antigen detection enzyme immunoassay compared to standard BACTEC blood culture in the diagnosis of talaromycosis.
    (Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2020-06-21) Thu, Nguyen TM; Chan, Jasper FW; Ly, Vo Trieu; Ngo, Hoa T; Hien, Ha TA; Lan, Nguyen PH; Chau, Nguyen VV; Cai, Jian-Piao; Woo, Patrick CY; Day, Jeremy N; van Doorn, Rogier; Thwaites, Guy; Perfect, John; Yuen, Kwok; Le, Thuy
    BACKGROUND:Talaromycosis is an invasive mycosis endemic in Southeast Asia and causes substantial morbidity and mortality in individuals with advanced HIV disease. Current diagnosis relies on isolating Talaromyces marneffei in cultures, which takes up to 14 days and is detectable only during late-stage infection, leading to high mortality. METHODS:In this retrospective case-control study, we assessed the accuracy of a novel Mp1p antigen-detecting enzyme immunoassay (EIA) in stored plasma samples of 372 patients who had culture-proven talaromycosis from blood or sterile body fluids(reference standard) and of 517 individuals without talaromycosis (338 healthy volunteers; 179 with other infections). All participants were recruited between 2011-2017 in Vietnam. RESULTS:66.1% and 75.4% of cases and controls were male; the median age was 33 and 37, respectively. All cases were HIV-infected; median CD4 count was 10 cells/mm3. At an optical density cut-off of 0.5, the specificity was 98.1% (95% CI: 96.3%-99.0%); the sensitivity was superior to blood culture, 86.3% (95% CI: 82.3%-89.5%) versus 72.8% (95% CI: 68.0%-77.2%), P<0.001, McNemar test. The time-to-diagnosis was 6 hours versus 6.6 ± 3.0 days for blood culture. Paired plasma and urine testing in the same patients (N=269) significantly increased sensitivity compared to testing plasma alone P<0.001, or testing urine alone P=0.02, McNemar tests. CONCLUSIONS:The Mp1p EIA is highly specific and is superior in sensitivity and time-to-diagnosis compared to blood culture for the diagnosis of talaromycosis. Paired plasma and urine testing further increases sensitivity, introducing a new tool for rapid diagnosis, enabling early treatment and potentially reducing mortality.