9 results on '"Corzo Leon DE"'
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2. Methods for SARS-CoV-2 hospital disinfection, in vitro observations.
- Author
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Corzo-Leon DE, Abbood HM, Colamarino RA, Steiner MFC, Munro C, Gould IM, and Hijazi K
- Abstract
Introduction: Escalation of chemical disinfection during the COVID-19 pandemic has raised occupational hazard concerns. Alternative and potentially safer methods such as ultraviolet-C (UVC) irradiation and ozone have been proposed, notwithstanding the lack of standardized criteria for their use in the healthcare environment., Aim: Compare the virucidal activity of 70% ethanol, sodium dichloroisocyanurate (NaDCC), chlorhexidine, ozonated water, UVC-222 nm, UVC-254 nm against three SARS-CoV-2 variants of concern cultured in vitro ., Methods: Inactivation of three SARS-CoV-2 variants (alpha, beta, gamma) by the following chemical methods was tested: ethanol 70%, NaDCC (100 ppm, 500 ppm, 1000 ppm), chlorhexidine (2%, 1% and 0.5%), ozonated water 7 ppm. For irradiation, a je2Care 222nm UVC Lamp was compared to a Sylvania G15 UV254 nm lamp., Results: Viral inactivation by >3 log was achieved with ethanol, NaDCC and chlorhexidine. The minor virucidal effect of ozonated water was <1 log. Virus treatment with UVC-254 nm reduced viral activity by 1-5 logs with higher inactivation after exposure for 3 minutes compared to 6 seconds. For all three variants, under equivalent conditions, exposure to UVC-222 nm did not achieve time-dependent inactivation as was observed with treatment with UVC-254 nm., Conclusion: The virucidal activity on replication-competent SARS-CoV-2 by conventional chemical methods, including chlorhexidine at concentrations as low as 0.5%, was not matched by UVC irradiation, and to an even lesser extent by ozonated water treatment., (© 2024 The Authors.)
- Published
- 2024
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3. Malassezia sympodialis Mala s 1 allergen is a potential KELCH protein that cross reacts with human skin.
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Corzo Leon DE, Scheynius A, MacCallum DM, and Munro CA
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- Humans, Allergens, Amino Acid Sequence, Malassezia, Dermatitis, Atopic microbiology
- Abstract
Malassezia are the dominant commensal yeast species of the human skin microbiota and are associated with inflammatory skin diseases, such as atopic eczema (AE). The Mala s 1 allergen of Malassezia sympodialis is a β-propeller protein, inducing both IgE and T-cell reactivity in AE patients. We demonstrate by immuno-electron microscopy that Mala s 1 is mainly located in the M. sympodialis yeast cell wall. An anti-Mala s 1 antibody did not inhibit M. sympodialis growth suggesting Mala s 1 may not be an antifungal target. In silico analysis of the predicted Mala s 1 protein sequence identified a motif indicative of a KELCH protein, a subgroup of β-propeller proteins. To test the hypothesis that antibodies against Mala s 1 cross-react with human skin (KELCH) proteins we examined the binding of the anti-Mala s 1 antibody to human skin explants and visualized binding in the epidermal skin layer. Putative human targets recognized by the anti-Mala s 1 antibody were identified by immunoblotting and proteomics. We propose that Mala s 1 is a KELCH-like β-propeller protein with similarity to human skin proteins. Mala s 1 recognition may trigger cross-reactive responses that contribute to skin diseases associated with M. sympodialis., (© The Author(s) 2023. Published by Oxford University Press on behalf of FEMS.)
- Published
- 2023
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4. COVID-19-associated mucormycosis, diabetes and steroid therapy: Experience in a single centre in Western Mexico.
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Guzmán-Castro S, Chora-Hernandez LD, Trujillo-Alonso G, Calvo-Villalobos I, Sanchez-Rangel A, Ferrer-Alpuin E, Ruiz-Jimenez M, and Corzo-Leon DE
- Subjects
- Adrenal Cortex Hormones adverse effects, Adrenal Cortex Hormones therapeutic use, Antifungal Agents therapeutic use, COVID-19 Testing, Humans, Mexico epidemiology, Retrospective Studies, Steroids, COVID-19 complications, Diabetes Mellitus drug therapy, Diabetes Mellitus epidemiology, Mucormycosis diagnosis, Mucormycosis drug therapy, Mucormycosis epidemiology, COVID-19 Drug Treatment
- Abstract
Background: COVID-19-associated mucormycosis (CAM) has emerged as a challenging complication as the current pandemic has increased the population requiring treatment with corticosteroids. CAM has caused a massive outbreak in India, reported to be causing cases in Iran, Egypt and The Netherlands., Objectives: To describe CAM cases occurring in a single centre in Western Mexico., Methods: Our group carried out a retrospective study from May 2020 to May 2021 to identify CAM cases in patients with previous COVID-19 diagnosis., Results: Six CAM cases occurred in a single centre in Western Mexico during the study period, most of them with diabetes (n = 5/6) and all received corticosteroid therapy even when only three had severe COVID-19. After analysing local COVID-19 burden, it was estimated that in this region, CAM was 300 times more frequent among COVID individuals than the estimates for general population., Conclusion: Similar to large reports in India and other countries, CAM cases reported in this study were diagnosed in individuals with diabetes, hyperglycaemic status and with history of previous use of corticosteroids. Identifying these individuals at risk can help the early identification of CAM. In addition, strict glycaemic control and avoidance of unnecessary corticosteroid in non-severe COVID-19 cases could help in preventing this complicated fungal infection., (© 2021 Wiley-VCH GmbH.)
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- 2022
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5. Monoclonal Human Antibodies That Recognise the Exposed N and C Terminal Regions of the Often-Overlooked SARS-CoV-2 ORF3a Transmembrane Protein.
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Tan TH, Patton E, Munro CA, Corzo-Leon DE, Porter AJ, and Palliyil S
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- Animals, Biomarkers, COS Cells, Cell Surface Display Techniques methods, Chlorocebus aethiops, Epitopes immunology, HEK293 Cells, Humans, Membrane Proteins immunology, Protein Domains, Vero Cells, Antibodies, Monoclonal immunology, COVID-19 immunology, COVID-19 virology, SARS-CoV-2 immunology, Viroporin Proteins immunology
- Abstract
ORF3a has been identified as a viroporin of SARS-CoV-2 and is known to be involved in various pathophysiological activities including disturbance of cellular calcium homeostasis, inflammasome activation, apoptosis induction and disruption of autophagy. ORF3a-targeting antibodies may specifically and favorably modulate these viroporin-dependent pathological activities. However, suitable viroporin-targeting antibodies are difficult to generate because of the well-recognized technical challenge associated with isolating antibodies to complex transmembrane proteins. Here we exploited a naïve human single chain antibody phage display library, to isolate binders against carefully chosen ORF3a recombinant epitopes located towards the extracellular N terminal and cytosolic C terminal domains of the protein using peptide antigens. These binders were subjected to further characterization using enzyme-linked immunosorbent assays and surface plasmon resonance analysis to assess their binding affinities to the target epitopes. Binding to full-length ORF3a protein was evaluated by western blot and fluorescent microscopy using ORF3a transfected cells and SARS-CoV-2 infected cells. Co-localization analysis was also performed to evaluate the "pairing potential" of the selected binders as possible alternative diagnostic or prognostic biomarkers for COVID-19 infections. Both ORF3a N and C termini, epitope-specific monoclonal antibodies were identified in our study. Whilst the linear nature of peptides might not always represent their native conformations in the context of full protein, with carefully designed selection protocols, we have been successful in isolating anti-ORF3a binders capable of recognising regions of the transmembrane protein that are exposed either on the "inside" or "outside" of the infected cell. Their therapeutic potential will be discussed.
- Published
- 2021
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6. Neutralisation of SARS-CoV-2 by anatomical embalming solutions.
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Quondamatteo F, Corzo-Leon DE, Brassett C, Colquhoun I, Davies DC, Dockery P, Grenham S, Guild S, Hunter A, Jones J, Lee TC, Tracey C, Wilkinson T, Munro CA, Gillingwater TH, and Parson SH
- Subjects
- COVID-19 transmission, Cadaver, Cells, Cultured, Fixatives pharmacology, Humans, COVID-19 virology, Disease Transmission, Infectious prevention & control, Embalming methods, Formaldehyde pharmacology, Pandemics, SARS-CoV-2, Tissue Fixation methods
- Abstract
Teaching and learning anatomy by using human cadaveric specimens has been a foundation of medical and biomedical teaching for hundreds of years. Therefore, the majority of institutions that teach topographical anatomy rely on body donation programmes to provide specimens for both undergraduate and postgraduate teaching of gross anatomy. The COVID-19 pandemic has posed an unprecedented challenge to anatomy teaching because of the suspension of donor acceptance at most institutions. This was largely due to concerns about the potential transmissibility of the SARS-CoV-2 virus and the absence of data about the ability of embalming solutions to neutralise the virus. Twenty embalming solutions commonly used in institutions in the United Kingdom and Ireland were tested for their ability to neutralise SARS-CoV-2, using an established cytotoxicity assay. All embalming solutions tested neutralised SARS-CoV-2, with the majority of solutions being effective at high-working dilutions. These results suggest that successful embalming with the tested solutions can neutralise the SARS-CoV-2 virus, thereby facilitating the safe resumption of body donation programmes and cadaveric anatomy teaching., (© 2021 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)
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- 2021
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7. General hospital outbreak of invasive candidiasis due to azole-resistant Candida parapsilosis associated with an Erg11 Y132F mutation.
- Author
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Corzo-Leon DE, Peacock M, Rodriguez-Zulueta P, Salazar-Tamayo GJ, and MacCallum DM
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- Adult, Amino Acid Substitution, Drug Resistance, Fungal, Female, Hospitals, General statistics & numerical data, Humans, Male, Mexico, Microbial Sensitivity Tests, Middle Aged, Mutation genetics, Retrospective Studies, Antifungal Agents pharmacology, Azoles pharmacology, Candida parapsilosis drug effects, Candida parapsilosis genetics, Candidiasis, Invasive epidemiology, Disease Outbreaks statistics & numerical data, Fungal Proteins genetics, Mutation drug effects
- Abstract
An increasing number of outbreaks due to resistant non-albicans Candida species have been reported worldwide. Between 2014 and 2016, Candida isolates causing invasive candidiasis were recovered in a Mexican hospital. Isolates were identified to species level and antifungal susceptibility was determined. In the time period studied, 74 invasive candidiasis cases were identified, with 38% (28/74) caused by Candida parapsilosis, out of which 54% (15/28) were fluconazole resistant. The ERG11 gene was sequenced for 12 recoverable fluconazole-resistant C. parapsilosis isolates and SNPs identified. The 12 isolates had one common silent point mutation in ERG11 (T591C) and seven isolates had an additional (A395T) mutation, which corresponded to Y132F. Four of the isolates carrying this mutation were closely related within the same cluster by microsatellite typing. This is the first report of an invasive candidiasis outbreak in Mexico due to azole-resistant C. parapsilosis associated with the Y132F substitution., (© The Author(s) 2020. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
- Published
- 2021
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8. Influenza challenging the diagnosis and management of pulmonary coccidioidomycosis.
- Author
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Chora-Hernández LD, Sereno-Gómez B, Ruiz-Martínez F, Barajas-Magallon JM, Ruiz-Jiménez M, and Corzo-Leon DE
- Abstract
Lower respiratory infections are the most important cause of death due to a transmissible disease. We present a case of severe influenza and coccidioidomycosis lung coinfection in a 65-year-old Mexican migrant. This case highlights the challenges that respiratory viruses impose on the diagnosis of fungal infections and on the multidisciplinary management of these infections. In addition, this case shows how medical complications and superinfections could be potentially prevented if flu vaccination is provided., Competing Interests: All authors declare that they have no conflicts of interest regarding this manuscript., (© 2020 The Authors. Published by Elsevier B.V. on behalf of International Society for Human and Animal Mycology.)
- Published
- 2020
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9. Surveillance of Candida spp bloodstream infections: epidemiological trends and risk factors of death in two Mexican tertiary care hospitals.
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Corzo-Leon DE, Alvarado-Matute T, Colombo AL, Cornejo-Juarez P, Cortes J, Echevarria JI, Guzman-Blanco M, Macias AE, Nucci M, Ostrosky-Zeichner L, Ponce-de-Leon A, Queiroz-Telles F, Santolaya ME, Thompson-Moya L, Tiraboschi IN, Zurita J, and Sifuentes-Osornio J
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- Adult, Aged, Amphotericin B chemistry, Candida albicans, Candida glabrata, Candida tropicalis, Candidiasis epidemiology, Deoxycholic Acid chemistry, Drug Combinations, Female, Fluconazole therapeutic use, Humans, Incidence, Male, Mexico, Middle Aged, Proportional Hazards Models, Prospective Studies, Regression Analysis, Risk Factors, Tertiary Care Centers, Treatment Outcome, Candida, Candidiasis mortality
- Abstract
Introduction: Larger populations at risk, broader use of antibiotics and longer hospital stays have impacted on the incidence of Candida sp. bloodstream infections (CBSI)., Objective: To determine clinical and epidemiologic characteristics of patients with CBSI in two tertiary care reference medical institutions in Mexico City., Design: Prospective and observational laboratory-based surveillance study conducted from 07/2008 to 06/2010., Methods: All patients with CBSI were included. Identification and antifungal susceptibility were performed using CLSI M27-A3 standard procedures. Frequencies, Mann-Whitney U test or T test were used as needed. Risk factors were determined with multivariable analysis and binary logistic regression analysis., Results: CBSI represented 3.8% of nosocomial bloodstream infections. Cumulative incidence was 2.8 per 1000 discharges (incidence rate: 0.38 per 1000 patient-days). C. albicans was the predominant species (46%), followed by C. tropicalis (26%). C. glabrata was isolated from patients with diabetes (50%), and elderly patients. Sixty-four patients (86%) received antifungals. Amphotericin-B deoxycholate (AmBD) was the most commonly used agent (66%). Overall mortality rate reached 46%, and risk factors for death were APACHE II score ≥ 16 (OR = 6.94, CI95% = 2.34-20.58, p<0.0001), and liver disease (OR = 186.11, CI95% = 7.61-4550.20, p = 0.001). Full susceptibility to fluconazole, AmBD and echinocandins among C. albicans, C. tropicalis, and C. parapsilosis was observed., Conclusions: The cumulative incidence rate in these centers was higher than other reports from tertiary care hospitals from Latin America. Knowledge of local epidemiologic patterns permits the design of more specific strategies for prevention and preemptive therapy of CBSI.
- Published
- 2014
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