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Wembabazi A, Nassozi DR, Akot E, Ochola TI, Kweka PT, Katamu NT, Meya D, Achan B. Prevalence of Cryptococcus gattii in Ugandan HIV-infected patients presenting with cryptococcal meningitis. PLoS One 2022; 17:e0270597. [PMID: 35839221 PMCID: PMC9286220 DOI: 10.1371/journal.pone.0270597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 06/14/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction
Cryptococcal meningitis (CM) is a life threatening disease and leading cause of opportunistic fungal-related mortality in HIV/AIDS. Most CM infections are caused by C. neoformans species complexes but the prevalence of Cryptococcus gattii species complexes in Uganda is unknown however, it is known in a few other parts of Africa. We estimated the prevalence of C. gattii in patients living with HIV and a diagnosis of cryptococcal meningitis in Uganda.
Methods
Cryptococcus isolates (n = 200) obtained from cerebrospinal fluid of patients with CM recruited at the Infectious Diseases Institute, Kampala, Uganda, were tested by phenotypic methods. The Cryptococcus isolates were sub-cultured on Sabouraud Dextrose Agar plates for 48 hours. The yeast colonies were examined by India ink stain, urea hydrolysis, and C. gattii was identified by blue pigmentation on CGB agar. The results were analyzed for frequency of C. gattii. Patient demographic characteristics were collected from the case record forms.
Results
From the 200 patients’ case record forms, 87 (43.5%) were female and 113 (56.5%) were male. The median age was 35 (19–64) years. Most patients, 93% (187/200) were from Central Uganda in the districts of Kampala and Wakiso. 97.51% (157/161) of the patients had absolute CD4 lymphocyte counts of less than 200 cells per cubic millimeter; 1.86% (3/161) 200–350 cells per cubic millimeter and 0.62% (1/161) above 500 cells per cubic millimeter. 45.4% (74/163) were not yet on HAART and 54.6% (89/163) were on HAART. 66.7% (58/87) had poor adherence to HAART treatment and 33.3% (29/87) had reported good adherence to HAART treatment. A total of 200 clinical isolates of Cryptococcus isolates were tested. No (0% (0/200) C. gattii was identified among the Cryptococcus isolates.
Conclusion
In this study among patients living with HIV and a diagnosis of cryptococcal meningitis in Uganda, we found no C. gattii infections.
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Affiliation(s)
- Abel Wembabazi
- School of Health Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Dianah Rhoda Nassozi
- School of Health Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Enid Akot
- School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Timothy Isaac Ochola
- School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Prosper Tom Kweka
- School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Nelson Tom Katamu
- School of Health Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - David Meya
- Infectious Diseases Institute, College of Health Sciences, Makerere University, Kampala, Uganda
- Department of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail: (BA); (DM)
| | - Beatrice Achan
- Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda
- * E-mail: (BA); (DM)
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Cryptococcus spp. and Cryptococcosis: focusing on the infection in Brazil. Braz J Microbiol 2022; 53:1321-1337. [PMID: 35486354 PMCID: PMC9433474 DOI: 10.1007/s42770-022-00744-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 03/25/2022] [Indexed: 11/02/2022] Open
Abstract
Cryptococcosis is a global fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii yeast complex. This infection is acquired by inhalation of propagules such as basidiospores or dry yeast, initially causing lung infections with the possibility of progressing to the meninges. This infection mainly affects immunocompromised HIV and transplant patients; however, immunocompetent patients can also be affected. This review proposes to evaluate cryptococcosis focusing on studies of this mycosis in Brazilian territory; moreover, recent advances in the understanding of its virulence mechanism, animal models in research are also assessed. For this, literature review as realized in PubMed, Scielo, and Brazilian legislation. In Brazil, cryptococcosis has been identified as one of the most lethal fungal infections among HIV patients and C. neoformans VNI and C. gattii VGII are the most prevalent genotypes. Moreover, different clinical settings published in Brazil were described. As in other countries, cryptococcosis is difficult to treat due to a limited therapeutic arsenal, which is highly toxic and costly. The presence of a polysaccharide capsule, thermo-tolerance, production of melanin, biofilm formation, mechanisms for iron use, and morphological alterations is an important virulence mechanism of these yeasts. The introduction of cryptococcosis as a compulsory notification disease could improve data regarding incidence and help in the management of these infections.
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Gene, virulence and related regulatory mechanisms in Cryptococcus gattii. Acta Biochim Biophys Sin (Shanghai) 2022; 54:593-603. [PMID: 35593469 PMCID: PMC9828318 DOI: 10.3724/abbs.2022029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cryptococcus gattii is a kind of basidiomycetous yeast, which grows in human and animal hosts. C. gattii has four distinct genomes, VGI/AFLP4, VGII/AFLP6, VGIII/AFLP5, and VGIV/AFLP7. The virulence of C. gattii is closely associated with genotype and related stress-signaling pathways, but the pathogenic mechanism of C. gattii has not been fully identified. With the development of genomics and transcriptomics, the relationship among genes, regulatory mechanisms, virulence, and treatment is gradually being recognized. In this review, to better understand how C. gattii causes disease and to characterize hypervirulent C. gattii strains, we summarize the current understanding of C. gattii genotypes, phenotypes, virulence, and the regulatory mechanisms.
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Firacative C, Meyer W, Castañeda E. Cryptococcus neoformans and Cryptococcus gattii Species Complexes in Latin America: A Map of Molecular Types, Genotypic Diversity, and Antifungal Susceptibility as Reported by the Latin American Cryptococcal Study Group. J Fungi (Basel) 2021; 7:jof7040282. [PMID: 33918572 PMCID: PMC8069395 DOI: 10.3390/jof7040282] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/20/2021] [Accepted: 04/01/2021] [Indexed: 02/07/2023] Open
Abstract
Cryptococcosis, a potentially fatal mycosis, is caused by members of the Cryptococcus neoformans and Cryptococcus gattii species complexes. In Latin America, cryptococcal meningitis is still an important health threat with a significant clinical burden. Analysis of publicly available molecular data from 5686 clinical, environmental, and veterinary cryptococcal isolates from member countries of the Latin American Cryptococcal Study Group showed that, as worldwide, C. neoformans molecular type VNI is the most common cause of cryptococcosis (76.01%) in HIV-infected people, followed by C. gattii molecular type VGII (12.37%), affecting mostly otherwise healthy hosts. These two molecular types also predominate in the environment (68.60% for VNI and 20.70% for VGII). Among the scarce number of veterinary cases, VGII is the predominant molecular type (73.68%). Multilocus sequence typing analysis showed that, in Latin America, the C. neoformans population is less diverse than the C. gattii population (D of 0.7104 vs. 0.9755). Analysis of antifungal susceptibility data showed the presence of non-wild-type VNI, VGI, VGII, and VGIII isolates in the region. Overall, the data presented herein summarize the progress that has been made towards the molecular epidemiology of cryptococcal isolates in Latin America, contributing to the characterization of the genetic diversity and antifungal susceptibility of these globally spreading pathogenic yeasts.
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Affiliation(s)
- Carolina Firacative
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogota 111221, Colombia
- Correspondence: ; Tel.: +57-1-297-0200 (ext. 3404)
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Research and Education Network Westmead Hospital, Faculty of Medicine and Health, Sydney Medical School-Westmead Clinical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead Institute for Medical Research, The University of Sydney, Sydney 2145, Australia;
| | - Elizabeth Castañeda
- Grupo de Microbiología, Instituto Nacional de Salud, Bogota 111321, Colombia;
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Epidemiology of antifungal susceptibility: Review of literature. J Mycol Med 2019; 28:574-584. [PMID: 29773435 DOI: 10.1016/j.mycmed.2018.04.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 11/24/2022]
Abstract
Fungal infections are a major cause of morbidity and mortality despite the latest developments of diagnostic tools and therapeutic options. Early initiation of the appropriate antifungal therapy has been demonstrated to have a direct impact on the patient's outcome. Antifungal susceptibility testing methods are available to detect antifungal resistance and to determine the best treatment for a specific fungus. American and European standards have been developed, as well as equivalent commercial systems, which are more appropriate for clinical laboratories. These studies have allowed the development of interpretative breakpoints against the most frequent agents of fungal infections in the world. Surveillance of antifungal susceptibility patterns can provide the local drug resistance data to the clinicians, which can further aid better management of patients. Antifungal susceptibility tests have become essential tools to identify resistance to antifungals, to know the local and global disease epidemiology and to guide the treatment of fungal diseases. The distribution of species and the prevalence of antifungal resistance in fungi isolates varied among different areas. Here we summarize the epidemiology of antifungal susceptibility pattern of different fungal species.
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Molecular types of Cryptococcus species isolated from patients with cryptococcal meningitis in a Brazilian tertiary care hospital. Braz J Infect Dis 2018; 22:495-498. [PMID: 30508502 PMCID: PMC9425640 DOI: 10.1016/j.bjid.2018.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/10/2018] [Indexed: 12/20/2022] Open
Abstract
There are limited data on the molecular epidemiology of cryptococcosis in Brazil. Here, we report on the identification of the molecular pattern of the Cryptococcus species that caused meningitis in patients admitted in a Brazilian reference tertiary care hospital, and review the published studies addressing the molecular epidemiology of Cryptococcus in Brazil. Our study has shown the predominance of molecular type VNII in HIV-infected patients with cryptococcal meningoencephalitis. Molecular types VNII and VGII were occasionally detected in HIV-infected and non-infected patients with meningoencephalitis. In contrast, previous studies have shown that several regions exhibited a high prevalence of the VNI molecular type and sporadic cases of the VNII and VGII molecular types in patients with cryptococcosis in Brazil. Additional studies including VNII isolates will contribute to understanding the epidemiology and phylogenetic relationship of these genotype compared to the other ones. So far, no clear correlation has been established between genotypes, antifungal susceptibility for Cryptococcus and clinical outcome in cryptococcosis.
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Firacative C, Lizarazo J, Illnait-Zaragozí MT, Castañeda E. The status of cryptococcosis in Latin America. Mem Inst Oswaldo Cruz 2018; 113:e170554. [PMID: 29641639 PMCID: PMC5888000 DOI: 10.1590/0074-02760170554] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/06/2018] [Indexed: 12/23/2022] Open
Abstract
Cryptococcosis is a life-threatening fungal infection caused by the encapsulated
yeasts Cryptococcus neoformans and C. gattii,
acquired from the environment. In Latin America, as occurring
worldwide, C. neoformans causes more than 90% of the cases of
cryptococcosis, affecting predominantly patients with HIV, while C.
gattii generally affects otherwise healthy individuals. In this
region, cryptococcal meningitis is the most common presentation, with
amphotericin B and fluconazole being the antifungal drugs of choice. Avian
droppings are the predominant environmental reservoir of C.
neoformans, while C. gattii is associated with
several arboreal species. Importantly, C. gattii has a high
prevalence in Latin America and has been proposed to be the likely origin of
some C. gattii populations in North America. Thus, in the
recent years, significant progress has been made with the study of the basic
biology and laboratory identification of cryptococcal strains, in understanding
their ecology, population genetics, host-pathogen interactions, and the clinical
epidemiology of this important mycosis in Latin America.
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Affiliation(s)
- Carolina Firacative
- Westmead Hospital, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Jairo Lizarazo
- Internal Medicine Department, Hospital Universitario Erasmo Meoz, Universidad de Pamplona, Cúcuta, Colombia
| | - María Teresa Illnait-Zaragozí
- Diagnosis and Reference Centre, Bacteriology-Mycology Department Research, Tropical Medicine Institute Pedro Kourí, Havana, Cuba
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Bongomin F, Oladele RO, Gago S, Moore CB, Richardson MD. A systematic review of fluconazole resistance in clinical isolates of Cryptococcus species. Mycoses 2018; 61:290-297. [PMID: 29377368 DOI: 10.1111/myc.12747] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 12/30/2022]
Abstract
Fluconazole is the most commonly used antifungal agent for both the treatment of cryptococcal meningitis, and for prophylaxis against the disease. However, its prolonged use has the potential to exert selection pressure in favour of fluconazole-resistant strains. We evaluated the prevalence of fluconazole resistance in Cryptococcus spp. clinical isolates in 29 studies from 1988 to May 2017 included in EMBASE and MEDLINE databases. A total of 4995 Cryptococcus isolates from 3210 patients constituted this study; 248 (5.0%) of the isolates from relapsed episodes of cryptococcosis were included in this analysis. Eleven (38%) of the studies used minimum inhibitory concentrations (MICs) breakpoints of ≥64 μg/mL to define fluconazole resistance, 6 (21%) used ≥32 μg/mL, 11 (38%) used ≥16 μg/mL and 1 (3%) used ≤20 μg/mL. Overall, mean prevalence of fluconazole resistance was 12.1% (95% confidence interval [CI]: 6.7-17.6) for all isolates (n = 4995). Mean fluconazole resistance was 10.6% (95% CI: 5.5-15.6) for the incident isolates (n = 4747) and 24.1% (95% CI: -3.1-51.2) for the relapse isolates (n = 248). Of the 4995 isolates, 936 (18.7%) had MICs above the ecological cut-off value. Fluconazole resistance appears to be an issue in Cryptococcus isolates from patients with relapses. It remains unclear whether relapses occur due to resistance or other factors. There is an urgent need to establish antifungal breakpoints for Cryptococcus spp.
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Affiliation(s)
- Felix Bongomin
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,The National Aspergillosis Centre & NHS Mycology Reference Centre-Manchester, ECMM Center of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Rita O Oladele
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Sara Gago
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Caroline B Moore
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,The National Aspergillosis Centre & NHS Mycology Reference Centre-Manchester, ECMM Center of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Malcolm D Richardson
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,The National Aspergillosis Centre & NHS Mycology Reference Centre-Manchester, ECMM Center of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK
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Nascimento E, Vitali LH, Kress MRVZ, Martinez R. Cryptococcus neoformans and C. gattii isolates from both HIV-infected and uninfected patients: antifungal susceptibility and outcome of cryptococcal disease. Rev Inst Med Trop Sao Paulo 2017; 59:e49. [PMID: 28793019 PMCID: PMC5626223 DOI: 10.1590/s1678-9946201759049] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 03/31/2017] [Indexed: 12/30/2022] Open
Abstract
One of the factors causing treatment failure in cryptococcosis is the resistance of Cryptococcus spp. to antifungal drugs, which has motivated the susceptibility assessment of isolates from patients with cryptococcosis, different clinical conditions and infections outcomes. Clinical isolates of Cryptococcus spp. from three different groups of patients were studied in the present investigation: 19 HIV-positive patients with relapsing and/or refractory meningitis (Group 1), 30 HIV-positive patients who experienced a single and limited episode of cryptococcosis (Group 2), and 19 HIV-negative patients with cryptococcosis (Group 3). Eighty C. neoformans var. grubii isolates and 7 C. gattii isolates were studied. The minimum inhibitory concentration (MIC) of amphotericin B, azole drugs and flucytosine was determined for Cryptococcus spp. by broth microdilution test and E-test. The MIC50 and MIC90 were 0.25 and 0.50 µg/mL for amphotericin B, 4.0 and 8.0 µg /mL for fluconazole, 0.06 and 0.25 µg/mL for itraconazole, 0.25 and 0.50 µg/mL for voriconazole, and 8.0 and 16.0 µg/mL for flucytosine, respectively. Amphotericin B and itraconazole showed higher MICs for C. neoformans var. grubii and C. gattii, respectively. The MICs of fluconazole and itraconazole obtained with the E-test were higher than those obtained with broth microdilution. Isolates from non-HIV coinfected were less sensitive to the azoles. There was no difference in the susceptibility of C. neoformans var. grubii isolates from patients with a favorable or unfavorable outcome or along the episodes of relapsing and/or refractory meningitis.
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Affiliation(s)
- Erika Nascimento
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Ribeirão Preto, São Paulo, Brazil
| | - Lucia Helena Vitali
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Ribeirão Preto, São Paulo, Brazil
| | | | - Roberto Martinez
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Ribeirão Preto, São Paulo, Brazil
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Antifungal Susceptibility Testing of Candida and Cryptococcus Species and Mechanisms of Resistance: Implications for Clinical Laboratories. CURRENT FUNGAL INFECTION REPORTS 2017. [DOI: 10.1007/s12281-017-0282-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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