Cryptococcosis: Emergence of Cryptococcus gattii in Animals and Zoonotic Potential

Singh, Karuna; İlkit, Macit; Shokohi, Tahareh; Tolooe, Ali; Malík, Richard; Seyedmousavi, Seyedmojtaba

doi:10.1007/978-3-319-72093-7_12

Cited by 12 publications

(17 citation statements)

References 209 publications

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“…Several studies have characterized the properties of these yeasts that contribute to the colonization of new environmental niches (Granados and Castañeda, 2006; Randhawa et al, 2008; Ergin and Kaleli, 2010; Ergin et al, 2014; Sengul et al, 2019). With the exception of iatrogenic (Baddley et al, 2011) and zoonotic (Nosanchuk et al, 2000; Lagrou et al, 2005; Singh et al, 2018) cases, Cryptococcus infection is caused by the inhalation of airborne basidiospores or desiccated yeast cells from the environment (Hull et al, 2005; Lin and Heitman, 2006; Velagapudi et al, 2009; Springer et al, 2013; May et al, 2016), emphasizing the importance of identifying the natural reservoirs of C . neoformans and the molecular links between environmental and clinical isolates and their association with disease (Litvintseva et al, 2005; Chen et al, 2015; Kangogo et al, 2015; Noguera et al, 2015; Spina-Tensini et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Ergin

Şengül

Aksoy

et al. 2019

Front. Cell. Infect. Microbiol.

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Cryptococcus species are life-threatening human fungal pathogens that cause cryptococcal meningoencephalitis in both immunocompromised and healthy hosts. The natural environmental niches of Cryptococcus include pigeon (Columba livia) guano, soil, and a variety of tree species such as Eucalyptus camaldulensis, Ceratonia siliqua, Platanus orientalis, and Pinus spp. Genetic and genomic studies of extensive sample collections have provided insights into the population distribution and composition of different Cryptococcus species in geographic regions around the world. However, few such studies examined Cryptococcus in Turkey. We sampled 388 Olea europaea (olive) and 132 E. camaldulensis trees from seven locations in coastal and inland areas of the Aegean region of Anatolian Turkey in September 2016 to investigate the distribution and genetic diversity present in the natural Cryptococcus population. We isolated 84 Cryptococcus neoformans strains (83 MATα and 1 MATa) and 3 Cryptococcus deneoformans strains (all MATα) from 87 (22.4% of surveyed) O. europaea trees; a total of 32 C. neoformans strains were isolated from 32 (24.2%) of the E. camaldulensis trees, all of which were MATα. A statistically significant difference was observed in the frequency of C. neoformans isolation between coastal and inland areas (P < 0.05). Interestingly, the MATa C. neoformans isolate was fertile in laboratory crosses with VNI and VNB MATα tester strains and produced robust hyphae, basidia, and basidiospores, thus suggesting potential sexual reproduction in the natural population. Sequencing analyses of the URA5 gene identified at least five different genotypes among the isolates. Population genetics and genomic analyses revealed that most of the isolates in Turkey belong to the VNBII lineage of C. neoformans, which is predominantly found in southern Africa; these isolates are part of a distinct minor clade within VNBII that includes several isolates from Zambia and Brazil. Our study provides insights into the geographic distribution of different C. neoformans lineages in the Mediterranean region and highlights the need for wider geographic sampling to gain a better understanding of the natural habitats, migration, epidemiology, and evolution of this important human fungal pathogen.

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Section: Introductionmentioning

confidence: 99%

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Ergin

Şengül

Aksoy

et al. 2019

Front. Cell. Infect. Microbiol.

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“…Unlike the WHO recommendation, most of our HIV‐positive patients with CD4 counts >200 cells/μL were seropositive, revealing the importance of screening tests in this high‐risk group. However, among CrAg‐positive patients, we were unable to find any proven contact with the reservoir of these pathogens . By showing that CrAg can be detected before the onset of symptoms, the obtained data will aid in general efforts to reduce CM and related deaths and allow timely precaution measures to be taken.…”

Section: Discussionmentioning

confidence: 90%

“…Basidiomycetous yeast of the genus Cryptococcus cause a potentially life‐threatening disease, cryptococcosis, which can be either primary or opportunistic and is observed worldwide . Serological methods used to diagnose cryptococcosis for the last four decades are rapid and reliable; among them, tests for detecting the capsular polysaccharide, glucuronoxylomannan, the primary cryptococcal antigen (CrAg) released during infection into body fluids, are considered the most sensitive .…”

Section: Introductionmentioning

confidence: 99%

Identification of Cryptococcus antigen in human immunodeficiency virus‐positive Turkish patients by using the Dynamiker^® lateral flow assay

Karaman

İlkit

Kuşçu

2019

Mycoses

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Summary Cryptococcus neoformans causes life‐threatening meningoencephalitis, particularly in human immunodeficiency virus (HIV)‐positive individuals with low CD4 levels (<100 cells/μL). Although the burden of cryptococcal meningoencephalitis (CM) in Turkey is low (0.13 cases per 100 000 persons), asymptomatic individuals at risk of cryptococcosis should be screened for antigenemia to prevent the disease and/or promote early CM diagnosis. A lateral flow assay (LFA) is used to detect Cryptococcus antigen (CrAg) in cerebrospinal fluid and serum. We determined Cryptococcus antigenemia prevalence in serum samples of HIV‐positive and HIV‐negative adult patients by using Dynamiker® CrAg‐LFA, a point‐of‐care dipstick test. Patients’ demographic data, CD4 count, HIV‐RNA levels and anti‐retroviral therapy status were recorded. CrAg was detected in 28 (11%) of 254 HIV‐positive patients screened but not in 100 HIV‐negative control individuals; a significant difference was observed in the CrAg‐LFA positivity rate between HIV‐positive and HIV‐negative groups (x2 = 11.970; P < .05). In CrAg‐positive patients, the median CD4 level was 666 cells/μL (115‐1344 cells/μL), with a median viral load of 23 copies/mL (0‐3.69 × 106 copies/mL). In HIV‐positive CrAg‐negative patients, the median CD4 level was 633 cells/μL (31‐2953 cells/μL) and the median viral load was 12 copies/mL (0‐1.95 × 106 copies/mL; P > .05). Results indicate that HIV‐positive patients with both low (<200 cells/μL) and high (>200 cells/μL) CD4 counts should be screened for asymptomatic cryptococcal antigenemia. HIV‐associated asymptomatic cryptococcosis is not uncommon in Turkey, which warrants systematic screening. Updated strategies for CM prevention among HIV‐positive patients should be used even in non‐endemic countries.

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“…Phenotypic identification of cryptococcal isolates was done using standard methods including microscopy with Gram's stain and India ink, ability to grow at 37 ºC, and biochemical test for urease activity [24,25]. Finally, cryptococcus differential agar media (Himedia, India) was used for differentiation of C. neoformans and C. gattii on the basis of assimilation of tryptophan and glycine as carbon and nitrogen sources.…”

Section: Phenotypic Identificationmentioning

confidence: 99%

Multiplex PCR - RFLP Assay for Identification of Cryptococcus neoformans and Cryptococcus gattii Isolated from Birds’ Droppings and Eucalyptus Trees

Taha

Tartor

Ibrahim

2021

Zagazig Veterinary Journal

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Cryptococcus neoformans/ Cryptococcus gattii (C. neoformans/ C. gattii) species complex are encapsulated basidiomycetous yeasts, causing cryptococcosis which is a life-threatening fungal disease of the pulmonary and central nervous system of humans and animals. This study aimed to investigate the recovery rate of C. neoformans and C. gattii from bird droppings and Eucalyptus trees in Egypt as well as the performance of the phenotypic and molecular identification methods for Cryptococcus species identification. Overall, 27 Cryptococcus isolates (13.5%) were isolated from 200 examined samples including 70 pigeon droppings, 50 captive birds' droppings, and 80 Eucalyptus trees samples. The recovered isolates were phenotypically identified based on macro-and micro-morphological characters, urease test, and differentiation using cryptococcus differential agar media. Multiplex polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis using EcoRI restriction enzyme for confirmation of species identification. The molecular methods identified 20 C. neoformans from pigeon's droppings (12/70, 17.14%) and captive birds' droppings samples (8/50, 16%), as well as 7 C. gattii from Eucalyptus trees (7/80, 8.75%). Molecular identification results did not correspond with those of the phenotypic identification methods in three isolates (11.11%), as phenotypic methods identified only 4 C. gattii isolates and molecular methods identified 7 isolates. In conclusion, multiplex PCR and RFLP analysis of multiplex PCR products are rapid, sensitive, species-specific, and more reliable methods for identification of Cryptococcus species and may be used as a complementary to phenotypic methods to avoid false-negative and falsepositive results.

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Cryptococcosis: Emergence of Cryptococcus gattii in Animals and Zoonotic Potential

Cited by 12 publications

References 209 publications

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Identification of Cryptococcus antigen in human immunodeficiency virus‐positive Turkish patients by using the Dynamiker^® lateral flow assay

Multiplex PCR - RFLP Assay for Identification of Cryptococcus neoformans and Cryptococcus gattii Isolated from Birds’ Droppings and Eucalyptus Trees

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Cryptococcosis: Emergence of Cryptococcus gattii in Animals and Zoonotic Potential

Cited by 12 publications

References 209 publications

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Cryptococcus neoformans Recovered From Olive Trees (Olea europaea) in Turkey Reveal Allopatry With African and South American Lineages

Identification of Cryptococcus antigen in human immunodeficiency virus‐positive Turkish patients by using the Dynamiker® lateral flow assay

Multiplex PCR - RFLP Assay for Identification of Cryptococcus neoformans and Cryptococcus gattii Isolated from Birds’ Droppings and Eucalyptus Trees

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Product

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Identification of Cryptococcus antigen in human immunodeficiency virus‐positive Turkish patients by using the Dynamiker^® lateral flow assay