Occurrence and susceptibilities to disinfectants of &lt;i&gt;Cryptococcus neoformans&lt;/i&gt; in fecal droppings from pigeons in Bangkok, Thailand

Krangvichain, Prathomporn; Niyomtham, Waree; Prapasarakul, Nuvee

doi:10.1292/jvms.15-0594

Cited by 15 publications

(10 citation statements)

References 26 publications

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“…Contaminated soils near a hospital have been suggested as sites for hospital-acquired infection of C. neoformans (49). Remediation of C. neoformans -contaminated soils is a formidable challenge and current methods involve the application the noxious chemicals such as formalin (50) and quaternary ammonium salts (51). Given that amoeba predation can reduce fungal burden in contaminated soils (29), our results suggest that increasing the soil concentration of divalent cations with calcium and magnesium salts could potentiate the fungicidal capacity of amoeba and provide a more environmentally friendly biological alternative to chemical decontamination.…”

Section: Discussionmentioning

confidence: 99%

Divalent metal cations potentiate the predatory capacity of amoeba forCryptococcus neoformans

Casadevall

2017

Preprint

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19Among the best studied interaction between soil phagocytic predators and a human pathogenic fungus 20 is that of Acanthamoeba castellanii and Cryptococcus neoformans. The experimental conditions used in 21 amoeba-fungal confrontation assays can have major effects on whether the fungus or the protozoan is 22 ascendant in the interaction. . Cations enhanced A. castellanii activity against C. 29 neoformans through enhanced phagocytosis, which is the major mechanism for amoeba to kill fungal 30 cells. We found no evidence that amoeba uses extracellular killing mechanisms in their interactions with 31 C. neoformans. In summary, the presence of Mg 2+ and Ca 2+ enhanced cell adhesion on surface and 32 motility of amoeba, thus increasing the chance for contact of C. neoformans and the frequency of 33 phagocytosis. Our findings imply that divalent cation concentration in soils could be an important 34 variable for whether amoeba can control C. neoformans in the environment. 35Importance. Grazing of soil organisms by phagocytic predators such as amoeba is thought to select for 36 traits that allow some of them to acquire the capacity for virulence in animals. Consequently, 37 knowledge about the interactions between amoeba and soil microbes, such as pathogenic fungi, is 38 important for understanding how virulence can emerge. We show that the interaction between 39 amoeba and the pathogenic fungus C. neoformans is influenced by the presence of magnesium and 40 calcium in the assay, which potentiate amoeba. The results may also have practical applications since 41 enriching soils with divalent cations may reduce C. neoformans numbers in contaminated soils. 42 peer-reviewed)

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Section: Discussionmentioning

confidence: 99%

Divalent metal cations potentiate the predatory capacity of amoeba forCryptococcus neoformans

Casadevall

2017

Preprint

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“…Las frecuencias de muestras positivas en heces de palomas en otros países varían desde 1.4% hasta valores tan altos como 34% (Curo, 2005;Cermeño et al, 2006;Zarrini et al, 2010;Soltani et al, 2013;Huamán et al, 2018), así como en heces de canarios y gallinas (Criseo et al, 1995;Kuroki et al, 2004;Cafarchia et al, 2006). Esto evidencia su importancia como patógeno y el riesgo que representa para la salud pública (Kuroki et al, 2004 La ausencia de C. neoformans en las muestras de heces de las palomas mensajeras criadas en cautiverio en los cuatro palomares del estudio se debería posiblemente al manejo de los ambientes de crianza y a las actividades periódicas de desinfección que se realizan calendarizados, limpieza de excretas del suelo y de los nidales (Krangvichain et al, 2016;Huamán et al, 2018).…”

Section: Discussionunclassified

Cryptococcus neoformans en heces de palomas mensajeras y de Castilla (Columba livia) en Lima, Perú

Timmermann

Morales-Cauti

Villacaqui

2020

Rev. investig. vet. Perú

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El objetivo del presente estudio fue determinar la prevalencia de Cryptococcus neoformans en heces de palomas domésticas (Columba livia) en lugares públicos de la ciudad de Lima, Perú, en 2015-2016. Se recolectaron muestras de heces secas en palomares de palomas mensajeras criadas en cautiverio y en ambientes públicos de palomas de Castilla. Las muestras fueron procesadas y sembradas en agar Sabouraud dextrosa, e incubadas a 37 °C hasta por 10 días. Las colonias fueron identificadas a través de la evaluación macroscópica, visualización de cápsula con tinta china, prueba de ureasa, asimilación de azúcares, reducción rápida de nitrato, prueba de fenoloxidasa y crecimiento en agar CGB. Se determinó una frecuencia de 5.16% (16/310) de muestras positivas a C. neoformans en heces de ambos tipos de palomas evaluadas. En las heces de palomas de Castilla fue de 8.89% (16/180), en tanto que no hubo muestras positivas en las palomas mensajeras. En la simulación estocástica Beta Pert (@Risk 5.5®) se determinó una prevalencia mínima y máxima para el estudio de 4.59 y 5.61%, respectivamente. Se concluye que Cryptococcus neoformans se encuentra presente en heces de palomas Castilla en la ciudad de Lima, Perú.

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“…A prior study found that quaternary ammonium compounds effectively killed all C. neoformans yeasts in pigeon droppings within 30 min of contact time at a concentration of 0.062%, while rapid killing was observed at a concentration of 0.5% (44). At the facilities in this study, a concentration of 0.4% was typically used, with a 30-min contact period.…”

Section: Discussionmentioning

confidence: 99%

Jet-Setting Koalas Spread Cryptococcus gattii VGII in Australia

Danesi

Monroy-Nieto

Bowers

et al. 2019

mSphere

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Cryptococcus gattii molecular type VGII is one of the etiologic agents of cryptococcosis, a systemic mycosis affecting a wide range of host species. Koalas (Phascolarctos cinereus) exhibit a comparatively high prevalence of cryptococcosis (clinical and subclinical) and nasal colonization, particularly in captivity. In Australia, disease associated with C. gattii VGII is typically confined to Western Australia and the Northern Territory (with sporadic cases reported in eastern Australia), occupying an enigmatic ecologic niche. A cluster of cryptococcosis in captive koalas in eastern Australia (five confirmed cases, a further two suspected), caused predominantly by C. gattii VGII, was investigated by surveying for subclinical disease, culturing koala nasal swabs and environmental samples, and genotyping cryptococcal isolates. URA5 restriction fragment length polymorphism analysis, multilocus sequence typing (MLST), and whole-genome sequencing (WGS) provided supportive evidence that the transfer of koalas from Western Australia and subsequently between several facilities in Queensland spread VGII into uncontaminated environments and environments in which C. gattii VGI was endemic. MLST identified VGII isolates as predominantly sequence type 7, while WGS further confirmed a limited genomic diversity and revealed a basal relationship with isolates from Western Australia. We hypothesize that this represents a founder effect following the introduction of a koala from Western Australia. Our findings suggest a possible competitive advantage for C. gattii VGII over VGI in the context of this captive koala environment. The ability of koalas to seed C. gattii VGII into new environments has implications for the management of captive populations and movements of koalas between zoos. IMPORTANCE Cryptococcus gattii molecular type VGII is one of the causes of cryptococcosis, a severe fungal disease that is acquired from the environment and affects many host species (including humans and koalas). In Australia, disease caused by C. gattii VGII is largely confined to western and central northern parts of the country, with sporadic cases reported in eastern Australia. We investigated an unusual case cluster of cryptococcosis, caused predominantly by C. gattii VGII, in a group of captive koalas in eastern Australia. This research identified that the movements of koalas between wildlife parks, including an initial transfer of a koala from Western Australia, introduced and subsequently spread C. gattii VGII in this captive environment. The spread of this pathogen by koalas could also impact other species, and these findings are significant in the implications they have for the management of koala transfers and captive environments.

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Occurrence and susceptibilities to disinfectants of <i>Cryptococcus neoformans</i> in fecal droppings from pigeons in Bangkok, Thailand

Cited by 15 publications

References 26 publications

Divalent metal cations potentiate the predatory capacity of amoeba forCryptococcus neoformans

Divalent metal cations potentiate the predatory capacity of amoeba forCryptococcus neoformans

Cryptococcus neoformans en heces de palomas mensajeras y de Castilla (Columba livia) en Lima, Perú

Jet-Setting Koalas Spread Cryptococcus gattii VGII in Australia

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