Potentially pathogenic yeast isolated from the throat and cloaca of an Arctic colonial seabird: the little auk (Alle alle)

Abstract

Yeasts are a distinctive group of microfungi, but compared to other microorganisms, their ecological function and biodiversity are poorly known. This is especially so where polar ecosystems are concerned. With climate changes and increasing pollution levels in the Arctic, it can be anticipated that there will be an increase in the prevalence and diversity of fungi colonizing live organisms. With these changes, it is crucial to investigate and monitor species diversity and prevalence of fungi in this fragile environment. In this study, yeasts were examined from throat and cloaca of a small colonial seabird, the little auk (Alle alle), a keystone species in the Arctic ecosystem. Samples were collected from 94 adults and 17 nestlings in breeding colony in Magdalenefjorden (NW Spitsbergen) in 2009. In total, twelve species of yeast from eight genera were found in 12 % of the samples, with the Dipodascus genus being the most prevalent. All yeast species were found in the adults, but only one species, Cryptococcus macerans, was found in a single nestling. In individuals where fungus was isolated, it was only isolated from either the throat or the cloaca, except for two cases, where fungus was found in both throat and cloaca. The presence of yeast was not related to sex but age of the birds, with adults being more prone to colonization by yeasts than the nestlings. The relatively low prevalence and diversity of yeast in little auks suggest that these birds are random carriers of fungi, with minor health impacts.

Mallard duck (Anas platyrhynchos) as a potential link in the epidemiological chain mycoses originating from water reservoirs

“…Birds are especially susceptible to colonisation by fungi due to favourable conditions for their growth in poorly vascularised air sacs, very poor antimycotic activity in serum or its lack, and exceptionally thin skin devoid of sweat and sebaceous glands (5,10,28). In the case of wild birds not fed by man, mycoses are sporadic (5), whereas the carrier state -especially in waterfowl -is noted more frequently than in other vertebrates (2,(11)(12)(13). A physiological barrier that inhibits the growth and proliferation of most of potentially-pathogenic fungi in tissues of birds is high temperature of their body (40-42°C).…”

“…Birds feeding in water with substances being rich in organic matter and often colonised by fungi with a various trophic and taxonomic status are worth noticing (12,13).…”

“…Mycological data are significantly scantier and refer mainly to infected or dead birds originating from widely-understood cultures, from which single fungal species had been isolated (2,10,33). In turn, information on fungi isolated from wild fowl pertains mainly to microfungi colonising skin, feathers, and nails (22), as well as nests (17) and faeces (4,13,21). Mycological analyses of biological specimens collected from organ ontocenoses of live wild birds are sparse (11,13).…”

“…In turn, information on fungi isolated from wild fowl pertains mainly to microfungi colonising skin, feathers, and nails (22), as well as nests (17) and faeces (4,13,21). Mycological analyses of biological specimens collected from organ ontocenoses of live wild birds are sparse (11,13). Determination of the role of birds living in close proximity of man (23) in the mechanisms of potentially-pathogenic fungi circulation in the biosphere is of a key significance in the context of an extending spectrum of environmental factors predisposing to mycotic infections, as well as in evaluation of the sanitary status of the environment, and assessment of epidemiological risk.…”

Factors affecting leucocyte profiles in the little auk, a small Arctic seabird

“…Being long-lived seabirds, little auks are expected to invest strongly in their immune system to ensure survival. This species has relatively low rates of infection and prevalence of otherwise common pathogens, such as haemoparasites or fungi , 2011Dynowska et al 2013). So far, leucocyte profiles in the little auk have been studied mainly in adults (Jakubas et al 2008.…”