An analysis of the population of Cryptococcus neoformans strains isolated from animals in Poland, in the years 2015–2019

Abstract

Fungi belonging to the Cryptococcus neoformans/C. gattii species complex (CNGSC) are pathogens causing severe infections in humans and animals, that for humans may result in a mortality rate ranging up to 70%. The CNGSC is divided into eight major molecular types, that may differ in their virulence and susceptibility. In order to fully understand the epidemiology of cryptococcosis, it is important to study the world distribution and population structure of these pathogens. The present study is the first presenting a population of strains isolated in Poland and one of the few using a multi-species animal group as a source of the specimen. The pathogen was present in 2.375% of the tested animals. The URA5-RFLP and MALDI-TOF MS analyses have revealed that the population consisted exclusively of C. neoformans strains, with a predominance of major molecular type VNIV (C. neoformans var. neoformans). The MALDI-TOF MS was used to perform the CNGSC strains identification on both the species and sub-species level. Despite the fact that the animals providing the specimens were not treated with 5-fluorocytosine, around 10% of the tested population presented MIC values exceeding 64 mg/L, indicating the existence of the 5-fluorocytosine-resistant strains in the environment.

Prevalence, Genetic Structure, and Antifungal Susceptibility of the Cryptococcus neoformans/C. gattii Species Complex Strains Collected from the Arboreal Niche in Poland

“…In northern Portugal, [38] from arboreal specimens, the MMT VNI was obtained exclusively, whereas 15 in 23 isolates obtained from the samples originated from pigeons represented the MMT VNIV (while the rest was equally distributed between the MMTs VNI and VNIII). Similarly, in our previous study [26] among the non-clinical strains of animal origin, the MMTs VNIV, VNI, and VNIII were represented by 74.36%, 15.38%, and 10.26% of isolates, respectively. It was observed that in Europe, the MMT VNIII was detected more frequently compared to other continents [29].…”

“…It was observed that in Europe, the MMT VNIII was detected more frequently compared to other continents [29]. While among clinical strains, AD hybrids could comprise about 30% [50], and it was not uncommon to isolate the type from specimen of animal origin [26,38], to the best of our knowledge, the only European arboreal isolation of the MMT VNIII was reported in Greece [13]. Another rare type, the MMT VNII, has not been isolated from trees in Europe to date.…”

“…Despite the seriousness of cryptococcosis, the data concerning the occurrence of the agent and its population structure in Poland were not very well documented to date. In our previous study, the population of non-clinical strains of animal origin isolated in Poland was analysed [26]. With the present research, we would like to extend the knowledge of the Polish community of the CNGSC, this time by analysing isolates obtained from the arboreal specimen.…”

The role of veterinarians in zoonosis prevention: Advising families of immunocompromised children with pets

“…However, some authors have recently reported colonization of Cryptococcus in swabs from oropharynx, crop and cloaca obtained directly from birds. Thus, birds could also be colonized by this yeast [ 39 ]. Cryptococcosis preferentially affects immunocompromised patients, and it has dramatically increased in recent decades as new populations of immunocompromised hosts have emerged [ 40 ].…”

Molecular Markers Reveal Epidemiological Patterns and Evolutionary Histories of the Human Pathogenic Cryptococcus

“…MALDI-TOF MS has become a rapid, easy-to-use, and inexpensive method for identifying clinically important microorganisms ( Claydon et al., 1996 ; Krishnamurthy and Ross, 1996 ; Seng et al., 2009 ). Indeed, this technology has been used to identify hundreds of CNSC and CGSC strains isolated from both humans and animals ( Firacative et al., 2012 ; Posteraro et al., 2012 ; Jin et al., 2020 ; Zvezdanova et al., 2020 ; Florek et al., 2021 ). In a recent study, an expanded database allowed the MALDI-TOF MS technology to separate the two major lineages within CNSC, VNI ( C. neoformans ) and VNIV ( C. deneoformans ), including identifying most of their hybrids (VNIII) when the authors used a hierarchical clustering approach and focused on five selected biomarkers in the dataset ( Zvezdanova et al., 2020 ).…”