Molecular characterization of C ryptococcus neoformans and C ryptococcus gattii from environmental sources and genetic comparison with clinical isolates in Apulia, Italy

Abstract

The present study investigated the environmental distribution of Cryptococcus neoformans and C. gattii species complex molecular types, mating types and sequence types in Apulia, a region of Southern Italy. A total of 2078 specimens from arboreal and animal sources were analyzed. The percentage of positive samples was similar among both arboreal and animal specimens: 4.2% vs. 5.1% for C. neoformans species complex and 0.6% vs. 1.4% for C. gattii species complex. Molecular typing identified 78 isolates as VNI (76 αA and two aA), one as AD-hybrid αADa, and 16 as VGI aB. VNI isolates presented 10 different sequence types (STs) and VGI isolates two. The most frequent STs among C. neoformans and C. gattii species complex isolates were ST23 (51%) and ST156 (90%), respectively. Comparison with molecular types and STs results obtained from 21 clinical isolates collected in Apulia showed that one C. neoformans VNI clinical isolate shared an identical sequence type of one arboreal isolate (ST61) and that one C. gattii VGI clinical isolate matched with the main ST (ST156) present in the environment. In addition, molecular type VNIV was found only among clinical isolates and was absent in the investigated environmental area. In conclusion, the present study identified which C. neoformans and C. gattii species complex genotypes are circulating in Apulia, defined their ecological niches and revealed the relationship with clinical cases. It represents a basal study for addressing future investigations and public health interventions in the region.

Genotypes and population genetics of cryptococcus neoformans and cryptococcus gattii species complexes in Europe and the mediterranean area

“…In addition, some VGII isolates were the cause of infection in cases of cryptococcosis most probably acquired outside the continent (Hagen et al, 2010(Hagen et al, , 2012. In contrast, most infections due to VGI isolates were autochthonous (Hagen et al, 2012) as confirmed by recent European environmental surveys that showed the presence of VGI isolates in live trees and soil (Chowdhary et al, 2012;Colom et al, 2012;Linares et al, 2015;Cogliati et al, 2016a;Montagna et al, 2018). Monitoring the distribution of genotypes of C. neoformans and C. gatti species complexes in the European and Mediterranean environment is crucial to evaluate the evolution of this pathogen which seems capable to rapidly colonize new habitats.…”

First Autochthonous Case of Cryptococcal Meningitis in an Immunocompetent Host Due to Cryptococcus gattii VGIin Northern Italy

“…This was confirmed by molecular typing of the fungal isolate which showed it belonged to genotype ST156. This genotype is the most common C. gattii VGI genotype present in Europe [16] and in Italy and was previously identified in Apulia region from Eucalyptus and olive tree samples, and from a series of samples collected in the cages of exotic animals living in a zoo [17]. The only clinical isolate belonging to this genotype was responsible of disseminated cryptococcosis in an HIV patient living in Bari, in the same Italian region [10] (Table 1).…”

Molecular epidemiology of Colombian Histoplasma capsulatum isolates obtained from human and chicken manure samples

“…Nowadays, it is possible to compare isolates using the proteomic analysis. This approach could be used to elucidate genes related to pathogenicity by comparing gene expression and activity in environmental and clinical isolates (Kasap et al., 2017; Montagna et al., 2018; Jun et al., 2013). If the virulence genes have been not activated in the environmental isolates in the same form as in the clinical isolates, then the use of the mouse model for the isolation of H. capsulatum from environmental samples needs to be reconsidered as the gold standard technique.…”