Approaches by Rhodotorula mucilaginosa from a chronic kidney disease patient for elucidating the pathogenicity profile by this emergent species

Abstract

26Background: Traditionally known as a common contaminant, Rhodotorula mucilaginosa is 27 among the leading causes of invasive fungal infections by non-candida yeasts. They affect 28 mainly immunocompromised individuals, often mimicking the cryptococcosis infection, 29 despite invasive infections by Rhodotorula are still not well explained. Thus, here we aimed to 30 characterize microbiologically clinical isolates of R. mucilaginosa isolated from colonization 31 of a patient with chronic renal disease (CKD), as well as to evaluate their phylogeny, antifungal 32 susceptibility, virulence, and pathogenicity in order to infer the potential to become a possible 33 infection. 34 Methodology/Principal Findings: For this study, two isolates of R. mucilaginosa from oral 35 colonization of a CKD patient were isolated, identified and characterized by classical 36 (genotypic and phenotypic) methods. Susceptibility to conventional antifungals was evaluated, 37 followed by biofilm production, measured by different techniques (total biomass, metabolic 38 activity, colony forming units and extracellular matrix quantification). Finally, the 39 pathogenicity of yeast was evaluated by infection of Tenebrio molitor larvae. 40All isolates were resistant to azole and sensitive to polyenes and they were able to adhere and 41 form biofilm on the abiotic surface of polystyrene. In general, similar profiles among isolates 42 were observed over the observed periods (2, 24, 48 and 72 hours). Regarding extracellular 43 matrix components of biofilms at different maturation ages, R. mucilaginosa was able to 44 produce eDNA, eRNA, proteins, and polysaccharides that varied according to time and the 45 strain. The death curve in vivo model showed a large reduction in the survival percentage of 46 the larvae was observed in the first 24 hours, with only 40% survival at the end of the 47 Conclusions/Significance: We infer that colonization of chronic renal patients by R. 49 mucilaginosa offers a high risk of serious infection. And also emphasize that the correct 50 identification of yeast is the main means for an efficient treatment. 51 52 53 3 Author Summary 54The genus Rhodotorula is known to be a common contaminant, however, it has been 55 increasing in the last years, reports of different forms infections by this yeast, reaching mainly 56 individuals with secondary diseases or with low immunity. However, very little is known about 57 the mechanism that triggers the disease. Thus, this study aims to characterize microbiologically 58 clinical isolates of R. mucilaginosa isolated from a patient with chronic renal disease, as well 59 as to evaluate their phylogeny, antifungal susceptibility, virulence, and pathogenicity in order 60 to infer the potential to become a possible infection. It was possible to characterize in general 61 the clinical isolates, to determine that they are resistant to an important class of the antifungal 62 agents which are the azoles. In addition, they are able to adhere and to form biofilm on abiotic 63 surfaces, t...

Comparative Analysis of Capsular and Secreted Polysaccharides Produced by Rhodotorula mucilaginosa and Cryptococcus neoformans

“…Our results support previous findings regarding the presence of a polysaccharide capsule around R. mucilaginosa, analogous to the capsule found in C. neoformans. This finding is of particular importance due to the capsule's critical role as a virulence factor in C. neoformans [16,54]. In this species, the capsule plays a vital role in pathogenicity by assisting the fungus in evading the host's immune system and establishing infections.…”

Rhodotorula Mucilaginosa: Two Faces of the Yeast

“…PUFA is not synthesized by human body, therefore an exogenous supply is essential. mucilaginosa to be emerging pathogen with the common predisposing factors are malignancies, AIDS, cirrhosis, and gastrointestinal disorders as well as the use of CVCs [32] and chronic renal problem [33]. In china, between 2009 and 2019, a hospital survey was made to study the significance of R. mucilaginosa in causing fungemia, their genotyping and genetic transmission of drug resistance.…”