Virulence ofCandida aurisfrom different clinical origins inCaenorhabditis elegansandGalleria mellonellahost models

Abstract

Candida auris is an emerging multidrug-resistant fungal pathogen responsible for nosocomial outbreaks of invasive candidiasis. Although several studies on the pathogenicity of this species have been reported, the knowledge on C. auris virulence is still limited. This study aims to analyze the pathogenicity of C. auris , using one aggregating isolate and eleven non-aggregating isolates from different clinical origins (blood, urine and oropharyngeal specimens) in two alternative host models of candidiasis: Caenorhabditis elegans and Galleria mellonella . Furthermore, possible associations between virulence, aggregation, biofilm-forming capacity, and clinical origin were assessed. The aggregating phenotype isolate was less virulent in both in vivo invertebrate infection models than non-aggregating isolates but showed higher capacity to form biofilms. Blood isolates were significantly more virulent than those isolated from urine and respiratory specimens in the G. mellonella model of candidiasis. We conclude that both models of candidiasis present pros and cons but prove useful to evaluate the virulence of C. auris in vivo . Both models also evidence the heterogeneity in virulence that this species can develop, which may be influenced by the aggregative phenotype and clinical origin.

Candida auris: A Quick Review on Identification, Current Treatments, and Challenges

“…Diverse mutations in ERG11 were related directly to azole resistance in all geographic clades. Actually, WGS was proposed nearly immediately, and recently, independent emergence of unlike clonal populations has emerged on 3 continents [9]. facilities' surfaces notwithstanding the decontamination process [32].…”

“…Importantly, whole-genome sequencing (WGS) has allowed the identification of 4 major populations (clades) in which isolates cluster by geography (isolates from Pakistan, India, South Africa, and Venezuela during 2012–2015, and a specimen from Japan). The clades are, thus, from South Asian, East Asian, African, and South American (I to IV, respectively) [ 8 , 9 ]. Indeed, all infections have clustered in these 4 clades; however, recently, a potential fifth clade was identified, separated from the other clades by >200,000 single-nucleotide polymorphisms, in a clinical isolate from a 14-year-old girl in Iran who had never traveled outside the country.…”

“…The most worrisome aspects associated with infection caused by C. auris can be summarized in three levels: High rate of antifungal drug resistance [ 9 ], mode and pace of its easy transmission among healthcare workers and patients in hospitals, and misidentification. This last level is related to difficulties in a correct identification of C. auris strains, which are commonly misidentified as other phylogenetically-related pathogens, but also due to inadequacies of common diagnostic tools to precise identification of C. auris in many countries that result in misidentification and incorrect therapy, which lead to the acquisition of multiple genetic determinants that confer multidrug resistance [ 11 , 12 , 13 , 14 ].…”

“…Sources have been found within the patient’s room/bathroom including beds (e.g., bedding materials and bed side trolley), bathroom doors and walls, faucets, floors, sinks, medical equipment and disposable/reusable equipment (e.g., oxygen mask, axillary temperature probes, intravenous pole), and even on mobile phones, and can endure between one and two weeks [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. This yeast has the ability to survive for weeks on different moist and dry abiotic surfaces (e.g., plastic and steel) [ 1 , 5 , 6 , 10 , 11 ].…”

“…This yeast has the ability to survive for weeks on different moist and dry abiotic surfaces (e.g., plastic and steel) [ 1 , 5 , 6 , 10 , 11 ]. On biotic surfaces, C. auris can be found on skin in general, and, in particular, on hands and nares of care providers and healthcare workers [ 4 , 9 , 10 , 11 ].…”