Multicenter Candida auris outbreak caused by azole-susceptible clade IV in Pernambuco, Brazil.

BACKGROUND: Candida auris is an emerging multidrug-resistant yeast, frequently causing outbreaks in health care facilities. The pathogen persistently colonises human skin and inanimate surfaces such as catheters, aiding to its spread. Moreover, colonisation is a risk factor to develop invasive infection. OBJECTIVES: We investigated 61 C. auris strains isolated from non-sterile human body sites (n = 53) and the hospital environment (n = 8), originating from four different centres in a single Brazilian state. MATERIALS AND METHODS: Antifungal susceptibility testing (AFST) against common antifungals was performed, and resistance-associated genes were evaluated. Genetic relatedness was investigated with short tandem repeat (STR) genotyping and validated with whole-genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis. RESULTS: Antifungal susceptibility testing demonstrated that all isolates were susceptible to azoles, echinocandins and amphotericin B. No mutations were detected in ERG11 and FKS1 genes. With STR typing, isolates were allocated to clade IV and appeared closely related. This was confirmed by WGS SNP analysis of 6 isolates, which demonstrated a maximal difference of only 41 SNPs between these strains. Furthermore, the Brazilian isolates formed a distinct autochthonous branch within clade IV, excluding recent introductions from outside the country. A molecular clock analysis of clade IV isolates from various countries suggests that early in the previous century there was a unique event causing environmental spread of a C. auris ancestor throughout the Latin-American continent, followed by human introduction during the last decades. CONCLUSION: We report the emergence of C. auris patient colonisation in multiple centres by fluconazole-susceptible clade IV close-related strains in Pernambuco State, Brazil.

Novel Non-Hot Spot Modification in Fks1 of Candida auris Confers Echinocandin Resistance.

We determined the echinocandin susceptibility and FKS1 genotypes of 13 clinical isolates of Candida auris that were recovered from 4 patients at a tertiary care center in Salvador, Brazil. Three isolates were categorized as echinocandin-resistant, and they harbored a novel FKS1 mutation that led to an amino acid change W691L located downstream from hot spot 1. When introduced to echinocandin-susceptible C. auris strains by CRISPR/Cas9, Fks1 W691L induced elevated MIC values to all echinocandins (anidulafungin, 16 to 32×; caspofungin, >64×; micafungin, >64×).

Breakthrough Candidemia in Pediatric Patients With Cancer From a Brazilian Center.

We analyzed 19 cases of breakthrough candidemia from a referral pediatric cancer center in Brazil. All patients had neutropenia and were under antifungal prophylactic regimens, mostly micafungin (68%). Most of the patients were treated with amphotericin B formulations and 30-day mortality was 21%. Candida parapsilosis was the main etiologic agent (63%), and horizontal transmission was not evidenced by microsatellite analysis.

Trichosporon inkin as an Emergent Pathogen in Patients With Severe Pemphigus.

IMPORTANCE: To our knowledge, these are the first reports of bloodstream infections by Trichosporon inkin in patients with pemphigus. OBSERVATIONS: Trichosporon inkin, a novel organism causing bloodstream infection, was detected in 2 patients with pemphigus. An elderly man with pemphigus foliaceus died despite treatment with liposomal amphotericin B, 3 mg/kg/d, and a young girl with pemphigus vulgaris responded to treatment with voriconazole, 8 mg/kg/d, for 24 days. One of the T inkin isolates had a minimal inhibitory concentration of 2 mg/L against amphotericin B, suggesting resistance to the drug. CONCLUSIONS AND RELEVANCE: Delayed suspicion of invasive infection by T inkin may result in a poor outcome in patients with severe forms of pemphigus. This opportunistic infection is highly refractory to conventional potent antifungal treatment.

Evaluation of the MALDI-TOF VITEK MS™ system for the identification of Candida parapsilosis, C. orthopsilosis and C. metapsilosis from bloodstream infections.

Twenty-nine Candida parapsilosis, seventeen Candida orthopsilosis and two Candida metapsilosis bloodstream isolates were submitted for identification by VITEK-MS™ mass spectrometer. Four isolates, two C. orthopsilosis and two C. metapsilosis, were not identified. Inclusion of Superspectra of both species in this database is required to improve its discrimination power.