Whole-genome sequencing of Candida haemulonii species complex from Brazil and the United States: Genetic diversity and antifungal susceptibility.

Candida haemulonii complex species can be multidrug-resistant and cause infections such as candidemia. This study determined the genetic relationship between isolates from Brazil and the United States through whole-genome sequencing and performed antifungal susceptibility testing to investigate drug resistance. Contrary to what is widely described, most isolates were susceptible to azoles. However, an atypical susceptibility profile was found in 50% of Candida pseudohaemulonii strains, including resistance to the three echinocandins. Isolates from both countries formed distinct clusters with wide genetic diversity. Isolates from three hospitals in Brazil were clonal and involved in candidemia cases, pointing to the importance of improving hospital infection control measures and molecular identification.

Candida haemulonii complex species is worldwide distributed, and this study aimed to evaluate the resistance to antifungal drugs in cases from Brazil and the United States, and also compare their genetic relationships. A total of 50 strains were studied; most of them from Brazil were from cases of bloodstream infections, while the strains from the United States came from cases of wounds and may be associated with diabetic patients. The vast majority of strains were resistant to amphotericin B, one of the most effective drugs, and susceptible to fluconazole. In addition, 50% of C. pseudohaemulonii strains were resistant to echinocandins. The strains from Brazil and the United States had no genetic relationship and formed two distinct groups. In three Brazilian hospitals, strains were clonal, indicating an intra-hospital transmission. Our findings contribute to guiding therapy in bloodstream fungal infections caused by C. haemulonii species and alerting for nosocomial transmission of this yeast complex species.

Fungi in dialysis water and dialysate: occurrence, susceptibility to antifungal agents and biofilm production capacity.

The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017-June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10-40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested.

Latent and active tuberculosis infection in allogeneic hematopoietic stem cell transplant recipients: a prospective cohort study.

Tuberculosis (TB) is a major infectious complication in hematopoietic stem cell transplant (HSCT) recipients in countries with high TB prevalence. Identifying and treating latent tuberculosis infection (LTBI) helps to prevent TB reactivation after transplantation. Few studies have compared the tuberculin skin test (TST) with interferon Gamma release assays (IGRA) to diagnose LTBI in HSCT candidates. We compared TST and QuantiFeron TB gold in tube (QTF-GIT) and prospectively evaluated the incidence of active tuberculosis in 126 HSCT candidates and 58 HSCT recipients with chronic GVHD followed at the outpatient clinic. TB was diagnosed by culture in Mycobacteria media and by commercial real-time PCR kit. Considering the positivity of any test, the prevalence of LTBI was 8.7% in HSCT candidates (11 out of 126) and 12.5% in HSCT recipients with chronic GVHD (6 out of 48). QTF-GIT indeterminate results were detected in 2.4% of the HSCT candidates. Fair to good agreement (K > 0.50) between tests was observed in both cohorts. Cumulative incidence of TB was 3% in the GVHD cohort. TB was diagnosed in 2 chronic GVHD recipients, both cases confirmed by positive culture and PCR. None of the 11 patients with LTBI diagnosed pre-HSCT who received INH prophylaxis developed TB.

Apiotrichum veenhuisii isolated from a pediatric patient with acute myeloid leukemia: The first case in humans.

This is the first report of the yeast Apiotrichum veenhuisii (formerly Trichosporon veenhuisii) causing disease in humans; its virulence and in vitro behavior against antifungals were also studied. The sample was isolated from biopsy fragments of disseminated lesions on the skin of a pediatric patient with acute myeloid leukemia. The studied virulence factors evidenced that the strain tested negative for secretion of the enzymes proteinase, phospholipase, and hemolysin. The isolate was characterized as low biofilm producer. Except for amphotericin B and voriconazole, the sample presented high minimum inhibitory concentration values against azole and echinocandins.

Outbreak of fungemia caused by Candida parapsilosis in a neonatal intensive care unit: molecular investigation through microsatellite analysis.

BACKGROUND: Opportunistic infections are an increasingly common problem in hospitals, and the yeast Candida parapsilosis has emerged as an important nosocomial pathogen, especially in neonatal intensive care units (NICUs) where it has been responsible for outbreak cases. Risk factors for C. parapsilosis infection in neonates include prematurity, very low birth weight, prolonged hospitalization, indwelling central venous catheters, hyperalimentation, intravenous fatty emulsions and broad spectrum antibiotic therapy. Molecular methods are widely used to elucidate these hospital outbreaks, establishing genetic variations among strains of yeast. AIMS: The aim of this study was to detect an outbreak of C. parapsilosis in an NICU at the "Hospital das Clinicas", Faculty of Medicine of Botucatu, a tertiary hospital located in São Paulo, Brazil, using the molecular genotyping by the microsatellite markers analysis. METHODS: A total of 11 cases of fungemia caused by C. parapsilosis were identified during a period of 43 days in the NICU. To confirm the outbreak all strains were molecularly typed using the technique of microsatellites. RESULTS: Out of the 11 yeast samples studied, nine showed the same genotypic profile using the technique of microsatellites. CONCLUSIONS: Our study shows that the technique of microsatellites can be useful for these purposes. In conclusion, we detected the presence of an outbreak of C. parapsilosis in the NICU of the hospital analyzed, emphasizing the importance of using molecular tools, for the early detection of hospital outbreaks, and for the introduction of effective preventive measures, especially in NICUs.

Malassezia spp. in acoustic meatus of bats (Molossus molossus) of the Amazon Region, Brazil.

The yeasts of the Malassezia genus are opportunistic microorganisms and can cause human and animal infections. They are commonly isolated from the skin and auricular canal of mammalians, mainly dogs and cats. The present study was aimed to isolate Malassezia spp. from the acoustic meatus of bats (Molossus molossus) in the Montenegro region, "Rondônia", Brazil. From a total of 30 bats studied Malassezia spp. were isolated in 24 (80%) animals, the breakdown by species being as follows (one Malassezia sp. per bat, N = 24): 15 (62.5%) M. pachydermatis, 5 (20.8%) M. furfur, 3 (12.5%) M. globosa and 1 (4.2%) M. sympodialis. This study establishes a new host and anatomic place for Malassezia spp., as it presents the first report ever of the isolation of this genus of yeasts in the acoustic meatus of bats.

Candida isolated from vaginal mucosa of mothers and oral mucosa of neonates: occurrence and biotypes concordance.

BACKGROUND: The common occurrence of Candida spp. on the vaginal mucosa of pregnant women suggests this as the source of neonatal candidiasis. METHODS: This study investigated the occurrence of yeasts on the vaginal mucosa of 100 mothers at the time of birth, and on the oral mucosa of their respective neonates, all full-term, on the 1st, 3rd, and 9th days after birth by vaginal (72 cases) and cesarean (28 cases) routes. In each case where concordance at the level of species was found between the isolate from the mother and that from the neonate, tests were made to check for concordance between the genotypic and phenotypic profiles (susceptibility to killer toxins, serotyping, proteinase and phospholipase production, and susceptibility to antifungal agents). RESULTS: For the vaginal-route group, yeasts were recovered from the vaginal mucosa of 47.2% of the mothers and from 25% of the neonates. For the cesarean-route group, these rates were 46.4% and 3.6%, respectively. Species found most frequently in the samples from the mothers and the neonates were, respectively C. albicans and C. guilliermondii. For the vaginal-route group, the rate of mother/neonate concordance at the level of species was 23.5% and no cases of concordance for the cesarean births. Of these cases with species concordance, there was concordance between the genotypic and phenotypic profiles in 6% (2 cases). CONCLUSION: The vaginal mucosa was not the main route of transmission of the Candida species to the neonate, because there was concordance between the genotypic and phenotypic profiles in only 6% (2 cases).