(1,3)-ß-D-glucan is able to predict therapeutic failure of patients with candidemia and not only mortality.

BACKGROUND: Candidemia is a major cause of bloodstream infection in tertiary hospitals worldwide and fungal biomarkers may provide early diagnosis. OBJECTIVES: To evaluate the performance of (1-3)-ß-D-glucan (BDG) in the diagnosis of candidemia and its ability to predict therapeutic failure. PATIENTS AND METHODS: This was a prospective, multi-centre study conducted in 3 Brazilian hospitals. Clinical outcome was evaluated along 2 weeks of treatment, and therapeutic failure was defined as the occurrence of persistent candidemia, Candida deep-seated infection or death. Baseline BDG detection was performed with the Fungitell® assay (Associates of Cape Cod, Falmouth-USA). RESULTS: We enrolled a total of 71 patients with candidemia and a control group with 110 healthy volunteers. The sensitivity and specificity of BDG for diagnosing candidemia were as follows: 71.8% (95% confidence interval [95% CI] 59.7% - 81.5%) and 98.2% (95% CI 92.9% - 99.7%), respectively. The only predictor of therapeutic failure was a higher BDG value at diagnosis of candidemia; a value > 226 pg/mL predicted failure with sensitivity and specificity of 75% and 78%, respectively. CONCLUSIONS: A high baseline serum BDG value was associated with therapeutic failure.

Evaluation of the potential virulence of Candida haemulonii species complex and Candida auris isolates in Caenorhabditis elegans as an in vivo model and correlation to their biofilm production capacity.

Candida haemulonii species complex (Can. haemulonii sensu stricto, Can. duobushaemulonii and Can. haemulonii var. vulnera) and related species (Can. auris and Can. pseudohaemulonii) have attracted attention due to reduced susceptibility to azoles and amphotericin B. Furthermore, attributes of potential virulence have been recognized in Can. haemulonii species complex and Can. auris, like the capability to form biofilm, which represent the most important risk factors for persistent candidemia. However, the relationship between biofilm production and impact on host mortality is still unclear. To evaluate the potential virulence of Can. haemulonii species complex and Can. auris isolates by correlating biofilm production and capacity to kill Caenorhabditis elegans as an in vivo model. In this study, virulence factors were characterized among a total of sixty-six Can. haemulonii species complex and Can. auris isolates to gain insight about virulence traits of these pathogenic yeasts by evaluating the in vitro biofilm production and potential pathogenicity for Cae. elegans, as an in vivo infection model. All clinical isolates tested were biofilm producer, inter- and intra-specific differences on the biofilm forming capacity by the strains were observed. Can. auris and Can. haemuolonii var. vulnera showed similar biofilm production, both higher than Can. haemulonii sensu stricto and Can. duobushaemulonii. Regarding the virulence of the Cae. elegans model, Can. haemulonii species complex and Can. auris isolates were capable of causing infection in Cae. elegans, and our data suggest that the high biofilm production by Can. haemulonii var. vulnera and Can. duobushaemulonii isolates may impact in the pathogenicity caused on Cae. elegans.

Fatal pulmonary sporotrichosis caused by Sporothrix brasiliensis in Northeast Brazil.

BACKGROUND: A relevant case of pulmonary sporotrichosis due to Sporothrix brasiliensis is reported in a 50-year-old immunocompetent woman who had no history of skin trauma, but was in close contact with several stray cats at her nap time. The patient was hospitalized after 7 months of illness. The survey was conducted for pulmonary tuberculosis, an endemic disease in Brazil. She presented multiple central pulmonary nodules images, with central cavitation. METHODOLOGY/PRINCIPAL FINDINGS: The patient bronchoalveolar lavage was cultured and Sporothrix sp. growth was obtained. Then, the isolate (LMMM1097) was accurately identified to the species level by using species-specific polymerase chain reaction (PCR). Molecular diagnosis revealed that the emerging species Sporothrix brasiliensis was the agent of primary pulmonary sporotrichosis and the patient was treated with Amphotericin B lipid complex, but presented severe clinical symptoms and the fatal outcome was observed at day 25 after hospitalization. CONCLUSIONS/SIGNIFICANCE: Our report adds important contributions to the clinical-epidemiological features of sporotrichosis, showing the geographic expansion of the agent within different regions of Brazil and a rare clinical manifestation (primary pulmonary sporotrichosis) caused by the emerging agent S. brasiliensis in an immunocompetent female patient.

Identification of genes differentially expressed in hyphae of Candida albicans

The ability to switch from yeast to hyphal forms is essential for Candida albicans virulence. This morphological switch involves the expression of hyphal-specific genes under the control of transcriptional factors. To contribute to the discovery of hyphal-specific genes, we used a differential screening method where clones of a genomic DNA library were hybridized with yeast and hyphal cDNA probes. Two clones with increased expression in hyphae were selected for study. Sequencing these clones, we found that they encoded two important metabolic genes, CaHXT7 (high-affinity hexose transporter) and CaYLL34 (member of the AAA ATPase family). CaHXT7 and CaYLL34 ORFs were completely determined. Analyses of the putative proteins show that: (1) CaHxt7p has one hexose transporter domain and (2) CaYll34p has two AAA ATPase domains. These results show, for the first time, increased expression of metabolic genes in C. albicans hyphae. Also, because the proteins encoded by CaHXT7 and CaYLL34 may be necessary for the switching to hyphae, they could be new targets for antifungal drugs.

A transição morfológica de levedura para hifa é essencial para a virulência de Candida albicans. Esta transição envolve a expressão de genes hifa-específicos que estão sob o controle de fatores transcricionais. Para descobrir genes hifa-específicos utilizamos um método de triagem diferencial, onde clones de biblioteca de DNA genômico foram hibridizados com sondas de cDNA de levedura e hifa. Dois clones com aumento de expressão em hifa foram selecionados. O sequenciamento dos insertos destes clones permitiu a identificação de dois genes metabólicos importantes: CaHXT7 (high-affinity hexose transporter) e CaYLL34 (da família AAA ATPase). As ORFs completas destes genes foram caracterizadas e a análise das proteínas hipotéticas revelou que: (1) CaHxt7p tem um domínio de transportador de hexose e (2) CaYll34 tem dois domínios AAA ATPase. Este é o primeiro estudo que demonstra aumento de expressão de genes metabólicos em hifas de C. albicans. Ainda, a associação dos produtos de CaHXT7 e CaYLL34 com a formação de hifas torna estas proteínas potenciais novos alvos para drogas antifúngicas.