SARS-CoV-2 diagnostic diary: from rumors to the first case. Early reports of molecular tests from the military research and diagnostic institute of Rio de Janeiro

Corona virus disease (COVID-19) presents a serious threat to global health. A historical timeline of early molecular diagnostics from government alert (January 22) (D) was presented. After in silico analysis, Brazilian Army Institute of Biology (IBEx-RJ) tested samples in house using real-time reverse transcriptase polymerase chain reaction (RT-PCR) (fast mode) based on Centers for Disease Control and Prevention (CDC) recommendations. First cases from Brazil, Rio de Janeiro, IBEx, and diagnosis team were reported in D36, D44, D66, and D74 respectively. Therefore, after 1300 tests, we recommend N1/N2 primer sets (CDC) for preliminary and Charité protocol confirmation in case of positive results. Moreover, every professional should be tested before starting work, in addition to weekly tests for everyone involved.

Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD) [standard M27 A3 (with neutral and acid pH), ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test). Trailing growth, detection of cell-associated secreted aspartic proteases (Saps) and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC) values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100 percent of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels.