Multiple Genes of Candida albicans Influencing Echinocandin Susceptibility in Caspofungin-Adapted Mutants.

Candida albicans is an opportunistic human fungal pathogen that causes invasive infections in immunocompromised individuals. Despite the high anticandidal activity among the echinocandins (ECNs), a first-line therapy, resistance remains an issue. Furthermore, many clinical isolates display decreased ECN susceptibility, a physiological state which is thought to lead to resistance. Determining the factors that can decrease susceptibility is of high importance. We searched for such factors genome-wide by comparing the transcriptional profiles of five mutants that acquired decreased caspofungin susceptibility in vitro in the absence of canonical FKS1 resistance mutations. The mutants were derived from two genetic backgrounds and arose due to independent mutational events, some with monosomic chromosome 5 (Ch5). We found that the mutants exhibit common transcriptional changes. In particular, all mutants upregulate five genes from Ch2 in concert. Knockout experiments show that all five genes positively influence caspofungin and anidulafungin susceptibility and play a role in regulating the cell wall mannan and glucan contents. The functions of three of these genes, orf19.1766, orf19.6867, and orf19.5833, were previously unknown, and our work expands the known functions of LEU42 and PR26. Importantly, orf19.1766 and LEU42 have no human orthologues. Our results provide important clues as to basic mechanisms of survival in the presence of ECNs while identifying new genes controlling ECN susceptibility and revealing new targets for the development of novel antifungal drugs.

Use of SMOF lipid emulsion in very preterm infants does not affect the incidence of bronchopulmonary dysplasia-free survival.

BACKGROUND: We aim to assess whether the docosahexaenoic acid (DHA)-containing lipid emulsion (LE) SMOFlipid 20% (Fresenius Kabi Canada Ltd) is associated with bronchopulmonary dysplasia (BPD)-free survival at 36 weeks' postmenstrual age in very preterm infants. METHODS: This cohort study is nested in the MOBYDIck randomized clinical trial (NCT02371460), which investigated the effect of maternal DHA supplementation on BPD-free survival in breastfed very preterm infants born between 23 0/7 and 28 6/7 weeks' gestation in 16 Canadian neonatal intensive care units (2015-2018). Parenteral SMOF-LE was given to the infants according to the sites' routine care protocols. Relative risks (RRs) were estimated using a modified Poisson regression model with generalized estimating equations taking into account recruitment site, multiple birth, DHA supplementation, birth weight, sex, and gestational age. RESULTS: Among 528 infants (mean gestational age, 26.5 weeks [SD, 1.6]), 272 received SMOF-LE. Overall, 56.7% of the infants in the SMOF-LE group and 59.7% infants in the non-SMOF-LE group survived without BPD (adjusted RR, 0.94 [95% CI, 0.77-1.14]; P = 0.51). BPD rates were 39.3% in the SMOF-LE group vs 34.1% in the non-SMOF-LE group (adjusted RR, 1.10 [95% CI, 0.82-1.47]; P = 0.53). Severe BPD rates were 31.8% in the SMOF-LE group vs 28.8% in the non-SMOF-LE group (adjusted P = 0.59). Mortality was not significantly different between the SMOF-LE (6.7%) and non-SMOF-LE groups (9.5%; adjusted P = 0.40). CONCLUSION: In very preterm infants, intravenous DHA-containing SMOF-LE during the neonatal period was not associated with BPD-free survival.