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2607. Establishment of a Novel High-Throughput Fungal Infection Model in Zebrafish Larvae by Controlled Ablation of Epithelial Cells.
- Source :
-
Open Forum Infectious Diseases . 2019 Supplement, Vol. 6, pS906-S907. 2p. - Publication Year :
- 2019
-
Abstract
- Background Efficient animal models are needed in order to investigate fungal pathogenicity and antifungal therapy in the context of epithelial injury, e.g. due to anticancer chemotherapy. Using a Gal4 enhancer trap (GET) zebrafish line facilitating metronidazole (MTZ)-inducible ablation of epithelial (periderm) cells, we aimed to establish a mucositis model predisposing larvae for fungal invasion. Methods 4 days post-fertilization Et(Gal4-VP16)zc1044A;Tg(UAS-1b:nfsB-mCherry)c264 zebrafish larvae were exposed to 10 mM MTZ in E3 medium for 5 h. After washing, larvae were incubated in Candida albicans or Rhizopus arrhizus spore suspensions (5 × 105–5 × 107/mL) for 16 h. Thereafter, larvae were washed again and survival was monitored until 72 h post-infection. Fungal burden was assessed by 18S qPCR and histopathology. For drug protection studies, 5 µg/mL amphotericin B (AMB) or posaconazole (PCZ) was added to the medium of R. arrhizus -infected larvae at 16 h post-infection. Results In MTZ-treated GET larvae, inoculum-dependent mortality was found for both R. arrhizus (panel A) and C. albicans (panel B). High inter-experiment reproducibility of survival rates was seen (CV < 0.3). Using a GFP-expressing R. arrhizus strain, fungal invasion of the larval tissue was verified by fluorescence microscopy (panel C). PCZ and AMB improved survival rates of R. arrhizus -infected (5 × 106/mL) larvae from 46% to 85% and 51% to 86%, respectively (P < 0.001). Similarly, significantly reduced fungal burden in AMB and PCZ-treated larvae was documented by qPCR (panel D) and histopathology. In additional validation experiments, the hypo-virulent phenotypes of a CotH-depleted R. arrhizus strain and filamentation-defective C. albicans mutants (Δefg1 and Δcph1) were recapitulated in zebrafish larvae with epithelial cell loss. Conclusion We have established a robust and reliable model of invasive mycoses by controlled ablation of epithelial cells in zebrafish larvae, allowing for rapid immersion-based interrogation of different infection and treatment options. Our proof-of-concept experiments suggest that GET zebrafish larvae are positioned as an appealing high-throughput in vivo system for antifungal drug screening or comparative virulence studies. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]
- Subjects :
- *LABORATORY zebrafish
*EPITHELIAL cells
*MYCOSES
*LARVAE
*BRACHYDANIO
*AMPHOTERICIN B
Subjects
Details
- Language :
- English
- ISSN :
- 23288957
- Volume :
- 6
- Database :
- Academic Search Index
- Journal :
- Open Forum Infectious Diseases
- Publication Type :
- Academic Journal
- Accession number :
- 139394180
- Full Text :
- https://doi.org/10.1093/ofid/ofz360.2285