PUBLICATION
Functional Analysis of Two Novel Streptococcus iniae Virulence Factors Using a Zebrafish Infection Model
- Authors
- Soh, K.Y., Loh, J.M.S., Hall, C., Proft, T.
- ID
- ZDB-PUB-200910-3
- Date
- 2020
- Source
- Microorganisms 8(9): (Journal)
- Registered Authors
- Hall, Chris
- Keywords
- S5nAi, SpnAi, Streptococcus iniae, immune evasion, nuclease, nucleotidase, virulence, zebrafish infection model
- MeSH Terms
- none
- PubMed
- 32899555 Full text @ Microorganisms
Citation
Soh, K.Y., Loh, J.M.S., Hall, C., Proft, T. (2020) Functional Analysis of Two Novel Streptococcus iniae Virulence Factors Using a Zebrafish Infection Model. Microorganisms. 8(9):.
Abstract
Streptococcus iniae is a major fish pathogen that contributes to large annual losses in the aquaculture industry, exceeding US$100 million. It is also reported to cause opportunistic infections in humans. We have recently identified two novel S. iniae virulence factors, an extracellular nuclease (SpnAi) and a secreted nucleotidase (S5nAi), and verified their predicted enzymatic activities using recombinant proteins. Here, we report the generation of green fluorescent S. iniae spnAi and s5nAi deletion mutants and their evaluation in a transgenic zebrafish infection model. Our results show nuclease and nucleotidase activities in S. iniae could be attributed to SpnAi and S5nAi, respectively. Consistent with this, larvae infected with the deletion mutants demonstrated enhanced survival and bacterial clearance, compared to those infected with wild-type (WT) S. iniae. Deletion of spnAi and s5nAi resulted in sustained recruitment of neutrophils and macrophages, respectively, to the site of infection. We also show that recombinant SpnAi is able to degrade neutrophil extracellular traps (NETs) isolated from zebrafish kidney tissue. Our results suggest that both enzymes play an important role in S. iniae immune evasion and might present potential targets for the development of therapeutic agents or vaccines.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping