System for the biocontrol of pathogens in aquaculture and other animal systems
Inventors
Sayre, Richard T. • Vinogradova-Shah, Tatiana
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10774329-B2
Publication Date
2020-09-15
Expiration Date
Abstract
The inventive technology relates to novel paratransgenic strategies for the biocontrol of pathogens in animal systems using interfering RNA molecules expressed in genetically modified bacteria that may be configured to colonize a target host. In one preferred embodiment, the invention includes novel paratransgenic strategies for the biocontrol of pathogens in aquatic organisms raised in aquaculture environments.
Core Innovation
The invention relates to a paratransgenic, cross-kingdom biocontrol platform for white spot syndrome (WSS). In the disclosed compositions, genetically modified probiotic bacteria are configured to express at least one heterologous inhibitory polynucleotide encoded by a nucleic acid selected from SEQ ID NO. 1, SEQ ID NO. 2, and SEQ ID NO. 3. The heterologous inhibitory polynucleotide is a double stranded RNA polynucleotide molecule (dsRNA).
The expressed dsRNA targets an essential gene in a white spot syndrome virus (WSSV), with the essential gene selected from wsv477, vp28, and vp19. The platform is described as triggering host RNA interference, with the dsRNA processed through Dicer/RISC/Argonaute pathways and resulting in downregulation of the WSSV essential gene expression. The disclosure emphasizes a RNase III-related concept, including a RNaseIII-deficient Bacillus subtilis (BG322) expressing WSSV-targeting dsRNAs.
For aquaculture use, the genetically modified probiotic bacteria are delivered as a biocontrol composition for shrimp, including delivery via treated commercial feed and/or colonization of shrimp intestines. The described approach includes potential vertical transmission and/or horizontal transmission associated with the colonizing probiotic bacteria. Experimental support described in the disclosure includes reduced WSSV mortality and reduced viral replication, along with detection of sequence-specific siRNA associated with targeted WSSV genes.
Claims Coverage
The document provides multiple independent claims covering a biocontrol composition for white spot syndrome, including broad composition formats for shrimp and additional claims focused on sequence-defined dsRNA homology, RNaseIII-deficient engineered probiotic variants, treated commercial feed administration, and aquaculture shrimp with vertical transmission and a therapeutically effective amount. Across the independent claims, the main inventive features are a genetically modified probiotic or enteric delivery chassis expressing heterologous inhibitory dsRNA targeting WSSV essential genes; restriction to specific named dsRNA sequences and 95% homology variants; and use in aquaculture-raised shrimp to downregulate essential gene expression and reduce WSSV mortality.
Genetically modified probiotic bacteria expressing heterologous inhibitory dsRNA targeting WSSV essential genes
A composition for the biocontrol of white spot syndrome comprising a genetically modified probiotic bacteria that expresses at least one heterologous inhibitory polynucleotide encoded by a nucleic acid selected from SEQ ID NO. 1, SEQ ID NO. 2, and SEQ ID NO. 3, wherein said at least one heterologous inhibitory polynucleotide is a double stranded RNA polynucleotide molecule (dsRNA) that targets an essential gene in a white spot syndrome virus (WSSV), wherein said essential gene is selected from wsv477, vp28, and vp19.
Inhibitory polynucleotides with 95% homology to SEQ ID NO. 1, SEQ ID NO. 2, and SEQ ID NO. 3
The composition comprises at least one heterologous inhibitory polynucleotide having 95% homology with SEQ ID NO. 1, SEQ ID NO. 2, or SEQ ID NO. 3.
Vertical transmission of the genetically modified probiotic enteric bacteria to shrimp progeny
The composition includes genetically modified probiotic enteric bacteria transmitted to shrimp progeny through vertical transmission.
Therapeutically effective amount administered to aquaculture-raised shrimp to reduce WSSV mortality via downregulating a WSSV essential gene
A therapeutically effective amount of the genetically modified probiotic enteric bacteria is administered to shrimp raised in an aquaculture environment such that the heterologous inhibitory polynucleotide downregulates expression of the WSSV essential gene and results in a reduction in mortality due to WSSV.
Collectively, the claims define a white spot syndrome biocontrol composition in which genetically modified probiotic or enteric bacteria express heterologous inhibitory dsRNA targeting WSSV essential genes (wsv477, vp28, vp19), with dsRNA sequences constrained to SEQ ID NO. 1, SEQ ID NO. 2, and SEQ ID NO. 3 and 95% homology variants. Shrimp embodiments apply the composition in aquaculture-raised shrimp, optionally include vertical transmission to progeny, and require administration of a therapeutically effective amount to downregulate WSSV gene expression and reduce WSSV-related mortality.
Stated Advantages
reduces WSSV-related mortality in shrimp
results in reduction in viral replication
Documented Applications
biocontrol of white spot syndrome in shrimp using genetically modified probiotic or enteric bacteria expressing WSSV-targeting inhibitory dsRNA
administration to shrimp raised in an aquaculture environment, including via treated commercial feed
vertical transmission of the genetically modified probiotic enteric bacterium to shrimp progeny
downregulating expression of an essential gene in WSSV in shrimp to reduce WSSV mortality
Interested in licensing this patent?