title: Protection of Penaeus monodon against white spot syndrome by continuous oral administration of a low concentration of Bacillus subtilis spores expressing the VP28 antigen.
abstract: In this study, Bacillus subtilis spores expressing a chimeric protein, CotB-VP28, were used as a probiotic vaccine to protect black tiger shrimps (Penaeus monodon) against white spot syndrome virus (WSSV) infection. Oral administration of pellets coated with CotB-VP28 spores (at ≥1 × 109CFU per g pellet) to shrimps induced immune-relating phenoloxydase activity (PO) in shrimps after 14 days of feeding (prior challenge) and at day 3 post challenge (1·26 and 1·70 fold increase respectively). A 75% protection rate was obtained by continuous feeding of the spore-coated pellets at ≥1 × 109CFU per g for 14 days prior to WSSV challenge and during all the postchallenge period. Even when the amount of CotB-VP28 spores in feed pellets was reduced down to ≥5 × 107CFU per g and ≥1 × 106CFU per g, relatively high protection rates of 70 and 67·5%, respectively, were still obtained. By contrast, feeding pellets without spores (untreated group) and with naked spores (PY79 group) at ≥1 × 109CFU per g could not protect shrimps against WSSV. These data suggest that supplementation of CotB-VP28 spores at low dose of ≥1 × 106CFU per g could be effective as a prophylactic treatment of WSS for black tiger shrimps.
  
  
  CONCLUSIONS
  This study reports the protective efficacy of Bacillus subtilis CotB-VP28 spores on black tiger shrimps (Penaeus monodon) against white spot syndrome virus infection. Oral administration of pellets coated with CotB-VP28 spores (≥1 × 109CFU per g) conferred 75% protection after white spot syndrome virus challenge. Even after reducing CotB-VP28 spores in feed pellets to ≥1 × 106CFU per g, 67·5% protections was still obtained. These data indicate that supplementation of CotB-VP28 spores at a low dose of ≥1 × 106CFU per g could be effective in prophylaxis against white spot syndrome in black tiger shrimps.
authors.affiliation: Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam.|Department of Biochemistry, Institute of New Technology, Hanoi, Vietnam.
authors.forename: K-C
authors.initials: KC
authors.lastname: Pham
authors.affiliation: Faculty of Aquaculture, Can Tho University, Can Tho, Vietnam.
authors.forename: H T T
authors.initials: HT
authors.lastname: Tran
authors.affiliation: Southern Monitoring Center for Aquaculture Environment and Epidemic, Research Institute for Aquaculture No. 2, Ho Chi Minh City, Vietnam.
authors.forename: C
authors.initials: C
authors.lastname: Van Doan
authors.affiliation: Southern Monitoring Center for Aquaculture Environment and Epidemic, Research Institute for Aquaculture No. 2, Ho Chi Minh City, Vietnam.
authors.forename: P H
authors.initials: PH
authors.lastname: Le
authors.affiliation: Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam.
authors.forename: A T
authors.initials: AT
authors.lastname: Van Nguyen
authors.affiliation: ANABIO Research & Development JSC, Hanoi, Vietnam.
authors.forename: H A
authors.initials: HA
authors.lastname: Nguyen
authors.affiliation: School of Biological Sciences, Royal Holloway University of London, Egham, UK.
authors.forename: H A
authors.initials: HA
authors.lastname: Hong
authors.affiliation: School of Biological Sciences, Royal Holloway University of London, Egham, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Cutting
authors.affiliation: Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam.
authors.forename: T-N
authors.identifier: http://orcid.org/0000-0002-8878-801X
authors.initials: TN
authors.lastname: Phan
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D033561:Penaeidae / Q000276:immunology / Q000821:virology*; D013171:Spores, Bacterial / Q000235:genetics* / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014764:Viral Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D046848:White spot syndrome virus 1 / Q000235:genetics / Q000276:immunology / Q000502:physiology*
chemical_list: D014759:Viral Envelope Proteins; D014764:Viral Proteins; D014765:Viral Vaccines
keywords: B. subtilis spores; VP28; White Spot Syndrome virus; black tiger shrimp (Penaeus monodon); probiotic vaccine