The Quorum Quenching Bacterium Bacillus licheniformis T-1 Protects Zebrafish against Aeromonas hydrophila Infection
- 19 Downloads
Quorum sensing, bacterial cell-to-cell communication via small signaling molecules regulates virulence in many bacterial pathogens, and is a promising target for antivirulence therapy, which may inhibit virulence rather than cell growth and division. Herein, Bacillus strains capable of degrading QS molecules from freshwater environments were screened as potential aquaculture probiotics. A total of 34 Bacillus strains were isolated. Strain T-1 was selected with “H” streaking and double layer agar plate methods using Chromabacterium violaceum ATCC12472 as reporter, and eventually identified as Bacillus licheniformis based on biochemical and molecular identification. Quorum quenching by T-1 was confirmed using C. violaceum CV026. T-1 was non-hemolytic in vitro. In biocontrol experiments, T-1 reduced the pathogenicity of Aeromonas hydrophila cb15 in zebrafish co-injected intraperitoneally with both strains, achieving a relative percentage survival of 70%. Determination and analysis of the T-1 draft genome using the Illumina Hiseq 2500 platform identified the quorum quenching gene ytnP, encoding an acyl-homoserine lactone metallo-β-lactamase, as a potential QS quencher in T-1. In conclusion, B. licheniformis T-1 could be a safe and effective quorum quenching bacterium for protecting hosts against pathogenic bacterial infections in aquaculture.
KeywordsQuorum quenching Bacillus licheniformis Aeromonas hydrophila Zebrafish ytnP
This work was supported by the Innovation Fund of Nanjing Government Jiangsu Province, China.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- 6.Ponce-Rossi ADR, Pinto UM, Ribon ADOB, Bazzolli DMS, Vanetti MCD (2016) Quorum sensing regulated phenotypes in Aeromonas hydrophila ATCC 7966 deficient in AHL production. Ann Microbiol 66(3):1–10Google Scholar
- 12.Schneider J, Yepes A, Garcia-Betancur JC, Westedt I, Mielich B, López D (2012) Streptomycin-induced expression in Bacillus subtilis of ytnP a lactonase-homologous protein that inhibits development and streptomycin production in Streptomyces griseus. Appl Environ Microbiol 78(2):599–603CrossRefGoogle Scholar
- 20.Kang L, Han S, Wang J, Bo X, Ma X (2008) Detecting hematolysis of Enterococcus from sheep. Acta Microbiol Sin 48(7):924Google Scholar
- 21.Song ZF, Chen B, Guo J, Xu HD, Ren JF, Zhang QH (2015) Animal safety and ecological evaluation of Bacillus licheniformis T-1 with quorum sensing inhibitory effect. J Fish China 39(9):1395–1404Google Scholar
- 35.Alexopoulos C, Georgoulakis IE, Tzivara A, Kyriakis CS, Govaris A, Kyriakis SC (2010) Field evaluation of the effect of a probiotic-containing Bacillus licheniformis and Bacillus subtilis spores on the health status performance and carcass quality of grower and finisher pigs. Transbound Emerg Dis 51(6):306–312Google Scholar
- 39.Zhang Q, Tan B, Mai K, Zhang W, Ma H, Ai Q, Wang X, Liufu Z (2011) Dietary administration of Bacillus (B. licheniformis and B. subtilis) and isomaltooligosaccharide influences the intestinal microflora immunological parameters and resistance against Vibrio alginolyticus in shrimp Penaeus japonicus (decapoda: penaeidae). Aquac Res 42(7):943–952CrossRefGoogle Scholar