Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.
Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel vaccine against piscine S. agalactiae.
State Key Laboratory of Biocontrol/Key Laboratory for Aquatic Products Safety of Ministry of Education/Institute of Aquatic Economic Animals, The School of Life Sciences, Sun Yat-sen University, 135 Xingang West Street, Haizhu District, Guangzhou, 510275, Guangdong Province, PR China.
Wei
W
Li
College of Marine Sciences, South China Agricultural University, Guangdong Province, PR China.
Hai-Qing
HQ
Wang
State Key Laboratory of Biocontrol/Key Laboratory for Aquatic Products Safety of Ministry of Education/Institute of Aquatic Economic Animals, The School of Life Sciences, Sun Yat-sen University, 135 Xingang West Street, Haizhu District, Guangzhou, 510275, Guangdong Province, PR China.
Run-Zhen
RZ
He
College of Marine Sciences, South China Agricultural University, Guangdong Province, PR China.
Yan-Wei
YW
Li
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, Guangdong Province, PR China.
You-Lu
YL
Su
State Key Laboratory of Biocontrol/Key Laboratory for Aquatic Products Safety of Ministry of Education/Institute of Aquatic Economic Animals, The School of Life Sciences, Sun Yat-sen University, 135 Xingang West Street, Haizhu District, Guangzhou, 510275, Guangdong Province, PR China. Electronic address: lianxing@mail.sysu.edu.cn.
An-Xing
AX
Li
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D023681:Cichlids; D005393:Fish Diseases / Q000382:microbiology / Q000517:prevention & control*; D020543:Proteome / Q000235:genetics*; D013290:Streptococcal Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D022541:Streptococcal Vaccines / Q000235:genetics* / Q000276:immunology; D013292:Streptococcus agalactiae / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D020543:Proteome; D022541:Streptococcal Vaccines; D014614:Vaccines, Synthetic
Immunogenic secreted protein; Secretory proteins; Streptococcus agalactiae; Surface proteins; Tilapia; Vaccine