Publication Date:
2019
Description:
〈p〉Publication date: June 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 89〈/p〉
〈p〉Author(s): Chunsheng Liu, Xiucong Hu, Zhenjie Cao, Yun Sun, Xiaojuan Chen, Zhengshi Zhang〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉〈em〉Streptococcus iniae〈/em〉 is an important aquaculture pathogen that is associated with disease outbreaks in wild and cultured fish species. Streptolysin S has been identified as an important virulence factor of 〈em〉S. iniae.〈/em〉 With an aim to develop effective vaccines against 〈em〉S. iniae〈/em〉 for Japanese flounder (〈em〉Paralichthys olivaceus〈/em〉), in this study, we constructed a DNA vaccine based on the 〈em〉sagH〈/em〉 gene, which belongs to the streptolysin S-associated gene cluster. In fish vaccinated with pSagH, the transcription of 〈em〉sagH〈/em〉 was detected in tissues and SagH protein was also detected in the muscles of pSagH-vaccinated fish by immunohistochemistry. The immunoprotective effect of SagH showed that fish vaccinated with pSagH at one and two months exhibited a high relative percent survival (RPS) of 92.62% and 90.58% against 〈em〉S. iniae〈/em〉 serotype I, respectively. In addition, SagH conferred strong cross protection against 〈em〉S. iniae〈/em〉 serotype II and resulted in an RPS of 83.01% and 80.65% at one and two months, respectively. Compared to the control group, fish vaccinated with pSagH were able to induce much stronger respiratory burst activity, and higher titer of specific antibodies. The results of quantitative real-time PCR demonstrated that pSagH upregulated the expression of several immune genes that are possibly involved in both innate and adaptive immune responses. These results indicate that pSagH is a candidate DNA vaccine candidate against 〈em〉S. iniae〈/em〉 serotype I and II infection in Japanese flounder in aquaculture.〈/p〉〈/div〉
〈/div〉
Print ISSN:
1050-4648
Electronic ISSN:
1095-9947
Topics:
Biology
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Medicine
