title: Liver functional metabolomics discloses an action of L-leucine against Streptococcus iniae infection in tilapias.
abstract: Streptococcus iniae seriously affects the intensive farming of tilapias. Much work has been conducted on prevention and control of S. iniae infection, but little published information on the metabolic response is available in tilapias against the bacterial infection, and no metabolic modulation way may be adopted to control this disease. The present study used GC/MS based metabolomics to characterize the metabolic profiling of tilapias infected by a lethal dose (LD50) of S. iniae and determined two characteristic metabolomes separately responsible for the survival and dying fishes. A reversal changed metabolite, decreased and increased l-leucine in the dying and survival groups, respectively, was identified as a biomarker which featured the difference between the two metabolomes. More importantly, exogenous l-leucine could be used as a metabolic modulator to elevate survival ability of tilapias infected by S. iniae. These results indicate that tilapias mount metabolic strategies to deal with bacterial infection, which can be regulated by exogenous metabolites such as l-leucine. The present study establishes an alternative way, metabolic modulation, to cope with bacterial infections.
authors.affiliation: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: Ma
authors.affiliation: Tibet Vocational Technical College, Lhasha 850000, People's Republic of China.
authors.forename: Man-Jun
authors.initials: MJ
authors.lastname: Yang
authors.affiliation: School of Life Sciences, Xiamen University, University City, Xiamen 361005, People's Republic of China.
authors.forename: Sanying
authors.initials: S
authors.lastname: Wang
authors.affiliation: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China. Electronic address: lihui32@sysu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China. Electronic address: pxuanx@sysu.edu.cn.
authors.forename: Xuan-Xian
authors.initials: XX
authors.lastname: Peng
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism* / Q000494:pharmacology; D008099:Liver / Q000378:metabolism*; D055442:Metabolome; D055432:Metabolomics; D013290:Streptococcal Infections / Q000378:metabolism*; D013291:Streptococcus; D017210:Tilapia / Q000378:metabolism*
chemical_list: D007930:Leucine
keywords: Leucine and isoleucine metabolism; Metabolomics; Streptococcus iniae; Tilapia; Valine; l-leucine