title: L-proline increases survival of tilapias infected by Streptococcus agalactiae in higher water temperature.
abstract: Streptococcosis causes massive tilapia kills, which results in heavy economic losses of tilapia farming industry. Out of the Streptococcosis, Streptococcus agalactiae is the major pathogen. The bacterium causes higher mortality of tilapias in higher than lower temperatures. However, effect of temperature on metabolic regulation which is related to the mortality is largely unknown. The present study showed 50% and 70% mortality of tilapias cultured in 25 °C and 30 °C, respectively, in comparison with no death in 20 °C following infection caused by S. agalactiae. Then, GC/MS based metabolomics was used to investigate a global metabolic response of tilapia liver to the two higher water temperatures compared to 20 °C. Thirty-six and forty-five varied abundance of metabolites were identified in livers of tilapias cultured at 25 °C and 30 °C, respectively. More decreasing abundance of amino acids and increasing abundance of carbohydrates were detected in 30 °C than 25 °C groups. On the other hand, out of the pathways enriched, the first five biggest impact pathways belong to amino acid metabolism. Decreasing abundance of l-proline was identified as a crucial biomarker for indexing higher water temperature and a potential modulator to reduce the high death. This was validated by engineering injection or oral addition of l-proline. Exogenous l-proline led to elevated amino acid metabolism, which contributes to the elevated survivals. Our findings provide a potential metabolic modulator for controlling the disease, and shed some light on host metabolic prevention to infectious diseases.
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors: Xian-Liang
authors: XL
authors: Zhao
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors: Yi
authors: Y
authors: Han
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors: Shi-Tong
authors: ST
authors: Ren
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors: Yan-Mei
authors: YM
authors: Ma
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors: Hui
authors: H
authors: Li
authors: Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat 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: Xuan-Xian
authors: XX
authors: Peng
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology / Q000401:mortality; D029941:Fish Proteins / Q000378:metabolism*; D006358:Hot Temperature; D008136:Longevity; D055442:Metabolome; D011392:Proline / Q000008:administration & dosage / Q000378:metabolism*; D013290:Streptococcal Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D013292:Streptococcus agalactiae / Q000502:physiology*; D017210:Tilapia; D014867:Water / Q000737:chemistry
chemical_list: D029941:Fish Proteins; D014867:Water; D011392:Proline
keywords: Metabolomics; Streptococcosis; Streptococcus agalactiae; Tilapia; l-proline