title: Anti-parasitic effects of Leptomycin B isolated from Streptomyces sp. CJK17 on marine fish ciliate Cryptocaryon irritans.
abstract: The present study was conducted aiming to evaluate the in vitro and in vivo anti-parasitic efficacy of an isolated compound against the ciliate Cryptocaryon irritans. The compound was previously isolated from fermentation products of Streptomyces sp. CJK17 and designated as SFrD. Toxicity of the compound SFrD against the fish hosts (Larimichthys crocea) was also tested and its chemical structure was elucidated. The obtained results showed that the compound has potent anti-parasitic efficacy with the 10 min-, 1 h-, 2 h-, 3 h- and 4 h-LC50 (95% Confidence Intervals) of 6.8 (6.5-7.1), 3.9 (2.8-5.0), 3.3 (2.6-4.0), 2.7 (2.3-3.1) and 2.5 (2.2-2.8) mg L(-1) against theronts of C. irritans and the 6h-LC50 (95% CI) of 3.0 (2.8-3.2) mg L(-1) against the tomonts, respectively. Exposure of the compound SFrD remarkably reduced the mortality of fish infected with C. Irritans, from 100% in the control group to 61.7% and 38.3% in groups of 3.1 mg L(-1) and 6.3 mg L(-1), respectively. In the test of exposing fish to 40 mg L(-1) compound SFrD for 24h, no visible effects were observed affecting the normal behavior or any macroscopic changes. By spectrum analysis (EI-MS, (1)H NMR and (13)C NMR), the compound SFrD was identified as Leptomycin B. This study firstly demonstrated that Leptomycin B has potent anti-parasitic efficacy against ciliates in cultured marine fish.
authors.affiliation: Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China. Electronic address: yinf@ecsf.ac.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Yin
authors.affiliation: Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Sun
authors.affiliation: Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China.
authors.forename: Baojun
authors.initials: B
authors.lastname: Tang
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian Province 350003, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Gong
authors.affiliation: Ningde Fufa Fisheries Co., Ltd., Ningde, Fujian Province 352000, China.
authors.forename: Qiaozhen
authors.initials: Q
authors.lastname: Ke
authors.affiliation: Key Laboratory for Aquatic Products Safety of Ministry of Education, State Key Laboratory of Biocontrol, The School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China.
authors.forename: Anxing
authors.initials: A
authors.lastname: Li
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D016770:Ciliophora Infections / Q000188:drug therapy / Q000662:veterinary*; D003460:Crystallization; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use / Q000633:toxicity; D005393:Fish Diseases / Q000188:drug therapy*; D016803:Hymenostomatida / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D010473:Perciformes / Q000469:parasitology; D021241:Spectrometry, Mass, Electrospray Ionization; D013302:Streptomyces / Q000737:chemistry*; D016019:Survival Analysis
chemical_list: D005231:Fatty Acids, Unsaturated; C038753:leptomycin B
keywords: Cryptocaryon irritans; Fermentation products; Larimichthys crocea; Leptomycin B; Streptomycete