Yilmaz S, Sova M, Ergün S
Department of Aquaculture, Faculty of Marine Sciences and Technology, Çanakkale Onsekiz Mart University, Çanakkale, Turkey.
Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
J Appl Microbiol. 2018 Sep 4. doi: 10.1111/jam.14097.
Antibiotics and several other chemicals have been used to prevent fish diseases. However, this situation results in economic loss for the companies in the aquaculture industry and most importantly it pollutes the environment. Cinnamic acid is a naturally occurring aromatic acid and is considered to be safe for human consumption. Therefore, in this study, the antibacterial activity of trans-cinnamic acid and commonly used antibiotics, namely chloramphenicol, vancomycin, streptomycin and erythromycin, were tested against 32 bacteria, including fish pathogens, nonpathogenic isolates and collection strains.
Trans-cinnamic acid was applied against the bacteria using the disc diffusion and microdilution method under in vitro conditions. Antibiotics were also tested under similar conditions against all tested bacteria using the disc diffusion method. The results show that among 32 bacterial strains trans-cinnamic acid exhibited potent inhibitory effect on the Gram-negative fish pathogen Aeromonas sobria. In addition, a moderate inhibition of trans-cinnamic acid of fish pathogens Aeromonas salmonicida, Vibrio (Listonella) anguillarum, Vibrio crassostreae and Yersinia ruckeri was also observed for trans-cinnamic acid in our study. On the contrary, the majority of nonpathogenic intestinal isolates were resistant to trans-cinnamic acid.
To the best of our knowledge, this is the first report on the antimicrobial activity of trans-cinnamic acid on 24 of the studied bacteria isolated from fish. In conclusion, trans-cinnamic acid can be used as an environmentally friendly alternative additive to prevent and control primarily A. sobria, as well as other pathogenic bacteria such as A. salmonicida, V. anguillarum, V. crassostreae and Y. ruckeri.
This study indicated that trans-cinnamic acid may present an environmentally friendly alternative therapeutic agent against A. sobria infections in the aquaculture industry.
抗生素和其他几种化学物质已被用于预防鱼类疾病。然而，这种情况给水产养殖业的公司造成了经济损失，最重要的是它污染了环境。肉桂酸是一种天然存在的芳香酸，被认为对人类食用是安全的。因此，在本研究中，测试了反式肉桂酸和常用抗生素（即氯霉素、万古霉素、链霉素和红霉素）对32种细菌的抗菌活性，这些细菌包括鱼类病原体、非致病性分离株和收集菌株。
在体外条件下，采用纸片扩散法和微量稀释法将反式肉桂酸应用于这些细菌。抗生素也在类似条件下采用纸片扩散法对所有测试细菌进行了测试。结果表明，在32株细菌中，反式肉桂酸对革兰氏阴性鱼类病原体温和气单胞菌表现出强效抑制作用。此外，在我们的研究中还观察到反式肉桂酸对鱼类病原体杀鲑气单胞菌、鳗弧菌（利斯顿氏菌属）、牡蛎弧菌和鲁氏耶尔森菌有中度抑制作用。相反，大多数非致病性肠道分离株对反式肉桂酸具有抗性。
据我们所知，这是关于反式肉桂酸对从鱼类分离出的24种研究细菌的抗菌活性的首次报道。总之，反式肉桂酸可作为一种环境友好的替代添加剂，主要用于预防和控制温和气单胞菌以及其他病原菌，如杀鲑气单胞菌、鳗弧菌、牡蛎弧菌和鲁氏耶尔森菌。
本研究表明，反式肉桂酸可能是水产养殖业中对抗温和气单胞菌感染的一种环境友好的替代治疗剂。
