Department of Biotechnology, Science Campus, Alagappa University, Karaikudi 630 003, Tamil Nadu, India.
Mandapam Regional Centre, Central Marine Fisheries Research Institute, Mandapam, Tamil Nadu, India.
Int J Food Microbiol. 2018 Sep 20;281:60-71. doi: 10.1016/j.ijfoodmicro.2018.05.024. Epub 2018 May 25.
This study unveils the in vitro and in vivo antibiofilm potential of 2,6-Di-tert-butyl-4-methylphenol (DTBMP) from Chroococcus turgidus against Vibrio spp. In the preliminary study, cell free culture supernatant (CFCS) of C. turgidus inhibited the violacein production in biomarker strain Chromobacterium violaceum and its mutant strain CV026 in a dose dependent manner. The effective biofilm inhibitory concentration (BIC) of pure compound DTBMP from C. turgidus was identified as 250 μg/ml concentration in tested Vibrio species. Furthermore, DTBMP proved to effectively inhibit the bioluminescence production in V. harveyi and other biofilm related virulence traits such as exopolysaccharides (EPS) production, hydrophobicity index, swimming and swarming motility at its BIC concentration in three major pathogenic vibrios: V. harveyi, V. parahaemolyticus and V. vulnificus. The antibiofilm potential of DTBMP was validated through light, confocal laser scanning and scanning electron microscopic analyses. In addition, the non-bactericidal effect of DTBMP was determined through growth curve and 2,3-bis (2-methyloxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. Real-time PCR studies revealed the down-regulation of master quorum sensing (QS) regulator genes of V. harveyi such as luxR, luxS, luxP, luxQ and luxO on treatment with DTBMP. In vivo results confirmed that DTBMP augmented the survival rate of Litopenaeus vannamei larvae up to 75, 88 and 66% upon infection with V. harveyi, V. parahaemolyticus and V. vulnificus, respectively. The results of this study ascertain the promising effects of DTBMP as an antibiofilm agent, which could be positively explored to treat biofilm-associated vibrios infections in aquaculture.
本研究揭示了来自 Chroococcus turgidus 的 2,6-二叔丁基-4-甲基苯酚（DTBMP）在体外和体内对 Vibrio spp. 的抗生物膜潜力。在初步研究中，C. turgidus 的无细胞培养上清液（CFCS）以剂量依赖的方式抑制生物标志物菌株 Chromobacterium violaceum 及其突变株 CV026 的紫色素产生。从 C. turgidus 中分离得到的纯化合物 DTBMP 的有效生物膜抑制浓度（BIC）在测试的 Vibrio 种中被确定为 250 μg/ml 浓度。此外，在其 BIC 浓度下，DTBMP 有效抑制了 V. harveyi 的生物发光产生以及其他生物膜相关毒力特性，如胞外多糖（EPS）产生、疏水性指数、泳动和群集运动在三种主要致病性弧菌：V. harveyi、V. parahaemolyticus 和 V. vulnificus。通过光、共聚焦激光扫描和扫描电子显微镜分析验证了 DTBMP 的抗生物膜潜力。此外，通过生长曲线和 2,3-双（2-甲氧基-4-硝基-5-磺苯基）-2H-四唑-5-羧基苯胺（XTT）测定确定了 DTBMP 的非杀菌作用。实时 PCR 研究表明，V. harveyi 的主群体感应（QS）调节剂基因 luxR、luxS、luxP、luxQ 和 luxO 的下调。体内结果证实，DTBMP 可将凡纳滨对虾幼虫的存活率提高至 75%、88%和 66%，分别在感染 V. harveyi、V. parahaemolyticus 和 V. vulnificus 时。本研究结果证实了 DTBMP 作为抗生物膜剂的有前途的效果，这可能会被积极探索用于治疗水产养殖中的生物膜相关弧菌感染。
