Vinoj Gopalakrishnan, Jayakumar Rengarajan, Chen Jiann-Chu, Withyachumnarnkul Boonsirm, Shanthi Sathappan, Vaseeharan Baskaralingam
Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, Alagappa University, Karaikudi 630 004, Tamil Nadu, India.
Central Marine Fisheries Research Institute (CMFRI), Marine Fisheries Post, Mandapam Camp, 623520 Tamil Nadu, India.
Fish Shellfish Immunol. 2015 Jan;42(1):204-12. doi: 10.1016/j.fsi.2014.10.033. Epub 2014 Nov 6.
Four strains of N-hexanoyl-L-homoserine lactone (AHL)-degrading Pseudomonas spp., named PsDAHP1, PsDAHP2, PsDAHP3, and PsDAHP4 were isolated and identified from the intestine of Fenneropenaeus indicus. PsDAHP1 showed the highest AHL-degrading activity among the four isolates. PsDAHP1 inhibited biofilm-forming exopolysaccharide and altered cell surface hydrophobicity of virulent green fluorescent protein (GFP)-tagged Vibrio parahaemolyticus DAHV2 (GFP-VpDAHV2). Oral administration of PsDAHP1 significantly reduced zebrafish mortality caused by GFP-VpDAHV2 challenge, and inhibited colonisation of GFP-VpDAHV2 in the gills and intestine of zebrafish as evidence by confocal laser scanning microscope and selective plating. Furthermore, zebrafish receiving PsDAHP1-containing feed had increased phagocytic cells of its leucocytes, increased serum activities of superoxide dismutase and lysozyme. The results suggest that Pseudomonas aeruginosa PsDAHP1 could protect zebrafish from V. parahaemolyticus infection by inhibiting biofilm formation and enhancing defence mechanisms of the fish.
从印度对虾肠道中分离并鉴定出四株N-己酰基-L-高丝氨酸内酯（AHL）降解假单胞菌，分别命名为PsDAHP1、PsDAHP2、PsDAHP3和PsDAHP4。PsDAHP1在这四株分离菌中表现出最高的AHL降解活性。PsDAHP1抑制了生物膜形成胞外多糖，并改变了携带绿色荧光蛋白（GFP）的致病性副溶血性弧菌DAHV2（GFP-VpDAHV2）的细胞表面疏水性。口服PsDAHP1显著降低了由GFP-VpDAHV2攻击引起的斑马鱼死亡率，并通过共聚焦激光扫描显微镜和选择性平板培养证明其抑制了GFP-VpDAHV2在斑马鱼鳃和肠道中的定殖。此外，投喂含PsDAHP1饲料的斑马鱼白细胞吞噬细胞增加，血清超氧化物歧化酶和溶菌酶活性增强。结果表明，铜绿假单胞菌PsDAHP1可通过抑制生物膜形成和增强鱼类防御机制来保护斑马鱼免受副溶血性弧菌感染。
