几种海产双壳贝类血淋巴中抗菌物质的诱导及其活性测定

INDUCTION AND ASSAYS OF ANTIBACTERIAL SUBSTANCES FROM THE HEMOLYMPH OF SEVERAL BIVALVE MOLLUSCS

以贻贝 (Mytilusedulis)、毛蚶 (Scapharcasubcrenata)、海湾扇贝 (Argopectenirrdians)和菲律宾蛤仔 (Ruditapesphilippinesis)为试验材料 ,分别用活的和灭活的大肠杆菌为诱导物进行诱导 ,采用3种革兰氏阳性细菌和3种革兰氏阴性细菌作为指示菌 ,对4种供试双壳贝类血淋巴进行抗菌活性测定。结果表明:(1)贻贝在诱导前其血淋巴对金黄色葡萄球菌和四联微球菌有抑菌活性 ,免疫诱导可使血淋巴对鳗弧菌出现抑菌作用 ;(2)毛蚶在诱导前其血淋巴中含有对金黄色葡萄球菌和鳗弧菌有抑菌活性的物质 ,诱导对这两种菌的抑菌活性有明显的提高 ,但未诱导出对另外4种供试细菌有活性的物质 ;(3)海湾扇贝在诱导前其血淋巴对所有供试细菌均无抑菌活性 ,但经诱导后产生对金黄色葡萄球菌、副溶血弧菌和鳗弧菌有抑菌活性的物质 ,且活菌诱导比灭活菌诱导效果好 ;(4)菲律宾蛤仔在诱导前其血淋巴仅对金黄色葡萄球菌和鳗弧菌表现出抑菌活性 ,经诱导后其血淋巴不仅对这两种菌的抑菌活性增强 ,而且还诱导出对副溶血弧菌有抑菌活性的物质。

Four kinds of bivalve molluscs, Mytilus edulis, Scapharca subcrenata, Argopecten irrdians and Ruditapes philippinesis, were challenged with a suspension of heat killed or live Escherichia coli and hemolymph was collected periodically. The activities of antibacterial substances in the hemolymph from challenged and unchallenged molluscs were measured using a plate growth inhibition assay with Gram positive bacterial strains and Gram negative bacterial strains, respectively. The results showed that: (1) The hemolymph of unchallenged Mytilus edulis was active against Staphylococcus aureus and Micrococcus tetragenus, and the activities against Vibrio anguillarum was present in the hemolymph of challenged Mytilus edulis; (2)The hemolymph of unchallenged Scapharca subcrenata presented activities against Staphylococcus aureus and Vibrio anguillarum, and the activities against the two strains were highly improved after challenge; (3) The hemolymph of unchallenged Argopecten irrdians had no antibacterial activities against all of bacterial strains tested. However, the hemolymph of challenged Argopecten irrdians was found to contain antibacterial substances against Staphylococcus aureus, Vibrio parahaemolyticus and V. anguillarum, and the activities in the hemolymph challenged with live Escherichia coli were stronger than those in the hemolymph challenged with heat killed Escherichia coli; (4) The antibacterial activities were observed against Staphylococcus aureus and Vibrio anguillarum in the hemolymph of unchallenged Ruditapes Ruditapes philippinesis. After challenge, the activities against Staphylococcus aureus and Vibrio anguillarum increased and a new activity against Vibrio parahaemolyticus was found in the hemolymph.