Garland C D, Nash G V, McMeekin T A
Appl Environ Microbiol. 1982 Nov;44(5):1205-11. doi: 10.1128/aem.44.5.1205-1211.1982.
Healthy, actively feeding intertidal oysters were removed from an estuarine environment (Pipeclay Lagoon, Tasmania). The epithelial surfaces of various organs of the mantle cavity and alimentary tract were explored by scanning and transmission electron microscopy. All epithelial tissues examined were ciliated, and nearly all were partly covered with secreted mucus. However, microorganisms were seen rarely in the adhesive mucus and never attached to the epithelium. Electron microscopy also failed to demonstrate a surface microflora in emersed oysters which had been incubated at 5 to 25 degrees C for 6 or 24 h. The absence of an internal surface microflora did not vary on a seasonal basis. In laboratory experiments, oysters were allowed to filter feed from seawater containing diverse types of marine bacteria at concentrations of 10(3) to 10(7)/mL. However, no surface microflora could be found within actively feeding oysters or in emersed animals incubated at 20 degrees C for 6 or 24 h. In contrast, surface-associated microorganisms were detected readily by scanning electron microscopy on the external shell of healthy oysters and on various internal tissues in spoiled oysters. It is suggested that the major mechanisms restricting microbial growth within oysters are ciliary movement and mucus secretion.
从河口环境（塔斯马尼亚州的派普克莱泻湖）采集健康且正在积极摄食的潮间带牡蛎。通过扫描电子显微镜和透射电子显微镜观察外套腔和消化道各器官的上皮表面。所有检查的上皮组织都有纤毛，并且几乎所有组织都部分覆盖有分泌的黏液。然而，在黏性黏液中很少见到微生物，且微生物从未附着在上皮细胞上。电子显微镜检查也未能在5至25摄氏度下孵育6或24小时的离水牡蛎中发现表面微生物群落。内表面微生物群落的缺失不存在季节性变化。在实验室实验中，让牡蛎从含有浓度为10³至10⁷/mL多种海洋细菌的海水中滤食。然而，在正在积极摄食的牡蛎中或在20摄氏度下孵育6或24小时的离水动物中均未发现表面微生物群落。相比之下，通过扫描电子显微镜很容易在健康牡蛎的外壳以及变质牡蛎的各种内部组织上检测到与表面相关的微生物。据推测，限制牡蛎体内微生物生长的主要机制是纤毛运动和黏液分泌。
