A mechanism of association of lactobacilli with the rat stomach epithelium.

The stomach wall of the rat is colonised by a dominant lactobacilli flora. The bacteria are localised mainly on the squamous epithelium (Table 1). They adhere tightly, covering the whole surface of the squamous epithelium (Fig. 1). On the secreting epithelium yeasts and bacteria were found only in connection with mucus (Fig. 2). In the present paper a mechanism of adhesion will be discussed. Piliform appendages (PA) were investigated with the aid of electron microscopy between the bacteria and the top cell layer of the epithelium and between the bacterial cells themselves (Fig. 3 and 4). They contain, following indications with scanning and transmission electron microscopy, material from the thin capsulae of acidic mucopolysaccharides, reported by Savage. Lactobacilli isolated from the squamous epithelium and cultivated in vitro are connected by the same piliform appendages. It seems, that the piliform appendages have an affinity to special receptor sites of the bacterial cell wall and also of the gastric epithelium. Lactobacilli situated on the secreting epithelium show piliform appendages, too, but they don't have a tight connection with the epithelial cells, only with the mucus.