Characterisation and differentiation of lactobacilli by lectin typing

Lactobacillus isolates from healthy Estonian and Swedish children were char acterised by a lectin typing technique; 56 isolates from six species (L. ac idophilus, L. paracasei, L. plantarum, L. fermentum, L. brevis and L. buchn eri) were tested. The typing system was based on an agglutination assay wit h a panel of six commercially available lectins, which,were chosen on the b asis of their carbohydrate specificities. The isolates were also subjected to proteolytic degradation before lectin typing to decrease auto-agglutinat ion of whole cells in the assay. The 56 isolates were divided into 15 diffe rent lectin types by their lectin agglutination patterns. Proteolytic treat ment reduced auto-agglutination for the majority of species, apart from L. acidophilus, which remained predominantly auto-agglutinating (eight of nine strains). The system produced stable and reproducible results under standa rdised culture conditions. Lactobacilli are important bacteria for use as p robiotics and this system may supplement current molecular typing technique s and may help in identification of strains that could be useful in this ro le.