ADHESION OF LACTIC ACID BACTERIA TO CACO-2 CELLS - EVALUATION OF DIFFERENT DETECTION METHODS

摘要

Adhesion of Laclobacillus casei subsp. pseudoplantarum 2750, Lactobacillus sakei DSM 20017 and Bifidobacterium bifidum B3.2 to Caco-2 cell line was investigated in vitro. The adhesion ability of the tested strains was quantified with three methods: fluorescent-labelling, Gram-staining - followed by cell counting and image analysis - and plate count enumeration in order to compare the different detection methods. Results were in good correlation in terms of number of adhered bacteria, however, aggregate formation resulted in a significantly lower result with plate count enumeration in case of L. casei subsp. pseudoplantarum 2750. Percent coverage was found to be an appropriate method to compare adhesion ability of the strains, provided the cell sizes are similar. Gram-staining gives satisfactory results, however, fluorescent staining was not a suitable method in this study, since fluorescent dye hexidium iodide also labelled the intestinal cells.