Laboratory study on bacteriological aspects of beverages and thickeners for dysphagia patients : Growth survey of Escherichia coli on thickeners and beverages

Abstract

Currently, there is little evidence-based guidance on bacteriological aspects of thickeners or beverages for dysphagia patients in Germany that can be recommended to prevent aspiration pneumonia. Therefore, the aim of this study was to evaluate the lowest cell amount of E.coli on M9 agar media with beverages and thickeners. In the laboratory experiment 1 · 107 cells of E.coli were plated on adefined minimal medium (M9 agar plates) with different carbon sources and incubated at 37 °C for 2 days. The increase in cell number was determined using aphotometer. Carbon sources were water, beer, orange juice, thickened beer, maltodextrin-xanthan gum-based thickeners, corn starch-based thickeners and potato starch-based thickeners. The lowest E.coli cell amount was measured on water compared to beer, orange juice and all thickeners. A higher E.coli cell count was measured on maltodextrin-based thickeners than on potato starch-based and corn starch-based thickeners. In the present laboratory experiment, no individual risk factors for the development of aspiration pneumonia in humans were considered; however, initial bacteriological evidence for dysphagia patients could be collected. Due to the high growth of E.coli on maltodextrin, yeast, fructose and glucose, these ingredients should be used with caution by dysphagia patients. Further research on thickeners and beverages is needed to make acomprehensive recommendation for action in this aspect.