[Infrared spectrophotometry of culture broth and toxins of enteropathogenic strains of Escherichia coli].

Lyophilized preparations of sterile broth, broth used for cultivation of enteropathogenic E. coli strains from which endotoxin and enterotoxin had been removed, were prepared for spectrophotometry by mixture with potassium bromide, and examined in heavy water. Despite basic biochemical differences, all the preparations showed similar or identical curves, with the same absorption maximum and wave length. The substances present in broth (proteins, lipids, sugars, etc.) were so dominant that that completely masked substances specific for E. coli and its toxins. Spectrophotometry revealed only the pattern belonging to broth, so that toxins can be only examined by this method after they have been separated from the broth. It is hoped to do this in the future.