An animal model of byssinosis was used to investigate the ability of various Enterobacter agglomerans - derived solutions to evoke the acute respiratory response. Materials included: two preparations of endotoxin isolated by phenol-water extraction, an acetone powder of E. agglomerans and a preparation of E. agglomerans bound to inert cellulose powder. Each of the materials was able to elicit the "rapid shallow breathing" typical of that seen in guinea pigs upon exposure to cotton dust. At high concentrations, airflow interruption was also noted. Thus, every feature of the respiratory response upon first exposure to cotton dust was reproduced by exposure to E. agglomerans solutions.