SWINE INFLUENZA Ii . A I-IEMOPHILIC BACILLUS FROM THE RESPIRATORY TRACT OF IN~ECTED SWll'm

Murray (1), MeBryde, Niles, and Moskey (2), and recently Fulton (3) have attempted to discover the nature of the inciting agent of swine influenza. Murray described a small Gram-negative coccus as the cause of the disease. By inoculating normal swine intravenously with relatively small doses of pure cultures of this organism, he induced a disease which he believed was clinically and pathologically swine influenza. McBrydc, Niles, and Moskey failed to obtain Murray's micrococcus in their cultures. They isolated only two types of organisms from cases of the disease with any degree of frequency, a pleomorphic Gram-positive bacillus and Bacillus suisepticus. Neither of these organisms produced the disease when injected into susceptible swine. Fulton recently confirmed the presence of McBryde's pleomorphic Gram-positive bacillus in the respiratory tracts of swine with influenza and, with very freshly isolated cultures, reproduced the disease experimentally. However, cultures that had been transferred only three times or original cultures that had been kept on ice for as short a period as 2 weeks were incapable of inducing influenza when administered intranasally to normal swine. Spray (4) using slaughter house material cultured the respiratory tracts of a large number of normal swine and of those showing pneumonia. From both classes he frequently isolated an inulin-fermenting streptococcus and B. suisepticus. These organisms were encountered more often from pneumonic than from normal lungs; the inulin-fermenting streptococcus was frequently present in pure culture from the pneumonic areas. Since Spray did not differentiate infectious pneumonia, hemorrhagic septicemia, and influenza, his findings are not of great value.