Maximum Oxygen Tolerance of CL. Botulinum A, B and C, of CL. Sporogenes and CL. Welchii

Abstract

The recent communications by Dack, Starin and Werner 1 and Dack and Baumgartner 2 on the effect of reduced oxygen and carbon dioxide pressures on the growth of CI. botulinum and CI. sporogenes in veal infusion broth recalled certain experiments which had been conducted in this laboratory 6 years ago by Belle Anderson. Her untimely death prevented the completion of the studies in which she was so deeply interested. The data to be presented have been compiled from the carefully kept notes and the marginal annotations which the writer made during the course of the tests. Relatively little information concerning the oxygen requirements of pathogenic anaerobic bacteria is available. From the older observations which may be found in the papers by Chudiakow,3 Porodka4 and Matzuschita5 one may conclude that bacteria generally considered strictly anaerobic, may grow at certain minimal oxygen tensions. In connection with studies on the gas metabolism of anaerobes it appeared desirable to have further information on the oxygen tolerance of CI. botulinum, since the aerobic index figures 59o to 10^o (5 to 10 cm. atmospheric pressure) as determined by Dozier 6 in 1920 according to the method of Harris 7 for two strains were found to be too high. Subsequent tests leave no doubt that the majority of type A and B strains and particularly type C strains exhibit a much greater intolerance to oxygen than these earlier tests would indicate. Several strains of CI. botulinum, CI. sporogenes and CL welchii grown in 2% peptone and l^o glucose broth (Ph 7.2 to 7.4) were trans-