The effect of osmotic stabilizers on the radiometric detection of osmotically sensitive populations of some gram-negative bacteria.

The effect of four osmotic stabilizers on the radiometric detection of osmotically sensitive populations of E. coli, S. typhimurium, and E. cloacae was studied. The addition of sucrose, sorbitol, glycerol, or ethylene glycoll to BACTEC 6B blood culture medium failed to improve the sensitivity of the system and produced an inhibitory effect on the level of 14CO2 released by organisms previously exposed to lysozyme and ECTA or to penicillin followed by the lysozyme treatment. The same effect was observed both in blood free media and simulated blood cultures. The addition of proline to sucrose-containing hypertonic media had no effect on growth index readings.