Low Temperature Growth of Salmonella

Abstract

SUMMARY—Salmonellae, normally grown at 3.5–37°C, can grow at much lower temperatures. Experimentally, minimum growth temperatbres were obtained when salmonellae were grown on the surface of agar in a temperature‐gradient incubator over a temperature range of 1.1 to 12.3°C. These minimum temperatures, as determined by visible growth for 7 serotypes, ranged from 5.5 to 6.8°C. The pattern of survival or growth of S. derby, S. heidelberg , and S. typhimurium was followed by inoculating the organisms into tubes of broth and incubating the tubes in a polythermostat over a temperature range of 1.1 to 12.3°C. Minimum growth temperature obtained for S. heidelberg after 19 days' incubation was 5.3°C. The minimum growth temperature for the same length of time for S. typhimurium and S. derby were 6.2 and 6.9°C respectively. The results indicate a growth temperature shift during extended incubation of Salmonella at low temperatures. This phenomenon and the low temperature. growth capability of Salmonella could be significant in foods stored for long periods of time at temperatures above 5°C.