Growth Dynamics of Salmonella, Isolated from Different Sources, at different Temperature and pH

A total of 350 samples 50 each from raw poultry meat, poultry cloacal swabs and human diarrheic cases, besides 200 eggs were processed for the isolation of Salmonella. Effect of varying temperature and pH on growth of Salmonella isolates was evaluated by growing the organism in Brain Heart Infusion Broth at 4, 10, and 30°C with pH values of 4.5, 5.5 and 6.5. At 10°C, the mean generation time of the isolates at pH values of 4.5, 5.5 and 6.5 was 44.23 ± 0.44, 15.51 ± 0.08 and 10.23 ± 0.10 hrs, respectively, while at 30°C, the generation time of the isolates at pH values of 4.5, 5.5 and 6.5 was 126.10 ± 0.68, 59.96 ± 0.14 and 36.22 ± 0.07 min, respectively. No growth observed at 4°C, at any given pH value. As the temperature and pH were lowered, significant increase in generation time of the organism was observed.