A Comparison of three Enrichment Media for Isolating Salmonella

Salmonella균(菌) 분리용(分離用) 증균배지(增菌培地)의 비교실험(比較實驗)

The practical significance of using a selective enrichment procedure for detecion and enumeration of salmonella is well recognized. There are still various selective enrichment media has been communly used. Early years selenite broth was recomnended as an enrichment media for the isolating of salmonella. Hajna introduced a modified tetrathionate broth and demonstrated the greater efficiency to compare with the previous enrichment media. Raj also described that the new medium called dulcitol selenite enrichment and has been found to be very satisfactory, especially general implication in food poisoning. Authors tried to compare these 3 enrichment media for isolating salmonella. 1. When salmonella strains were inoculated $1{\sim}10^6$ cells per tube to these 3 enrichment media, mostly similar results were obtained between selenite broth and DS broth. In these 2 enrichment broth were showed $10^7/ml-10^8/ml$ cells of all tested salmonella strains. But in the case of TT broth it was found that the growth was $10^3/ml{\sim}10^4/ml$ cells for tested strain. 2. When E. coli, Proteus, Citrobacter were inoculate $10{\sim}10^6$ cells per tube to these 3 enrichment media. It was suggested that DS broth was showed more inhibitory action than that of selenite broth. TT broth showed high inhibition to these 3 organisms tested. 3. It was generally known that the incubation time is influenced to the frequency of salmonella detection. For this tendency, DS broth and selenite broth were showed similar results within 24 hrs to 48hrs incubation to the test. But DS broth showed more inhibitory action to E. coli and Proteus than that of selenite broth. 4. When $1{\sim}10$ cells were inoculated(per tube) to these 3 enrichment media, DS broth was found to be more sensitive than that of selenite broth.