This investigation was done in the laboratories of Faculty of Agriculture –
Damascus University Department of Food Sciences. The aim of this research
was to study the inhibition effect of the growth of Lactic acid bacteria used as
starter, on the
growth of S. typhi O9 bacteria. We used for this study a pure
strains of Salmonella typhi O9 and Lactic acid bacteria (Streptococcus
thermophilus and Lactobacillus bulgaricus). The effect of Lactic acid bacteria on
the number of S. typhi O9 was studied in 37 ◦C and 4◦C. The Lactic acid bacteria
were inoculeted in milk for the yoghurt manufacturing. The number of S. typhi
O9 decreased gradually with time. This decrease number of this bacteria was
more clear when both Str. thermophilus and Lb. bulgaricus were used as a
mixted starter, Lb. bulgaricus then when was used a single starter, or when Str.
thermophilus was used a alone. The S.typhi O9 disappear
