Listeria monocytogenes is one of the most important emerging foodborne pathogens. The
objectives of this work were to investigate the incidence of Listeria spp. and L. monocytogenes in soft
cheese and ice cream in Assiut city, Egypt, and to examine the effect of some probiotic Bifidobacterium
spp. (Bifidobacterium breve, Bifidobacterium animalis, or a mixture of the two) on the viability of
L. monocytogenes in soft cheese. The existence of Listeria spp. and L. monocytogenes was examined
in 30 samples of soft cheese and 30 samples of ice cream. Bacteriological analyses and molecular
identification (using 16S rRNA gene and hlyA gene for Listeria spp. and L. monocytogenes, respectively)
were performed on those samples. Additionally, Bifidobacterium spp. were incorporated in the making
of soft cheese to study their inhibitory impacts on L. monocytogenes. Out of 60 samples of soft cheese
and ice cream, 25 samples showed Listeria spp., while L. monocytogenes was found in only 2 soft
cheese samples. Approximately 37% of soft cheese samples (11 out of 30) had Listeria spp. with about
18.0% (2 out of 11) exhibiting L. monocytogenes. In ice cream samples, Listeria spp. was presented by
47% (14 out of 30), while L. monocytogenes was not exhibited. Moreover, the addition of B. animalis to
soft cheese in a concentration of 5% or combined with B. breve with a concentration of 2.5% for each
resulted in decreasing L. monocytogenes efficiently during the ripening of soft cheese for 28 d. Listeria
spp. is widely found in milk products. Probiotic bacteria, such as Bifidobacterium spp., can be utilized
as a natural antimicrobial to preserve food and dairy products.