Mohammad Mehdi Soltan Dallal , Hamid Emadi Koochak , Mohammad Kazem Sharifi Yazdi , Ali Taheri Mirghaed , Hamid Choobineh,
Volume 8, Issue 1 (5-2014)
Background and Aim: Cream is a rich dairy product with the pH close to neutral and
limited preservation capability. Cream is suitable and rich for microbial
growth. In the past few decades, there was a great concern in contamination of
food products.
Salmonella and Yersinia species are two
important pathogens causing food poisoning and human gastroenteritis. The aim
of the present study is to investigate the quality of traditional cream for
bacterial contamination.
Materials and Methods: This is a cross-sectional study. In total, 100 unpasteurized
cream samples were collected from 5 regions in Tehran. The Salmonella was
enriched in Selenite-F broth, and Yersinia in
phosphate buffer in two weeks in cold condition according to CDC, and then were
inoculated in MacConky and CIN agar for 24 hours. The suspected colonies were
examined for phenotype and their identification was confirmed by API-20 E.
Results: In
general, 29% of tested cream samples were contaminated with at least one kind
of bacteria, 3% with Yersinia (1strain Y.enterocolitica, 1 Y.intermedia, 1
frederiksenii), and 2% with Salmonella paratyphi B. The other bacteria like
Escheichia coli, Enteobacter, klebsiella, and Citobacter were also isolated.
Five samples were contaminated with two kinds of bacteria.
Conclusion: The
results of this study indicate that more quality control should be applied on
the cream produced in the city of Tehran by health control office for food
products.