Detection of Listeria monocytogenes in Soft-Cheese and Sweet Yogurt Produced Locally in Baghdad Ali H.A. AL-Shamary and Najim H. Najim

Abstract

In order to investigate the presence of Listeria monocytogenes in soft cheese and sweet yogurt produced
locally, this study was done by random collection of samples from different areas in Baghdad province and its
surrounding from different animals (Cows and Buffalos) as 55 total samples (47 soft –cheese samples and 8
sweet-yogurt samples) from October 2007 till January 2008 and processed according to standard protocols of
Listeria monocytogenes .
The results showed isolation of 6 isolates from 55 samples(10.9%) as 5 isolates from 47 soft – cheese samples
(10.638%) and 1 isolated from 8 sweet yogurt samples (12.5%),these revealed significant differences (P≤0.05) in
isolation percentages between Cows and Buffalos .Samples of raw –dairy products from local Buffaloes recorded
highest isolation percentage of Listeria monocytogenes as 73.5%(23.5% represented 4 isolates from 17 soft –
cheese samples and 50% represented 1 isolate from 2 yogurt samples) highest percentage of isolation of Listeria
monocytogenes from soft cheese samples occurred in January (2008) as 18.2% (2 isolates from 11
samples)especially from Buffalos in Al-Taji region as 33.4% (1 isolate from 3 samples ) while ,highest isolation
percentage of Listeria monocytogenes from yogurt occurred in December (2007)as 50%,1 isolate from 2 samples
especially from Buffaloes at Al-Fadhyllea region.
We concluded from this study by contamination of soft –cheese and sweet-yoghurt samples produced locally
in Baghdad by Listeria monocytogenes .