Prevalence and behaviour of aeromonas hydrophila in raw milk and pefrigerated soft cheese

he prevalence of A.hydrophila in marketing raw milk, Kariesh and Domiati cheese was investigated. A total of 120 samples (50 raw milk, 35 Kariesh cheese and 35 Domiati cheese), collected from different localities in Cairo Governorate and examined for the presence and countable population of A.hydrophila. The results indicated that 38 % of raw milk samples were contaminated with A. hydrphila and showing colony counts varying from 5x10 to 3.2x104 cfu/ml. while the contamination rates of A. hydrophila in Kareish and Domiati cheese samples were 57 % and 20 %, respectively and colomy counts varying from 6x102 to 1.3x105 and 4x10 to 2.1x103 of Kareish cheese and Domaiti cheese samples respectively. The survival of A.hydrophila in Domiati cheese salted with 2% and 5% NaCl and stored at 5±1°C was studied Domiati cheese salted with 2% and stored at 5±1°C had a suitable condition for growth of bacterium for about two and half months. The last decetion (60cells/g) was observed at 10th week (pH 3.39). Also results indicated that the high concentration (5%) of salt has destructive effect against the A.hydrophila at the 4th day of cold storage (pH 4.1).