INCIDENCE AND CHARACTERIZATION OF AEROMONAS SPECIES IN DOMIATI AND KAREISH CHEESE SOLD IN ASSIUT PROVINCE

A total of 100 random samples of locally manufactured Domiati and Kareish cheese (50 from each) were collected from dairy shops, groceries and farmers houses in Assiut province. The samples were examined for enumeration and isolation of Aeromonas species as well as to evaluate their haemolytic activity and degree of virulence. The Aeromonas species could be isolated from 14% and 16% of the examined Domiati cheese samples using MacConkey mannitol ampicillin agar (MMA) and Trypticase soy ampicillin agar (TSA) with an average count of 1 x10* and 1x10*/g, respectively. However, in case of Kareish cheese, the percentages of positive samples were 66% by using MMA medium and 64% by using TSA medium, as well as the average counts were 5x10' and 9x10*/g, respectively. A. caviae was the most common species isolated from Domiati cheese (68.7%) followed by A. hydrophila (18.8%) and A. sobria (12.5%). While in case of Kareish cheese, A. hydrophila and A. caviae were the predominant species comprising (39.5%, while A. sobria comprising (21.0%) of the total isolates. Concerning the haemolytic activity of the isolated species recovered from Domiati cheese samples, one of each of A. hydrophila and A. sobria and 2 of A. caviae had the ability to produce haemolysin. While 10, 2 and 3 strains of A. hydrophila, A. caviae and A. sobria isolated from Kareish cheese were positive for haemolysin, respectively. The public health hazard of Aeromonas species and the suggestive measures for improving the quality of Domiati and Kareish cheeses were discussed.