VILLALON, A FRESH EWES MILK SPANISH CHEESE, AS A SOURCE OF POTENTIALLY PATHOGENIC AEROMONAS STRAINS

Presumptive aeromonads were detected in 8 batches of Villalon cheese p roduced in dairy plants from pasteurized ewe's milk, the mean count be ing 2.85 +/- 0.24 log CFU/g. Only four isolates from 2 batches were co nfirmed as motile aeromonads and they fitted the description of Aeromo nas hydrophila. During cheese making of 5 batches of farmhouse-made ra w milk Villalon cheese, presumptive aeromonads decreased in numbers fr om 3.6 log CFU/ml in raw ewes' milk to 2.2 log CFU/g after salting, bu t after storage for 48 h at 4 degrees C, multiplication occurred in al l cheeses (mean count, 3.7 log CFU/g). Motile aeromonads were detected in raw ewe's milk, curd, and cheese. Identification to species' level of 38 isolates which shared the properties of A. hydrophila and A. ca viae was based on the ''suicide phenomenon'' (22 strains were identifi ed as A. hydrophila and 16 as A. caviae). AU strains of A. caviae were beta-hemolytic, showed suicidal activity, and failed to produce casei nase.