Sources and characterisation of spore-forming bacteria in raw milk

Farm surveys were conducted in two dairying regions of Victoria to determin e the probable sources of Bacillus spores in the raw milk supply. The resul ts suggested that Bacillus spores in Victorian milk are present in lower nu mbers than reported overseas. Contamination of teat surfaces by soil and fa eces appears to be the major contamination source but other factors such as water and silage can play a role in increasing the spore content of raw mi lk. Spore isolates collected during these surveys were characterised on the basis of their morphological and biochemical characteristics. The vast maj ority of isolates had identical characteristics and closely resembled B, li cheniformis. Other types of spore formers were present only in very low num bers.