Microbiological quality of raw cow milk and survival of Acinetobacter baumanii in processed cow milk

The aim of this study was to determine microbiological quality of raw cow milk, to compare the number of raw milk bacteria at different temperatures and to examine the adjustment of Acinetobacter bumanii in processed cow milk. A sample of raw milk is taken from the small family farm with one cow. Prior to milking, the udder was washed with warm water. Sample of 500mL was collected in a sterile bottle. For the determination of the microbiological quality the aerobic mesophilic bacteria (AMB), Salmonella, Staphylococcus aureus, Clostridium spp. and Enterobacteriaceae were analysed. The samples of 100mL of raw milk was exposed to three different temperatures (4°C, 22°C and 37°C) and the AMB was monitored during 48 hours. The adaptation of A. baumanii was analyzed by inoculation of 10² CFU/mL in processed milk. The survival was monitored for 13 days at 22°C. The raw milk from the small family farm was good microbiological quality according to limits proscribed by “Guidelines of the microbiological food criteria”. A. baumanii showed a good adjustment in processed cow milk during the first 10 days at 22°C. From 11ʰ till 13ʰ day the number of A. baumanii was the same. Although A. baumanii has a good adoptable mechanisms, the acidic environment is not adequate for this species and this was also proven by the examination of the raw milk microflora on 37°C. On this temperature the growth of most bacterial species present in the raw milk was inhibited.