Analysis of the resistance behaviour of indicator bacteria to several antibiotics in bulk milk using spatial point pattern methodology.

Between 2002 and 2004, indicator bacteria (Enterococcus, Escherichia coli) isolated from 799 bulk milk samples were tested against thirty different antibiotics for resistance. Systematic sampling over space (every eighth Styrian cattle breeding farm on an unaligned grid) was conducted within the scope of the bovine virus diarrhoea (BVD) control programme. Results of resistance testing were assigned to their respective farms by means of LFBIS (information system for agricultural and forestry enterprises: land- und forstwirtschaftlichen Betriebsinformationssystem) numbers.