Fig. 4
Interpretation chart for semi-quantitative colony forming unit counts of sow urine inoculated on blood agar. The urine samples were inoculated on standard 5% calf blood agar immediately after collection. Semi-quantitative colony counts were obtained by inoculating half an agar plate with 1 µL and the other half with 10 µL urine. Following aerobic incubation for 18–26 h at 37 °C, the number of colonies on each half of the agar plate were counted in order to determine the number of colony forming units per ml. If the two sides of the agar plate gave inconsistent results, the 10 µL side was used to maximize accuracy. The one µL loop determined the result for samples where doubt about the 105 and 106 categories occurred