FIGURE 6.
The microbial count in water samples, expressed as Log10 (CFU/mL). The microbial count was carried out in plate count agar (PCA) media (black bars) and MacConkey (MC) media (gray bars) after incubation at 20°C for 48 h in the absence of antibiotics (A), and with the addition of antibiotics at a final concentration of 20 μg/mL. Frequency of the antibiotic-resistant colonies (B) was calculated as the ratio of the colony growth in the presence of a specific antibiotic compared to colony growth in its absence. Numbers are expressed as the percentage ± the standard deviation.