On the other hand, the presence of Salmonella (Kendall's tau-c, p b 0.001) or STEC (Kendall's tau-c, p = 0.019) was significantly correlated with the observed contamination level of E. coli, thus the presence of Salmonella or STEC in a sample was significantly associated with a higher E. coli count in that sample (Fig. 2)