Total (viable and dead) bacteria were quantified with the
LightCycler 1.1 system (Roche Diagnostics GmbH, Mannheim,
Germany). The uidA beta-D-glucuronidase gene from E. coli and the
slo streptolysin O gene from S. pyogenes were amplified with the
primers listed in Table 1. The uidA-F (forward) and uidA-R (reverse)
primers were designed previously.9 The other primers were