Figure 1. Comparison of the number of colony-forming units (cfu) found in 8 cm2 locations within the Portland public transit system. There were significant mean differences in the number of cfu between these types of surface. (A) Number of cfu shown for various surface types within TriMet buses and trains, and for bus stops (mean ± standard error). (B) Number of cfu for all seats broken down into surface type:cloth seats found on buses, and vinyl seats found on trains (mean ± standard error).
