Figure 1.

Results of Bayesian phylogenetic analysis of Pseudomonas-related 16S rRNA gene sequences representing the most common clones found in PCR-amplified libraries from swabs samples of toys and surfaces. Cloned sequences are indicated by "CCTR" (Children's Center Toddler Room) or "CCIR" (Children's Center Infant Room) prefixes followed by the date of sampling and whether the sequence was obtained from a toy (T) or a surface (S). The phylogeny includes sequences of closely related cultured and uncultured organisms. GenBank accession numbers are presented next to the names. The values above the branches indicate the Bayesian posterior probabilities (above 0.5) under the specified model of evolution for each node (see Methods for details). Maximum Parsimony and Maximum Likelihood analyses produced highly similar tree topologies. MP bootstrap values were similarly high at nodes well-supported by Bayesian analysis.