FIG. 5.

Analysis of RS-PCR profiles of C. difficile strains isolated from the stools of patients with C. difficile infection, the hands of health care workers, and the environment of two medicine hospital wards for elderly patients. The dendrogram includes a small representative group of the predominant hospital genotype (type I) and all other genotypes found in the study. Strains isolated from the hands of health care workers are marked with an asterisk. The DNA profiles were analyzed by using BioNumerics software (Applied Maths, BioSystematica). Dendrograms were constructed by unweighted pair group method with arithmetic mean clustering by using the Dice correlation coefficient. The percentage level of similarity chosen for group assignments (roman numerals) is indicated by the thick black line and was based on the guidelines recommended by Tenover et al. (29).