FIG. 2.

(A) Frequency distribution of the different PFGE types of CoNS in the SCH NICU (left) and the WCH NICU (right). PFGE types are identified by capital-letter codes. Bar height shows the number of clinical isolates identified in 1995. The “others” column accounts for the number of unique types encountered (i.e., those types occurring only once in 1995). (B) Longitudinal persistence of endemic clones of CoNS in the SCH NICU (top bar) and the WCH NICU (bottom bar). The period depicted covers the year 1995. The most prevalent strain of type AA is identified by the letter A. Note that this strain was introduced into the WCH NICU in the month of May and subsequently persisted.