collected between patient scans during
the day. One author collected the specimens from each MR unit’s core, head coil,
table, and control panel using the Remel
BactiSwab specimen collection system
(see Figures 1–4). The author swabbed
the interior portion of the head coil and
the portion of the table closest to the
bore. Cultures were obtained within an
hour of specimen collection approval.
All inoculated swabs were plated to
commercially prepared media within
24 hours of collection and incubated in
ambient air. Two sheep blood agar plates
were used; one plate was maintained
at 22°C (room temperature) to recover
mold and the other at 35°C to recover
bacteria. Chocolate agar and MacCon-key agar plates also were maintained at
35°C. Bacterial cultures were evaluated at
24 and 48 hours. The room temperature
sheep agar plates were evaluated at two
and seven days.
Bacterial isolates were first Gram
stained. The Gram stain is routinely
used to differentiate microorganisms
microscopically and is the initial step
in organism identification. Standard
identification procedures were used as
necessary to identify bacterial isolates
to the genus level. Gram negative bacilli
were identified using the MicroScan
Walk-Away bacterial identification and
antibiotic susceptibility testing system.
A conventional transparency tape preparation was used to microscopically identify mold isolates to the class, genus, or
None of the MR cultures recovered clinically significant isolates that are established HAI pathogens. 20 All culture sites
grew Staphylococcus species coagulase
negative, a normal skin flora (Figure 5).
All sites also grew normal environmental
contaminants from the Bacillus species
(Figure 6), along with Micrococcus species
(Figure 7), which are normal skin flora
and environmental contaminants typically found in the hospital environment.
Figure 2 • MR bore.
Figure 3 • MR head coil.