Conner-Kerr TA, Sullivan PK, Gaillard J, Franklin ME, Jones RM, et al.
Ostomy/wound management. Date of publication 1998 Oct 1;volume 44(10):50-6.
1. Ostomy Wound Manage. 1998 Oct;44(10):50-6.
The effects of ultraviolet radiation on antibiotic-resistant bacteria in vitro.
Conner-Kerr TA(1), Sullivan PK, Gaillard J, Franklin ME, Jones RM.
Author information:
(1)Department of Physical Therapy, School of Allied Health Sciences, East
Carolina University, Greenville, NC 27858, USA.
Wound infections produced by antibiotic-resistant bacterial strains are
particularly difficult to manage. This study examined the effectiveness of
ultraviolet (UV) light treatment in killing antibiotic-resistant strains of
Staphylococcus aureus and Enterococcus faecalis in vitro. Between 2 and 5
replications of each organism at 10(8) organisms/ml were prepared and plated on
sheep blood agar medium and treated with UV light (254 nm, 15.54 mW/cm2 output).
Irradiation times were 0, 2, 5, 8, 15, 30, 45, 60, 90 or 120 seconds. Bacterial
cultures were then incubated at 35 degrees C for 24 hours. Kill rates were 99.9
percent for the methicillin-resistant strain of S. aureus (MRSA) at 5, 8, 15, 30,
45, 60 seconds and 100 percent at 90 and 120 seconds. Kill rates were 99.9
percent at 5, 8, 15, 30 seconds for vancomycin-resistant E. faecalis (VRE) and
100 percent at 45, 60, 90, 120 seconds. Similar results were found with UV light
treatment of the antibiotic-susceptible strains of S. aureus and E. faecalis. A
significant difference in kill rates at 30 seconds of UV exposure was detected
between the antibiotic-resistant strain of S. aureus and the antibiotic-resistant
strain of E. faecalis (Student's t test, p < 0.01). Significant differences were
also detected in the kill rates at 30 second exposure times for the
antibiotic-susceptible strains of S. aureus and E. faecalis. These findings
suggest that the Enterococcal bacteria is more susceptible to the killing effects
of UV. This data also suggests that UV light at 254 nm is bactericidal for
antibiotic-resistant strains of S. aureus and E. faecalis at times as short as 5
seconds and that the enterococcal bacteria is more susceptible to the killing
effects of UV. With recommended patient treatment times for infected wounds being
significantly longer than 5 seconds, this data indicates that patient treatment
times need to be re-examined.
PMID: 9866596 [Indexed for MEDLINE]
