Ultraviolet C light for Acinetobacter baumannii wound infections in mice: potential use for battlefield wound
Tianhong Dai1, Clinton K Murray, Mark S Vrahas
1Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Background:
Since the beginning of the conflicts in the Middle East, US Army physicians have noted a high rate of multidrug-resistant Acinetobacter baumannii infections among US soldiers wounded and initially treated in Iraq. In this study, we investigated the use of ultraviolet C (UVC) light for prevention of multidrug-resistant A. baumannii wound infections using mouse models.
Methods:
Partial-thickness skin abrasions and full-thickness burns in mice were infected with a multidrug-resistant A. baumannii isolate recovered from a wounded US soldier deployed to Iraq. The luxCDABE operon, which was contained in plasmid pMF 385, was cloned into the A. baumannii strain. This allowed real-time monitoring of the extent of infection in mice using bioluminescence imaging. UVC light was delivered to the mouse wounds at 30 minutes after the inoculation of A. baumannii. Groups of infected mouse wounds without being exposed to UVC served as the controls.
Results:
In vitro studies demonstrated that A. baumannii cells were inactivated at UVC exposures much lower than those needed for a similar effect on mammalian cells. It was observed in animal studies that UVC (3.24 J/cm(2) for abrasions and 2.59 J/cm(2) for burns) significantly reduced the bacterial burdens in UVC-treated wounds by approximately 10-fold compared with nontreated controls (p = 0.004 for abrasions, p = 0.019 for burns). DNA lesions were observed by immunofluorescence in mouse skin abrasions immediately after a UVC exposure of 3.24 J/cm(2); however, the lesions were extensively repaired within 72 hours.
Conclusion:
These results suggested that UVC may be useful in preventing combat-related wound infections.
Insights
Ultraviolet C (UVC) light effectively reduced multidrug-resistant Acinetobacter baumannii in mouse wound models. This study suggests UVC is a promising method for preventing combat-related wound infections.
Area of Science:
- Microbiology
- Photomedicine
- Infectious Diseases
Background:
- US Army physicians observed high rates of multidrug-resistant Acinetobacter baumannii infections in soldiers wounded in the Middle East.
- Acinetobacter baumannii poses a significant threat in combat-related wound infections.
Purpose of the Study:
- To investigate the efficacy of ultraviolet C (UVC) light in preventing multidrug-resistant Acinetobacter baumannii wound infections.
- To evaluate UVC as a potential prophylactic measure for combat wounds.
Main Methods:
- Mouse models with partial-thickness skin abrasions and full-thickness burns were infected with multidrug-resistant A. baumannii.
- Bioluminescence imaging was used to monitor infection extent in real-time.
- UVC light was applied to infected wounds 30 minutes post-inoculation, with untreated wounds serving as controls.
Main Results:
- In vitro studies showed UVC inactivated A. baumannii at lower exposures than mammalian cells.
- UVC treatment significantly reduced bacterial burdens in mouse wounds by approximately 10-fold.
- Transient DNA lesions in mouse skin were observed post-UVC but were repaired within 72 hours.
Conclusions:
- UVC light demonstrates significant potential for reducing bacterial load in infected wounds.
- The findings suggest UVC is a viable strategy for preventing combat-related wound infections.
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