By Sandy Hemphill, Contributing Writer, BabyMed
Superbugs, including the methicillin-resistant Staphylococcus aureus (MRSA) bacterium, can be difficult, if not impossible, to treat. New and more powerful antibiotics are under development while the search for other means of killing off these killer germs continues. One promising new approach is to use a special kind of ultraviolet (UV) light to destroy drug-resistant bacteria.
Once perfected, this UV-light therapy is expected to be safe for people of all ages but it could greatly benefit the smallest patients, those in NICUs and PICUs (neonatal and pediatric intensive care units) around the world. Infants and young children don’t have full-strength immune systems so infections can become critical in very short order and potent antibiotics may be too harsh for the smallest patients to handle. Using UV light on them, however, may cure infections without the need for strong antibiotics or other medications and may eliminate the need for surgeries and other painful means of treating infection.
MRSA in the NICU / PICU
A study published in 2014 in the journal, Pediatrics, found that MRSA can quickly spread through a NICU or PICU. Most MRSA outbreaks in these facilities are introduced by a new patient bringing the bacterial infection into the ICU from outside the hospital:
- 1.9% of NICU / PICU patients had a MRSA infection during the study period.
- 5.8% MRSA-infected newborns were born outside the NICU’s hospital.
- 0.2% had been born in the hospital housing the NICU.
A MRSA infection in newborns can damage skin and soft tissue and cause lower respiratory and bloodstream infections. Infection by a drug-resistant bacterium can quickly become a life-threatening emergency when a newborn, infant, or young child gets it.
Comparing UV Light Wavelengths for Treating Infection
In 2013, a team of researchers led by Dr. David J. Brenner of the Center for Radiological Research at Columbia University Medical Center in New York City compared two forms of UV light and their ability to kill drug-resistant bacteria in a laboratory setting using human cell tissues.
Germicidal (germ-killing) UV lamps currently in use produce wavelengths in the range between 200 and 400 nanometers (nm). Light rays in this spectrum do kill germs but they can also harm the patient and threaten the safety of the medical staff treating the patient.
Brenner’s research team discovered that wavelengths in the 200 nm range are just as effective as stronger wavelengths but do not penetrate the skin as deeply. The team found a filtered 207-nm wavelength killed germs but didn’t produce the tissue damage stronger wavelengths cause.
207-nm UV Light Effective and Safe on Living Tissue
Brenner and his research team advanced their study to include differing UV light effects on hairless mice. The skin of these mice responds to UV light much the same way human skin does. The findings of this study were published in June 2016.
A conventional germicidal UV lamp producing wavelengths of 254 nm produced skin and eye damage but did kill germs, as it has proven to do in previous studies and in clinical applications.
The 207-nm UV light effectively killed germs but did not damage skin and eye tissue. Wavelengths of 207 nm aren’t strong enough to penetrate the outer layer of dead skin cells to damage underlying living tissue. It could not penetrate the outer layers of the eye, either. It posed no physical risk to patient or attending medical personnel.
Further studies on humans are in order before the lower-wavelength UV light is available for widespread use in hospitals, including NICUs and PICUs, but Brenner has plans to do so. He also speculates UV light at low wavelengths might become an effective way to combat airborne bacteria and viruses that cause diseases such as influenza and tuberculosis.
Sources:
Brenner, David J, et al. "207-nm UV Light—A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. II: In-Vivo Safety Studies."PLOS | One. PLOS, June 2016. Web. 29 June 2016.
Zervou, Fainareti N, et al. "MRSA Colonization and Risk of Infection in the Neonatal and Pediatric ICU: A Meta-analysis."Pediatrics 133.4 (2014): 1015-23. American Academy of Pediatrics. Web. 30 June 2016.
Brenner, David J, et al. "207-nm UV Light - A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. I: In Vitro Studies."PMC. PLOS | One / PLOS, 16 Oct. 2013. US National Library of Medicine / National Institutes of Health. Web. 30 June 2016.