Featured Research

from universities, journals, and other organizations

Narrow-spectrum UV light may dramatically reduce surgical infections

Date:
October 16, 2013
Source:
Columbia University Medical Center
Summary:
Despite major efforts to keep operating rooms sterile, surgical wound infections remain a serious and stubborn problem, killing up to 8,200 patients a year in the U.S. Researchers suggests that narrow-spectrum UV light could dramatically reduce such infections without damaging human tissue.

Left panel: Although 207-nm UV light can penetrate and kill bacteria such as MRSA, it is unable to penetrate to the nucleus of human cells. UV from conventional lamps can penetrate and damage human cells. Right panel: Unlike UV from conventional lamps, 207-nm UV light is unable to penetrate the surface layer of dead skin to reach sensitive cells in the epidermis.
Credit: Dr. David Brenner, Columbia University Medical Center

Despite major efforts to keep operating rooms sterile, surgical wound infections remain a serious and stubborn problem, killing up to 8,200 patients a year in the U.S. A study by Columbia University Medical Center (CUMC) researchers suggests that narrow-spectrum ultraviolet (UV) light could dramatically reduce such infections without damaging human tissue. The study, conducted in tissue culture, was published today in the journal PLOS ONE.

Approximately 200,000 to 300,000 patients suffer surgical wound infections in the U.S. each year, accounting for $3 billion to $10 billion in health-care expenditures, the researchers report. Patients with surgical wound infections, compared with those without such infections, are 60 percent more likely to spend time in an ICU, are five times as likely to be readmitted to the hospital, have twice the mortality rate, have longer hospital stays, and have roughly double the total health-care costs.

Scientists have known for many years that UV light from a standard germicidal lamp (which emits a broad spectrum of wavelengths, from about 200 to 400 nanometers [nm]) is highly effective at killing bacteria; such lamps are routinely used to decontaminate surgical equipment.

"Unfortunately, this UV light is also harmful to human tissue and can lead to skin cancer and cataracts in the eye," said study leader David J. Brenner, PhD, the Higgins Professor of Radiation Biophysics, professor of environmental health sciences, and director of the Center for Radiological Research at CUMC. "UV light is almost never used in the operating room during surgery, as these health hazards necessitate the use of cumbersome protective equipment for both surgical staff and patients."

Dr. Brenner and his team hypothesized that a very narrow spectrum of UV light -- around 207 nm -- might be capable of destroying bacteria while leaving human tissue unaffected. Because UV light at this wavelength is strongly absorbed by proteins, it is expected to be safe for two reasons: At the cellular level, it cannot reach the nucleus of human cells, and at the tissue level it cannot reach the sensitive cells in the skin epidermis and the eye lens. But because bacteria are much smaller than human cells, this UV light can reach their DNA. "What this means is, if you shone 207-nm light on human skin or eyes, you would not expect to see any biological damage," said Dr. Brenner, "but it should kill any airborne bacteria that land on a surgical wound."

To test this hypothesis, Dr. Brenner and his colleagues exposed MRSA (methicillin-resistant S. aureus) bacteria, a common cause of surgical wound infections, and human skin cells to a krypton-bromine excimer lamp (also known as a KrBr excilamp), which emits UV light only at 207 nm, as well as to a standard germicidal UV lamp.

The researchers found that 207-nm UV light was as effective at killing MRSA bacteria as a conventional UV lamp. However, the 207-nm light resulted in 1,000-fold less killing of human skin cells than did the standard UV light.

In another experiment, the researchers tested the two UV lamps on a standard tissue-culture model of human skin (which includes the major skin layers, the epidermis and dermis). Exposure to a standard UV lamp caused extensive precancerous changes in the epidermis, while exposure to the same level of 207-nm light did not.

"Our results to date suggest that 207-nm UV light may be an effective add-on to current infection-control measures, without the need for protective equipment for staff or patients," said Dr. Brenner. "We need all the tools we can get to reduce surgical wound infections, especially those involving drug-resistant strains of bacteria, which have become increasingly common."

According to Dr. Brenner, a main route to surgical infection is through the air. "Despite every possible effort to promote sterility, MRSA and other bacteria are essentially raining down on the wound during the entire surgery," he said. "If this UV lamp were continuously shone on the wound during surgery, the bacteria would be killed as they landed." The lamps, known as excimer lamps, are small, rugged, inexpensive, and long-lived, the researchers noted.

"These findings have important clinical significance for mitigating surgical infections," said K.S. Clifford Chao, MD, the Chu H. Chang Professor of Radiation Oncology and chair of radiation oncology at CUMC and professor and chair of radiation oncology at Weill Cornell Medical College. "Right now, incidental infections occur unexpectedly. But with the use of narrow-spectrum UV light, surgical care may be improved at an affordable cost."

The researchers are now conducting in vivo tests of the 207-nm lamp.

The paper is titled, "207-nm UV Light -- A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. I: In-Vitro Studies." The other contributors are Manuela Buonanno, Gerhard Randers-Pehrson, Alan W. Bigelow, Sheetal Trivedi, Franklin D. Lowy, Henry M. Spotnitz, and Scott M. Hammer (all at CUMC).

Columbia University has filed international patent applications for a method for generating a narrow wavelength of UV radiation that can selectively affect and/or kill bacteria. The authors declare no financial or other conflicts of interests.

The study was supported in part by a grant from the Columbia-Coulter Translational Research Partnership.


Story Source:

The above story is based on materials provided by Columbia University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Manuela Buonanno, Gerhard Randers-Pehrson, Alan W. Bigelow, Sheetal Trivedi, Franklin D. Lowy, Henry M. Spotnitz, Scott M. Hammer, David J. Brenner. 207-nm UV Light - A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. I: In Vitro Studies. PLoS ONE, 2013; 8 (10): e76968 DOI: 10.1371/journal.pone.0076968

Cite This Page:

Columbia University Medical Center. "Narrow-spectrum UV light may dramatically reduce surgical infections." ScienceDaily. ScienceDaily, 16 October 2013. <www.sciencedaily.com/releases/2013/10/131016212436.htm>.
Columbia University Medical Center. (2013, October 16). Narrow-spectrum UV light may dramatically reduce surgical infections. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/10/131016212436.htm
Columbia University Medical Center. "Narrow-spectrum UV light may dramatically reduce surgical infections." ScienceDaily. www.sciencedaily.com/releases/2013/10/131016212436.htm (accessed July 30, 2014).

Share This




More Matter & Energy News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
China's Drone King Says the Revolution Depends on Regulators

China's Drone King Says the Revolution Depends on Regulators

Reuters - Business Video Online (July 30, 2014) Comparing his current crop of drones to early personal computers, DJI founder Frank Wang says the industry is poised for a growth surge - assuming regulators in more markets clear it for takeoff. Jon Gordon reports. Video provided by Reuters
Powered by NewsLook.com
3Doodler Bring 3-D Printing to Your Hand

3Doodler Bring 3-D Printing to Your Hand

AP (July 30, 2014) 3-D printing is a cool technology, but it's not exactly a hands-on way to make things. Enter the 3Doodler: the pen that turns you into the 3-D printer. AP technology writer Peter Svensson takes a closer look. (July 30) Video provided by AP
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins