Featured Research

from universities, journals, and other organizations

Get a whiff of this: Low-cost sensor can diagnose bacterial infections

Date:
April 28, 2011
Source:
University of Illinois at Urbana-Champaign
Summary:
Bacterial infections really stink. And that could be the key to a fast diagnosis. Researchers have demonstrated a quick, simple method to identify infectious bacteria by smell using a low-cost array of printed pigments as a chemical sensor. In only a few hours, the array not only confirms the presence of bacteria, but identifies a specific species and strain. It even can recognize antibiotic resistance -- a key factor in treatment decisions.

The researchers tested their array on ten common infectious bacteria. The color changes of the sensor array show what kind of bacteria is growing and even if they are antibiotic resistant.
Credit: K. S. Suslick

Bacterial infections really stink. And that could be the key to a fast diagnosis. Researchers have demonstrated a quick, simple method to identify infectious bacteria by smell using a low-cost array of printed pigments as a chemical sensor. Led by University of Illinois chemistry professor Ken Suslick, the team published its results in the Journal of the American Chemical Society.

Hospitals have used blood cultures as the standard for identifying blood-borne bacterial infections for more than a century. While there have been some improvements in automating the process, the overall method has remained largely constant. Blood samples are incubated in vials for 24 to 48 hours, when a carbon dioxide sensor in the vials will signal the presence of bacteria. But after a culture is positive, doctors still need to identify which species and strain of bacteria is in the vial, a process that takes up to another day.

"The major problem with the clinical blood culturing is that it takes too long," said Suslick, the Marvin T. Schmidt professor of chemistry, who also is a professor of materials science and engineering and a member of the Beckman Institute for Advanced Science and Technology. "In 72 hours they may have diagnosed the problem, but the patient may already have died of sepsis."

While there has been some interest in using sophisticated spectroscopy or genetic methods for clinical diagnosis, Suslick's group focused on another distinctive characteristic: smell. Many experienced microbiologists can identify bacteria based on their aroma. Bacteria emit a complex mixture of chemicals as by-products of their metabolism. Each species of bacteria produces its own unique blend of gases, and even differing strains of the same species will have an aromatic "fingerprint."

An expert in chemical sensing, Suslick previously developed an artificial "nose" that can detect and identify poisonous gases, toxins and explosives in the air.

"Our approach to this problem has been to think of bacteria as simply micron-sized chemical factories whose exhaust is not regulated by the EPA," Suslick said. "Our technology is now well-proven for detecting and distinguishing among different chemical odorants, so applying it to bacteria was not much of a stretch."

The artificial nose is an array of 36 cross-reactive pigment dots that change color when they sense chemicals in the air. The researchers spread blood samples on Petri dishes of a standard growth gel, attached an array to the inside of the lid of each dish, then inverted the dishes onto an ordinary flatbed scanner. Every 30 minutes, they scanned the arrays and recorded the color changes in each dot. The pattern of color change over time is unique to each bacterium.

"The progression of the pattern change is part of the diagnosis of which bacteria it is," Suslick said. "It's like time-lapse photography. You're not looking just at a single frame, you're looking at the motion of the frames over time."

In only a few hours, the array not only confirms the presence of bacteria, but identifies a specific species and strain. It even can recognize antibiotic resistance -- a key factor in treatment decisions.

In the paper, the researchers showed that they could identify 10 of the most common disease-causing bacteria, including the hard-to-kill hospital infection methicillin-resistant Staphylococcus aureus (MRSA), with 98.8 percent accuracy. However, Suslick believes the array could be used to diagnose a much wider variety of infections.

"We don't have an upper limit. We haven't yet found any bacteria that we can't detect and distinguish from other bacteria," he said. "We picked out a sampling of human pathogenic bacteria as a starting point."

Given their broad sensitivity, the chemical-sensing arrays also could enable breath diagnosis for a number of conditions. Medical researchers at other institutions have already performed studies using Suslick's arrays to diagnose sinus infections and to screen for lung cancer.

Next, the team is working on integrating the arrays with vials of liquid growth medium, which is a faster culturing agent and more common in clinical practice than Petri dishes. They have also improved the pigments to be more stable, more sensitive and easier to print. The device company iSense, which Suslick co-founded, is commercializing the array technology for clinical use.

The National Institutes of Health supported this research through the Genes, Environment and Health Initiative. Co-authors of the paper included professor James Carey, of the National University of Kaoshiung; U. of I. microbiology professor James Imlay; research specialist Karin Imlay; and co-workers Crystal Ingison, Jennifer Ponder, Avijit Sen and Aaron Wittrig.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Journal Reference:

  1. James R. Carey, Kenneth S. Suslick, Keren I. Hulkower, James A. Imlay, Karin R. C. Imlay, Crystal K. Ingison, Jennifer B. Ponder, Avijit Sen, Aaron E. Wittrig. Rapid Identification of Bacteria with a Disposable Colorimetric Sensing Array. Journal of the American Chemical Society, 2011; 110427110353066 DOI: 10.1021/ja201634d

Cite This Page:

University of Illinois at Urbana-Champaign. "Get a whiff of this: Low-cost sensor can diagnose bacterial infections." ScienceDaily. ScienceDaily, 28 April 2011. <www.sciencedaily.com/releases/2011/04/110427171636.htm>.
University of Illinois at Urbana-Champaign. (2011, April 28). Get a whiff of this: Low-cost sensor can diagnose bacterial infections. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2011/04/110427171636.htm
University of Illinois at Urbana-Champaign. "Get a whiff of this: Low-cost sensor can diagnose bacterial infections." ScienceDaily. www.sciencedaily.com/releases/2011/04/110427171636.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
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