Electronic nose sniffs out C. diff

Date: Sep-02-2014A team of chemists and a microbiologist at the University of Leicester in the UK has developed a rapid and sensitive electronic nose that sniffs out the highly infectious hospital superbug C. diff.

Clostridium difficile (C. diff) is a highly infectious bacterium that causes diarrhea, high temperature and stomach cramps, and is associated with many deaths in the hospital. The pathogen is shed in feces of sick patients and spreads in hospitals mainly via the hands of health care workers.

Now, using a mass spectrometer, the scientists have shown it is possible to identify the unique chemical fingerprint of C. diff, and established the potential for rapid diagnosis.

Electronic nose also identifies unique strain of C. diff

The researchers say rapid detection of C. diff is of concern in hospitals, where risk of infection is high.

Not only does the new method detect the bacterium, but it also identifies the particular strain.

Paul Monks, a professor in the Department of Chemistry at Leicester, who, along with his colleagues, reports the findings in the journal Metabolomics, says rapid detection of C. diff is a big worry in hospitals, not only to reduce infections but also to make sure patients get the right treatment:

"Delayed treatment and inappropriate antibiotics not only cause high morbidity and mortality, but also add costs to the health care system through lost bed days," he adds, explaining that "different strains of C. difficile can cause different symptoms and may need to be treated differently so a test that could determine not only an infection, but what type of infection could lead to new treatment options."

Using the large collection of well-characterized strains of C. diff held in Leicester's Microbiology Department, the team discovered C. diff emits a total of 69 Volatile Organic Compounds (VOCs), unique combinations of which feature in different strains.

Study establishes proof of concept

The study did not go into the clinical practicalities of using the method - for instance on stool samples - but it has established the principle that it has potential for delivering rapid and detailed results, as Prof. Monks explains:

"Our approach may lead to a rapid clinical diagnostic test based on the VOCs released from fecal samples of patients infected with C. difficile. We do not underestimate the challenges in sampling and attributing C. difficile VOCs from fecal samples."

One of the challenges is that the toxin C. diff produces degrades at room temperature and may be undetectable within 2 hours after collection of a stool specimen.

Co-author Andy Ellis, a physical chemistry professor who heads the Spectroscopy and Dynamics lab at Leicester, is nevertheless optimistic about the potential of their discovery:

"This work shows great promise. The different strains of C. diff have significantly different chemical fingerprints and with further research we would hope to be able to develop a reliable and almost instantaneous tool for detecting a specific strain, even if present in very small quantities."

In May 2014, Medical News Today learned that scientists in Finland are working on a noninvasive electronic nose to sniff out prostate cancer. Writing in the Journal of Urology, they suggest in the not-too-distant future, doctors may be making rapid, early diagnoses of prostate cancer using an "eNose" that sniffs a urine sample.

Written by Catharine Paddock PhD

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.