EMBARGOED UNTIL: Tuesday 5/21, 3 PM MDT

(Symposium Session 219)

Luisa De Sordi
National Medical Laser Centre, University College London
London, United Kingdom
Phone: 44 (0)20 34561008
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The bacterial pathogen Clostridium difficile is a major cause of hospital acquired infections with symptoms ranging from mild to severe diarrhoea and occasionally serious complications like pseudomembraneous colitis and toxic megacolon. C. difficile infections are linked to 14,000 deaths in the US each year with an estimated healthcare associated economic burden of at least $1 billion annually. Our research group has identified a number of non-toxic light sensitive compounds that are able to kill C. difficile upon irradiation with laser light of a specific wavelength. The technique, known as Photodynamic Antimicrobial Chemotherapy (PACT), shows potential as a novel, rapid, and efficient alternative to traditional antibiotic treatments for C. difficile infection.

This work is being performed at University College London (UCL), UK. Dr Luisa De Sordi is working as a Research Associate on this project led by Dr Laurence Lovat and Dr Adil Butt from the UCL National Medical Laser Centre (NMLC) in collaboration with Prof Peter Mullany and Dr Elaine Allan from the UCL Eastman Dental Institute (EDI). This study will be presented at the ASM General Meeting in Denver (CO) the 21st May 2013 and it is supported by the Charles Wolfson Foundation.

The therapeutic use of light is already being exploited for the treatment of cancer and skin conditions, and there is now strong evidence that it can be used to treat bacterial infectious agents, such as MRSA or Helicobacter pylori. In our laboratory, a model was developed for the screening of selected light-activated molecules to assess the potential of PACT in the control of C. difficile. Remarkably, three compounds were able to kill more than 99.99% of bacteria under anaerobic conditions without harming model colon cells.

We have also identified an alternative powerful and non-toxic method for killing C. difficile that does not require addition of photosensitiser and uses only specific wavelength blue light. The innovation and simplicity of this approach offers the prospect of a new antimicrobial therapy using light to treat C. difficile infection of the colon, as well as for the decontamination of hospital surfaces and devices which are the main vehicle of transmission of this pathogen.