Some kinds of bacteria can join forces to form protective communities called biofilms. These thin layers of bacteria, which grow on the surfaces of medical implants or directly on tissue in the body, can be difficult to treat because they are more resistant to drugs than the bacteria on their own. Currently there is no established way to image biofilms in or out of the body.
Pavlos Anastasiadis and colleagues at the University of Hawaii at Manoa have developed a method to watch and measure growing biofilms with ultrasound. The researchers used contrast agents, microparticles that are normally injected into the body to improve the quality of ultrasound images. They modified the surface of bubbles in the agents to stick to two kinds of infectious bacteria that form biofilms. Acoustic pulses of ultrasound cause the bubbles to "ring" like a bell, revealing their location and the attached biofilm.
The research was done on isolated biofilms. The next step will be to test it in living tissue. Anastasiadis hopes to develop the technique to diagnose infective endocarditis, a disease in which bacterial biofilms form on the inner walls of damaged heart valves.
The talk "Targeted ultrasound contrast agents for the imaging of biofilm infections" (2aBB10) by Pavlos Anastasiadis is at 10:45 a.m. on Tuesday, May 19, 2009. Abstract: http://asa.aip.org/web2/asa/abstracts/search.may09/asa323.html
157th ASA Meeting
Sound has a long history in medicine, from the earliest 19th century stethoscopes to the latest ultrasound techniques that image growing fetuses and beating hearts. These days, sound waves are emerging as the basis of many new medical technologies -- helping to deliver genes and drugs to specific tissues, detecting bacterial infections and kidney stones, trimming the prostate, and many other applications. Acoustics is also blending with other disciplines such as neuroscience to help people with speech and hearing problems.
Journalists are invited to discover the world of medical acoustics at the 157th meeting of the Acoustical Society of America (ASA), which convenes from May 18-22 at the Hilton Portland & Executive Tower in Portland, Oregon. Medical acoustics is only one theme represented in more than 1,100 talks and posters to be presented at the meeting. Overall, acoustics is a cross-section of diverse disciplines that also includes architecture, underwater research, psychology, physics, animal bioacoustics, music, noise control, and speech.