Imagine a bacteria bio-film being vigorously shaken to make it more pliant when presented with anti-biotics. The first-of-its-kind treatment method has been developed by Scientists from the Indian Institute of Science (IISc) who have used shock-waves— using the same processes of sonic waves of speeding airplanes or the sudden jerks of earthquakes in a much smaller scale — to effectively tackle Salmonella, Pseudomonas and Staphylococcus biofilms.
Bio-films have been persistently difficult to treat, as these bacteria embed themselves in a secreted framework of extracellular polymer matrix on substrates (teeth, medical devices, and inner layers of the heart, among others). This form makes it difficult to remove, and is estimated to be more than 1,000 times more immune to anti-biotics than non-film infections.
A previous US study has shown that more than two-thirds of the bacterial infections are biofilms.
“It is generally very difficult to disrupt the biofilm…If there’s a space between the biofilm, only then the antibiotic can work,” says Jagadeesh Gopalan from IISc’s Department of Aerospace Engineering and one of the authors of this paper.
However, the researchers have successfully demonstrated the use of shock waves to weaken the bacteria. The research involved a group of aerospace and materials engineers and cell biologists from IISc as well as an immunologist from University of Melbourne, Australia, and was published recently in the journal Scientific Reports .
A handheld shock-wave generator was used to create the pulses of pressure and energy (around 0.3 calorie for periods of a few hundred micro-seconds). The process was tested on infections forming on urinary catheters as well as the Pseudomonas chronic pneumonia lung infection and Staphylococcus skin suture infection model in mice (the shockwaves were generated through a diaphragm-less shock tube which is inserted close to the infection to reduce collateral tissue damage).
Immediately, it was seen that bacteria were released out of the bio-film and the colony size decreased. The results showed that the use of shock wave increased the biofilm community’s sensitivity to antibiotic by between 100 to more than 1,000-fold. When tested on mice, it was found that in a matter of three days, the mice who were given shockwave treatment along with the anti-biotic ciprofloxacin had started to recover from the initial weight loss of the infection, while the control group given just the antibiotic showed no decrease in bacterial concentration.
