Microbial biofilms—dense, sticky mats of bacteria in which are hard to treat as well as can lead to dangerous infections—often form in medical equipment, such as flexible plastic tubing used in catheters or in tubes used to help patients breathe. By some estimates, more than 1 million people contract infections through medical devices in U.S. hospitals each year, many of which are due to biofilms. A study through The University of Texas at Austin suggests a possible brand-new way to prevent such biofilms through forming, which could sharply reduce incidents of related hospital-borne infection.
Vernita Gordon, an assistant professor of physics as well as senior author of the paper appearing today inside the Proceedings of the National Academy of Sciences, detected the key mechanism in which triggers biofilms to form. She next envisions creating coatings for medical devices as well as various other surfaces in which could block the trigger as well as keep bacteria through clustering to form intractable biofilms.
“in which’s important to prevent biofilms before they start,” Gordon said. “in which’s much easier to wipe out free-floating bacteria than a biofilm.”
Certain patients are especially susceptible to biofilm related infections. People with cystic fibrosis, diabetes as well as chronic obstructive pulmonary disease often develop serious as well as even life-threatening bacterial infections in which are hard to treat, in large part because the bacteria—such as Pseudomonas aeruginosa—form biofilms in which are resistant to the host’s immune cells as well as to antibiotics.
Earlier work had shown in which before Pseudomonas bacteria form a biofilm, they have to sense in which they are attached to a surface. nevertheless in which wasn’t clear what cues the bacteria sense. currently, according to the brand-new study, the bacteria sense something called mechanical shear, which is usually a kind of stretching in which happens when a bacterium is usually attached to a surface as well as the surrounding liquid is usually moving as well as/or in which pulls itself along.
So what is usually shear? Imagine you’re in a river as well as you’re trying to pull yourself along underwater by grabbing rocks on the bottom as well as pulling forward. Shear is usually the force in which is usually stretching your body; in which’s what you feel in your arms as well as legs as you pull against the resistance of the water. You might not feel much shear if the water is usually still as well as you’re moving slowly, or in which might be high if the river is usually moving fast as well as you’re going the opposite way. Let go of the rocks as well as just “go with the flow” of the river, as well as you won’t feel any shear.
Sensing shear tells Pseudomonas in which in which’s no longer free-floating nevertheless attached to a surface as well as triggers in which to start producing a biofilm. Gordon says the discovery paves the way for biomedical engineers to begin developing methods to stop bacteria through sensing shear. So far, most strategies being developed to prevent the formation of biofilms use one of two approaches: kill the bacteria outright or prevent them through attaching to the surface.
Both those methods are problematic. Antimicrobials usually only work against certain types of bacteria under certain circumstances, as well as they can become ineffective if susceptible bacteria evolve resistance. in which’s also hard to develop a universal anti-stick surface because bacteria have many ways to attach to a surface.
“What we suggest is usually, if they are responding to a mechanical cue, then you could make a third class of biofilm-preventing surface,” Gordon said. “You could modulate the mechanics of the surface so they never get the signal in which they are attached, as well as they never start doing a biofilm.”
Gordon suggests in which for maximum effectiveness, surfaces could be engineered that has a combination of these three approaches.
Because of inconsistent reporting as well as differences in analytical methods, in which is usually difficult to measure exactly how many people inside the U.S. each year acquire infections through biofilms forming on medical devices. Estimates range widely—through 185,000 infections (based on a 2014 CDC study) to 2.8 million (based on a 2007 study inside the journal Clinical Infectious Diseases estimating up to 4 million health-care acquired infections (HAI’s) as well as a 2008 study inside the journal Biotechnology as well as Bioengineering estimating up to 70 percent of HAI’s are associated with medical implants).
Bacteria harness the lotus effect to protect themselves
Christopher A. Rodesney el al., “Mechanosensing of shear by Pseudomonas aeruginosa leads to increased levels of the cyclic-di-GMP signal initiating biofilm development,” PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1703255114