Hospital superbug uses tiny sticky fingers to infect medical tools and devices

The antibiotic-resistant Acinetobacter baumannii bacterium is one of the most globally harmful bacteria that causes nosocomial infections. Researchers at the University of Turku have discovered that the bacterium attaches to plastic medical devices using tiny finger-like structures. The researchers were able to develop antibodies that prevent the bacterial spread.
Infections related to hospitals and medical devices form major healthcare problems worldwide. These infections are associated with the ability of pathogens to colonise both biotic and abiotic surfaces.
The research group discovered a unique molecular mechanism that enables Acinetobacter baumannii and related pathogenic bacteria to colonise medical devices. This mechanism enables the bacteria to spread in hospitals.
Acinetobacter baumannii is capable of colonising medical devices by means of archaic chaperone-usher (ACU) pili. Using X-ray crystallography, the researchers found three finger-like loops at the tips of the pili. These “fingers” stick extremely tightly to hydrophobic plastics which are commonly used in medical devices and tools.
– We believe that these fingers are attached into small cavities on the surfaces. This hypothesis could explain why the bacteria spread and attach so strongly to so many different hydrophobic materials, notes Zavialov.
The researchers produced antibodies that bind to the tips of the pili and completely block the bacterial attachment and biofilm formation.
Another antibiotic-resistant pathogen, Pseudomonas aeruginosa, has similar pili, and it forms similar biofilms. The researchers predict that the means suggested for battling A. baumannii might also be applied to control the spread of P. aeruginosa infections and possibly also battle against several other pathogens that use ACU pili.

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