An extremely dangerous, antibiotic-resistant bacterium seen in hospitals, can be wiped off by taking control of its haem-acquisition system to choose and deliver antimicrobials. It is believed that the strategy should also be effective for other dangerous bacteria.
The new methodology has been discovered by Nagoya University researchers and the team in Japan. It can be read in the journal ACS Chemical Biology.
Pseudomonas aeruginosa is a deadly bacterium that results in infections in hospital settings and in people with a weak immune system. It can also be a source for blood infections and pneumonia, while severe infections can be often life-threatening.
Since it is highly resistant to antibiotic treatment, P. aeruginosa is one of the most deadly pathogens and demands an immediate need to seek alternative treatment strategies, according to the World Health Organization.
This bacterium is amongst many others that have evolved a system that enables them to extract difficult-to-access iron from the human body.
Iron is key for bacterial growth and survival, but in humans, most of it is stored inside the ‘haem’ complex of hemoglobin. To get a grip on it, P. aeruginosa and other bacteria release a protein, called HasA, which jumps onto haem in the blood.
This complex is identified by a membrane receptor on the bacterium called HasR, allowing haem entry into the bacterial cell, while HasA is recycled to pick up more haem.
Bioinorganic chemist Osami Shoji of Nagoya University and collaborators have discovered a method to hijack this ‘haem acquisition system’ for drug delivery. They created a powder formed of HasA and the pigment gallium phthalocyanine (GaPc), which, when applied to a culture of P. aeruginosa, was consumed by the bacteria.
When tested upon, over 99.99% of the bacteria were killed after treatment with one micromolar of HasA with GaPc and ten minutes of irradiation.