Penicillin Could Be Back In Battle Against Antibiotic Resistant Bugs

Link: Penicillin Could Be Back In Battle Against Antibiotic Resistant Bugs That Kill Millions.

Research led by the University of Warwick has uncovered exactly how the bacterium Streptococcus pneumoniae has become resistant to the antibiotic penicillin. The same research could also open up MRSA to attack by penicillin and help create a library of designer antibiotics to use against a range of other dangerous bacteria. Worldwide Streptococcus pneumoniae causes 5 million fatal pneumonia infections a year in children. In the US it causes 1 million cases a year of pneumococcal pneumonia in the elderly of which up to 7% are fatal.  Penicillin normally acts by preventing the construction of an essential component of the bacterial cell wall: the Peptidoglycan. This component provides a protective mesh around the otherwise fragile bacterial cell, providing the mechanical support and stability required for the integrity and viability of cells of Streptococcus pneumoniae and other bacteria including MRSA. The researchers targeted a protein called MurM that is essential for clinically observed penicillin resistance and has also been linked to changes in the chemical make up of the peptidoglycan that appear in penicillin resistant Streptococcus pneumoniae isolated from patients with pneumococcal infections. The researchers found that MurM acted as an enzyme that was key to the formation of particular structures within the S. pneumoniae peptidoglycan called dipeptide bridges that link together strands of the peptidoglycan mesh that contributes to the bacterial cell wall. The presence of high levels of these dipeptide bridges in the peptidoglycan of Streptococcus pneumoniae is a pre-requisite for high level penicillin resistance.