Research could put penicillin back in battle against antibiotic resistant bugs that kill millionsMarch 13, 2008Research 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. This new research has completely exposed how Streptococcus pneumoniae builds its penicillin immunity and opens up many ways to disrupt that mechanism and restore penicillin as a weapon against these bacteria. The research was led by Dr Adrian Lloyd of the University of Warwick's Department of Biological Sciences along with other colleagues from the University of Warwick, the Université Laval, Ste-Foy in Quebec, and The Rockefeller University in New York. The research was funded by Welcome Trust and the MRC. 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. The Warwick team were able to replicate the activity of MurM in a test tube, allowing them to define the chemistry of the MurM reaction in detail and understand every key step of how Streptococcus pneumoniae deploys MurM to gain this resistance. The results will allow the Warwick team, and any interested pharmaceutical researchers, to target the MurM reaction in Streptococcus pneumoniae in a way which will lead to the development of drugs which will disrupt the resistance of Streptococcus pneumoniae to penicillin. The same research also offers exciting possibilities to disrupt the antibiotic resistance of MRSA which uses similarly constructed peptide bridges in the construction of the peptidoglycan component of its cell wall. Therefore, thanks to this research, even MRSA could now be opened up to treatment by penicillin. A further spin-off from this new MurM research, is that the Warwick led researchers are also able to readily reproduce every precursor step the bacterial cell uses to create its peptidoglycan. The tools developed at Warwick open up each step of the creation of the peptidoglycan (MurA, MurB, MurC etc, etc) used by an array of dangerous bacteria. This provides a valuable collection of targets for pharmaceutical companies seeking ways of disrupting antibiotic resistance in such bacteria. The University of Warwick part of the research team have now established a new network of academics from the fields of chemistry, biology and medicine, as well as pharmaceutical companies to share and exploit this new treasure trove of targets which could help create a range of new designer antibiotic based treatments targeted at a range of bacteria that can cause significant health problems. This network is the UK Bacterial Cell Wall Biosynthesis Network or UK-BaCWAN and it is supported by the Medical Research Council of the UK. The network web site is http://www.warwick.ac.uk/go/bacwan Note for editors: the full research paper is called Characterization of tRNA-dependent Peptide Bond Formation by MurM in the Synthesis of Streptococcus pneumoniae Peptidoglycan and it has just been published (March 2008) in The Journal of Biological Chemistry, vol 283(10), pages 6402-6417. University of Warwick |
|||||||||||||||||||||
| Related Penicillin Current Events and Penicillin News Articles New imagining technique could lead to better antibiotics and cancer drugs A recently devised method of imaging the chemical communication and warfare between microorganisms could lead to new antibiotics, antifungal, antiviral and anti-cancer drugs, said a Texas AgriLife Research scientist. Scientists visualize how bacteria talk to one another Using imaging mass spectrometry, researchers at the University of California, San Diego have developed tools that will enable scientists to visualize how different cell populations of cells communicate. Progress made on group B streptococcus vaccine Scientists supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have completed a Phase II clinical study that indicates a vaccine to prevent Group B Streptococcus (GBS) infection is possible. Henry Ford Hospital study: A MRSA strain linked to high death rates A strain of MRSA that causes bloodstream infections is five times more lethal than other strains and has shown to have some resistance to the potent antibiotic drug vancomycin used to treat MRSA, according to a Henry Ford Hospital study. Despite Risk, Older African Americans More Likely Than Others To Avoid Flu Vaccine A study about why African American seniors do or do not get influenza vaccinations finds that many of them do not have accurate and complete information about the flu itself, the safety and efficacy of the inoculations, and the ease and necessity of getting the shots. Syphilis survey reveals need for accurate testing for early infection Although syphilis is one of the oldest known diseases, most health professionals do not have access to the tests necessary to reliably diagnose it in its earliest and most infectious stage. Structure of antibiotic ramoplanin reveals promising mechanism With the "last resort" antibiotic Vancomycin now plagued by the first signs of bacterial resistance, a scientific collaboration centered at Duke University has identified how a candidate successor antibiotic known as Ramoplanin A2 can kill pathogenic bacteria by interrupting how they form their cell membranes. Antibiotic prescribing should be standardized across Europe to help tackle resistance Antibiotic prescribing for respiratory illnesses should be standardised across Europe to help reduce inappropriate prescribing and resistance. Researchers describe 'implausible' chemistry that produces herbicidal compound A soil microbe that uses chemical warfare to fight off competitors employs an unusual chemical pathway in the manufacture of its arsenal, researchers report, making use of an enzyme that can do what no other enzyme is known to do: break a non-activated carbon-carbon bond in a single step. Researchers find 'surprising link' leads toward a new antibiotic As the best drugs become increasingly resistant to superbugs, McMaster University researchers have discovered a completely different way of looking for a new antibiotic. More Penicillin Current Events and Penicillin News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||