The mystery of the plate: Fleming's discovery and contribution to the early development of penicillin

History of penicillin

The history of penicillin was shaped by the contributions of numerous scientists. The ultimate result was the discovery of the mould Penicillium's antibacterial activity and the subsequent development of penicillins, the most widely used antibiotics. Following an accidental discovery of the mould, later identified as Penicillium rubens, as the source of the antibacterial principle (1928) and the production of a pure compound (1942), penicillin became the first naturally derived antibiotic. There is anecdotal evidence of ancient societies using moulds to treat infections and of awareness that various moulds inhibited bacterial growth. However, it is not clear if Penicillium species were the species traditionally used or if the antimicrobial substances produced were penicillin. In 1928, Alexander Fleming was the first to discover the antibacterial substance secreted by the Penicillium mould and concentrate the active substance involved, giving it the name penicillin. His success in treating Harry Lambert's streptococcal meningitis, an infection until then fatal, proved to be a critical moment in the medical use of penicillin. Many later scientists were involved in the stabilisation and mass production of penicillin and in the search for more productive strains of Penicillium. Among the most important were Ernst Chain and Howard Florey, who shared with Fleming the 1945 Nobel Prize in Physiology or Medicine.

A Phenotarget Approach for Identifying an Alkaloid Interacting with the Tuberculosis Protein Rv1466

In recent years, there has been a revival of interest in phenotypic-based drug discovery (PDD) due to target-based drug discovery (TDD) falling below expectations. Both PDD and TDD have their unique advantages and should be used as complementary methods in drug discovery. The PhenoTarget approach combines the strengths of the PDD and TDD approaches. Phenotypic screening is conducted initially to detect cellular active components and the hits are then screened against a panel of putative targets. This PhenoTarget protocol can be equally applied to pure compound libraries as well as natural product fractions. Here we described the use of the PhenoTarget approach to identify an anti-tuberculosis lead compound. Fractions from Polycarpa aurata were identified with activity against Mycobacterium tuberculosis H37Rv. Native magnetic resonance mass spectrometry (MRMS) against a panel of 37 proteins from Mycobacterium proteomes showed that a fraction from a 95% ethanol re-extraction specifically formed a protein-ligand complex with Rv1466, a putative uncharacterized Mycobacterium tuberculosis protein. The natural product responsible was isolated and characterized to be polycarpine. The molecular weight of the ligand bound to Rv1466, 233 Da, was half the molecular weight of polycarpine less one proton, indicating that polycarpine formed a covalent bond with Rv1466.

Are animals necessary in 2002? Reply to Dr Michael Festing's book review of Sacred Cows and Golden Geese: the Human Cost of Experiments on Animals

We appreciate this opportunity to defend the concepts we expressed in 2000, in Sacred Cows and Golden Geese: The Human Cost of Experiments on Animals. Enthusiastic critiques such as Dr Michael Festing's are extremely valuable, if those within and without the field of science are finally to understand, choose among, and embrace viable research modalities that are meant to result in cures and treatments for human disease. Criticisms also help to clarify misunderstandings. We hope this essay will shed light on the debate.