Practice Tests
IELTS Reading (AC) Task 1 #114

A. The discovery of penicillin by Scottish scientist Alexander Fleming in 1928 is a classic story of scientific serendipity, marking a watershed moment in the history of medicine. Fleming, a bacteriologist, returned from a holiday to his laboratory at St Mary''s Hospital in London to find that one of his Petri dishes containing Staphylococcus bacteria had been accidentally contaminated by a mould, Penicillium notatum. He observed that the bacteria in the immediate vicinity of the mould had been destroyed, while those further away were growing normally. This led him to hypothesise that the mould was producing a substance that was lethal to the bacteria.

B. Fleming named this active substance "penicillin" and conducted further experiments confirming its antibacterial properties and its apparent harmlessness to animal cells. Despite recognising its immense therapeutic potential, Fleming lacked the resources and chemical expertise to isolate and purify the active compound in sufficient quantities for clinical use. Consequently, for over a decade, his groundbreaking discovery remained largely an academic curiosity, and its practical application in medicine was unrealised.

C. The full potential of penicillin was only unlocked during the Second World War, driven by the urgent need for a treatment for bacterial infections that were devastating wounded soldiers. A team of scientists at Oxford University, led by Howard Florey and Ernst Chain, successfully developed a method for mass-producing a stable form of the drug. By 1944, penicillin was being produced on an industrial scale and was used to treat Allied soldiers, dramatically reducing mortality rates from infected wounds and diseases like pneumonia.

D. The introduction of penicillin heralded the dawn of the antibiotic age. For the first time, physicians had a powerful weapon against a wide range of previously fatal bacterial infections, including septicaemia, scarlet fever, and syphilis. This revolutionised medical practice, making complex surgeries safer and significantly increasing average life expectancy. Fleming, Florey, and Chain were jointly awarded the Nobel Prize in Physiology or Medicine in 1945 for their transformative work, which laid the foundation for modern antibiotic therapy.