Twentieth-century was the golden 100-year for modern medicine. Therewere batteries of medical breakthroughs in both basic research and clinicalpractice. “Classical (Mendelian) genetics was essentially born in 1900 with therediscovery of Mendel’s work.” (Choudhuri, 2003) And, finally, James Watson andFrancis Crick solved the DNA structure in 1953, so that the classical geneticsand molecular biology were merged. Modern medicine has been at the molecularlevel ever since. Antibiotics was first introduced in 1940s and was regarded asthe last medical revolution. In the early 1950s, the first kidney andbone-marrow transplants were performed in the United States and were consideredone of the most significant breakthroughs in modern medical technology. Humanbeing found the code of life – DNA; Penicillin saved millions of lives sufferedfrom pneumonia; Transplants can cure 60% of leukemia. But, cancer is still killingpatients; TB came back because of drug-resistance; and, only rich people canafford transplant. Is the medical science winning or losing? I would like to probeinto the advantages and drawbacks of the usage of penicillin to try tounderstand the twentieth-century medical breakthroughs.

Penicillin, the first true antibiotic, was discovered by ProfessorAlexander Fleming at St. Mary’s Hospital in London. In September 1928, whenProfessor Fleming came back from a vacation, he found that a blue-green moldcalled Pennicilium Notatum had contaminated petri dishes in his lab… and werekilling some of the bacteria he’d been growing. He suggested that the mold musthave secreted an antibacterial substance and he concentrated the activesubstance and named it to be penicillin. It was an accidental discovery, and ittriggered the first medical breakthrough in the twentieth century, the era ofantibiotic arrived. In 1939, Dr. Howard Florey and three colleagues at OxfordUniversity began intensive research and were able to demonstrate penicillin’sability to kill infectious bacteria. In 1940s, Howard Florey and Ernst Chainisolated the active ingredient and developed a powdery form of the medicine. InWorld War II, penicillin saved thousands of lives from various kinds ofinfection. “Penicillin inhibits the protein struts that link the peptidoglycanstogether in the wall. This inhibition prevents the bacterium from completingtranspeptidation, which is necessary to close the hole in its wall. Because ofthe osmotic pressure difference between the inside of the bacterium and thesurrounding fluid, water rushes in to the bacterium’s unhealed holes and itexplodes.” (Newman, 2015)  Penicillin isa broad-spectrum antibiotic. The bacteria can be controlled successfully by penicillinare as follows: streptococci, staphylococci, clostridium, listeria, chlamydia, andthe bacteria causing gas gangrene, gastritis, peptic ulcer, leptospirosis, lymedisease and typhoid. Penicillin and the following new generations ofantibiotics saved millions of lives suffered from bacterial infections.

Unfortunately, from the very first day penicillin in use, it does“do harm” at the same time. Here is the long list of side effects of penicillinantibiotics: diarrhea, dizziness, heartburn, insomnia, nausea, itching,vomiting, confusion, abdominal pain, easy bruising, bleeding, rash, andallergic reactions, and, even worse: seizures, severe allergic reactions(anaphylaxis), and low blood platelet levels or red blood cell count. The mainreason causing the side effects of antibiotics is that they kill normal defensebacteria at the same time. In a 2008 study, antibiotic side effects led togreater than 140,000 emergency department admissions per year in the UnitedStates. About 50 percent were due to reactions to penicillin class. The factthat antibiotics have unwanted side-effects indicated the inherent deficiencyof this important medical discovery.

But, scientists believe that it is not the inherent deficiency indrugs themselves but the widespread misuse that cause the medical fatigue ofantibiotics. Alexander Fleming, the discoverer of penicillin, warned in his1945 Nobel Peace Prize acceptance speech that indiscriminate use of penicillinmight spur the development of penicillin resistant bacteria. His prediction hasproved accurate. For example, the PRSP (penicillin-resistant streptococcuspneumoniae) is prevailing dramatically in recent years because of the overuseof penicillin. Bacteria are evolutionary microorganisms, they can easily sharegenetic information with one another, even across the barriers of divergentspecies. By this process, they can enhance their survival either by mutatingtheir genetic code or acquiring additional genetic information from othermicroorganisms. Very terribly, many bacterial species have become resistant tomultiple antibiotics, making some infections virtually untreatable. The“post-antibiotic era” is coming, a diagnosis of pneumonia, sepsis, meningitis,or TB can be a death sentence again, just like before the antibiotics wereinvented.

From the analysis on penicillins’ advantages and drawbacks, we doneed to consider that there might be a deep-rooted insufficiency in modernmedicine. Hopefully changes will be made and new medical breakthroughs willhappen in the near future.