In the 1940 of the 20th century, mankind has not been able to master a highly effective treatment of bacterial infections and side effects of the drug.
If a person is suffering from tuberculosis, then it means that the person will die soon.
Bacterial infections as well as terminally ill people in fear, once infected surgery means death.
However, all this change is because of the invention of the world's first antibiotic penicillin – 1928 United Kingdom bacteriologist Alexander Fleming, penicillin was found due to a lucky mistake.

你可以下载一个海辞词典，里面专业英语都有的，我也是到里面试着翻译了下，觉着还可以，上面的语法后面的几句有点别扭，你可以试着修改下。

我手机发的，看不到应助

Before 1940s, the mankind has never been able to master a drug which can cure the bacterial infections in highly effective and lower side effects. If someone get the tuberculosis means he/she will die in a few days. Bacterial infections just like the terminal disease threaten people's life. Because once someone get infected during a surgery means death. however, this situation has been changed by the invention of the world's first antibiotic penicillin which is found due to a lucky mistake by UK's bacteriologist Alexander Fleming in 1928.