bacteriologist

例句：

1. 1. He is a bacteriologist who studies the effects of antibiotics on bacteria.
   他是一名细菌学家，研究抗生素对细菌的影响。
2. 2. The bacteriologist examined the samples and found that they were contaminated with bacteria.
   这位细菌学家检查了样本，发现它们被细菌感染了。
3. 3. In his research, he discovered new ways to combat bacterial infections.
   在他的研究中，他发现了对抗细菌感染的新方法。