細菌

1. Origins, structure, and basic meaning

• Structure: The spelling is 細菌, read さいきん, and it combines 細, meaning small or fine, with 菌, meaning microorganism or germ.
• Basic usage: 細菌 refers to bacteria, single-celled microorganisms small enough to require magnification for detailed observation.

2. Common pitfalls and similar expressions

• An object of observation and something whose spread is prevented
  • Both examples use the form 細菌. Through a microscope, their varied shapes are observed; in a hygiene context, handwashing helps stop them from spreading.
• Shapes under a microscope and prevention through handwashing
  • 顕微鏡で細菌の形を観察した。 — We observed the shapes of bacteria through a microscope.
  • 手を洗うことで細菌が広がるのを防げる。 — Washing your hands helps prevent bacteria from spreading.