细菌 (xìjūn) means 'bacteria' or 'germs.' It is a scientific term commonly used in both everyday and academic Chinese. For example, 细菌都死了 means 'the bacteria all died.'
洗手可以减少细菌的传播。
xǐ shǒu kěyǐ jiǎnshǎo xìjūn de chuánbō.
Washing your hands can reduce the spread of bacteria.
这种细菌在高温下会被杀死。
zhè zhǒng xìjūn zài gāowēn xià huì bèi shā sǐ.
This type of bacteria will be killed at high temperatures.
食物放太久容易滋生细菌。
shíwù fàng tài jiǔ róngyì zīshēng xìjūn.
Food left out too long easily breeds bacteria.