细菌的英文是：bacteria。
bacteria
英 [bæk'tɪəriə] 美 [bæk'tɪriə]
n. (复数)细菌。
Bacteria are too small to see with the naked eye.
细菌太小，肉眼看不见。
It is possible to multiply bacteria and other living organisms in the laboratory.
在实验室能够繁殖细菌和其他生物。
近义词：
bacterium
英 [bæk'tɪəriəm] 美 [bæk'tɪriəm]
n. 细菌。
Most of disease is caused from bacterium.
大多数疾病都是由细菌引起的。
A bacterium was identified as the cause for his duodenal ulcer.
一种细菌被断定为造成他十二指肠溃疡的根源。