(microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants
例句
用作名词 (n.)
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。