microbial contamination

例句：

1. 1. The hospital was heavily contaminated with bacteria after the outbreak.
   在这次疫情爆发后，医院被大量细菌严重污染。
2. 2. The food was contaminated with harmful bacteria, causing severe illness.
   食物被有害细菌污染，导致严重的疾病。
3. 3. The research team found evidence of microbial contamination in the water samples.
   研究团队在水样中发现了微生物污染的证据。