viral and bacterial infection causing living organism - larvae or worms

pollution worm environment water background ecology biology closeup polluted worms environmental parasite tapeworm problem infection disease roundworms zoology decay contaminate abandon flatworm larvae dirty bacteria toxic insects microorganism pollute pathogen larva parasites contaminants fox dark contaminated dirt illness pathogenic contaminant endoparasite whipworm ecosystem bacterium microorganisms organisms insect viral bacterial causing living organism