microbes of different s

background bacteria bacterium biology cells close closeup clostridium cocci disease enterovirus epidemic fusobacterium hiv human illustration infection influenza isolated klebsiella macro medical medicine metagenomic micro microbes microbiology microorganisms microscope microscopic mycobacterium neisseria pathology purulent pyogenic sample science scientific shapes staphylococci staphylococcus streptococcus threedimensional virus zika