Modifiers matching microbe:

• damaging,
• positive,
• larger,
• model,
• pathogenic,
• harmful,
• nasty,
• conventional,
• intestinal,
• opportunistic,
• invasive,
• heterotrophic,
• dangerous,
• cellular,
• tiny,
• hazardous,
• toxic,
• photosynthetic,
• small,
• higher,
• indigenous,
• unicellular,
• useful,
• parasitic,
• beneficial,
• undesirable,
• environmental,
• new,
• biological,
• intracellular,
• latent,
• lethal,
• waterborne,
• infectious,
• effective,
• invisible,
• common,
• contagious,
• primitive,
• anaerobic,
• destructive,
• viable,
• marine,
• eukaryotic,
• real,
• animal,
• deadly,
• unwanted,
• smaller,

Simple categories matching nasty:

• thing,
• animal,
• content,
• preservative,
• stuff,
• disease,
• happening,
• condition,
• substance,
• chemical,
• creature,
• contaminant,
• component,
• insect,
• predator,
• bacteria,
• infection,
• parasite,
• pathogen,
• weather,
• cause,
• allergen,
• vice,
• item,
• critter,
• beast,
• material,
• sickness,
• pest,
• program,
• microbe,
• illness,
• std,
• software,
• bug,
• germ,
• weapon,
• compound,
• virus,
• disorder,
• emotion,