pathogenicity circular colorful in thin line

abstract allergen amoeba bacillus background bacteria bacterial bacteriology bad biological biology blue care cell cells chemical cholera circle circular collection colony colored concept contaminant contaminants danger dark discovery disease education element epidemic experiment flora formula graphic health hygiene icon illness illustration immune influenza isolated life line linear lined logo macro medical micro microscopic outline pandemic pathogen pathogenicity pollen research round science set shape sick sign silhouette simple spore structure style substance symbol symbols system technology test thin vector