| Bakterien | Viren | Pilze | Parasiten |
| R | |||
| Rhodococcus Spp. (+) | Reoviren | Rhizomucor Spp. | Rhabditida |
| Rickettsia Spp. (-) | Respiratory Syncytial Virus (RSV) | Rhizopus Spp. | Rundwürmer (Nematoda) |
| Rothia dentocariosa (+) | Rhabdoviren | Rhodotorula Spp. | |
| Rhinovirus | |||
| Rotavirus | |||
| RSSE-Virus | |||
| Rötelnvirus | |||