The Baltimore Classification of Viruses

This week's #micromeded explores the genomic diversity of viruses! These amazing bugs hijack the host machinery to replicate and disseminate their progeny. Viruses use various proteins to replicate their genome or alter the nucleic acid species. Some examples of virus-specific proteins include RNA-depended-RNA polymerase (seen in classes III, IV, and V) and reverse transcriptase (seen in classes VI and VII). Sometimes, the virus uses host machinery to complete part of the genome replication including repair mechanisms, transcription and translation mechanisms, and even export and import mechanisms. The Baltimore Classification is a useful tool for classifying viruses by genomic structure. There are other classification schemes based on size, capsid shape, presence of an envelope, or the organism the virus infects. The Baltimore scheme, however, has endured because of the usefulness in diagnostics, the clinic, and biology. Check out the microbiology module in the clinical pathology division of PathElective for more info on the viruses in these classes.