Viral Taxonomy of Human Pathogens

Class IV viruses have just a single plus strand of RNA in their genome. These viruses basically have viral messenger RNA in each virion. The RNA in the particle is by itself infectious, which isn’t true of other types of viruses. There is a minus strand made from the viral genome that gets utilized to make even more plus strands, acting as a template. Two types of these viruses are known, including polioviruses, which makes a long strand of protein that later gets cleaved to make several proteins. Others are those that cause yellow fever and viral encephalitis among humans. These make more than one messenger RNA molecule that both get translated into proteins.

Class V viruses are all single negative strand RNA viruses, which are directly complementary to viral messenger RNA. These genomic strands do not themselves code for protein. There are two types, such as those represented by measles and mumps, which have one molecule of RNA per virion. Each has its own RNA polymerase to make positive strands that will code for one protein each. Another type is the influenza virus that has segmented genomes that each are templates for a single messenger RNA molecule. Some will be creative in that they can be read either way in order to make separate proteins with the same RNA strand.

Class VI viruses are of a special category of enveloped viruses that have two identical plus-strands of RNA in them. These are retroviruses, simply because their genome will direct the formation of a DNA molecule that itself will synthesize viral messenger RNA. It takes reverse transcriptase to make a minus strand of the DNA molecule plus a complementary positive-sense strand. This makes a double strand of DNA that gets integrated into the cell. From there, this DNA gets made into viral messenger RNA to make viral proteins. Budding is used to allow these viruses to leave each cell, which makes them automatically enveloped viruses.

VIRAL TAXONOMY OF HUMAN PATHOGENS

Taxonomy is the process of classifying and naming the different life forms, designed to group similar organisms together. It is not a simple process and involves the observations from many different researchers and constant reevaluation of the process. There are different organizations that keep track of the different prospective changes in