Rank: Species
Lineage: Bacteria;Actinobacteria;Actinobacteria;Corynebacteriales;Corynebacteriaceae;Corynebacterium;Corynebacterium diphtheriae
Description: Corynebacterium. This genus comprises about 50 species of a phenotypically diverse group of bacteria. Some of them (30) are animal and plant pathogens, while other are saprophytes (feeding on dead organics). They may be found as members of the normal microflora of humans, where these bacteria find a suitable niche in virtually every anatomic site. The name Corynebacterium comes from a Greek word that means "club" which in fact is the appearance of the cell arrangements of some species that undergo a so called snapping division (cells "snap apart" forming sharp angles).Corynebacterium diphtheriae. This organism is the best known and most widely studied species of the genus. It is the causal agent of the disease diphtheria, a deadly infectious disease spreading from person to person by respiratory droplets from the throat through coughing and sneezing. In the course of infection, the bacteria invade and colonize tissues of the upper respiratory tract, proliferate and produce exotoxin that inhibits protein synthesis and causes local lesions and systemic degenerative changes in the heart, muscles, peripheral nerves, liver and other vital organs. There are 3 known biotypes (variants) of C. diphteriae (in descending order of their virulence): gravis, intermedius, and mitis. In 1951, Victor Freeman discovered that pathogenic (toxigenic) strains of C. diphtheriae are all lysogenic, i.e. they are infected with a temperate B bacteriophage, whereas non lysogenized strains are avirulent (J. Bacteriol. 1952, 63(3):407-14). r, later it was found that the gene for toxin production is located in the DNA of the B-type phage.
Reference Material:
https://www.ncbi.nlm.nih.gov/genome/?term=Corynebacterium%20diphtheriae
