Final answer:
Toxin-producing strains of Corynebacterium diphtheriae cause diphtheria. These strains carry a phage that encodes the diphtheria toxin, leading to the formation of a pseudomembrane in the throat and other serious symptoms. Vaccination with DTaP and Tdap vaccines is the most effective prevention method.
Step-by-step explanation:
Only toxin-producing strains of Corynebacterium diphtheriae will cause disease. C. diphtheriae is a gram-positive rod that belongs to the phylum Actinobacteria and is typically a part of the normal nasopharyngeal microbiota. In some strains, the bacterium becomes pathogenic when it acquires a bacteriophage that encodes for the diphtheria toxin. When produced, this toxin can cause a host of symptoms including the formation of a pseudomembrane in the throat, which can lead to significant difficulty in breathing and potentially fatal outcomes if left untreated.
For C. diphtheriae to cause diphtheria, it must be infected by a temperate bacteriophage that provides the genetic information for the diphtheria toxin. This toxin is classified as an A-B toxin that blocks protein synthesis in the host cells by inactivating elongation factor-2. The progression of diphtheria can include severe complications such as myocarditis and nerve damage, emphasizing the importance of early diagnosis and treatment. The toxin's presence can be detected in vitro through methods such as the polymerase chain reaction (PCR) and immunological techniques.
Prevention through vaccination is the most effective control measure against diphtheria, which is included in the DTaP and Tdap vaccines for children and adults, respectively. These vaccines provide an inactive form of the diphtheria toxoid, protecting individuals from the disease.