Question

What is the characteristics of anthrax spores that make disinfection more difficult?

Answer 1

Solution

Bacteria can infect their host during vegetative state. These vegetative cells are viable states of bacteria but are susceptible to unfavourable heat, pH, osmolarity, starvation or other environmental and host stress factors. Some bacteria can also exist in another form called spores. These structures are extremely resistant to external stress conditions. Their unique chemical composition makes them dormant (non-reproductive and metabolically inactive) but, enable them to withstand adversities. When the environmental conditions are optimum, these spores can germinate again to give rise to vegetative cells.

Bacillus anthracis, the causative agent of anthrax form one endospore per cell.

The characteristics of B. anthracis spores are :

• inactive with highly ordered structure
• resistant to heat, cold, pH, desicction, chemicals and irradiation
• persists in soil and other environments for decades
• the spore consists of an outer exosporium layer surrounding coat proteins that mediates interactions with surfaces, including those encountered by the spore within the host. Interior to coat protein layer an outer membrane followed by cortex and inner membrane surrounds the core containing the genome and other preserved cellular constituents.
• these spores can germinate back to give rise to vegetative cells in presence of germinants (for examples, amino acids such as alanine, tyrosine etc.).