2. Virulence
• The degree of pathogenecity is reffered as
virulence
• Virulence influenced by several factors
3. Virulence factors
Virulence factors are molecules expressed and secreted
by pathogens (bacteria, viruses, fungi and protozoa) that enable them to
achieve the following:
•colonization of a niche in the host (this includes attachment to cells)
•immunoevasion, evasion of the host's immune response
•immunosuppression, inhibition of the host's immune response
•entry into and exit out of cells (if the pathogen is an intracellular one)
•obtain nutrition from the host
4. Virulence factors for Ustilago maydis
• cAMP-dependent protein kinase catalytic subunit
• MyosinMotor Domain of fungal chitin synthase V
• yap1 Gene Involved in H2O2 Detoxification
• Extracellular effector protiens like
» Hydrolytic enzymes
» Hydrophobins
» Metallo thioneins
» Tetraspanins
• Secreting proteins
• Mating type
5. yap1 Gene involved in H2O2 Detoxification
is required for Virulence
• Cytoplasmic catalase
• superoxide dismutase isoenzymes,
• alkyl hydroxide reductases,
• peroxiredoxins,
• glutathione peroxidase,
• cytochrome C peroxidase
yap1 Affects Survival of U. maydis under Oxidative
Stress Conditions
The Deletion of yap1 Attenuates Virulence
Yap1 Regulates the Expression of Two Peroxidase
Genes
A Fungal Peroxidase Gene Is Involved in the
Detoxification of ROS
Molina and kahmann., 2007
