Term
| Out of how many fungal species, how many are pathogens? |
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Definition
| Around 1.5 million, 200-3000 |
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Term
| What are the three types of aspergillosis |
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Definition
| Allergic, saprophytic and invasive |
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Term
| What are the pathogenciity factors for aspergillus? |
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Definition
Spore size
thermophilic properties
primary metabolism
secondary metabolism
Transporter genes and resistance
ROS protection
Hydrophobin layer |
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Term
| What size are aspergillus spores and why is this important? |
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Definition
2-3um - deep penetration into lungs - normally removed by immune system, but in immunocompromised patients....
They dead |
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Term
| What is Aspergillus optimum temperature, and why is it this? |
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Definition
| 37-42C - higher temperature in decaying vegetation |
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Term
| What is CgrA and why is it important? |
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Definition
| An aspergillus ribosome biogenesis gene - deletion reduces growth at 37C but not 25C |
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Term
| What does most of Aspergillus primary metabolism use, and what is important for pathogenciity? |
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Definition
| Glycosylhydrases, enzymes for plant tissue degredation, but genes that likely exist for versatility in soil - proteases and elastases, allow break down of lung tissue |
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Term
| What did a study in elastase producing isolates of A fumigates in mice find? |
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Definition
elastase isolates 100% mortality
Non elastase, 33% |
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Term
| What is phopholipase and why is it important? |
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Definition
| Alveoli covered by phospholipid rich layer - aspergillus can digest w/phospholipase |
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Term
| Why would aspergillus evolve toxins for saprophytic niche? |
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Definition
| Compete against other saprophytes? |
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Term
| What secondary metabolites cause pathogenesis in Aspergillus and how? |
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Definition
| Gliotoxin - has a disulfide bridge that can bind and inactivate proteins, and the toxin produces ROS 0 causes tissue damage and is an immunosuppressent |
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Term
| Why would Aspergillus have so many transporter genes for saprophytic life? |
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Definition
| To remove toxins from competitors |
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Term
| What does melanin do for Aspergillus in soil andin humans? |
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Definition
| Protects against UV radiation, protects against ROS |
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Term
| What is the spore surface hydrophobin layer? |
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Definition
| A rodlet layer of hydrophobic RodA, which is theorized to aid wind dispersal but also aids immune evasion |
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Term
| What are the proportions of people who get coccidiodomycosis? |
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Definition
| 60& no symptoms, 40% dry cough and flu-like fever, 5% of them get disseminated coccioidomycosis |
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Term
| What are the two main species of cocciodiodes? |
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Definition
| C. immitis and C. posadasii |
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Term
| What is the life cycle of coccidioides? |
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Definition
Filamentous form in soil
Arthrospore formation
Wind dissmeinatin
Inhaled, or settles back on soil
If inhaled, forms spherule, and granuloma formed around spherule
Spherules rupture, endospores disseminate around host |
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Term
| What suggests coccidiodes is becoming a true pathogen? |
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Definition
At 37-40C and elevated CO2 levels spherules are formed (conditions inside mammalian host)
Recent 7-fold increase in number of proteases
Massive reduction in enzymes for plant degredation
SOWgp - allows spherule binding, but elicits immune response, so degraded when endospores produced, as they are small enough to be phagocytosed, unlike spherules
10x easier to dinf in animals than soil |
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