Fungi And Viruses Flashcards
What is the difference of bacteria and fungi in their composition of cell wall
- Bacteria cell wall has peptidoglycan and their cell membrane contains cholesterol
- fungi cell wall has chitin, cell membrane contains ergesterol
What has ergosterol in the cell membrane
Only fungi (eukaryotes)
What has a very different ribosome type compared to us
Bacteria
70s (50s +30s)
Eukaryotes vs Prokaryote
Bacteria are the prokaryotes and they have different ribosomes than eukaryotes, making it easier to treat
- single cell
- peptidoglycan in the cell wall
Unicellular bacterial like colonies that reproduce by budding
Yeasts
Filamentous fungi; colonies appear cotton-like
Molds
What has branches like hyphae?
Molds
What kind of hyphae can a mold have
Septate: cross wall segments
Aseptate: no septa and many nuclei
Temperature dependent fungi
Dimorphic fungi
What is the parasitic dimorphic fungi
Yeast, parasitic when grown at 37 degrees
What is the saprophytic dimorphic fungi
Mold/mycelial: when grown at 25 degrees
How are dimorphic fungi grown
As yeast or furry mold
What is the most common yeast
Candida albicans
What reproduces by budding
Yeasts
What is the fungal cell wall component targeted by most antifungal drugs
Azoles target 14 a-demethylase preventing lanosterol from converting to zimosterol
How do polyene antimycotics act and why do they have significant toxicity
They directly target ergosterol
-bc cholesterol and ergosterol follow similar pathway, antifungal drugs are very toxic!
What is a primary fungal pathogen?
Can infect immunocompentent hosts
What are the 4 primary fungal pathogens
- blastomyces dermatitidis
- coccidioides immitis
- histoplasmosis capsulatum
- paracoccioides brasiliensis
What is the number one opportunistic fungal?
Candida albicans
What are the two fungi like bacteria
Actinomyces and Nocardia
Which of the two fungi like bacteria is confused with TB because it is partially acid fast
Nocardia asteroides
What are the viral nucleic acids
They can be DNA or RNA
-most are ssRNA
What is the most common viral nucleic acid
SsRNA
What are the dsDNA viruses
Herpesvirus -HSV Adenovirus -URIs -papillomavirus -HPV Poxvirus -pox like lesion
What are the two different subtypes of ssRNA viruses
Positive strand (+) sense Negative strand (-) nonsense
What is positive strand virus (+) sense
The RNA can directly translate to a protein
What is the negative strained (-) antisense ssRNA viruses
RNA strand servers as template to synthesize mRNA
-template has to be transcribed to (+) sense, then to protein
Pneumotropic virus
Respiratory system
-influence, rhinovirus, SARS, respiratory syncytial virus
Dermotropic virus
Skin
- chickenpox
- smallpox
- herpes
Viscerotropic virus
Blood and visceral organs
Neurotrophic viruses
Central nervous systme
What is the viral replication cycle
- attachment
- penetration/uncoating (injects, fuses, or phagocytized)
- biosynthesis (viral genome and protein replication)
- maturation/assembly (new viruses ar assembled)
- release (new viruses are released, burst size
Dormant viral infection, reactivation of viral infection may induce transformation and proliferation with resulting neoplasia (EBV, HPV, HBV, HTLV-1)
Latency
What kind of viruses are latent
Lysogenic
What is the only hepatitis virus that has DNA instead of RNA
HBV
Also latent
These types of viruses rupture the cell, they have a burst size which is the number of virions released from one cell
Lytic viruses
Number of virions released from one cell
Lytic
Can virus be both lytic and lysogenic?
Yes
-cold sore
What kind of cancer does HPV cause
Cervical cancer
What kind of cancer does HBV cause
Liver cancer
What are the two common DNA tumor viruses
HPV
HBV
What are the common RNA tumor viruses
HCV
HTLV-1
HIV/HHV-8
What kind of cancer does HCV cause
Liver cancer
What kind of cancer does HTLV-1 cause
T-cell leukemia
What kind of cancer does HIV/HHV-8 cause
Kaposi sarcoma
Is it HIV or HHV-8 that causes kaposi sarcoma
HHV-8 actually causes it
