Infectious Disease Flashcards by Dayne Moore

What is a fomite?

Contaminated obese to

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Explain the process of IFN and its effects.

Interferon
When dsDNA is found in the cell from a virus
Can either active EIF 2a protein kinase or oligo adenylate synthase
EIF 2a protein kinase then Phosphorylzes EIF 2a which then triggers the inhibition of translation of mRNA to stop virus synthesis

Oligo adenylate synthase using ATP can make 2,5 oligo adenylic acid
This acid then makes inactive RNAase L active to then chop up mRNA and tRNA

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Which bacteria produce results on a catalase test, and what is it testing?

Staph cocci is +
Strep cocci is -
Test turns H2O2 to H2O and O2

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Gram Positive Infections can cause what?

Erythema
Bollous Impetigo
Fever
Superficial Abcess

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Which test can differentiate S. Aureous?

Coagulase test.

If + it is S. Aureous

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What are some of the adverse effects of staphylococcus Aureous?

Superantigens
Toxins that induce cell lysis
Secreted factors that inhibit neutrophil recruitment: CHIPS

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What are three ways to test for Antibiotic Resistance

Broth Dilution
Antimicrobial gradient
Disc Diffusion

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What are the three ways that bacteria can inherit antibiotic immunity?

Conjugation: Connection
Transformation: Dead Bacteria
Transduction: Bacteriophage

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What are the 3 kinds of hemolysis?

B-Hemolytic: Complete Lysis of RBC
A-Hemolytic: Partial Lysis of RBC, greenish color
Y-Hemolytic: No Lysis of RBC

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Which bacteria form spores?

Gram + Bacilli that are anaerobic

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What color are Gram + and - in stains?

+ is purple

- is pink

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Which agars can be used to culture gram - bacteria?

Blood agar
Chocolate agar
Thayer-Martin agar: Selective for N. Gonorrehea and Meningitidis
Miconkay agar: Selective and Differential

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How can you distinguish Neiserria?

It is positive to both oxidase and Catalase, and also gram negative.

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What is the main cause of acquiring gram negative bacteria?

Hospitalization

-In surgery, dialysis, catheterization, war wounds

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Enterobacteriacae are good causers of what?

Urinary tract, lung, and blood stream infections

Food poisoning.

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Explain mycoplasma pneumonia bacteria? How are they stained? How are they cultured?

They are very small 500-1000 genes
Parasitic
No cell wall (use sterols for integrity of three layer membrane)
They don’t stain well
They are cultured with serum that must have cholesterol. ONLY bacteria that use cholesterol in cell membrane as well.
They affect Upper Respiratory Tract by latching on to epithelial cells and shooting hydrogen peroxide to cause lysis.
They spread by droplets, and immunity is not long lasting. Reinfections are common.
Leads to either atypical pneumonia or tracheobronchitis

Explain Mycobacteria (mycobacterium tuberculosis). How is it stained? How is it cultured?

Aerobic, rod-shaped (Bacilli), gram positive
Doesn’t gram stain very well. You can use mycolic acid for staining in the cell wall. (acid fast)
Use the Lownstein-Jensen Culture (malachite green) to culture.
Droplet infection through air.
Acid fast turns red when positive. Turns everything else blue or green.

Also mycobacterium Leprosae

Explain Legionella? Stain? Culture?

Gram negative Bacilli
Stains pink on gram stain
Found in water droplets (hospital fountain)
Cultured using Buffered Charcoal Yeast Extract Agar

Explain the development cycle of Chlamydia and how is it cultured? Stained?

Gram negative with high lipopolysaccharide
Purely Parasitic
Has Elementary Body (Eb) goes into cell and makes Reticulate Body (Rb). The Rb divides into many Eb which causes cell lysis and releases the Eb.
Cultured only in other Eukaryotic cells

Explain Bacteria Rickettsciae. Stained? Culture

This is pleomorphic cocobacilli
It doesn’t stain well with gram stain.
It is strictly parasitic in nature (culture probably in eukaryotic cells)
Spread by arthropod like tick.
Multiply in small Endothelial cells and vessels.

Parvoviridae

Small, NO ENVELOPE
Linear ssDNA

Replication only occurs in actively dividing cells
Use hairpin turns as DNA primers

DNA and RNA Polymerase are cellular

Examples: Parvovirus B19 aka: fifth disease, aplastic crisis

Polyomaviridae

Small
No Envelope
Circular dsDNA
Must replicate in the Nucleus 
Uses cellular DNA and RNA polymerase

Ex: JC virus: Multifocal leukoencephalopathy
BK virus: Nephropathy in transplants
Markel Cell Virus: Markel cell skin carcinoma

Adenoviridae

Medium
No envelope, FIBER SPIKES aid attachment
Linear dsDNA
-Uses cellular polymerases

Endocytosed
Uses “pan handle duplex” in 2nd strand of replication.

Ex: Acute Respiratory disease
Conjunctivitis
Gastroenteritis

Papillomaviridae

Small
No envelope
Circular dsDNA
Needs Epidermis cycle to replicate

Hepadnaviridae

Small Envelope: w/ surface antigens and lipids Circular Partially dsDNA Uses host DNA polymerase to complete dsDNA. It is transcribed, and translated to get its own DNA polymerase reverse transcriptase to make RNA into the partially dsDNA Ex: Hepatitis B

Herpesviridae

``` Large Envelope Linear dsDNA Encodes own DNA polymerase Needs host RNA polymerase Cytolytic in nature ``` Chicken pox, Epstein-Barr: Mono, Herpes, genital lesions, Roscommon

Poxviridae

``` Large Brick shaped Envelope with lipids Linear covalently close dsDNA Has DNA-dependent RNA Polymerase Happens ENTIRELY IN THE CYTOPLASM ``` Ex: smallpox, vaccinia Molluscum contagious, monkey pox

Picornaviruses

Rhinovirus/Enteroviruses Naked + sense ssRNA Upon infection RNA undergoes immediate translation Enteroviruses: Wide pH replication 3-10 -Best in Small intestine at 37 deg C Rhinovirus: pH of 6-8 -Best in nasal mucosa at 33 deg C

Paramyxoviruses

- ssRNA Envelope Respiratory Tract infections Mumps Measles RNA polymerase makes - to + sense for translation. Buds off plasma membrane ***Has fusion proteins to make syncytia

Orthomyxoviruses

``` - sense segmented ssRNA Envelope Antigenic Variantion: High error rate Has Surface Glycoproteins: -Hemagglutinin: attach -Neuraminidase: Egress, leaving ***Uses endocytosis even with envelope ``` Enters the nucleus and takes CAP from host mRNA to stop host transcription and begin viral transcription Ex: Influenza

Reoviruses

Segmented dsRNA Naked Brings own RNA Polymerase. Copies - to make + sense mRNA Ex: Rotavirus: infant infection of enterocytes to cause diarrhea

Retroviruses

Envelope w/ glycoproteins 2 copies of + sense ssRNA Reverse Transcriptase packaged with RNA. Makes + ssDNA to dsDNA ***DNA is integrated into the cells DNA Ex: HIV

What is specific to the cell wall of Fungi?

Chitin and Ergosterols in plasma membrane

What is used to culture Fungi? What is are very common bodily reactions to fungal infections? Examples of fungal infections?

Sabouraud’s Agar Formation of granulomas (large particles) Acute Suppurations True Pathogens: Asperuillus, Histoplasma, Candida Mycotic Infections Mycotoxicoses: Amanitin and phalloidin (mushrooms, Alfatoxin (peanut), Ergotism (Grain)

How can you treat fungal infections, and what are the agents names?

Bind ergosterol: Polyenes Inhibit ergosterol synthesis: Azoles, Allylamines Inhibit Nucleic acid synthesis: Pyrimidines

What are 6 medically significant parasites?

Enteric Protozoa: Giardia, Entamoeba, Cryptosporidium ``` Plasmodium Leishmania Trypanosomiasis Filariae (roundworms) Schistosomiasis ```

What are some common antiprotozoals? Antihelminthics?

Protozoan: Heavy metals Quinolone derivatives Folic acid antagonists Helminths: Benzimidazoles Tetrahydropyrimidines Piperzaines

Prions?

Misfolded or infectious proteins. Can change normal proteins into misfolded proteins as well. Make up many fatal neurodegenerative diseases ``` Ex: Creutzfeldt-Jakob Diseases Variant Creutzfeldt-Jakob Gerstmann-Straussler-Scheinker Syndrome Fatal Familial Insomnia Kuru ```