Which types of bacteria are acid fast?

If found in the lungs what kind of bacteria are they most likely to be?

Mycolic acid containing bacteria are acid-fast. They are called acid-fast because water based stains do not penetrate their waxy cell wall, rather acid-fast stains are required.

If found in the lungs it is most likely Mycobacterium tuberculosis since there are no normal types of acid-fast bacteria found in the lungs

When dead Gram negative bacteria release the lipid portion of the lipopolysaccharide called Lipid A, which is an endotoxin. 

Lipid A causes fever, inflammation, shock and blood clotting.

T/F

-Binary fission results in exponential/logarithmic growth

1. Lag Phase- no division, just adapting to environment, gearing up to divide

2. Log Phase-Rapid division and increases in population

3. Stationary phase-resources become scare, the number of cells dividing is balanced out by the number of cells dying.

4. Death Phase-the number of cells dying outweighs the  number of cells dividing-depletion of resources. 

Describe some characteristics of endospores

-2 membranes, 1 thick peptidoglycan, 1 spore coat

Contains acopy of genome and small amount of cytoplasm

Highly dehydrated

Chromosomes are circular double stranded DNA found in the  nucleoid region

Plasmids are also circular and double stranded by they are much much smaller than chromosomes. They do not contain genetic material necessary for vital functions, rather contain information that confer advantage to the cell.

1. Conjugation

2. Transduction

3. Transformation

Differentiate between transformation and transduction

Transformation is simply the uptake of genetic info from the environment

Transduction occurs when a newly synthesized virus takes up bacterial host DNA rather than viral. When this new virus infects another bacterium it transfers the original bacteria's DNA

Donor needs F+ plasmid

Recipient must have F- plasmid

An F+ cell has the gene for the F pilus in its plasmid

The Hfr cells contain that genetic info in their chromosomes

1. Immunosuppression

2. Disturbance of normal microbiota

3. Introduction of bacteria to an incorrect location

1. Extracellular enzymes (allow bacteria to invade)

2. Exotoxins

3. Endotoxins-only a problem if bacteria dies

4. Anti-phagocytic factors

1. Lysozyme and immunoglobulin in tear film

2. Movement of tear film by blinking

3. Normal microbiota (competitive exclusion)

Chlamydia

(mostly the ensuing inflammatory response)

1. Type of genetic material

2. Host range

3. Size

4. Nature of capsid

5. presence/absence of envelope

T/F

Viruses synthesize everything they need for themselves, including their envelope

False

Their envelope is derived from their host's membrane

Rather than immediately invading and replicating and lysing the cells they incorporate into host genome as a provirus and may remain dormant for years.

When they do activate they proceed through the lytic cycle.

1. Herpes Simplex

2. Herpes Zoster

3. Adenovirus

They are due to the misfolding of normal proteins found in every cell (every mammal).

These prions can then cause the misfolding of other normal proteins. 

Incineration

Normal sterilization is ineffective

The normal structure has several alpha helices, it is termed cellular PrP

The disease causing form has beta-pleated sheets and is termed prion PrP

What is the name for Spongiform encephalopathy in humans?

In sheep?

Kuru or Creutzfeld-Jakob disease

Is called Scrapie in sheep

Basically Neurological Degeneration

Deposition of fibrils in the brain

Loss of brain matter resulting in the formation of large vacuoles.

Mushrooms

Molds 

Yeast

Fungi lack chlorophyll

Fungi have cell walls that are made up of chitin

-for food

-for manufacturing beverages and food

-antibiotics

-immunosuppressants

-cholesterol-reducing agents

Molds are large and are made up of hyphae which are long, branched, tubular filaments

Yeast are single celled, small and globular. 

Yeasts typically bud

Molds produce spores

The cell undergoes mitosis

Then the daughter nucleus is sequestered in a small bleb of cytoplasm. 

A new wall forms to separate the daughter from the parent

T/F

Spores produced by molds are diploid

T/F 

Spores are no different than endospores

Falso

Endospores are completely different

Spores produced by asexual reproduction of molds are simply lightweight cells that can be carried off in the wind

In terms of sexual reproduction of fungi, what is the name of the event when two haploid cells fuse together?

What is the name of the result of this fusion?

The process is termed plasmogamy.

 Note this process does not include the fusion of the nuclei, just the cells.

The result is a dikaryon

They have to be from two different mating types, 1 +

and 1 -.

The nuclei fuse to form one diploid nucleus=fruiting body

This process is called karyogamy

The diploid nucleus immediately undergoes meiosis, forming haploid, genetically diverse nuclei.

They are partitioned into + and - cells. 

T/F

Fungi spend most of their life in the haploid state

Superficial is confined to outer dead layers of skin/nails/hair (keratin containing)

Subcutaneous require traumatic introduction of fungi beneath the outer layer of the skin and they remain localized to subepidermal tissues

Systemic mycoses affect internal organs.

Common soil organisms

Althought exposure is common, infection is rare

T/F 

Systemic mycoses only affect the inside of the body, not the skin. 

False,

They can affect the skin

Also lungs, bone, brain and eyes

What are the important risk factors for Mycotic keratitis

(she has 7 listed)

Trauma

Chronic ocular surface diseases

Contact lens usage

Surgery

Topical steroid use

Corneal anesthetic abuse

Immunodeficiencies

Which layer of the cornea do lesions from mycotic keratitis usually invade?

They generally invade the deep stroma of the cornea,

this results in development of the fungus throughout each part of the cornea

Acute Suppurative inflammatory process (basically inflammation accompanied by the production of pus, I believe)

Coagulative necrosis (tissue death where the tissue remaisn fairly liquified)

Fusarium

Aspergillus

Acremonium

Candida

It is the event where a systemic or cutaneous fungal infection has gotten into the blood and spreads throughout the body.

Eye involvement is typically a later event, may involve optic nerve, retina, sclera, conj and orbit. 

Rhizopus

-starts in upper respiratory, travels to the eye, major vessels and CNS.

Ingestion

Vector-borne transmission

Direct contact and penetration of skin/mucous membranes

Flagellates

Amoebae

Ciliates

Sporozoa

Budding

Binary Fission

Schizogeny-

def'n: an episode of the popular American science fiction tv series The X-files (Thank you Wiki)

Schizogeny def'n: a cell where the nucleus undergoes meiosis then mitosis, so you end up with a single cell that has 4, then 8 and then 16 nuclei, then it breaks up into 16 individual cells.

Meiosis and gamete fusion

Conjugation (NOT the same as what happens in bacteria)

-from my notes it is where the chromosomes are split up into a big and little (micro) nucleus, then 2 diploid cells fuse and swap micronuclei. When they separate 2 genetically new cells are formed.

Trophozoites-feeding and reproducing stage

Cyst-dormant, infective stage

Not much, they are basically both dormant cells with thick, resistant walls

Bacterial spores are just more resistant

-lack of nutrients/moisture

-low temp

-toxic chemicals

Definitive-harbors mature,sexually-reproducing forms

Intermediate-immature, asexually reproducing forms

cuts or scrapes on skin/conjunctiva

Inhalation

When acanthamoeba infect their trophozoites invade the eye.

This can lead to the extent where a corneal transplant is required.

-Ingestion of the egg form in cat fecal matter which can contaminate fruit/veggies

-Ingestion of the cyst form in raw, undercooked meat

-from their mama during pregnancy

T/F 

Most humans get infected by Toxoplasmosis by eating cat litter

ummm....False

Most cases are caused by reactivation of in utero infection

Toxoplasmosis gondii

(few infections actually result in serious disease)

Floaters

Reduced vision

Vitreous infiltrate

retinal lesion (creamy white)

anterior uveitis

high IOP

Nematodes (round)

Cestodes (tape)

Trematodes (flukes)

Hermaphroditic-produce both eggs and sperm, do not fertilize themselves

Dioecious-simply male or female

T/F

Disease causing helminths do so by producing toxins

False

Rather they steal nutrients and invade host tissues

Taenia Solium (pork tapeworm)

Loa Loa (from flies)

Toxocara (dog/cat intestines)

Onchocerca volvulus (River blindness)

What is the first leading cause of infectious blindness in the world?

and the second?

1st-Chlamydia

2nd-Onchochera Volvulus

Cysticercosis

-->Neurocysticercosis

the cysticerci float in teh eye-->blurry vision

Can also cause swelling and retinal detachment

Loiasis is caused by the nematode Loa loa (African eye worm)

-is transmitted by the biting deer fly

Larvae move through subdermal connective tissue, can be seen in the eye.

Basically only cause allergic reactions (no blindness)

Onchocerca volvulus

Spread by bite of an infected Similium  black fly (99% in Africa)

The larvae migrate to the eye where they are attacked by the immune system-->chronic keratitis.

Resulting in the affected area becoming opaque