Infectious Disease -Yeast and Molds

yeasts are unicellular or multicellular

unicellular

How do yeast proliferate?

by budding

How are mold (myecelium) formed

hyphae

most yeasts and molds are

ubiquitous

Do molds and yeast cause infections

typically no, minor if they do

When do molds and yeast cause infections

when someone is immunocompromised

Fungal meningitis occurred when contaminated steroids were used for what?

spinal and eye injections

Are fungi all around us?

yes

List 5 common fungi diseases

ringworm, jock itch, athletes foot, scalp infection, infection of the nails

Fusarium is a fungi that causes infections of what?

skin and nails

Fusarium leads to what in eyes

keratitis and corneal ulcerations

What are the characteristics of fungal keratitis 

dark spot in the middle of the fungal growth 

What does the dark spot in fungal keratitis tell us fungi are doing

making spores that are resistant to treatment

The 2006, Renu recall was likely not due to contamination, but rather

the solution increased fungi growth

Candida albicans can lead what in immunocompromised individuals?

oral thrush, yeast infections, diaper rash, GI candidiasis

How are fungal infections diagnosed

by culture of KOH

Corneal fungal infections are caused by what?

contact lenses, surgery, trauma due to vegetative matter

How does the contact lens grow fungi

biofilm in the contact lens case

Treating a corneal fungal infection with antibiotics and steroids would cause what?

more problems, suppresses the immune system

What is the first line of treatments for corneal fungal infections

natamycin and voriconazole

How are natamycin and voriconazole effective

disupts the cell membrane

Histoplasmosis symptoms can vary from ___ to__

asymptomatic to flu-like

How is histoplasmosis spread?

birds and bats

What is the common presentation in the eye for someone with histoplasmosis?

chorioretinitis

Presumed Ocular Histoplasmosis syndrome causes what?

chorioretinal scars (“punched-out lesions) and peripapillary atrophy (around optic nerve head)

POHS lesions can reactivate causing what?

neovascularization and areas of scarring

What is malaria caused by

plasmodium

Malaria is a protozoal disease that is ___ prevalent

highly

Step 1 of Malaria transmission

sporozoite in salivary glands of female anopheles mosquitos transmitted by bite

Step 2 of malaria transmission

within minutes, invade liver cells and multiply

Step 3 of malaria transmission

liver cells rupture and release merozoites (asexual form)

stage 4 of malaria transmission

invade RBC’s, grow and digest in vacoule to hydrolyze hemoglobin

stage 5 of malaria transmission

release from dying RBCs, leads to fever chills due to release of cytokines

Why does someone get fever and chills with malaria

release of cytokines

The immune response in malaria occurs from the protozoa doing what?

being released in mass from RBCs

if left untreated, what will happen in malaria

reoccurs

What causes RBCs to stick to vascular endothelial cells in malaria

P. falciparium

What does the RBC’s sticking to vascular endothelium cause in malaria?

infarctions and ischemia responsible for cerebral malaria

What is highly prevalent in parts of the world where malaria is endemic

mutations affecting RBCs

Diagnosis for Malaria

blood smear and microscopy

Treatment for malarai

artermisinins in combination with other anti-malarials

Chagas is caused by what

Trypanosoma cruzi

Trypanosoma cruzi is carried by bugs that are attracted to what?

mucous membranes (eyes, nose, and mouth)

Where are the bugs that cause chagas most common

rural southern areas

How is chagas transmitted

bug droppings

What may occur at the site of the bite in chagas

erythematous nodule 

T.cruzi requires what for their life cycle?

acidic environment of phagolyososome

20-30% of chagas patients develop what?

debilitating, life threatening illness

What is acute eye lid swelling a sign of in chagas?

infection

Acanthamoeba is an amoeba common where?

soil and water

Acanthoamoeba can lead to what eye infections

keratitis and encephalitis

How can acanthamoeba infect the eye?

contact lens wear, swimming pools, showers, hot tubs

Acanthamoeba are what

free-living (trophozoite) and encysted phases

why are acanthoamoeba infections commonly misdiagnosed?

they can look like bacterial infections

Does antibiotics and steroids help get rid of acanthamoeba 

No, can make things worse

What do acanthamoeba cause in the cornea

ring or dendritic ulcers

What is acanthamoeba favorite food?

E.coli

Amoeba feed on the biofilm of what to proliferate?

biofilm

An outbreak of what disease in 2010 was connected to complete moisture plus contact lens solution? 

ancathoamoeba

toxoplasmosis is caused by what

eating infected meat or changing kitty litter

symptoms of toxoplasmosis can range from

asymptomatic to flu-like

Infants born with a toxoplasmosis infection can have lead to what?

TORCH lesions/cysts

The cysts associated with toxoplasmosis can reactivate later and cause what?

chorioretinitis 

What two fungal/protozoal diseases cause chorioretinitis?

Histoplasmosis and Toxoplasmosis

What are the 4 diseases caused by protozoal?

toxoplasmosis, acanthoamoeba, chagus and malaria

pthirius pubus is what?

pubic lice

How is pthirus pubis transmitted

sexual contact

Where does phtharius pubis typically like to live

eyelashes and eyebrows

What should you do if a patient comes in with pubic lice?

pick them out with tweezers and put them in alcohol

Where do bedbugs hide

in bedding and cracks

bedbugs normally feed _____, but can survive how long without feeding

5-10 days, up to a year

How do bedbugs infect humans?

pierce hosts skin with stylet and suck blood leaving an itchy welt on the skin

What infection can be caused by the welts and rashes due to bedbugs

MRSA

treatment for bedbugs

heat

which “diseases” are considered parasites

pubic lice and bedbugs