Chapter 22 terms

opportunistic mycoses

• Fungal infections that occur in individuals with weakened immune system

True pathogen

•  microorganism that can cause disease in healthy individuals with a normally functioning immune system 

3 important fungal pathogens

Candida albicans, Coccidioides immitis, Aspergillus

Candida albicans

• A opportunistic mycoses (yeast) that resides in the human mouth, throat, intestine, or vagina for a short lived time provident skin irritations > can been seen as a off-white pasty 

Coccidioides immitis (fungi)

• a true pathogen fungus that resides in the alkaline soils in hot climates in southwest of U.S (CA, AZ, TX, NM)> when inhaling airborne spores (arthroconidia) of the fungus it can create spherules in our lungs that release spores leading to respiratory symptoms, flu like symptoms, and rashes on skin

Aspergillus (mold)

• A opportunistic mycoses that is consumed by airborne contaminants fungus from soil, decaying vegetation, and grains > spores germinate in lungs and can spread to sinuses, ear canals, eyelids, and conjunctiva (the membrane that protects your eye) 

leads to allergic reactions, lung infections

thermal dimorphism (occurs in coccidioides immitis)

these are true pathogens fungi involves changes in shape, size, and other physical characteristics that help organisms adapt to different thermal environments

• Is it a mold at 25-30 celsius (environmental conditions) 

• It is a yeast in response to increase in temp (body temperature, inside the host of 37 celsius)  

why is thermal dimorphism important

• Species can adapt to climate change 

• Ability to survive and reproduce

Dermatophytes + what type of pathogen are they

• a group of fungi specifically mold (ringworms) that causes infections of the skin, hair, and nails usually from contaminated soil from airborne/contac  > looks like ring shaped lesions

• grow when inoculated (injected) into the skin wounds and abrasions (scratches) of healthy people

• true pathogen

the types of Dermatophytes

Trichophyton

Epidermophyton

Microsporum

Trichophyton (genus)

 ringworm of the scalp, body, beard, and nails > focuses more on hiar, skin, nails ex is athlete foot

produces thin walled, smooth macroconidia (multicellular spores), and numerous microconidia (unicellular spore)

Epidermophyton (genus)

 ringworm > affects ONLY skin and nails (no hair)

has ovoid (egg shaped), smooth, clustered macroconidia (multicellular spore), and no microconidia (unicellular spores)

Microsporum (genus)

• ringworm > affects ONLY skin and hair (no nails) 

produces thick-walled, rough macroconidia (multicellular spores), and sparser (scattered) microconidia (unicellular spore)

Thrush (Candida albicans)

thick, white adherent grown on the mucous membranes of mouth, throat > overgrowth of Candida > can cause redness and irritation

Diaper rash (Candida albicans)

• develops in warm, moist environment of a baby’s diaper > skin barrier is compromised + wet, dirty diapers allowing Candida to overgrow > causing skin irritation, redness, inflammation, peeling

the types of Yeast infections (Candida albicans)

This includes Vaginal Candidiasis (Vaginal yeast infection) > which can cause itching, inflammation, white/thick discharge in the vaginal area

can also in be…

• Cutaneous candidiasis: anywhere in the body where overgrowth of Candida > red, itchy rash, blisters on skin  

• thrush 

Effective drugs for Candida albicans and there diseases >Nystatin (pill or liquid form)

• treat fungal infections inside the mouth + lining stomach + intestines 

Effective drugs for Candida albicans and there diseases > topical antifungals

• medications applied directly to the skin or nails to treat fungal infections.

Effective drugs for Candida albicans and there diseases >Amphotericin B

•  treat severe fungal infections inserted by IV or injection

• only chronic or systemic infections

Effective drugs for Candida albicans and there diseases > Fluconazole

• used to treat serious fungal or yeast infections, including vaginal candidiasis, thrush, oral thrush, esophageal candidiasis (throat) > a pill or tablet

Mycotoxicosis

• illness resulting from eating/inhaling toxins from fungi 

Aflatoxins

• when exposed to Aspergillosis > a type of mycotoxicosis aka toxic/poisoning compound > dangerous toxins + carcinogenic (can increase risk of cancer) > ingested from contaminated food > can affect poultry and livestock  

What produces Aflatoxins

• Produced by a fungi called aspergillus genus

Where can Aflatoxins be found

• grown on grains, corn, and peanuts

Pseudohyphae and their role in Candida albicans

• elongated, connected, attached chains of oval/cylindrical cells that resemble true hyphae that are found in fungi specifically yeast

• in candida albicans

  • ability to adhere to host tissues, invade deeper into the body, and contribute to the development of infections

what fungi have Pseudohyphae

Candida Albicans

Valley fever Aka Coccidioidomycosis (the pathogen)

• lives in alkaline soils in semiarid(dry with slight rain), hot climates in southwest united states > caused by inhalation of airborne spores (arthrospores) from the fungus Coccidioides immitis > will cause respiratory symptoms + skin rash + fatigue/headache

Arthroconidia: from Valley Fever aka Coccidioidomycosis

Arthroconidia is the more specific term used for conidia (asexual spores) formed by hyphal fragmentation in fungi like Coccidioides immitis (causes Valley Fever).

Spores

a cell that certain fungi, plants (moss, ferns) produce

Sick building disease

•  refers to a set of health-related symptoms caused by Mycotoxins from indoor mold growth

What causes Sick building disease

indoor air quality + contaminants (fungal)

What does Sick building disease affect

respiratory system,

neurological and

cognitive effects,

skin and eye irritation,

psychological effect

musculoskeletal symptom

tinea

a type of trichophyton infection; a fungal infection > rash may appear on different parts of the body

arthrospores

Arthrospores is a broader term referring to spores formed by hyphal fragmentation, sometimes used interchangeably with arthroconidia.

Life cycle and distribution of Coccidioides

1. exists as a mold with septate hyphae

2. hyphae fragment produces arthrospores when disturbed

3. Arthrospores are inhaled by susceptible host > travel to the lungs

4. warmer temp within the lungs initiate a change > arthrospores develop into spherules

5. Spherule ruptures, the endospores are released, allowing them to spread within the lungs or to other organs > growing into new spherules

candida auris

fungus (yeast) that can cause serious infections in humans, particularly in healthcare settings > Candida auris is resistant to many antifungal medications

• contact with contaminated surfaces or medical equipment + prolonged antibiotic therapy

• unhygienic places

• forms biofilms