exam 4 - n251 fungi

fungi

are fungi prokaryotic or eukaryotic?

eukaryotic

do fungi possess a nucleus?

yes

what organelles do fungi possess?

Nucleus, ER, Golgi apparatus, mitochondria.

 What is the fungal cell wall made of?

chitin

what do fungi lack of that plants do posses?

chlorophyl

what’s the term use for the way of how fungi require an external carbon source?

heterotrophs

what are the 2 types of heterotrophs?

saprophytes and parasite

what is an organism that obtains nutrients from decomposing organic matter

saprophyte

what’s an organism that obtain nutrients from living host plant/animals/humans

parasite

what are yeast?

single celled fungi

what are mold?

multicellular organisms

what do mold form?

filamentous mycelium

how do fungi reproduce

by spore

what type of reproduction does fungi do?

sexual/asexual

what fungal structure is important for identification of species

spores

whats the habitat of fungi

everywhere organic matter

a fungus that infects insects; also known as zoobie - antfugus that is a chinese medicine.

cordyceps

What are the four ways fungi cause harm to humans?

-allergic reaction

-reaction to toxin

-destroy food supply

-colonizing the human body (mycoses)

what type of reaction is caused by fungi allergies

immediate sensitivity

 What symptoms can mold allergies cause?

Coughing, itchy eyes, asthma symptoms.

what type of reaction to toxin does fungi produced?

-hallucinations (ergot fungus)

-poisonous toxins (mushrooms)

-carcinogenic toxins (aflatoxin)

What fungal toxin is produced by Aspergillus?

aflatoxin

 Why is aflatoxin important?

It is carcinogenic.

What fungus causes ergotism?

Ergot fungus.

What crop is commonly infected by ergot fungus?

rye

What does symptoms do ergotism cause?

Severe vasoconstriction and gangrene.

 What neurological symptoms can ergotism produce?

Hallucinations, convulsions, irrational behavior.

What ergot-derived drug is used to induce uterine contractions and to control bleeding after childbirth.?

Ergometrine

what fungus causes wheat rust?

Puccinia graminis

what organism causes potato blight

phytophthora infestans.

 What is a mycosis?

Colonization/infection of the body by fungi.

What are the three categories of mycoses?

superficial / intermediate / systematic

examples of superficial mycosis

athlete foot / thrush / vaginal yeast / nail fungus / sporotrichosis / blastomycosis (skin)

Which fungus causes candidiasis?

Candida albicans

 What is oral candidiasis called?

thrush

What is vaginal candidiasis commonly called?

 Yeast infection.

What is another name for athlete's foot?

tinea pedis

What disease is known as the gardener's hazard?

sporotrichosis

What superficial fungal infection can affect skin and nails?

Dermatophyte infections

Which fungus can form a fungal ball in the lungs?

Aspergillus

Which fungus can affect lungs and brain; lives in the environment people with weakened immune system particularly those who have advanced HIV/ AIDS?

Cryptococcus

Which fungus causes a rare infection cause by mold that live throughout the environment affects mostly sinus or the lungs?

Mucormycosis

What genus causes aspergillosis?

Aspergillus

Who is at high risk for invasive aspergillosis?

Immunocompromised individuals. (tuberculosis, chemo, AIDS)

What disease can Aspergillus cause in the lungs?

 Pulmonary aspergillosis

What may occur if aspergillosis spreads through the bloodstream?

Widespread organ damage.

What does ABPA stand for?

Allergic Bronchopulmonary Aspergillosis.

Which fungal infection is rapidly necrotizing and fulminant?

Mucormycosis

Which fungal infections are classified as systemic mycoses?

Mucormycosis, Aspergillosis, Candidiasis, Cryptococcus, Dimorphic.

What is a dimorphic fungus?

A fungus that changes morphology depending on temperature.

Name three dimorphic fungi discussed in lecture

Histoplasmosis, Blastomycosis, Coccidioidomycosis.

What disease is caused by Histoplasma capsulatum?

Histoplasmosis

 What disease is caused by Blastomyces dermatitidis?

Blastomycosis

What was mucormycosis formerly called?

Zygomycosis

how do people usually acquire mucormycosis?

 Inhalation of spores or skin trauma.

Which body sites are commonly affected by mucormycosis?

 Sinuses and lungs.

Who is most susceptible to mucormycosis?

Immunocompromised patients.

Which species causes cryptococcosis?

 Cryptococcus neoformans

How is Cryptococcus acquired?

 Inhalation of fungal cells/spores.

Who is at highest risk for Cryptococcus infection?

 AIDS patients and other immunocompromised individuals.

what are some useful (fungi) tools for genetic and biochemical studies?

neurospora crassa (common mold) and yeast

What mold is used extensively in genetic research?

Neurospora crassa.

what type of engineered yeast produces?

human insulin / growth hormone / somatostatin / vaccine against viral hepatitis

How are fungi used in food production?

Mushrooms, bread, alcoholic beverages.

What symbiotic association involves fungi?

Lichens

what type of methods are used in laboratories used for fungi diagnosis?

direct observations / cultures

What specimens can be used for direct observation of fungi?

Skin scrapings, hair, nail clippings, tissue sections.

what type of media are used for cultures for fungi?

non-selective / selective / enriched

 What is the standard non-selective fungal medium?

 Sabouraud's dextrose agar.

 What is a selective fungal medium?

 Mycobiotic agar / Sabouraud w/ antibiotic / Cyclohexamine

 Why are antibiotics added to fungal media?

To inhibit bacterial growth.

 What does cycloheximide do in fungal media?

 Prevents mold contamination overgrowth.

What enriched medium is used for fungi?

Brain Heart Infusion with blood. / Potato dextrose agar

 Which medium promotes sporulation?

Potato dextrose agar.

identification elements for fungi in laboratory:

• yeast

• mold

• growth rate

• colony pigmentation

• growth media

• dimorphic growth

How do yeast colonies appear?

 Creamy, pasty, mucoid.

How do mold colonies appear?

Cottony or wooly.

what are the two mount preparations (mold)

scotch tape mount / tease mount

What stain is used for fungal tease mounts?

Lactophenol aniline blue. (T)

What stain is used for Scotch tape mounts?

 Lactophenol aniline blue. (S)

What is examined in fungal mount preparations?

Morphological structures

 Besides morphology, how can fungi be identified?

Subculture, biochemical tests, DNA techniques.