fungi

Question 0

Grows on wheat and Barley during wet season. Produces ergot toxin(neurotoxin), causes Seizures, hallucination,tremors, death.

Answer 0

Claviceps purpura- Ergotism

Question 1

Fungus found in soil of dry low rainfall areas.endemic in many areas of SW USA,Mexico,C&S America. Valley fever, common cause of pneumonia in endemic areas.

Answer 1

Coccidioides imitis

Question 2

Fungi causing systemic infection, primarily of lungs and central nervous system. Devision Basidiomycota. Pathogenic yeast found in soil enriched with bird/bat dropping.

Answer 2

Cryptococcus neoformans. Cryptococcosis. Decision Basidiomycota

Question 3

Fungal meningitis. Opportunistic pathogen. Pathogenic yeast found in soil enriched with bird/bat dropping.Risk to immune compromised subjects. Inhalation of spores begins infection.
Treatment: Amphotericin B and Flucytosine ( 6-10 weeks)

Answer 3

Cryptococcal meningitis . Decision Basidiomycota

Question 4

Deuteromycota. Red raised lesions on and around the toes and soles of the feet. Webbing between the toes is heavily infected.

Answer 4

Athlete’s foot. Tinea pedis.

Question 5

Tines capitis

Answer 5

Ringworm. In human can be acquired following contact with contaminated soil or animals.Deuteromycota

Question 6

Tinea cruris

Answer 6

Jock itch. Human mycoses. Usually spreads from the feet. Deuteromycota

Question 7

Histoplasmosis. Deuteromycota

Answer 7

Mycoses of the lower respiratory system. Cause: dimorphic ascomycetes fungus. Signs: dry, unproductive cough, shortness of breath,chest pain,fever,chills,headache and malaise. Incubation period: 10days. More common in children up to 15yrs exposed to soil. Treatment: Itraconazole, ketoconazole or Amphotericin B.

Question 8

Blastomycosis dermatitidis

Answer 8

Found in soil with decomposing organic matter. Enter through breaks in skin. Symptoms: similar to flu, include fever,chills,cough, muscle aches,joint pain and chest pain. Fungus can spread (disseminate) to other parts of the body such as skin and bones.

Question 9

Mucormycosis

Answer 9

Most commonly affects the sinuses or lungs. Symptoms: sinus infection include fever, headache and sinus pain. Lung infections with fungus can cause fever and cough. Skin infection can develop after fungus enters through a break in the skin caused by surgery,burns or trauma. Skin infection can look like a blisters or ulcers and the infected tissue may turn black. Other symptoms of skin infection include fever and tenderness, pain, heat,excessive redness or swelling around a wound.

Question 10

Candidiasis

Answer 10

Nonvenereal diseases of the reproductive system

Question 11

Candida albicans

Answer 11

Entry: Mucous membrane. Signs and symptoms: white curdlike discharge, burning, itching, painful intercourse. Incubation period: typically 7-10 days. Susceptibility: women on anti microbial drugs, immune compromised individual such as AIDS patients. May overgrow after a course of antibiotics. Treatment: Antifungal drugs: Clotrimazole, Miconazole,Nystatin, diflucan,Amphotericin B. Prevention: avoid moisture in the genital area, good personal hygiene, use of probiotics( lactobacillus in yogurt).

Question 12

Mycoses of the lower respiratory system caused by Pneuocystis jiroveci

Answer 12

Pneumocystis pneumonia (PCP). Signs: difficulty breathing, anemia,hypoxia and fever. Infection occurs by inhalation of droplets containing the fungus. Common disease in AIDS patients. Treatment: Trimethoprim and Sulfamethoxazole.

Question 13

Fungi divisions:

Answer 13

Zygomycota, Ascomycota, Basidiomycota, Deuteromycota

Question 14

Fungi Reproduction

Answer 14

Asexual : transverse fission, budding, spore production

Sexual: zygosopres, ascospores, basidiospores ( union of compatible nuclei followed by formation of sexual spores.

Question 15

Fungi Nutrition and Metabolism

Answer 15

Saprophytes. Secrete hydrolytic enzymes. Chemoorganoheterotrophs. Glycogen is primary storage polysaccharide. Most are aerobic. Some facultative anaerobes. Obligate anaerobic fungi are found in rumen of cattle.

Question 16

Dimorphism

Answer 16

Some fungi change from Yeast form (Y) to Mold form (M)
In animals Y in host M outside host
In plants M in host and Y outside host

Question 17

Fungi structure

Answer 17

Thallus : body or vegetative structure

Cell walls composed of Chitin, polysaccharide consisting of N-acetylglucosamine residue

Question 18

Mycorrhizae

Answer 18

Association with plant roots

Question 19

Lichen

Answer 19

On algae or Cyanobacteria

Question 20

Coenocytic hyphae

Answer 20

Rhizopus stolonifer- bread mold

Question 21

Dimorphic fungi

Answer 21

Candida albicans

Question 22

Saccharomyces cerevisiae

Answer 22

the common bakers€™s and brewers€™ yeast.

Question 23

asexual spores that a fungus can produce?

Answer 23

Arthrospore is a spore formed by fragmentation of the tip of the hyphae. Blastospore is produced as an outgrowth along a septate hypha. Conidiospores are unprotected spores formed by mitosis at the tips of the hyphae. Sporangiospores are spores produced within a sac called a sporangium.

Question 24

Eumycophyta

Answer 24

True fungi

Question 25

Five named classes of the Eumycophyta.

Answer 25

Chytridiomycetes, Zygomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes. Sexual reproduction occurs in the first four classes, but it has not been observed in members of the class Deuteromycetes. Species in this class multiply by an asexual method only.

Question 26

The Chytridiomycetes characteristics

Answer 26

The Chytridiomycetes form zoospores that are flagellated and motile. In the asexual life cycle, a chytridiomycete zoospore settles on a solid surface and forms a special branching system of hyphae called rhizoids. Rhizoids anchor the fungus to a land environment. Zoospores develop within the zoosporangium. Each zoospore then germinates to form a new mycelium. Sexual reproduction in the Chytridiomycetes involves male and female gametes that unite and form a sexual spore called the oospore.

Question 27

Zygomycetes characteristic

Answer 27

Zygomycetes have nonseptate hyphae and produce sporangiospores within sacs called sporangia. In the sexual reproductive cycle, the cells of sexually opposite hyphae fuse and develop to sexual spores called zygospores. The zygospores then move off to a surface such as a slice of bread and germinate to reproduce the fungus. Rhizopus stolonifer, the common bread mold, is a zygomycete having anchorlike rhizoids and strong surface structures called stolons.

Question 28

Ascomycetes features

Answer 28

Ascomycetes produce a sexual spore called the ascospore. Ascospores form within microscopic sacs called asci (singular: ascus), which are found on macroscopic structures known as ascocarps. Typically, there are eight ascospores per ascus. The ascus develops from the fusion of sexually opposite hyphae. Within the Ascomycetes group are Saccharomyces cerevisiae (the brewing and baking yeast) and the organism that causes ergot disease, Claviceps purpurea.

Question 29

Basidiomycetes features

Answer 29

Basidiomycetes are a diverse class of mushrooms, puffballs, morels, and truffles known collectively as basidiocarps. During their sexual reproductive cycles, the fungi in this group form spore-bearing structures called basidia (singular: basidium). On these structures, a number of sexual spores called basidiospores form. Basidiospores are spread about in the wind and germinate to reproduce the fungus.

Question 30

human pathogens in the Basidiomycetes group?

Answer 30

agricultural pests including the rust and smut fungi are classified as Basidiomycetes. Rust and smut diseases occur in corn, wheat, and other agricultural crops. Other than the toxic mushrooms, there are very few human pathogens in the Basidiomycetes group.

Question 31

In which classes of fungi are many of the human pathogens classified?

Answer 31

Pathogens are found in all classes of the fungi. Numerous human pathogens are currently classified as Deuteromycetes, including Candida albicans, the cause of thrush, yeast infection, and other maladies. Also classified here is Cryptococcus neoformans, the cause of spinal meningitis, and the fungi that cause histoplasmosis, blastomycosis, and coccidioidomycosis.