Chapter 12 Flashcards
(86 cards)
1
Q
What % of the world’s population is infected with eukaryotic pathogens
A
50%
2
Q
Name 7 common eukaryotic pathogens “CCHAMPS”
A
Cryptosporidium
Cyclospora
hookworm
amebiasis
malaria
Pneumocystis (AIDS)
shistosomiasis
3
Q
How do we benefit from fungi?
A
bread, beer, penicillin
4
Q
What is Mycology
A
the study of fungi
5
Q
True or False: Yeast is part of the normal skin flora?
A
True
6
Q
How many species of fungi are pathogenic?
A
about 200 of 100,000
7
Q
How are decomposing fungi helpful?
A
They recycle nutrients in the soil
8
Q
Humans exploit fungi for __________ and medical purposes. (fill in blank)
A
food
9
Q
What is a chemoheterotroph?
A
organism that acquire carbon and nrg from organic compounds
10
Q
Are fungi unicellular, multicellular or both?
A
Both
11
Q
What are fungal cell walls composed of?
A
Chitin
12
Q
Do fungi tolerate a low or high pH?
A
Lower. Approx. 5
13
Q
What do fungi have that help in digesting hard parts of plants?
A
Cellulases
14
Q
Facultative anaerobic fungi are called ___________?
A
Yeasts
15
Q
Are fungi photosynthetic?
A
No
16
Q
True or False: Fungi are anaerobic…
A
False. Very few are anaerobic.
17
Q
Why are fungal infections more difficult to treat?
A
B/c they are more similar to human cells than bacterial cells.
18
Q
Fill in the blank for FUNGI:
- Cell Type ______________
- Cell Membrane _______________
- Cell Wall ______________
- Spores ______________
- Metabolism ___________________
A
- Eukaryotic
- Sterols present
- Glucans; mannans; chitin (no peptidoglycan)
- Sexual and asexual reproduction
- Limited to heterotrophic; aerobic, facultatively anaerobic
19
Q
Fill in the blank for BACTERIA:
- Cell Type ______________
- Cell Membrane _______________
- Cell Wall ______________
- Spores ______________
- Metabolism ___________________
A
- Prokaryotic
- Sterols absent, excepts in Mycoplasma
- Peptidoglycan
- Endospores (not for reproduction); some asexual reproductive spores
- Heterotrophic, autotrophic; aerobic, facultatively anaerobic, anaerobic
20
Q
How are Multicellular fungi identified/classified?
A
On the basis of physical appearance
21
Q
Fungal colonies are described as _______________ structures
A
Vegetative
22
Q
The __________ is the body of a mold or fleshy fungus that is composed of filaments, or hyphae.
A
thallus
23
Q
What are hyphae?
A
Filaments that grow by elongation at the tips.
24
Q
Vegetative hyphae form _________________, and are involved in ________bolism and growth.
A
mycelium, cata…
25
Aerial hyphae are \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
reproductive structures
26
Vegetative hyphae obtain \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
nutrients
27
What are the characteristics of Fleshy Fungi?
-muticellular w/ a solid mass of hyphae
28
What are the characteristics of Yeasts? Give an example of this.
spherical (non-filamentous), facultative anaerobes -psilocybin mushroom
29
Budding is ____________ division.
uneven
30
Fission is ______________ division.
even
31
Under which condition do yeasts grow faster? anaerobic or aerobic?
aerobic
32
How do yeasts reproduce?
budding AND fission
33
Candida albicans, a \_\_\_\_\_\_\_\_\_(type of rep.) yeast, invades deep tissues through \_\_\_\_\_\_\_\_\_\_\_\_\_.
budding, pseudohypha
34
What does it mean when a fungi is considered dimorphic? What is this dependent upon?
they have two forms of growth: as a mold or a yeast. Temperature dependent.
35
What are the temp. specs for dimorphic fungi?
1) 37 deg. celcius = yeast
2) 25 deg. celcius = mold
36
What does fungal fragmentation refer to?
asexual reproduction
37
Reproductive structures of fungi are called \_\_\_\_\_\_\_.
spores (NOT endospores!)
38
Where does the fungus grow from on a fungal spore?
from the tip
39
What is Mycosis?
Why is it chronic?
a fungal disease. generally chronic becasue
1. fungi are slow-growing
2. depends on initial dose and the resistance of host
40
What are mycoses?
plural form of mycosis
41
Why are treatments of Mycosis often ineffective?
b/c they are non-specific and often toxic.
42
What are Systemic Mycoses?
fungal disease that results in deep tissue disease and often affects organs. Dimorphic fungal spores are inhaled and then the organism spreads through the body.
43
What is Histoplasmosis?
fungal disease caused by *Histoplasma capsulatum*, which is a dimorphic fungus that thrives in **soil rich in nitrates** because of **bird** and **bat** droppings.
- asymptomatic
- like TB
- 50 deaths/year in US
44
What is *Coccidioidomycosis*?
fungal disease caused by *Coccidioides immitis*, a _dimorphic fungus_ that thrives in dry, alkaline soil
- usually asymptomatic
- flu-like symptoms, chest pain, fever, weight loss
- 100,000 infections/yr
- 50 deaths/year in US
- increasing due to HIV
45
What is *Cryptococcosis*?
fungal disease caused by *Cryptococcus*, which is a yeast in **pigeon dung** and **soil**.
- usually an urban disease
- inhaled then spreads to CNS
- chronic meningitis
- becoming more common because of HIV
46
Subcutaneous mycoses
fungal mycosis disease under the skin due to infection by saprophytic soil fungi. These diseases result in skin ulcers and lesions on lymphatics.
47
How do fungi that cause subcutaneous mycoses commonly enter the body?
skin lesion
48
What is *Sporotrichosis*?
caused by *Sporothrix schenkii*, a saprophytic soil fungus.
- called “gardener’s disease”
- rarely infects other organs
- can cause lesions on lymphatics
- rarely fatal
- treated with potassium iodide
49
What are *Cutaneous mycoses* (*dermatomycoses*)?
caused by dermatophytes that secrete an enzyme keratinase, which degrades keratin.
50
What is a dermatophyte?
infects hair shafts, epidermidis, and nails. Dermatomycoses are spread through contact transmission.
51
What is a common name for Tineas?
Ring Worm (fungal disease)
52
What are three types of Tineas?
tinea pedis – athlete’s foot
tinea cruris – jock itch
tinea capitis – ringworm of scalp
53
What are Superficial Mycoses?
fungal disease caused by fungi that feed on dead cells (hair and skin). These diseases are cosmetic (non-destructive) and passed through contact transmission.
54
What is Candidiasis?
fungal disease Candidiasis (yeast infection) is caused by Candida albicans, a yeast which is part of the normal flora. -oral candidiasis = thrush
- vulvovaginal candidiasis = vaginitis
- can lead to rare systemic infections
- seen in AIDS patients
55
What is Mucormycoses?
fungal disease Mucormycoses is caused by Mucor or Rhizopus.
-seen in immuno-compromised patients, patients with diabetes mellitus, patients with leukemia, and patients with AIDS
56
What is Pneumocystis?
Pneumocystis pneumonia is caused by Pneumocystis jirovecii and is the leading cause of death in AIDS patients. -seen in immuno-compromised patients
57
What are Protozoa? Describe
Protozoa are unicellular, eukaryotic chemoheterotrophs that are mostly aerobic.
58
How many of the Protozoa species is pathogenic?
Relatively few (~15) of the 20,000 species of protozoa are pathogenic.
59
Where are Protozoa found? How do they survive?
- normally inhabit soil and water
- have vegetative cells called trophozoite
- feed on bacterial and particulates
- no cell walls (pellicle).
60
How do Protozoa reproduce?
Asexually - fission, budding, or schizogony
sexually - conjugation
61
What is schizogony?
Schizogony is multiple fission: the nucleus undergoes multiple divisions to produce many daughter cells at once.
62
How do Protozoa reproduce sexually?
Protozoa can reproduce sexually through conjugation or by forming a zygote from haploid gametes.
-This type of conjugation is very different from bacterial conjugation.
63
What is encystment in protozoa?
forms a protective cyst that can withstand a lack of food, moisture, or oxygen; high temperatures; or toxic chemicals. Some parasitic species form cysts to survive outside hosts.
64
What does a Trophozoite do in Protozoa?
Trophozoite forms cyst, then the cyst enters host to form a trophozoite, etc.
65
How are Protozoa classified?
The classification of Protozoa is based upon
- DNA
- cell structure
- means of locomotion
66
What (3) groups make up Excavata Superkingdom?
1) G. lamblia
2) T. vaginalis
3) Euglenozoa
67
Characteristics of Excavata?
- have mitosomes
- may live as symbionts in digestive tract
- spindle shaped
- use front-end flagella (2+) for locomotion
"Groove on one side of the cell body, modified (or reduced) mitochondria. Think about giardia."
68
Giardiasis
- Class
- Which parasite?
- Nickname?
- Method of spreading?
- Type of movement?
- Cyst or Vector?
- Effects?
"Gerald took a hike then got the shit's"
- Protozoa: Excavata
- Caused by the human parasite *Giardia lamblia*
- "Hiker's diarrhea"
- attaches to intestinal wall
- spreads via cyst
- most common cause of waterborne diarrhea
69
*Trichomonaisis*
- Class
- Which parasite?
- Nickname?
- Method of spreading?
- Type of movement?
- Cyst or Vector?
- Effects?
| ("I tricked you into sleeping with me")
- Protozoa: Excavata
- caused by the human parasite *Trichomonas vaginalis* -"STD"
- spreads quickly from hosts to host (male to female)...found in vagina (females) and urethra (males) -moves by undulating membrane
- NO CYST STAGE
- itching, foul smell, discharge, irritation (female only)...asymptomatic in males
70
Euglenzoans
- disc-shaped mitochondria
- lack sexual reproduction (asexual)
- Euglenoids = photoautotroths
- transmitted by Arthropod vectors
- move with flagella
71
African Sleeping Sickness
- Class
- Which parasite?
- Method of spreading?
- Type of movement?
- Cyst or Vector?
- Effects?
- Excavata: Euglenzoans
- caused by human parasite *Trypanosum brucei* gambiense
- Tse-Tse fly deposits cyst into bite wound
- long undulating membrane, bordered by flagellum
- Cyst
72
Chagas Disease
- Class
- Which parasite?
- Nickname?
- Method of spreading?
- Type of movement?
- Cyst or Vector?
- Effects?
- Excavata: Euglenzoans
- caused by human parasite *Trypanosoma cruzi*
- "Kissing Bug" -carried by insect vector
- Vector
- 2 Stages:
1) Acute=fever, malaise
2) Chronic = cardiac/digestive problems
- 18 mil infected; 50 deaths/yr.
73
Amebae
- move w/ Pseudopods
- engulf food w/ Pseudopods
- exhibit one intestinal pathogen
74
Amebic dysentery
- Class
- Which parasite?
- Method of spreading?
- Cyst or Vector?
- Effects?
- Protozoa: Amebae
- caused by the human parasite *Entamebae histolytica* -passed by cyst
- cysts
- causes diarrhea/intestinal distress
- blood/mucus in stool
- intestinal cell lysis
- Systemic: can spread to organs
75
Apicomplexans
- not motile (adults)
- obligate INTRACELLULAR PARASITES
- special organelles at apex for Host cell penetration -COMPLEX LIFE CYCLE
76
Malaria
- Class
- Which parasite?
- Method of spreading?
- Effects?
- Protozoa: Apicomplexans
- caused by (4) species of *Plasmodium*
- Transmitted by female Anopheles mosquito
- fever, chills
77
Describe the life cycle of Malaria
1. Mosquito carries infective SPOROZOITE
2. Mosquito bites human and sporozoite travel through blood steam --\> Liver
3. SCHIZOGANY in Liver --\> MEROZOITES are produced & released into blood stream
4. RBC's are infected --\> MEROZOITE develops into 'ring stage' in RBC's
5. 'Ring Stage' grows/divides --\> producing more MEROZOITES
6. RBC ruptures and merozoites released (some M infect new RBC's, others develp into male/female GAMETOCYTES
7. Another MOSQUITO bites and ingest the gametocytes...cycle continues with newly infected Anophele Mosquito
78
Why are Mosquito Bed Nets a cheap and effective method to stop the spread of malaria?
Gametocytes are forming at the same time that Mosquitos are feeding, which happens to be at night. Humans are most vulnerable at night because they are sleeping and can't fend off the mosquito. Nets keep the mosquitos away when they are most active and dangerous.
79
Toxoplasmosis
- Class
- Which parasite?
- parasite reproduction
- Method of spreading?
- Effects?
- Primary Host
Protozoan: Apicomplexan
- caused by *Toxoplasma gondii*
- asexually and sexually in domestic felines
- cat feces / eating raw meat
- causes congenital infection in utero
- Cat
80
Cryptosporidiosis
- Class
- Which parasite?
- Method of spreading?
- Where does organism live?
- Effects?
- Stats?
Protozoan: Apicomplexan
- caused by *Cryptosporidium*
- contact w/ animal feces
- intestinal lining
- infected can lose up to 13L of fluid/day (seen in AIDS patients)...diarrhea
- accounts for up to 30% of diarrhea cases in underdeveloped countries (RECENT OUTBREAK ON EVERY CONTINENT BUT ANTARCTICA)
81
Cilates
- use cilia for locomotion
- exhibit ONE human pathogen (Balantidium coli)
82
* Balantidiasis*
- Class
- Which parasite?
- Method of spreading?
- Cyst or Vector?
- Effects?
- Protozoa: Ciliate
- caused by *Balantidium coli*
- water/fruits/vegetables
- cysts (in L. intestine release TROPHOZOITES=damage and feed off cells)
- dysentery (severe but rare)
83
Name the genus
*Aspergillus*
84
Name the genus
*Coccidioides*
85
Name the genus
*Candida albicans*
86
What is a SAPROPHYTE?
Fungus that recycles nutrients in the soil
