Exam 1: Pt. 2 Ch.12, 13, 25 Flashcards
Ch.12: Characterizing and Classifying Eukaryotes Ch.13: Characterizing and Classifying Viruses and Prions Ch.25: Applied and Env. Microbiology
What are the three eukaryotic microbes of clinical interest for us?
- Fungi
- Protozoa
- Helminths
(F and P = microscopic)
(P and H = “parasites”)
What microorganims are in the group of fungi?
yeast and mold
What do we call fungus that causes disease?
mycoses
(mycosis = singular)
30% cause disease of plants, animals, and humans
What type of eukaryotic microbes can spoil fruit, pickles, jams, and jellies?
fungi (b/c they love sugar, esp. yeast)
What is the non-reproductive part/body of the fungus called?
Thallus
What are the two types of Thallus of fungus?
(the non-reproductive body)
Hyphae–> long filaments = mold
Buds–> spherical = yeasts
What type of thallus do molds have?
Hyphae
- long filaments
What type of thallus do yeasts have?
spherical Buds
What do we call fungi that produce two types of thalli?
Dimorphic
Generally, what part of the dimorphic fungus causes disease?
the yeast form;
- breast in hyphae (long filaments) and then turn into yeast-like form
T/F. All fungi have some means of asexual reproduction.
True
What are two types of asexual reproduction of fungi?
- Budding
2. Spore Formation
Describe the Budding fungi reproduction form.
- similar to prokaryotic budding
- makes pseudohypha
What are Pseudohypha?
what the budding form of fungal reproduction makes
= a series of buds that remain attached to one another and to parent cell
Can fungi reproduce sexually?
yes, most also reproduce sexually (recall, all can reproduce asexually)
T/F. Protozoa are very pathogenic.
False, very few protozoa are pathogens
Do protozoa have a cell wall?
typically lack a cell wall–>therefore can burst if not in certain env.
What type of environments do protozoa require? What are they like morphologically? How do they reproduce?
- require moist env.
- great morphological diversity (pleiomorphic)
- most reproduce asexually ONLY
What type of form to all protozoa have that is the motile feeding stage?
trophozoite
What type of form do SOME protozoa have that is their hardy resting stage/ encapsulated protozoa?
cyst (similar to endospores of bacteria)
- more successful at being pathogens
What do some protozoa have that actively pump water from the cells? Why important?
contractile vacuoles
- protect them from osmotic lysis
How do viruses pick their host? (very general)
- may be specific–only infect particular kind of cell in particular host (Ex: HIV)
- may be generalists– infect many kinds of cells in diff hosts (Ex: West Nile Virus)
What are the three kinds of viral capsid shapes?
- complex
- helical
- polyhedral
What type of viral capsid shape is…
- spiral
- many shapes
- geodesic dome
- helical
- complex
- polyhedral
What is the MC viral capsid shape?
icosahedron (20 sides) polyhedral
What is Lysogeny?
modified replication cycle of viruses
- infected host cells grow and reproduce normally for generations before they lyse
What is it called when phages carry genes that alter phenotype of a bacterium, changing them from harmless to harmful?
lysogenic conversion
What is the lysogenic replication cycle in bacteriophages?
added steps that cause replication of chromosome and virus and cell division of the bacteria–> until the virus decides it wants to kill the bacteria and release the replicated viruses
What is it called when animal viruses remain dormant in host cells?
latent viruses or proviruses
- could be years with no viral activity
Latent viruses can have a temporary or permanent change, what do those terms mean?
- Temporary = some latent viruses do not become incorporated into host chromosome
- Permanent = incorporation of provirus into host DNA
What are proteinaceous infectious agents that lack nucleic acid?
prions
T/F. Prion are living organisms.
False
How can prions affect cells?
Prion PrP converts cellular PrP into a prion PrP, by inducing conformational change
What two things can only destroy prions?
- incineration
- autoclaving in sodium hydroxide
Where is the body is the expression of prion diseases predominantly occur?
nervous system*
can occur in other tissues too
What effect do prion disease have on the brain?
- form large vacuoles in brain
- spongy appearance
What is the name of conditions that are caused by prions and affect the brain and NS?
Spongiform encephalopathies
What are two spongiform encephalopathies?
- Bovine Spongiform Encephalopathy (BSE)—mad cow disease
- Variant Creutzfeldt Jacob Disease (vCID)—humans inf.
Prions composed of different proteins MAY lie behind other muscular and neuronal degenerative diseases like…
- Alzheimer’s disease
- Parkinson’s disease
- Amyotrophic Lateral Sclerosis
T/F. Viruses are considered acellular.
True. Required a host in order to replicate
What is the most common human prion disease?
Variant Creutzfeldt Jacob Disease (vCID)
What causes mad cow disease?
Prion disease; Bovine Spongiform Encephalopathy (BSE)*
How does one get a foodborne illness?
due to consumption of spoiled foods, or foods containing harmful microbes or their products (toxins)
What are symptoms of foodborne illnesses?
nausea, vomiting, diarrhea, fever, fatigue, and muscle cramps
What are the two categories of food poisoning?
- Food infections
2. Food intoxications
What type of foodborne illness is consumption of the living microorganisms?
food infections
What type of food borne illness is consumption of microbial toxins, NOT the microbe?
food intoxications
Where is the most common place that foodborne illnesses come from? What is second and third?
60 % – restaurants
14% caterers/banquets
12% home preparation
7% other
7% unknown
What are number 1-3 MC organism to cause foodborne illness in the US?
- Norovirus
- Salmonella spp.
- Shigella spp.
What are two organisms that are responsible for foodborne illnesses that can grow at refrigerator temperature?
- Listeria monocytogenes
- Yersinia enterocolitica
What is the MC cause of foodborne illness in the US?
norovirus
What are 4 of the MC bacterial and protozoan agents to cause foodborne illnesses?
- Salmonella spp. (2nd MC)
- Shigella spp. (3rd MC)
Grow at fridge temp:
- Listeria monocytogenes
- Yersinia enterocolitica
T/F. Waterborne diseases are common in the US.
False, they are RARE
What are the two MC waterborne agents and the diseases they cause?
Norovirus –> acute gastroenteritis
Giardia intestinalis–> giardiasis
What is the term for water that is considered safe to drink?
potable water
T/F. Potable water is devoid of microorganisms and chemicals.
False. Water is not devoid of microorganisms and chemicals– levels are just low enough that it is not a health concern
What is the indicator bacteria of presence of fecal contamination in water?
Coliform bacteria
- is an indicator of sanitary quality
What are the two levels of treatment of water?
- Municipal Water Treatment– aka drinking water
2. Wastewater Treatment — aka sewage
What level of water treatment is clean water that is used in homes and businesses?
Municipal water treatment (aka drinking water)
What level of water treatment involves water that leaves homes or businesses after use?
Wastewater Treatment (aka sewage)
What does “remediate” mean?
to solve a problem
What is it called to use biological organisms to solve an environmental problem such as contaminated soil or groundwater?
“Bio-remediate”
What is the use of organisms to clean up toxic, hazardous, or recalcitrant compounds by degrading them to harmless compounds?
bioremediation
What is the term for using microbes or their toxins to terrorize human populations?
Bioterrorism
What is the term for using microbes to terrorize human populations by destroying the food supply?
Agroterrorism
What is the ability of hospitals and clinics to handle the casualties?
public health impact
What is the term for how easily agent cant be introduced into the population?
delivery potential
What is the term for the effect of public fear on ability to control an outbreak?
public perception
What term is used for existing response measures?
public health preparedness
What are the four criteria for Assessing Biological threats to humans?
- Public health impact
- Delivery potential
- Public perception
- Public health preparedness
T/F. Category A is the worst bioterrorist threats.
true
What are the top 6 (in order) of the diseases in Category A of Microbial Bioterrorist Threats to Humans?
- Smallpox
- Anthrax
- Plague
- Botulism
- Tularemia
- Viral hemorrhagic fevers (Ebola, etc,)
What are the Biosafety Levels established by CDC?
Biosafety Level 1 (BSL-1)—-through—> BSL-4
What Biosafety Level is handling of moderately hazardous agents?
BSL-2
What Biosafety Level is handling pathogens that do not cause disease in healthy humans?
BSL-1
What Biosafety Level is handling of microbes in safety cabinets or handling microbes that may cause serious or potentially lethal disease after inhalation?
BSL-3
What Biosafety Level is handling of microbes that cause severe or fatal disease?
BSL-4
Ex: working with Ebola virus cultures–must where self-contained suit
What is the part of the fungus that is typically subterranean called?
mycelium (basically a tangled mass of hyphae)
