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99 Cards in this Set
- Front
- Back
What are the three levels of organization, smallest to largest?
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1. POPULATION
(sames species) 2. COMMUNITY (all organisms in a given habitat) 3. ECOSYSTEM (includes communities and the abiotic components) |
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What is a primary producers role?
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They fix C02
Includes: chemoautotrophs and photoautotrophs |
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What is a chemoautotroph?
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Use chemicals as their energy source
And CO2 as their Carbon source Ex: microbes on ocean floor that use H2S (only prokaryotes) |
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What is a photoautotroph?
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Uses sunlight as their energy source
Uses CO2 as their carbon source Can be euks or proks |
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What do decomposers do?
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degrade/decay organic matter
Ex: chemoheterotrophs (fungi, decaying microbes) |
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What are consumers?
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They consume producers
Ex: Chemoheterotrophs Can be euks and proks |
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What is symbiosis?
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Living together
Can be neutral, beneficial, or harmful |
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What are the three types of symbiosis?
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1. commensalism
2. mutalism 3. parasitism |
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What is commensalism?
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One species benefits, while the other is unharmed
+,0 Ex: Pseudomonis is unharmed while Clostridium benefits |
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What is mutualism?
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Both species benefit
+,+ Ex: Lichen (fungus and algae) Algae is protected from drying out, and the fungus gets Carbon and Nitrogen |
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What is parasitism?
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One species benefits while the other is harmed
+,- Ex: HIV, TB |
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Carbon Cycle
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global carbon reservoirs: atmosphere, land, aquatic
microorganisms are responsible for many steps in C-cycle |
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Carbon Fixation
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Inorganic C to organic C
(CO2 to CH20) |
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Respiration
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Organic C to Inorganic C
Can be done with or without O2 |
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Fermentation
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Organic carbon to inorganic carbon WITHOUT oxygen
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Methanogenesis
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CH4 production
(producing methane) |
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Methane Oxidation
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CH4 consumption
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Nitrogen Cycle
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N is need for proteins, nucleic acids, etc
N2 constitutes about 80% of earth's atmosphere Euks cannot use N2 |
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Denitrification
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NO3- to N gas
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Nitrogen Fixation
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N2 gas to NH3
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Nitrogen Minneralization
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Organic N to NH4+
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Nitrification
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NH4+ to NO2- and NO3-
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What are characteristics of microbes in the wild?
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Oligotrophic - require low nutrients
They face tough competition for resources in nature |
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What are some adaptions so they can survive in nature?
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- They become better at nutrient capture (like getting Fe)
- Change shape - Form biofilms (like plaque on your teeth) - Store critical nutrients |
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How do biofilms form?
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1. stick (irreversible)
2. attach and multiply (reversible) 3. Other things stick to them 4. Eventually forms a biofilm |
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What is bioremediation?
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The use of microbes to detoxify or degrade pollutants
Can be INTRINSIC or ENHANCED |
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What is intrinsic bioremediation?
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Letting the microbes take care of the contaminant
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What is enhanced bioremediation?
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Helping out a little
- fertilization: adding limited nutrients like N, P, K, S, etc - Bioaugmentation: adding microbes that can degrade the contaminant |
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What is waste water?
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From domestic/industrial effluents
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What is domestic water?
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black water (sewer) and gray water (shower, sink)
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What does waster water needed to be treated?
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- its high in nutrients
- its high in pathogens - its low in oxygen |
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What are the treatment goals?
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1. Remove organic compounds/nutrients
2. Eliminate pathogens 3. Increase oxygen * the water you're releasing has to be cleaner than the source its entering |
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Primary Treatment
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- physically screen out large junk, let settle
- settling basic (grit) - primary tanks (sludge at bottom settles and is removed) - large junk gone, still high in organics, nutrients, and pathogens |
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Secondary Treatment
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- microbial treatment to decrease nutrient load and organics
- bio towers (remove C) rotating contactors (remove N) - digestors (capture Methane for fuel plants to use) |
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Tertiary Treatment
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removes excess chemicals
Ex: Phosphorus |
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Disinfection
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Adding chlorine
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How do we treat drinking water?
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1) remove potentially pathogenic microbes
2) decrease turbidity (cloudiness) 3) eliminate taste and odor 4) reduce chemicals (ex: arsenic) |
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What is an indicator organism?
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If present, it indicates contamination
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What are characteristics of an ideal indicator organism?
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1. survive as long as the pathogen
2. present in greater #s than the pathogen 3. present whenever pathogens are 4. easy to detect |
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What are commonly used indicators?
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1. Total Coliforms
- problem: coliforms can be of environmental origin 2. Fecal coliforms - subset of coliforms that are thermotolerant (37 degrees C) 3. E. Coli and Enterococci - more specific indicators of fecal contamination |
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What is the coliform drinking limit?
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0/100 mL
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What is epidemiology?
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The study of disease in populations
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What is an endemic?
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Disease is constantly present in a population
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What is an epidemic?
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Unusually large number of cases present
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What is an outbreak?
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Cluster of cases in a short period
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What is a pandemic?
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Epidemic that spreads worldwide
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What is a reservoir?
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Where pathogens persist
Can be human, non-human, and environmental |
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Human Reservoirs
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- Symptomatic: obvious symptoms
- Asymptomatic: carriers Ex: gonorrhea, meningitis |
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Non-human Reservoirs
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Zoonoses - diseases of animals that can be transmitted to humans
Ex: west nile |
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Environmental Reservoirs
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- Soil (botulism)
- Water (Legionaire's) - Hospitals (nosocomial infections) |
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What are the four different types of disease transmission?
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1. Contact
2. Food and Water 3. Air via droplets, dust, soil 4. Vectors |
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1. Transmission via Contact
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a) Direct
b) Indirect c) Droplets |
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direct contact
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when one person directly contacts another
Ex: fecal-oral (feces to food to mouth) |
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indirect contact
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via inanimate objects
Ex: fomites - inanimate objects that can transfer microbes (doorknobs, railings, phones) |
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droplet contact
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inhalation of contaminated respiratory droplets
Ex: sneezing |
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2. Transmission via Food and Water
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- gastrointestinal pathogens through water
- ingestion of contaminated food - cross-contamination |
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3. Air transmission via droplets, dust, and soil
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-
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4. Transmission via Vectors
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organisms that carry disease
- Mechanical - Biological |
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What is a mechanical vector?
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Vector that transfers microbes from one host to another on a surface
Ex: flies |
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What is a biological vector?
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vector is required in microbes life cycles
Ex: mosquitos |
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What are the two main pathogens of the skin?
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Staph and Strep
- both are gram + cocci - Strep: catalase negative - Staph: catalase positive |
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What does Streptococcus pyogenes cause?
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Strep throat
Group A Strep (GAS) Its easily treatable on the skin (as impetigo, erysipelas) |
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What is Invasive GAS?
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Flesh Eating Strep
- subcutaneous tissue infection - breaks down protein up to 1 in/hr |
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What does Staphylococcus aureus cause?
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Staph infection
- also responsible for Toxic Shock Syndrome and eye stys |
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What is MRSA?
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Methicillin Resistant Staph Aureus
- produces a penicillin binding protein - treat with a cillin or vancomyocin (block cell wall synthesis) and rifamprin (block MRNA synthesis) |
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Why is the nervous system susceptible to infections?
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The immune system (our blood) and antibiotic delivery (which occurs in the blood stream) is far away from the nervous system
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What is Meningitis?
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Inflammation of the meninges
(bacterial, viral, or fungal) |
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Which type of meningitis has the highest fatality?
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Bacterial
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What are three types of bacteria that commonly affect the nervous system?
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Streptococcus pneumoniae
Haemophilus influenza Neisseria meningitidis |
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What is Neisseria meningtidis responsible for?
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Epidemic Meningitis - the one there is a vaccine against
(gram -, diplococci) -LPS, capsule, fimbriae - Humans are the only host = reservoir - 5-20% are asymptomatic carriers |
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What is the primary transmission route for N. meningitidis?
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Respiratory air droplets
(smoking greatly increases chances of getting it) |
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What are the symptoms of meningitis?
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Fever, stiff neck, nausea, vomitting, sleepiness, rash
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What are two common disease that affect the cardiovascular and lymphatic systems?
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1. Hemorrhagic Fevers
2. Lyme Disease |
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What is a hemorrhagic fever?
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- widespread vascular damage
- caused by small RNA viruses (like ebola) - zoonotic (bats) - infection via aerosols - no treatment for it - prevention = stay away |
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What is Lyme disease caused by?
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Borrelia borgdorferi
gram negative, spriochete Its the most common tickborne illness in the US |
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What animals serves as hosts for Lyme Disease?
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Deer and field mice
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How is it transmitted?
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Its transmitted by infected deer ticks
- the deer is the reservoir, the tick is the biological vector |
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Describe the progression of Lyme Disease
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- 7 to 10 days post bite: target lesion, flu symptoms
- Weeks to months later: arthritis, heart problems, neurological problems - Years later: brain degeneration |
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How is Lyme disease treated?
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Early Antibiotics
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How can we prevent the disease?
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- highest transmission is from may to june
- light colored pants, socks tucked in - insecticides - examine for ticks, remove promptly |
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What are digestive disease illnesses caused by?
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Foodborne pathogens
Two ways: 1) Food poisoning by toxins 2) Food poisoning by microbes that establish an infection in the GI tract |
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Food Poisoning by Toxins
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- bacteria need not enter the body
- they don't need to be alive either - toxins are secreted into food prior to ingestion - toxins aren't destroyed by heating |
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What is Clostridium botulism often found in?
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Canned food
Used in Botox |
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What is Bacillus cereus found in?
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Rice
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Staphylococcus aureus?
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Meats/custards
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Clostridium perfringes?
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Meat
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What is one of the most common foodborne illnesses caused by?
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S. aureus
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What are some characteristics of S. aureus?
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- Gram positive cocci in clusters
- Catalase + - Can tolerate low moisture and high salt - Mesophile (rapid growth @ 20-37 degrees C) - Heat stable enterotoxin (targets intestines, and heating doesn't kill it) |
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What do we find S. aureus in?
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Processed/salted meats
Potato salad Custard filled pastries |
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When is S. aureus most commonly seen?
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Nov-Dec and July-August
Seen year round though |
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How is it transmitted?
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Contamination through human carrier
Human is the mechanical vector |
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How is it treated?
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Symptoms appear quickly after consumption of toxin - anywhere from 30 minutes to 6 hours
It resolves spontaneously in 24 hours |
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What are some illnesses that are a result of food poisoning by microbes that establish infection in the GI tract?
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Salmonella
E. coli Listeria VIbrio Campylobacter |
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Characteristics of Salmonella enteritidis
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Enterobacteriacea
Gram negative rods Ferment glucose, produce acid NOT A COLIFORM |
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Where is S. enteritidis found?
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Its found in nearly all animals and is mostly spread from them
(iguanas, snakes, etc) Its an obligate pathogen in humans |
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What are the most contaminated foods that cause Salmonella?
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eggs, unpasteurized milk, chicken
(incidence peaks in summer) |
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How much salmonella much you ingest to become infected?
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Very large #s ( > 1 million)
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Where does it attach and multiply?
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In the small intestine
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When do symptoms occur?
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Onset is 6-48 hrs after ingestion (nausea, diarrhea, cramps, fever)
It needs time to grow to it takes longer than Staph aureus) Resolves spontaneously in 2 days to a week |