Lecture 15: Foodborne and Waterborne Bacterial Diseases; Lecture 16: Environment

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What are three characteristics of food intoxications?: 1) Bacteria make toxins
2) toxins are ingested with food or water
3) Short incubation time

fast way of getting food poisoning. food toxins go down with food into tummy. gets digested. get sick!

Intoxications are diseases in which bacterial toxins, or poisons, are ingested in food or water.
What are three characteristics of food infections?: 1) live bacteria ingested with food or water
2) bacteria grow
3) comparatively long incubation time

Ex: eat eggs. eggs protect bacteria from your stomach so bacteria can grow. Get sick after awhile.

Infections refer to diseases in which live bacteria in food and water are ingested and subsequently grow in the body.
What causes Botulism?: Clostridium botulinum
Botulism is a food intoxicaation. It is caused by Clostridium botulinum, a G+ _______: anaerobic spore-former.

The spores exist in human and animal (fish, birds, cows) intestines
Spres germinate in ______ environments: anaerobic (cans, jars)
When spores enter the anaerobic environment of cans or jars, they germinate to vegetative bacilli, and the bacilli produce _____: a powerful botulism toxin (900kD)
one ounce would kill all the ppl in the US
The Growth of Clostridium botulinum is not a problem. But ______ is lethal.: botulism toxin
Symptoms of Botulism?: slured speech, difficulty swallowing

flaccid paralysis (limbs lose their tone and become flabby. The toxin penetrates the ends of nerve cells and inhibits the release of the neurotransmitter acetylcholine into the junctions between nerves and the muscles do not contract.)
flaccid paralysis: limbs lose their tone and become flabby. The toxin penetrates the ends of nerve cells and inhibits the release of the neurotransmitter acetylcholine into the junctions between nerves and the muscles do not contract.
Failure of the diaphragm and rib muscles to function leads to _______ and death within a day or two.: respiratory paralysis
What is used to treat botulism?: antitoxin against particular toxin type
How can you prevent botulism?: heat foods to 90oC for 10 minutes before eating them. toxin will be destroyed.
What should not be given to infants to prevent botulism?: honey. spores present in honey may cause infant botulism
What is the mechanism behind botulisM?: Botox, a neurotoxin, blocks the release of acetylcholine. If acetylcholine is not released, nerve impulses are not transmitted
What can type A botox be used for?: strabismus, blepharospasm

eye difficulties- clenched eyelid or cross eyed. good for ppl whose muscles contract constantly.
Staphylococcal Food Poisoning is caused by what?: Staphylococcus aureus, a Gram + cocci
Where can Staphylococcus aureus, a gram + cocci, be found?: nose and skin
How is staphylococcus aureus transmitted?: by sneezing or boils or abscesses
S. aureus is ____-tolerant and can grow over a very broad ______: salt
temperature range (8-45oC)

It loves to grow in meats, fish, dairy products: ham is a favorite
What are the symptoms of Staphylococcal Food Poisoning?: abdominal cramps, nausea, vomiting, diarrhea
Why is Staphylococcus aureus so pathogenic?: It is a heat-resistant enterotoxin (30' at 100oC is not enough)

It is G+. It secretes protein, exotoxin, which goes to intestines, so called enterotoxin.
Enterotoxin of staphylococcus aureus binds nerves in the intestine causing the brain to send signals for _____: vomiting and intestinal water secretion (which results in diarrhea)

toxin is tasteless
Incubation period is relatively short: 1-6 hours. No treatment necessary, bacteria identified by growth on ____: mannitol salt agar

S. aureus mannitol- carbohydrate salt agar --> high concentration
Salmonellosis is caused by?: salmonella
how are Salmonella species introduced into humans?: contaminated water or food

if not cooked properly, organisms are not killed
There are hundreds of serotypes of Salmonella. Name four of them: S. typhimurium
S. heidelberg
S. enteritidis
S. newport
Is Salmonella gram-negative or gram-positive?: gram-negative rods
Name three ways Salmonella is transmitted.: 1) poultry products, eggs (in ovaries of hens)
2) cutting boards
3) live animals (easter chicks and iguanas)
How long is the incubation period for Salmonellosis?: 1-3 days
inflammatory response to the infection increases ____: fluid secretion
What are the symptoms of Salmonellosis?: nausea, fever, vomiting, diarrhea, abdominal cramps, possible dehydration, possible intestinal ulceration
How do you treat Salmonellosis?: Antibiotic, if symptoms are severe
What is the causing agent of typhoid fever?: Salmonella typhi, a G- rod
Where does Salmonella typhi, the causing agent of typhoid fever live?: lives in sewage, water, and on food
Salmonella typhi is tough and is able to resist environment conditions. Most importantly, it will survive ____: stomach acid
What is Salmonella typhi only pathogenic to?: humans
How is Typhoid Fever transmitted?: Five F's

1) flies
2) fingers
3) foods
4) feces
5) fomites
Salmonella typhi invades tissues in ____ causing ____ and ___: small intestine

deep ulcers and bloody stools
If Salmonella typhi causes blood invasion, then what symptoms occur?: ver and delirium (typhos), rose spots on abdomen (hemorrhaging)
How do you treat typhoid fever?: chloramphenicol
Treatment is generally successful with the antibiotic chloramphenicol, except when antibiotic resistance due to R plasmids is noted. About 5 percent of recoverers become _____ and continue to harbor and shed the organisms for a year or more.: carriers
ex: typhoid mary

(s. typhi in gallbladder)
What is the causing agent of cholera?: vibrio cholerae
Is vibrio cholerae gram-negative or gram-positive?: gram-negative curved rod
How is Cholera transmitted?: water or food (raw oysters) contaminated with feces
Vibrio cholerae is susceptible to stomach acid, but f enough ingested, it will ___: colonize intestines
What are the symptoms of Cholera?: diarrhea (1L/hour)- rice water stools
dehydration, cramps
blood thickens, shock/coma
70% mortality
Pathogenicity of Cholera. ____ stimulates fluid loss: Enterotoxin
How is Cholera treated?: Antibiotics and ORS (oral rehydration solution of electrolytes and glucose)

ex: gatorade
How is E.coli transmitted?: mostly ground meat and inadequately washed fruits and vegetables
Symptoms of E. coli: dehydration and salt imbalance by various mechanisms
E. coli may induce diarrhea by enterotoxic or enteroinvasive mechanisms. Enterotoxic strains makes an _____ which causes diarrhea: enterotoxin
Enteroinvasive strains penetrates ____, which leads to possible ____: small intestine
dysentery
_____ is a term usually applied to a disease in which the victim experiences diarrhea within two weeks of traveling to a tropical location.: Traveler's diarrhea
E. coli is a principal agent of Traveler's diarrhea. The bacilli adhere by ____ to the intestinal lining and produce _____, which induce water loss: pili

enterotoxin
Name two enterotoxic strains which causes bloody diarrhea: O157:H&, O104:H21
O157:H7 amd P104:H21 are enterotoxic strains which causes bloody diarrhea. What does the O and the H stand for?: O- cell wall antigen

H- flagellar antigen
When O157:H7 and O104:H21 are confined to the large intestine, it can lead to ___: hemorrhagic colitis
When E.coli involves the kidney and leads to kidney failure, it is called ___: hemolytic uremic syndrome

kidney failure, seizure, coma, and heart attack have all been associated with hemolytic uremic syndrome
Over 100 serological types of E. coli have been implicated in hemolytic uremic syndrome. Low ____, lots of toxins produced: infectious dose

The organism is particularly pathogenic because 100 bacilli are enough to establish infection; it produces toxins at an unusually high rate; and, since it colonizes the intestines, it can deliver toxins to this area efficiently.
What treatment is used for E.coli?: antibiotics and rehyrdration
Peptic Ulcer Disease is caused by what?: Helicobacter pylori
Peptic Ulcer Disease is transmitted by?: contaminated food and water, houseflies
Helicobacter pylori twists its way through the mucous coating of the stach lining and attaches to the stomach wall. There it secretes the enzyme ____: urease
Urease digests urea in the area and produces ____ as an end product. THis neutralizes stomach acid.: ammonia

The ammonia neutralizes acid in the stomach, and the organism begins its destruction of the tissue, supplemented by digestive enzymes normally found in the stomach tissue and secreted cytotoxins.
Helicobacter pylori secretes toxins which cause ___: ulcers
What three things are used to treat peptic ulcer disease?: 1) tetracyline
2) biaxin (clarithromycin)
3) prilosec (omeprazole)
What is used as a diagnosis for peptic ulcer disease?: urea breath test
Helicobacter pylori can make urease. Urea gets broken down into ___ and ____: ammonia and carbon dioxide
Water is classfied into two major types: groundwater and surface water. Groundwater originates from ____: deep wells and subterranean springs
Because of the filtering action of soil, deep sand, and rock, it is virtually ____: free of microorganisms
Surface water is found in ___: lakes, streams, shallow wells
Surface water microbial populations are from ____: environment

Its microbial population may reflect the air through which rain has massed, the meat-packing plant near which a stream flows, or the sewage-treatment facility located along a riverbank
Water is considered contaminated when?: it contains a chemical or biological poison, or an infectious agent
In water that is polluted, the same conditions as contaminated water apply, but ___: the poison or agent is obvious

unpleasant smell or appearance
Potable water refers to?: fit for consumption

potable water is fit for consumption, while unpotable water is unfit
What does BOD stand for?: Biochemical Oxygen Demand
What does BOD refer to?: the amount of oxygen that microorganisms require to decompose organic matter in water
As # of microorganisms increase, BOD ___: increases

As the number of microorganisms increases, the demand for oxygen increases proportionally.
There are 6 steps to the Death of a River. What are they?: 1) Nutrients enter the river from such sources as sewage-treatment facilities, and the river suddenly develops a high nutrient content.
2) Algae bloom rapidly
3) The algae die and settle to the bottom as sediment
4) Microorganisms from the sewage multiply furiously and decompose the sediment.
5) This process quickly uses up the available oxygen in the water.
6) Fish and other small animals and plants then die from lack of oxygen.
What are the 3 types of water pollution?: 1) Physical
2) Chemical
3) Biological
Physical pollution of water occurs when ____: particulate matter such as sand or soil makes the water cloudy, or when cyanobacteria bloom during midsummer and their remains give water the consistency of pea soup
Chemical pollution reseults from the introduction of ____ and ____ to the water.: inorganic and organic
Give examples of chemical pollution (the introduction of inorganic and organic waste to the water): - Water passing out of a mine contains large amounts of copper or iron.
- Phosphates and nitrates from laundry detergents or fertilizer
Biological pollution develops from microorganisms that enter water from ____: human waste, meat-packing plants

leads to diseases like cholera, typhoid fever, E. coli diaarheas
Biological water pollution can lead to what diseases?: cholera
typhoid fever
E. coli diarrheas
What are the three steps towards water purification?: 1) Sedimentation
2) Filtration
3) Chlorination
What three things happen during Sedimentation?: 1) Large particles removed
2) Aluminum sulfate added to form flocs (jelly-like)
3)Flocs settle out and drag organic particles to botoom
During Sedimentation, chemicals such as aluminum sulfate or iron sulfate are dropped as a powder onto water and they form jelly-like masses of coagulated material called ____: flocs
The flocs fall through the water and cling to organic particles and microorganisms, dragging a major portion to the bottom sediment in the process of ___: flocculation
Filtration removes 99% of microbes. What two filters are used?: Slow sand filter
Rapid sand filter
A slow sand filter, containing fine particles of sand several feet deep, is efficient for smaller-scale operations. Within the sand, a layer of microorganisms acts as a supplementary filter. This layer is called a ____, or dirty layer.: schmutzdecke
A rapid sand filter contains coarser particles of gravel. A ____ does not develop in this filter, but the rate of filtration is much higher.: shmutzdecke
The final step in water purification is chlorination, in which chlorine gas is added to the water. A residue of ____ to ____ parts of chlorine per million (ppm) of water often is the standard used: 0.2-1.0

kills most microbes in 30 minutes
What else can be done to the water after chlorination?: soften water and fluoridation
Give an overview of the steps in the purification of municipal water supplies: A) In the reservoir, large objects are removed
B) The water is then sprayed in the air to increase its oxygen content
C) The water is piped to a mixing champer where flocculating agents are added. The flocculating agents are churned in the water and large jelly-like masses, or flocs, form.
D) The flocs settle to the bottom of the sedimentation tank.
E) The water is then filtered.
F) It is chlorinated before being piped off to storage tanks.
What are the three steps towards wastewater treatment?: 1) Pretreatment
2) Primary treatment
3) Secondary treatment
Pretreatment involves ___: grit and insoluble waste removal
Primary treatment involves raw sewage being piped into huge open tanks for organic waste removal. This waste, called sludge, is passed into sludge tanks for further treatment. What are the first three things raw sewage passes through?: Bar screens, grit chamber, primary sedimentation tank
_____ is the solid organic matter that remains in the primary sedimentation tank: primary sludge
Primary treatment removes _____ of the solids: 40-60%
Secondary treatment of sewage has two phases, a liquid phase and a solid phase. Secondary treatment removes ____ of pollutants: 90%
After pirmary treatment, water goes through what three things?: aeration tank, secondary sedimentation, disinfection with chlorine
____ is the solid waste that clumps and settles in the secondary sedimentation tank: activated sludge
Give an overview of wastewater treatment: A) Sewage is initially pretreated with a bar screen to remove grit.

B) The sewage then is piped to a primary settling tank where organic waste passes out to a sludge tank. The water is separated from the microorganisms and passes out.

C) In the liquid phase of secondary treatment, microorganisms digest the soluble organic matter as the water percolates through a filter. In the solid phase treatment, sludge is treated in an activated sludge tank.

D) The settled material flows to the anaerobic sludge tank.

E) Water from the settling tanks may be further processed in tertiary treatment.

F) In the anaerobic sludge tank, sludge is held for several weeks, while anaerobic bacteria break down the sludge into usable end products
What happens after wastewater treatment?: - Water is returned to nearby streams and waterways
- Or, used to irrigate farmland for cultivation of crops and pastures
Name one of the most frequently used indicator organisms: coliform bacteria
Coliform bacteria are normally found in ___: the intestinal tracts of humans and many warm-booded animals
What is the most important indicator organism within coliforms?: E. coli
Name two typical tests used to test water quality: membrane filter technique
DNA-based analysis
What happens in the membrane filter technique?: A water sample is collected and then filtered through membrane filter. Membrane filter is removed and placed on pad containing appropriate medium. Incubation for 24 hours. Typical coliform colonies will appear.
DNA-based analysis also can be used to conduct water-quality tests based on the detection of indicator bacteria such as E.coli. When would you use DNA-based analysis?: if concerned about what organism on plate, do DNA analysis. Take filter from membrane filter technique and put it in lysis solution.
AMMONIFICATION. nitrate is converted to ___: ammonia
NITRIFICATION. Ammonia may be used by plants, or it may be converted by ____ and ____ species to nitrate, which also is used by plants: Nitrosomonas
Nitrobacter
DENITRIFICATION. Some nitrate is broken down to ___: atmospheric nitrogen. This nitrogen is returned to the leguminous plants by nitrogen-fixing microorganisms as nitrate, which is convertee to ammonia.
Nitrogen fixation is the chemical process by which atmospheric nitrogen is incorporated to ___: organic compounds
Two general types of microorganisms are involved in nitrogen fixation: ___and ___: free-living species and symbiotic species
Name two free-living species: Pseudomonas
Azotobacter

free-living species fix nitrogen during their growth cycles.
Symbiotic species of nitrogen-fixing microorganisms live in association with plants that bear their seeds in pods. These plants, known as ____, include peas, beans, soybeans, alfalfa, peanuts, and clover. Species of gram-negative rods known as _____ infe: legumes

Rhizobium
Rhizobium fixes nitrogen and makes nitrogen compounds available to the plant while taking energy-rich carbon compounds in return. The bulk of the nitrogen compounds accumulates when Rhizobium cells die. Legumes then use the compounds to construct amino a: completing the cycle
Give an Overview of the Nitrogen Cycle: Plant and animal protein and metabolic wastes are decomposed by bacteria into ammonia. The ammonia may be used by plants, or it may be converted by Nitrosomonas and Nitrobacter species to nitrate, which also is used by plants. Some nitrate is broken down to atmospheric nitrogen. This nitrogen is returned to the leguminous plants by nitrogen-fixing microorganisms as nitrate, which is converted to ammonia. nimals consume the plants to obtain proteins that contain the nitrogen.

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