Midterm Flashcards by Emma Holland

Bacillus cereus

++Spore forming bacteria
Preformed toxin in rice= stat vom
Cereals & dried foods
Salt tolerant, wide temp range, alkaline

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Campylobacter jejuni

—spore forming bacteria
Guillain-barre- LPS mimics gangliosides
Environmentally fragile but big abx resister
Can be found in healthy animals but not commensal to humans (no asymptomatic human carriage)
Incubation 2-5 hrs, bloody diarrhea
NEEDS 5% O2

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Clostridium perfringens

++spore forming bacteria

Die when frozen

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Clostridium botulinum

++spore forming bacteria
No antibodies it kills you too fast
Home canning & baby honey
Preformed toxin, strictly anaerobic (could still grow on that shipping container) boil that shit (if in acid, can boil less)
Prevented by sodium nitrite which turns meat red but babies blue

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Escheria coli

—vegetative bacteria 
Aerobe &amp; facult anaer, commensal
Infx dose <10 cells, 0.5-2 microns
Sensitive to heat but resistant to acid 
Petting zoos &amp; ground beef 
Enterohemorrhagic EHEC= HUS kidney failures &amp; seizures, TTP (STEC) bloody diarrhea
Enterotoxigenic ETEC= travelers

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Legionella pneumophila

—vegetative bacteria Legonairres disease & Pontiac fever- flu with PNA
Water reservoirs, 10% fatality
Philadelphia outbreak inhalation
Sensitive to heat & chlorine

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Listeria monocytogenes

++ vegetative bacteria
Rare but deadly, likes the cold 4•
Resistant to acid & salt
Crosses placenta, meningitis, Septicemia, encephalitis. intracellular moves thru actin

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Salmonella Enteritidis

—vegetative bacteria
Eggs & turtles, raw dog food, can hang out on dry foods like chocolate- susceptible to heat but resistant to freezing & drying
Very environmentally adaptable
1-2 days

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Salmonella typhii & paratyphii

—vegetative bacteria
10% fatality
Onset 1-3 weeks, fever & anorexia
Anaer & aer

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Shigella dysenteriae, flexneri, boydii, sonnei

—vegetative bacteria
Waterborne af, does not survive pH <4.5
Mucus & bloody diarrhea, anal tremors
Humans only carriers- daycares & cruise ships
Infective dose just ten cells “bacillary dysentery”

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Staphylococcus aureus

—vegetative bacteria
Toxin resistant to heat & stomach enzymes
.5-6 hrs incubation
Less than 1mcg infx dose, likes to grow in the cold!

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Vibrio cholerae

—vegetative bacteria

60% fatality; food & bev, ricewater stools

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Vibrio parahaemolyticus

—vegetative bacteria

Halophilic, marine, can grow in alkaline conditions

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Vibrio vulnificus

—vegetative bacteria 
Most severe, fatality >50% (alcoholics who eat oysters) gastroenteritis or sepsis 
If immunocomp, wounds exposed to water
Can survive super cold 
Infx dose <100

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Calicivirus- Noro

Virus - ssRNA & naked
SMOL 0.03 microns with tiny infectious dose
6-12 hrs incubation, diverse af, cruise ships. Sensitive to chlorine. Think American vandal

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Hepatitis A

Virus- ssRNA & naked
Lifelong immunity, vaccine
Very environmentally tough- stable at low temps and low pH

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Hepatitis E

Virus- ssRNA & naked

No sequelae, pigs, fatal in preg women

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Rotavirus

Virus- DsRNA & naked

Kids, vaccine doesn’t work well in tropical areas

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Adenovirus

DsDNA, naked. Toughest virus, takes more uv light to kill because repairs DNA. Causes all waterborne conjunctivitis

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Giardia

Protozoa
Large & filterable
Can withstand chlorination, susceptible to heat
Wilderness
Infx dose one cyst. Trophs=upper small intestine. 50% asymptomatic. Fatty & smells bad

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Cryptosporidium Parvum/Hominis

No kryptonite! Can’t filter tiny eggs, Milwaukee, resistant to chlorination- pools & spas. Very zoonotic.
3 microns
Killed by conventional cooking

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Toxoplasma gondii

CATS- mice not afraid. Mild flu then stays in muscles. Sensitive to heat, 50% ppl have antibodies (exposed). Causes abortions

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Trichinella

Pork & game, also goes to muscles

Sensitive to freezing

Agent factors

Psychro=cold (lister, ecoli, staph) and thermo (taq poly)

Most to least resistant to environmental degradation= parasites, enteric viruses, vegetative bacteria

Ethnic host factors

Japan- vibrio parahem

Eskimo & México- botulism

Environmental factors

Temp sensitivity

Least to most temp sensitive- fungi, gram pos, gram neg, viruses,
Aw- bacteria, yeast, mold. CO2 reduces growth because both o2 and pH.

Tetrodotoxin

Intoxication. Neuro, puffer fish, fugu. Paralysis resp distress and hypotension.

Scromboid

Intoxication. Histamine poisoning- esp tuna. Must chill fish immediately, never let warm. Most common. Immediate- 30 min, tingling, rash, n/v/d

Ciguatera

Intoxication. From dinoflagellates (microalgae {harmful algal bloom comes from too many nutrients. Suffocate fish and wipe out fish farm}), most in big old fish (fat deposits) not affected by temp or acid. N/v/d, vertigo, chills, arrhythmia, hypotension

Shellfish toxin (diarrheic, neurotoxic, amnesic, paralytic)

Also dinoflagellates, heat stable. PSP <2hrs, fatal

Water measures

Turbidity= cloudiness, nephelometric turb units
pH= acid disinfects but corrodes pipes
Temp= cold takes longer

International alternatives

(1) slow sand- schmutzdecke, only get liters per day
(2) solar combines heat & UV
(3) chlorine vessels (CDC SWS- treatment, storage, and behavior change)
(4) coag floc with chlorine (PUR)

Removal potential from water

Most bacteria, then viruses, then Protozoa

Milwaukee 3 mistakes

1) changed to polyaluminum chloride
2) tested in the summer
3) reused backwash

Drinking water treatment

Coagulation, flocculation, sedimentation

C- alum+++

Take off bottom and sent as sewage

Drinking water treatment Filtration

Rapid sand filtration- coal & sand bed. Frequent backwash necessary due to buildup. Activated carbon (tortuous pores, made by heat and steam) can even remove pesticides.
Low pressure membrane filtration- different size holes, reverse osmosis tightest but micro is reasonable. Fiber membrane bundles

Drinking water treatment

Disinfection

“To such a level that disease can not be detected” options are
-chlorine (DBPs)
-ozone ($$, no residual, put oxygen across an electrode and produce an o3 radical and bubble through water- rips apart)
-UV (no residual, interfered by dissolved solids, prevents replication in nucleus)
C= amount of disinfectant
T= time
Low CT= strong disinfectant

Drinking water treatment

Distribution

Pressure changes and biofilm

Waste water treatment

Primary treatment

Take out debris & sediment, lipids float to top. Grit chamber & bars etc

Waste water treatment

Secondary

Sludge & solids go into anaerobic acidophilic bacteria eat the organic stuff into acids, methane, CO2. Press water out and that sludge can get eaten by cows
Microorganisms also chew up organic matter in aerobic chamber

Waste water treatment

Tertiary

Sand filter, chlorinate, dechlorinate

SSO

sanitary sewer overflows
Waste pipes are not pressurized
the system is 30-100 years old
Ppl poop 500 grams/day= 1 billion (9 zeroes) noroviruses… think of 10-20 poops a day

Three prongs of investigation

Epidemiological,
clinical (identify victims and source, tested with ELISA for igg to noro then RT-pcr analysis)
environmental (source of pathogen- from harvesters vomiting off board)

Detection of viruses

Environmental- cell culture.
EM & immunoassay- need stool sample.
RT-PCR heat stable but unsure if dead or nah
Whole genome sequencing= even better than PCR

HACCP

Hazard analysis critical control point - an alternative preventative system of quality control, involved complete control over raw materials, process, environment, personnel, distribution, and storage

Clean water act

1972 To protect navigable waterways and then clean drinking water.
Two parts- first says to cities & industries to prevent pollution (TMDLs) Second gives money to waste treatment plants.
Prevent HABs from too many nutrients (fertilizer)

NSSP

National shellfish sanitation project (because rich ppl care about the oysters) involves FDA, state, and shellfish industry. Oysters must grow in clean water, depurate, and tag. Downfall= only bacteria focused

SDWA

1974
Authorizes EPA to regulate 91 contaminants in water. Includes either a MCL=maximum contaminant level or TT= treatment technique and MRDL=maximum residual disinfectant levels
Primary standards- microorgs, DBP, inorganic chems, synthetic org chems, radionuclides
Secondary- metals, odor, chloride, sulfate
Publish consumer confidence reports

Disinfectant scale

1- low pressure membranes (filtration)

2- ozone, 3- chlorine dioxide/ free chlorine (chemicals, tied) 4- UV 5- granular media (filter) 6- chloramines suck

International difficulties

Transport- distribution, pressure, freeloaders
Storage= open containers/biofilm, dippers, vectors
Can boil but burns/pollution

Pb As Hg toxicities

Transplacenta

Cancer, <3 disease, immunotoxicity, reproductive dysfunction, neurotoxicity, nephropathy

LEAD

Not naturally occurring but comes in (1) occupational, (2) environmental, (3) waste & (4) water
Reported in ug/dl=ug/100g. Adults 10ug, kid 5ug= ELE^

MERCURY

Bioaccumulation from methyl (fish & ayurveda)

ARSENIC

naturally occurring but also anthropogenic (industry & farming)

What are metals?

They are elements- their ultimate sources are geologic and they aren’t degraded or detoxified
Transported & accumulated within ecosystems
Bioavailability= molecular form, particle size, and solvency

Cuperation

Recovering lead from earth

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Midterm Flashcards

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