Midterm Flashcards
Bacillus cereus
++Spore forming bacteria
Preformed toxin in rice= stat vom
Cereals & dried foods
Salt tolerant, wide temp range, alkaline
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
Clostridium perfringens
++spore forming bacteria
Die when frozen
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
Escheria coli
—vegetative bacteria Aerobe & facult anaer, commensal Infx dose <10 cells, 0.5-2 microns Sensitive to heat but resistant to acid Petting zoos & ground beef Enterohemorrhagic EHEC= HUS kidney failures & seizures, TTP (STEC) bloody diarrhea Enterotoxigenic ETEC= travelers
Legionella pneumophila
—vegetative bacteria Legonairres disease & Pontiac fever- flu with PNA
Water reservoirs, 10% fatality
Philadelphia outbreak inhalation
Sensitive to heat & chlorine
Listeria monocytogenes
++ vegetative bacteria
Rare but deadly, likes the cold 4•
Resistant to acid & salt
Crosses placenta, meningitis, Septicemia, encephalitis. intracellular moves thru actin
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
Salmonella typhii & paratyphii
—vegetative bacteria
10% fatality
Onset 1-3 weeks, fever & anorexia
Anaer & aer
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”
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!
Vibrio cholerae
—vegetative bacteria
60% fatality; food & bev, ricewater stools
Vibrio parahaemolyticus
—vegetative bacteria
Halophilic, marine, can grow in alkaline conditions
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
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
Hepatitis A
Virus- ssRNA & naked
Lifelong immunity, vaccine
Very environmentally tough- stable at low temps and low pH
Hepatitis E
Virus- ssRNA & naked
No sequelae, pigs, fatal in preg women
Rotavirus
Virus- DsRNA & naked
Kids, vaccine doesn’t work well in tropical areas
Adenovirus
DsDNA, naked. Toughest virus, takes more uv light to kill because repairs DNA. Causes all waterborne conjunctivitis
Giardia
Protozoa
Large & filterable
Can withstand chlorination, susceptible to heat
Wilderness
Infx dose one cyst. Trophs=upper small intestine. 50% asymptomatic. Fatty & smells bad
Cryptosporidium Parvum/Hominis
No kryptonite! Can’t filter tiny eggs, Milwaukee, resistant to chlorination- pools & spas. Very zoonotic.
3 microns
Killed by conventional cooking
Toxoplasma gondii
CATS- mice not afraid. Mild flu then stays in muscles. Sensitive to heat, 50% ppl have antibodies (exposed). Causes abortions
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
