🦠 the bacteria (main characters)
Salmonella enterica · Enterobacteriaceae family · ~2,500 serotypes (she contains multitudes)
sal is the regina george of foodborne illness. she shows up everywhere — poultry, eggs, raw produce, peanut butter, cantaloupe, pet turtles, your whole life — completely uninvited and fully committed to ruining whatever event you had planned. she doesn't care that it's your company's biggest trial day. she doesn't care that you have an SQF audit in december. she just DOES that.
her incubation period is 6–72 hours which is peak chaos behavior. long enough that you can't figure out where you got her, short enough to ruin the whole weekend. she causes nausea, vomiting, diarrhea, fever, and cramps for up to a week. she has approximately 2,500 known serotypes because she refused to be just one thing.
the most unhinged fact about sal: she doesn't need many cells to infect you. the infectious dose is as low as 10–100 CFU depending on the serotype. ten. cells. that's nothing. that's basically vibes.
Classification
Gram-negative rod (bacillus)
Infectious dose
10–100 CFU (terrifyingly low)
Common vehicles
Poultry, eggs, produce, peanut butter
Kill step
165°F (74°C) internal temp
FSQA relevance
Major dairy concern. PMO regulated.
Her vibe
💅 "I contain 2,500 multitudes"
Listeria monocytogenes · grows at 0.4°C–45°C · laughs at your refrigerator
listeria is the quiet girl who is actually the most dangerous person in the room. she seems like nothing — she's just there, in your fridge, on your deli counter, in your soft cheese, in your ready-to-eat products — not doing anything dramatic. she doesn't even look like she's trying. that's the bit.
she grows at refrigerator temperatures. REFRIGERATOR TEMPERATURES. the thing we put food in specifically to stop bacterial growth. she looks at 4°C and goes "that's fine, actually." she is the reason RTE products are terrifying from a food safety perspective. she is the reason your environmental monitoring program exists.
she is especially dangerous to pregnant women, the elderly, and immunocompromised individuals — she can cross the blood-brain barrier and the placental barrier. she is small but she has places to be. case fatality rate of listeriosis: 20–30%. for context: most foodborne illnesses kill almost no one. listeria kills one in five.
Classification
Gram-positive rod, non-spore-forming
Grows at
0.4°C–45°C. Yes. Zero degrees.
Survives
Salt, low pH, refrigeration, drying
High risk foods
RTE meats, soft cheese, smoked fish
Case fatality
20–30% (extremely high)
Kill step
Pasteurization (72°C/15 sec)
FSQA relevance
Environmental pathogen of concern. Biofilm former. Your EMP is because of her.
Her vibe
🧊 unbothered at 4°C
Clostridium botulinum · produces botulin toxin · most acutely lethal substance known to science
clostridium botulinum produces the most acutely lethal toxin on earth. the estimated lethal dose for a human is 1–2 nanograms per kilogram of body weight. for reference, a nanogram is one billionth of a gram. she is not playing around.
she is an obligate anaerobe and a spore-former, which means she thrives in low-oxygen environments (improperly canned goods, vacuum-sealed food, your mistakes), and her spores survive boiling at 100°C for several hours. you need 121°C and pressure to kill the spores. she is the reason commercial canning has kill step requirements. she is the reason botulism is a regulatory concern. she is the reason low-acid canned foods need retort processing.
her toxin works by blocking the release of acetylcholine at neuromuscular junctions — which means the nerve signal to contract your muscles simply never arrives. descending flaccid paralysis. if it reaches your respiratory muscles, you stop breathing.
✨ the most unhinged pivot in all of science
this same neurotoxin — botulin type A — is commercially produced as Botox (onabotulinumtoxinA). injected in nanogram quantities into facial muscles, it causes temporary paralysis of the specific muscles that create wrinkles. same mechanism: blocks acetylcholine at the neuromuscular junction. the difference between "cosmetic treatment" and "fatal poisoning" is literally the dose and the location. she is doing two jobs and she is thriving.
Classification
Gram-positive rod, spore-former
Oxygen requirement
Obligate anaerobe — no oxygen
Spore heat resistance
Survives 100°C for hours. Needs 121°C.
Toxin mechanism
Blocks acetylcholine → flaccid paralysis
High risk foods
Improperly canned, vacuum-packed, garlic in oil
Botox connection
Botulin type A = Botox. Same toxin. Different dose.
Prevention
Proper retort processing, water activity control, pH <4.6
Her vibe
💉 "I'm a healthcare professional actually"
Escherichia coli O157:H7 · Shiga toxin-producing (STEC) · serotype that ruined E. coli's reputation
most E. coli are fine. this is important context. E. coli naturally lives in the intestines of humans and animals and is actually important for gut health. most strains are completely harmless. some are even studied for producing insulin. E. coli as a species did not deserve this.
O157:H7 is the evil twin who destroyed the family reputation. she produces Shiga toxins (Stx1 and Stx2) which damage the lining of blood vessels, particularly in the kidneys. her most serious complication is hemolytic uremic syndrome (HUS) — kidney failure, especially in children under 5. the infectious dose is horrifyingly low: as few as 10 CFU. ten. again.
she is primarily associated with undercooked ground beef (the serotype designation came from a 1982 Jack in the Box outbreak), but also unpasteurized juice, raw produce, and contaminated water. the Jack in the Box outbreak that killed four children and sickened 700 is why we now have HACCP in the US. she literally changed food safety law.
Classification
Gram-negative rod, Enterobacteriaceae
Toxin
Shiga toxins Stx1 and Stx2
Infectious dose
10–100 CFU. Catastrophically low.
Complication
HUS — hemolytic uremic syndrome
Vehicles
Ground beef, raw produce, unpasteurized juice/milk
Kill step
160°F (71°C) for ground beef
Historical impact
1993 Jack in the Box → HACCP mandate
Her vibe
🥩 "don't blame the species, blame me specifically"
Yersinia pestis · caused the Black Death (1347–1351) · killed an estimated 75–200 million people
yersinia pestis killed somewhere between one-third and one-half of Europe's population between 1347 and 1351. historians still argue about the exact number but the conservative estimate is 75 million people and the upper bound is 200 million. either way she simply ended the medieval world as it was known and restructured european society, labor markets, religious institutions, and art for the next century.
she is transmitted by the bites of infected fleas, which pick her up from infected rodents (rats primarily). she causes three forms of plague: bubonic (infects lymph nodes → swollen, painful buboes), septicemic (infects the blood), and pneumonic (infects the lungs — and this form is transmissible person to person via respiratory droplets). untreated bubonic plague kills 30–60% of infected people. untreated pneumonic plague is nearly 100% fatal.
she still exists. there are 1,000–2,000 cases globally per year. she is treatable with antibiotics (streptomycin, doxycycline) if caught early. she didn't go anywhere. she's just waiting.
Classification
Gram-negative rod, Yersiniaceae
Transmission
Flea bite → bubonic/septicemic. Respiratory → pneumonic.
Forms
Bubonic, Septicemic, Pneumonic
Historical body count
75–200 million. Restructured civilization.
Untreated mortality
30–60% bubonic. ~100% pneumonic.
Still exists?
Yes. 1,000–2,000 cases/year globally.
Treatment
Streptomycin, doxycycline (if caught early)
Her vibe
🐀 "I restructured feudalism. what have you done."
Bacillus cereus · two toxins · two syndromes · one identity crisis
bacillus cereus is the two-faced girl of foodborne pathogens and she has fully committed to the bit. she causes not one but TWO completely different illnesses depending on which toxin she's feeling that day. she didn't want to be limited. she wanted range.
syndrome one — emetic (the fried rice special): she produces a heat-stable toxin called cereulide directly in the food while it sits at room temperature. heat-stable means reheating does NOTHING. the toxin is already there. it was always there. incubation is 1–5 hours and the symptoms are nausea and vomiting. this is the classic leftover fried rice scenario — rice cooked, left out, reheated, assumed to be safe. it is not safe. she made sure of that.
syndrome two — diarrheal: a completely different heat-labile toxin produced in the small intestine after ingestion. incubation 6–15 hours. diarrhea and cramps. this one actually behaves more like other foodborne illnesses. she's almost normal here which makes the emetic syndrome even more unhinged by comparison.
she is a spore-former, which means she survives cooking, waits patiently in the food, and germinates when conditions are right (room temperature, time). she is the reason cooked rice should go straight into the refrigerator. she doesn't care that you're tired and will deal with it tomorrow. she is already dealing with it.
Classification
Gram-positive rod, spore-former
Syndromes
Emetic (1–5 hrs) AND diarrheal (6–15 hrs)
Emetic toxin
Cereulide — heat-STABLE. Survives reheating.
Diarrheal toxin
Heat-labile — destroyed by cooking
Classic vehicle
Cooked rice left at room temp. Also meats, stews, gravies.
Spore heat resistance
Survives boiling. Germinates when food cools.
Prevention
Time-temp control. Don't leave cooked starchy foods out.
Her vibe
🍚 "I contain multitudes. two of them specifically."
💧 the waterborne ones (she doesn't even go here, she came through the water)
Hepatitis A Virus · RNA virus · ssRNA(+) · attacks the liver · 1.4 million cases/year globally
HAV is a virus, not a bacterium, which she would like you to know because she thinks it makes her more sophisticated. she is fecal-oral transmitted, which means she gets from infected feces to your mouth via contaminated food or water, and she is deeply unbothered by this fact.
she specifically loves shellfish — particularly oysters and clams — because filter feeders concentrate whatever is in the water including her. she also shows up in raw produce irrigated with contaminated water, and on the hands of infected food handlers who don't wash thoroughly. she is the reason handwashing is a kill control and not optional.
her incubation period is 15–50 days which is exceptionally long and makes outbreak investigations extremely difficult. you ate the oyster a month ago and you're only now getting sick. she attacks the liver, causing jaundice, fatigue, nausea, and abdominal pain. she is preventable by vaccine. she is very upset that you have options.
Type
RNA virus, Picornaviridae family
Transmission
Fecal-oral — contaminated food/water
Incubation
15–50 days (extremely long)
Target organ
Liver → jaundice, fatigue, nausea
High risk foods
Shellfish (oysters, clams), raw produce, water
Prevention
Vaccine (HAV vaccine, 2-dose series)
Kill step
Heat (185°F/85°C for 1 min) or thorough cooking
Her vibe
🦪 "I'm a virus. I'm different."
Norovirus · most common cause of foodborne illness globally · 685 million cases/year
norovirus is the most contagious foodborne pathogen on earth and she wants you to know it. the infectious dose is 18–1,000 virus particles. eighteen. she has over 40 known genotypes. she survives temperatures from near-freezing to 60°C (140°F). she can survive on surfaces for weeks. she is resistant to many common disinfectants. she is immune to your best efforts.
she is the cruise ship queen because the enclosed environment, shared surfaces, and buffet-style food service are exactly her preferred operating conditions. one infected food handler who doesn't wash their hands after vomiting can infect hundreds of passengers within hours. she causes projectile vomiting and diarrhea simultaneously and she is not apologetic about this.
she is also spread by aerosolized vomit particles — which means if someone vomits in a room you are in, you have potentially already been exposed. she is the reason cruise ship protocols include immediate quarantine and chlorine bleach disinfection. she is the reason "the norovirus outbreak on a cruise ship" is an entire news genre.
Type
RNA virus, Caliciviridae family
Infectious dose
18–1,000 particles. Eighteen.
Illness
Vomiting + diarrhea, 1–3 days
Transmission
Fecal-oral, surfaces, aerosolized vomit
Global impact
685 million cases/year. #1 foodborne illness.
Disinfection
Chlorine bleach (1,000–5,000 ppm). Most sanitizers fail.
Her vibe
🚢 "I am everywhere. I am everything."
Cryptosporidium parvum · protozoan parasite · chlorine resistant · waterborne pathogen of major public health concern
crypto is a protozoan parasite — not a bacterium, not a virus, a parasite — and she would like everyone to acknowledge that she is built differently. she forms oocysts that are essentially armor plating for her dormant stage. these oocysts are resistant to chlorination at standard water treatment concentrations. standard. water treatment. concentrations. the thing we designed specifically to kill waterborne pathogens. crypto files that under "not my problem."
she gets into water supplies through contaminated runoff (animal feces, primarily calves and humans) and survives the treatment process. she is the reason that swimming pools, despite being chlorinated, can harbor crypto outbreaks — a single infected swimmer can shed 100 million oocysts per bowel movement. the infectious dose is as low as 10 oocysts. the math on this is upsetting.
she causes cryptosporidiosis: profuse watery diarrhea, cramping, nausea, and vomiting lasting 1–2 weeks. in immunocompromised individuals it can be chronic, severe, and life-threatening. she is killed by UV light and ozone — which is why modern water treatment uses these in addition to chlorination. she made them add extra steps.
Type
Protozoan parasite, Apicomplexa
Infectious form
Oocyst — extremely hardy
Infectious dose
As low as 10 oocysts
Chlorine resistance
Resistant to standard water treatment concentrations
Transmission
Contaminated water, swimming pools, direct contact
Illness
Profuse watery diarrhea 1–2 weeks
Kill step
UV light, ozone, boiling (1 min). Not standard chlorine.
Her vibe
💧 "your chlorine is a suggestion"