IU Indy Micro Exam 3 Lecture 1

What are spores?

reproductive cells that form without fertilization

What is infant botulism?

Infant botulism is a rare but serious illness caused by the bacterium Clostridium botulinum. When a baby swallows the bacteria's spores, they can grow in the intestines and produce a toxin that affects the nerves and causes muscle weakness.

-Due to being given honey

-Causes baby to not eat, constipation, loss of head control, decreased muscle tone, droppy eyelids.

Common gram- bacteria

Salmonella, shigella, e.coli, campylobacter

Found in meat, eggs, fish, shrimp, cream-filled desserts, poultry and unpasteurized milk.

-Onset: 6-48 hrs. and lasts 4-7 days

-Stomach pain, diarrhea, nausea, chills, fever, headache

-15-20 infective cells

-Oral/injected antibotics for treatment

Salmonella

Symptoms start 1-2 days after exposure

-Diarrhea, fever, abdominal pain, tenesmus

Shigella

Bacteria infect the intestine of cattle and when slaughtered, bacteria contaminate the outer surface of meat.

-Hamburger, ground beef, raw vegetables, apple cider, ham, turkey, etc.

-Person-to-person

-7-10 days of illness

E. Coli 0157.H7 (specifically)

REMEMBER:

E.Coli 0157.H7 spread in a KFC in Johnson County and over a dozen people got sick from eating the coleslaw. Someone still had the coleslaw at home and sent it for testing and found the E.Coli. The cabbage farm was traced and the cattle had got lose in the cabbage patch and contaminated it.

C. jejuni

-Sensitive to o2, drying, freezing, salting, and acid

- Heat-labile toxin

-Very fragile outside of the body so proper food handling can control it.

-Common in most animals, mostly in poultry, and also found in shellfish and unpasteurized milk

- Gram-negative, S-shaped rod

-Invasive gastroenteritis in humans can lead to Guillain-Barré syndrome.

Camplyobacter

Abdominal cramps, diarrhea, headache, watery and sometimes bloody stools, fever

-Onset-2-3 days

Dose: 400-500 cells

-Can become antibiotic-resistant due to antibiotics in animals' food.

Camplyobacter

Gram+ bacteria

listeria, Staphylococcus, Clostridium, bacillus

More dangerous outbreak

-Gram +, facultative anaerobic, and no production of endospores

-Incubation between 3-70 days (long time)

-Struggle to figure out the outbreak because we don't remember what we ate a week- months ago

Listeria

-Main species of importance: Listeria monocytogenes, Listeria ivanovii, Listeria innocua

Where is Listeria found?

-In soil, contamination of vegetables and fruit

-Dairy products

- Ready-to-eat foods such as hot dogs and deli meats

-Pasteurized and ready-to-eat foods may become contaminated through handling.

Most virulent foodborne pathogen

Estimated 1,600 illness and 250 deaths in U.S alone annually (reported)

-Dangerous with prego people because can cause baby to die

Listeria monocytogenes

Listeria in Lab with be:

Gram ?

Beta hemolysis

Motile at 30 C

Catalase ?

Oxidase ?

Gram +

Catalase +

Oxidase -

Foodborne illness caused by Staph enterotoxin (Main thing)

-Bacteria are killed by heat but toxin tends to persist

-Vomiting more common than diarrhea

-2-8 after eating

Staphylococcus aureus

Form spores

Gram + rodes

Two main ones are Clostridum perfingens and botulinum

Clostridum

Very common in nature

-Rapid generation every 6.3 min

-Produce heat labile toxin

-Produce sub terminal spores which can survive cooking

-Takes 6-24 hrs for incubation and normally 10-12

-Disease: Abdominal cramps, watery diarrhea, nausea

-Large infective dose of 10 to the 8th cells

-Cooked meat and poultry as well as gravy

Clostridium perfingens

12-36 hrs after ingestion

-Transmitted through spores, soil, and contaminate vegetables and meat

-Dangerous

-Foods that are canned or vacuum-packed without adequate sterilization: spores survive and germinate in the anaerobic environment

-Absorbed from the gut and carried via blood to peripheral nerve synapses, where it blocks the release of acetylcholine

-IN BOTOX

Clostridium botulinum

Deaths due to --

A guy died due to his canned potatoes

Do not give honey to infant bc it has bacteria and a baby died from this

Clostridium Botulinum

Gram +

Spore forming

Facultative anaerobe

-Widespread in nature

-Found in rice, potatoes, casseroles

Bacillus cereus

Two distinct illnesses

-Diarrheal illness with an incubation of about 10-16 hrs

-Vomiting illness with an incubation of 1-6 hrs

-Infectious dose of 10 to the fifth CFU/gram

B. Cereus

REMEMBER

-in a Tex-Mex buffet-style restaurant on their opening night, they discovered they had two foodborne outbreaks

Baciullus cereus was in the rice dish and Clostridum perfringerns was is in chicken dish

-No sink in food prep area to wash hands

-Warming trays weren't hot enough

D. Mannitol and phenol red

Agar plate

-Egg yolk enrichment

-Media looks orange at first

Mannitol Egg Plates of B. Cereus

Bacteria that produce lecithinase are a

enzyme

Bacteria that ferment mannitol produce acid products and form colonies that are

yellow

Bacteria that produce lecithinase hydrolyze the lecithin and a zone of white percipate forms around the colonies

-Mannitol-neg (pink-red colonies_ and lecithinase-pos (zone of precipitate around the colonies)

B .Cereus

-1/15 Americans get each year

-800 americans die

-Infected through food, people, or surfaces

-Vomiting, nausea, diarrhea and sick for 1-3 days

-Highly contagious when you are sick and could still have it 2 weeks later

Norovirus