Bacillus Flashcards
What does the toxin of gastrointestinal anthrax do?
Necrotic lesions in intestine or mouth, pharynx
How is gastrointestinal anthrax taken in?
Contaminated meat (it’s rare!!)
When did we most recently see inhalational anthrax?
After 9/11, people were mailed envelopes of it and caused 4 deaths
What damage does the toxin of inhalational anthrax cause?
Necrosis and bleeding in lungs
How is bacillus cereus transported?
Through food (food poisoning)
What are the 2 strains (toxins) of bacillus cereus?
Diarrheal toxin (veg, salads, meat, casseroles) Emetic toxin (dense carbs like mashed potatoes, other starchy foods and vegetable sprouts) - causes vomiting
Do bacillus cereus create endospores?
Yes!
Do bacillus anthracis form endospores?
Yes!
Does corynebacterium form endospores?
Nope
What is the shape of corynebacterium diphtheriae?
Club shaped pleomorphic rod (Caveman clubs!)
What is propionibacterium known for causing?
Acne (the bane of high school pizza faces and bacne)
Which toxic fragment of corynebacterium diphtheriae causes necrosis?
Toxin fragment A
What is the primary reservoir of corynebacterium diphtheriae?
Humans!
We inhale it or introduce through wound
What is the characteristic appearance of corynebacterium diphtheriae infection?
Whitish gray PSEUDOMEMBRANE at back of the throat
If it bursts and toxin enters the blood, it will attack the nerves, heart and kidneys and cause defects, even if the person survives
How do you diagnose corynebacterium diphtheriae?
Throat swab but not ready for days
Schick test - inject dilute toxin and see if they had a reaction (testing children’s immunities at school)
PCR and look for specific tox gene
ELISA to detect toxin
Does listeria monocytogenes form endospores?
Nope
What is unique about the size of listeria?
It is comparatively small to other bacteria we have looked at
Where does listeria thrive?
Food (refrigerated goodies like cheese - Blue Bell problem)
Who is at risk?
Neonates (from mom)
Pregnant moms and particularly their fetuses (lose their fetus)
Immunosuppressive patients
What is granulomatosis infantiseptica?
Sepsis of the fetus acquired across the placenta (term not in notes)
Why you shouldn’t eat unpasteurized dairy or cold cuts when pregnant
What are the virulence factors of enterobacteriaceae?
All have endotoxins (LPS)
Many have capsule
Many have enterotoxins, both heat stable and heat labile
How do you start to differentiate between enterics?
Do they ferment lactose or not?
What does coliform mean?
Rod shaped Ferments lactose with gas production Facultative anaerobes Gram negative Non-endospore forming
How are enterics spread?
Fecal-oral
Migration up urethra
What are coliforms useful indicators of?
Water quality testing (can see if sewage plants are working properly, seeing if people or animals are pooping in water… Lovely)
Where does escherichia coil found normally?
It resides in the GI tract without causing disease! But they are opportunistic pathogens….
What are unique about E. coli appearance?
Possess pili for adherence
Posses flagella for motility (unipolar)
What are 3 common illnesses caused by E. coli?
E. coli sepsis Urinary tract infections Meningitis Gastroenteritis Diarrhea (travelers diarrhea)
What are subgroups of diarrhea-causing e. Coli?
Enterotoxin producing E. coli (ETEC)
(Traveler’s diarrhea from production of toxins disabling the cells ability to absorb electrolytes)
Enteroinvasive E. coli (EIEC)
(Invades intestinal cells so we see bleeding)
Enteropathogenic E. coli (EPEC)
(Adheres to cells and causes poor absorption causing non-bloody diarrhea in bottle-fed infants)
Enterohemorrhagic E. Coli
(Produce toxin known as verotoxin which attacks blood vessels of glomerulus so causes kidney problems and bloody diarrhea)
Strain O157:H7
What is E. Coli O157:H7 disease?
Severe abdominal pain and diarrhea that started out watery and becomes severely bloody
Some develop hemolytic uremic syndrome (HUS) = renal failure and lysis of RBCs
How do we diagnose E. Coli?
Eosin methylene blue agar (Lactose fermenters)
What is caused by the toxin of cutaneous anthrax?
A painless black lesions, usually resolves on its own
Is Klebsiella part of the normal flora?
Yes
How does Klebsiella appear on an agar plate?
Shiny, sticky, red jelly
Does Klebsiella pneumoniae ferment lactose?
Yes
How do we separate enterobacter aerogenes from Klebsiella pneumoniae?
Enterobacter produces ornithine decarboxylase and Klebsiella does not
Does enterobacter ferment lactose?
Yes
Does serratia marcescens ferment lactose?
NO
Which bacteria forms the pinkish ring around the water of your toilet bowl?
Serratia marcescens
What are the 3 enzymes produced by serratia marcescens?
DNase
Lipase
Gelatinase
What is a unique characteristic of proteus species?
It is highly motile and can move across AGAR!! (Streak line with a fog around it is proof of its movement)
Do proteus species ferment lactose?
Yes
What makes proteus different from all other enterics?
It has the ability to break down urea so it is an opportunistic pathogen of the urinary tract and form a particularly type of kidney stone (struvite kidney stone)
Does salmonella ferment lactose?
Nope
What are the 2 groups of salmonella strains?
Enteric fever causing strains
Gastroenteritis causing strains
How do we get salmonella in a restaurant?
People handling food don’t wash their hands enough (fecal-oral transfer)
What was Typhoid Mary’s infamous food through which she contaminated families?
Iced peaches (not cooked so bacteria would not die)
Where was the salmonella bacteria being stored in the carrier Typhoid Mary?
Gallbladder
How many salmonella bacteria do you have to consume to become infected?
Only a few hundred bacteria cells (low infective dos required)
Which bacteria can be harboured and contracted by our reptilian pets?
Salmonella
Which bacteria is a facultative intracellular parasite? (When eaten by macrophages, they can survive and divide inside the macrophage!)
Salmonella
