Gram Positive Bacilli Flashcards
Bacillus Anthracis ID
Gram —–
—- shaped
presence of —–
obligate ——–
Encapsulated made up of ——
—– forming bacteria
- Gram positive
- bacilli shaped (rod)
- presence of black Eschar
- obligate aerobe
- Encapsulated made out of Protein (polyD glutamate)
- spore forming bacteria
what are the bacillus anthracis toxin
- Edema factor (EF)
- Lethal factor (LF)
Edema factor (EF)
- causes edema that prevents phagocytosis, increases cAMP
Lethal factor (LF)
- cleaves MAP kinase.
- Responsible for tissue necrosis
Bacillus anthracis causes —– disease
Pulmonary anthrax (wool sorters disease)
Symptoms of pulmonary anthrax
- Dry cough
- pulmonary hemorrhage
- widened mediastinum on Xray
Treatment for pulmonary anthrax
- Primary treatment- Fluoroquinolones
- secondary treatment- Doxycycline
Bacillus cereus ID
Gram —–
—– shaped
—– forming bacteria
obligate ——-
Gram positive
bacilli shaped
spore forming bacteria
obligate aerobe
Bacillus cereus is associated with
food poisoning when someone comes in with vomiting and diarrhea after eating reheated fried rice
Clostridium tetani ID
Gram ——
—– shaped
obligate ——-
—– forming bacteria
Gram positive
bacilli shaped
obligate anaerobes
spore forming bacteria
Spores from clostridium tetani are found in
- soil and rusty nails
- ideally in puncture wounds closed off to air
what is the clostridium tetani toxin that causes the symptoms
Tetanospasmin
Tetanospasmin trends ——- through the motor axons to the spinal cord
Retrograde
Tetanospasmin
- acts as a protease cleaving SNARE proteins
- cleavage of SNARE inhibits GABA and Glycine
—— senses if there is overactivity in the motor neurons. When they sense overactivity or tetanus, they fire inhibitory motor neuron
Renshaw cells
Symptoms of clostridium tetani
- Spastic paralysis
- Risus sardonicius (lockjaw)
- Opisthothonus (exaggerated arching of back)
Treatment for clostridium tetani
Toxoid vaccine
Clostridium Botulinum ID
Gram ——
—– forming bacteria
obligate ——
- Gram positive
- spore forming bacteria
- obligate anaerobe
Clostridium botulinum is often transmited by
Improper canning of food
Symptoms of clostridium botulinum
- Flaccid paralysis (affects PNS, not CNS, descending paralysis)
- Eye symptoms such as diplopia and ptosis
Botulinum toxin targets
- neurons that releases Ach
Botulinum toxin cleaves
SNARE protein
What are the symptoms of botulinum toxin in babies
- Flaccid paralysis (called floppy baby syndrome)
Where do babies get the botulinum toxin?
- honey (the spores are in honey)
Clostridium perfingens ID
Gram ——
—– forming bacteria
obligate ——-
Gram positive
spore forming bacteria
obligate anaerobe
Clostridium perfingens is directly associated with
- motorcycle accidents
- deep penetrating wounds from military combat
Diseases caused by clostridium perfingens
- Gas gangrene
- Food poisoning
Gas gangrene caused by clostridium perfingens
- organism produces gas in tissue
- the mechanism behind the necrosis involves an alpha-toxin called lethicinase
- lethicinase causes red cell hemolysis
Food poisoning caused by clostridium perfingens
- the diarrhea is late (slow)
- Transient
Treatment for clostridium perfingens
IV Penicillin G
Clostridium difficile ID
Gram —–
—– shaped
obligate ——
—- forming bacteria
- gram positive
- bacilli shaped
- obligate anaerobe
- spore forming bacteria
Clostridium difficile is part of the normal flora of the ——
Gut
Transmission of C.difficile
- fecal oral route
- nosocomial (hospital acquired) infection
How do you prevent C.difficile
- wash hands thoroughly
- gown and glove contact precaution
What factors are required for development of C.diff
- presence of toxigenic C.diff
- recent antibiotic use like (clindamycin, FQ, penicillin like ampicillin, broad spectrum like certain cephalosporins)
- PPIs
what are the toxins of C.diff
- Toxin A
- Toxin B
Toxins of pseudomembrane causes
- Pseudomembranous collitis
- watery diarrhea
- can cause toxic megacolon
Testing for C.diff
- NAAT
- EIA
- Glutamate dehydrogenase
Treatment of C.diff
- oral vancomycin
- Oral fidaxomicin
- IV metronidazole + Oral vancomycin if severe
- If abx fails, use fecal microbiota implant
Cornybacterium diphtheriae ID
Gram —–
—- shaped
—– granules
Gram positive
club shaped (Y or V formation)
Metochromic granules
Exotoxins of Cornybacterium diphtheriae?
- A and B
- A is the active subunit
- B is the binding subunit
In cornybacterium diphtheriae, toxins inhibits ——– to inhibit protein synthesis
Elongation factor 2 (EF2)
In cornybacterium diphtheriae, toxins act by ——
Ribosylation
Cornybacterium diphtheriae infection is transmitted by —–
Respiratory droplets
Corynbacterium diphtheriae can cause ——-, this could be severe enough to cause the thickening of the neck called ——
- lymphadenopathy
- bulls neck
Infections caused by cornybacterium diphtheriae
- life threatening myocarditis. This presents with arrhythmia and heart block
-local paralysis that generally begin in the posterior pharynx and can lead to other cranial nerve deficits
- Cardiotoxic effects are myocarditis, arhythmias and heartblock
DDX of cornybacterium diphtheriae
- good clinical history and examination
- definitive diagnosis requires culturing or toxin assay on tellurite agar or loeffler’s medium
How can we differentiate between toxic and non-toxic strains of diphtheriae
Elek’s test
Patients of diptheriae are often
Immigrants because they are not vaccinated
diphtheriae vaccine
- toxoid vaccin
diptheriae treatment
- passive immunization
- administering anti-toxoid
Listeria monocytogenes ID
Gram —–
—- shaped
—– hemolytic
—– intracellular
Catalase —–
- gram positive
- bacilli shaped
- beta hemolytic
- facultative intracellular
- Catalase positive
when listeria monocytogenes is outside the cell (motility outside the cell)
- gram positive
- bacillus
When listeria monocytogenes is inside the cell
“Acting rocket” intracellular movement
Listeria monocytogenes can survive in ——- temperatures
freezing cold
Listeria monocytogenes can contaminate food even though they are ——
Refrigerated
Listeria monocytogenes is most likely in
Pregnant women
Listeria monocytogenes infection early in pregnancy can lead to
Termination
Listeria monocytogenes infection later in pregnancy can lead to
infection of the baby
INfections of listeria monocytogenes
- 3rd most common cause of meningiits in new borns after GBS and E.coli
- causes meningitis in adults over 60
Treatment of meningitis in adults
Vancomycin + ceftriaxone
Treatment of meningitis in adults to cover listeria too
Vanco+ ceftriaxone + Ampicillin
what is the treatment for listeria
Ampicillin