SPORE FORMING GRAM POSITIVE RODS Flashcards
Bacterial Spore Position
CENTRAL
Bacillus anthracis
Bacterial Spore Position
TERMINAL
Clostridium tetani
Bacterial Spore Position
SUBTERMINAL
Clostridium botulinum
Only bacteria w/ AMINO ACID CAPSULE (D-glutamic acid)
Bacillus anthracis
McFadyean Reaction
polychrome methylene blue – capsule appear PINK
body appear DARK BLUE
Bacillus anthracis
ANTHRAX
CUTANEOUS
- exotoxin causes localized tissue necrosis
- eschar formation w/ edema
RESPIRATORY
- woolsorter’s disease
- PULMONARY HEMORRHAGE - cause of death
- hemorrhagic mediastinitis - WIDENED MEDIASTINUM
GI
- rare but fatal
- ingestion of infected meat
Calmodulin dependent adenylate cyclase
Edema Factor (EF)
INHIBITS signal transduction in cell division
Lethal Factor (LF)
Mediates the ENTRY of the other 2 components into cell
Protective antigen (PA)
Direct epidermal contact w/ spores causes formation of a MALIGNANT PUSTULE w/ subsequent eschar and central necrosis
Cutaneous Anthrax
Inhaled spores from animals (Woolsorter’s disease) or from weaponized preparations (bioterrorism)
PROLONGED LATENT PERIOD
MASSIVELY ENLARGED MEDIASTINAL LYMPH NODES, pulmonary hemorrhage, meningeal symptoms
Inhalational Anthrax
Ingestion of live spores leads to UGI ulceration, edema and sepsis
Gastrointestinal Anthrax
DOC for cutaneous anthrax
CIPROFLOXACIN
DOC for inhalational anthrax
CIPROFLOXACIN or DOXYCYCLINE w/ one or 2 additional
antibiotics
Drug used for anthrax
Raxibacumab - binds w/ PA
The heat resistance of bacterial spores such as those of B. anthracis is due in part to their dehydrated state and in part to the presence of large amounts which of the ff sign?
Calcium dipicolinate
MCC of death is PULMONARY HEMORRHAGE in the ff:
anthrax (pulmonary) aka woolsorter’s disease
leptospirosis, severe (Weil’s syndrome)
congenital syphilis
similar to enterotoxin of cholera and LT from E. coli
causes ADP-RIBOSYLATION INCREASING cAMP
causes DIARRHEA
Bacillus cereus
ENTEROTOXINS
heat LABILE
Staphylococcal-like enterotoxin function as SUPERANTIGEN
causes EMESIS
Bacillus cereus
ENTEROTOXINS
heat STABLE
RICE - SUKA
Produces the most potent neurotoxin (BLOCKS THE RELEASE OF ACETYCHOLINE from THE PRESYNAPTIC NERVE TERMINALS) – flaccid
Clostridium botulinum
TRIAD OF BOTULISM
symmetric descending flaccid paralysis - w/ prominent bulbar involvement
absence of fever
intact sensorium
Occurs when babies ingest spores found in household dust or honey
d.t. absence of competitive bowel microbes
Infant Botulism (Floppy Baby Syndrome)
Protease that cleaves proteins involved in the release of glycine from Renshaw cells in spinal cord
Prevents release of GABA by cleaving of synaptobrevin 2
GABA and glycine - inhibitory
Tetanospasmin (Tetanus Toxin)
Muscles affected in tetanus toxoid
Risus sardonicus - ORBICULARIS ORIS
Lock jaw (trismus) - muscles of mastication - MASSETER, LATERAL PTERYGOID, TEMPORALIS
Opisthotonos - ERECTOR SPINAE
In a patient sustaining cat bite below the angle of the mandible, 3 mm in size, w/ nonspontaneous bleeding, which of the ff PEP should be given?
A. rabies vaccine + rabies Ig
B. rabies vaccine + tetanus vaccine
C. rabies vaccine + tetanus vaccine + tig
D. rabies vaccine + rabies Ig+ tetanus vaccine + tig
D. rabies vaccine + rabies Ig+ tetanus vaccine + tig
Drug for tetanus
METRONIDAZOLE - 400 mg rectally OR 500 mg IV q6 for 7 days
Penicillin - ALTERNATIVE
DOUBLE HEMOLYSIS on blood agar
EGG YOLC AGAR - nonmotile but with rapidly spreading growth on culture media
Clostridium perfringens
LECITHINASE that cleaves cell membrane and causes GAS GANGRENE
ALPHA TOXIN
Clostridium perfringens
*Nagler’s reaction
Responsible for food poisoning (enteritis necroticans/pig bel disease)
BETA TOXIN
Clostridium perfringens
MCC of superinfection
PSEUDOMEMBRANOUS COLITIS
severe diarrhea, abdominal cramping
Clostridium (Clostridioides) difficile
Drug of choice in treating pseudomembranous colitis
VANCOMYCIN (PO)
-poor intestinal absorption; coats the lesions w/ antibiotics
METRONIDAZOLE (PO)
Antibiotics suppress normal flora, allowing C. difficile to overgrow
CLINDAMYCIN
AMPICILLIN
2nd and 3rd gen CEPHALOSPORINS
Nonbloody diarrhea associated w/ PSEUDOMEMBRANES (yellow-white plaques) on the colonic mucosa
pseudomembranous colitis
Nontraumatic myonecrosis in immunocompromised patients
C. septicum
Toxic shock syndrome associated w/ septic abortion
C. sordellii
Traumatic wound infections
C. tertium
Edema Toxin
PA + EF = edema toxin
Lethal Toxin
PA + LF
Important virulence factor of Bacillus anthracis
Protective antigen
Young man sustains major soft tissue injury and open fracture of his right leg. One day later he has fever, increased HR, sweating and restlessness. On examination leg is swollen and tenses. The skin if the leg is cool, pale, white and shining. (+) Crepitus
serum shows free hemoglobin
A. Clostridim tetani B. Staphylococcus aureus C. Escherichia coli D. Bacillus anthracis E. Clostridium perfringens
E. Clostridium perfringens
PENICILLIN G
Responsible for hemolysis in gas gangrene caused by C. perfringens
LECITHINASE
Reported incubation period for INHALATIONAL ANTHRAX
6 weeks
Food commonly associated w/ Bacillus cereus food poisoning
Fried rice
Tetanus toxin (tetanospasmin) diffuses to terminal of inhibitory cells in the spinal cord and brainstem and blocks
release of inhibitory glycine and GABA
Which of the ff statements about tetanus and tetanus toxoid is correct?
A. Tetanus toxin kills neurons
B. Tetanus toxoid immunization has a 10% failure rate
C. The mortality rate of generalized tetanus is <1%
D. Double vision is commonly the first sign of tetanus
E. Tetanus acts on inhibitor interneuron synapses
E. Tetanus acts on inhibitor interneuron synapses
Infant botulinum has been associated w/ all of the ff Clostridium species EXCEPT
A. Clostridium baratti
B. Clostridium septicum
C. Clostridium butyricum
D. Clostridium botulinum
B. Clostridium septicum
All of the ff are properties characteristic of Bacillus anthracis EXCEPT
A. motility on wet mount exam B. medusa head colonies C. poly-D glutamic acid capsule D. in vitro susceptibility to penicillin E. absence of hemolysis on 5% sheep blood agar
A. motility on wet mount exam
Large gram positive rod that cause NECROSIS of tissue by producing an exotoxin that DEGRADES LECITHIN – lysis of cell mebranes
Clorstridium perfringes
