Micro lecture exam 3 Flashcards
what are two Bacillus species?
Bacillus anthracis and Bacillus cereus
what is the action of the botulin toxin?
causes a flaccid paralysis by inhibiting acetylcholine release in the neuromuscular junction
Gas gangrene is caused by…
Clostridium perfringens
Which of the following is not classified as an unevenly staining non-spore forming Gram-positive bacilli?
Corynebacterium
Propionibacterium
Mycobacterium
Listeria
Nocardia
Listeria
Leprosy is a communicable disease, however, approximately 95% of the human population have a natural immunity?
True or False
True
What is the name of the human anthrax vaccine?
Biothrax
The genera of human pathogens that produce endospores include…
Bacillus and Clostridium
The human anthrax vaccine is readily available for travelers and civilians.
True or False
False
Bacillus cereus is a gram positive motile rod.
True or False
True
______ are often _______ to prevent the spread of Erysipelothrix rhusiopathiae which causes a specific type of cellulitis.
Pigs/vaccinated
what are the 2 gram-positive regular non-sporeforming bacilli?
Listeria monocytogenes and Erysipelothirx rhusiopathiae
Genus Bacillus fill in the blank
1. primary habitat is _____
2. ____ and ___ positive
3. source of _______
4. versatile in degrading ______ _______
5. gram-____
motile or nonmotile?
endospore-forming or nonendospore-forming?
- soil
- aerobic/catalase
- antibiotics
- complex macromolecules
- gram positive
motile/endospore forming
Central spores in Bacillus anthracis develop under all conditions except in…
the living body
what are the virulence factors of Bacillus anthracis?
polypeptide capsule and exotoxins
what was anthrax thought of for years and how can humans get anthrax?
was thought of as a Zoonotic disease and it is acquired through contact with animals (sheep, cattle, goats) and their hides
what organism did Robert Kich work with for his postulates and proving the germ theory?
Bacillus anthracis
Human infection for anthrax depends on what 3 different portal of entries?
cutaneous- spores enter through the skin; least dangerous
pulmonary- inhalation of spores; most deaths
gastrointestinal- ingested spores; least common
what are the symptoms of cutaneous anthrax?
small papule or blisters that may itch; progress to a black eschar
20% fatality
what is pulmonary anthrax also called and what are it’s signs and symptoms?
also called woolsorter’s disease
early symptoms: fatigue, malaise, fever, aches, cough
late symptoms: high fever, labored breathing, shock
rapid death in 99% of untreated cases
causes- capillary thrombosis/cardiovascular shock
what is gastrointestinal anthrax’s symptoms and fatality rate?
symptoms: flu-like symptoms with fever and tiredness, sore throat, neck swelling, difficulty swallowing, nausea, anorexia, abdominal pain, vomiting & diarrhea
25% - 60% fatality
no cases reported in US
what are the antibiotic treatments for Bacillus anthracis and do they counteract the toxin?
ciprofloxacin or doxycycline and it does not
Name 3 facts regarding Bacillus anthracis and animals
- animals that have died from anthrax are burned or chemically decontaminated before burial
- vaccine for animals
- imported products composed of animal hides and hair should be gas-sterilized (ethylene oxide)
what is the the new drug approved by FDA for pulmonary anthrax and what does it do?
Raxibacumab; monoclonal antibodies bind to exotoxin
what happened in history regarding Bacillus anthracis?
2001- mailing of anthrax- containing envelopes
Destination: journalists offices and government offices
This Bacillus is commonly airborne and dustborne. The usual methods of disinfection and antisepsis are ineffective.
Bacillus cereus
where does bacillus cereus multiply and survive?
multiplies readily in cooked foods like rice, potato, and meat dishes
spores survive cooking (short periods) and reheating
food stored at room temperate spores germinate and produce enterotoxin
what are the symptoms of Bacillus cereus if ingested and how long do these symptoms last?
is there any treatment?
symptoms: nausea, vomiting, abdominal cramps, diarrhea; 24-hour duration
no treatment
where has Bacillus cereus been increasingly reported?
in immunosuppressed, intubated patients and drig addicts
what causes listeriosis?
Listeria monocytogenes
What are the initial symptoms of Clostridium perfringens?
pain, edema, bloody exudate in lesion w/ fever, tachycardia, blackened necrotic tissue w/ gas bubbles
What is the difference between Anaerobic cellulitis and Myonecrosis?
both are bacteria spreading in necrotic muscle tissue but Myonecrosis can invade healthy healthy tissue and Anaerobic cellulitis remains localized
How can you get infected with C. perfringens
-surgical incision
-puncture
-gunshot wound
-crushing trauma
-compound fracture
-diabetic sore
-frostbite
-septic abortions
What is the treatment for C. perfringens?
immediate cleaning of wound, debridement, or amputation
-large doses of cephalosporin or PCN
-no vaccine available
Describe Genus Clostridium
Gram +, spore forming rods
-strict anaerobic; oval/spherical spores
-synthesize organic acids, alcohols, exotoxins
cause wound & tissue infx and food intoxication
What does Clostridium tetani cause and what are the symptoms
causes tetanus
Symptoms: clenching of jaw, arching of back, flexion of arms, extension of legs; death due to paralysis in respiratory mucles
What is the action of neurotoxin Tetanospasmin
blocking the release of inhibitory neurotransmitters
-causes paralysis by binding to motor nerve endings in spinal cord
-rigid paralysis (muscles contract uncontrollably)
How do you treat C. tetani and what is the vaccine you get?
Control infection with PCN or tetracycline, and muscle relaxers
Toxoid vaccine DTaP (2, 4, 6, 15 months, 5yrs, booster q10yrs)
What is the fatality of C. tetani?
10-70%
What does Clostridium difficile-Associated Disease (CDAD) cause?
causes antibiotic-associated (pseudomembranous) colitis
Where does C. difficile usually reside and how do you acquire it?
-Normal resident of colon; kept in low numbers
Acquired: treatment with broad-spectrum antibiotics kills other bacteria, allowing C. diff to overgrow=superinfection
What are the symptoms of C. diff?
diarrhea, abdominal cramps, fever, patches of colon lining sloughs off
*common in community-acquired diarrhea