Exam 2 Gram Positive Bacilli Flashcards
Gram positive spore forming bacilli
- Clostridium
- Bacillus
Gram positive branching bacteria
- Nocardia
- Actinomyces
Anaerobic non-spore forming rods: example?
Lactobacillus
Sporulation is common in ______ bacteria
gram positive
Prior to forming spores, bacteria are found in ____ state
Vegetative (non-spore, growing)
Bacteria will form spores in response to:
Adverse conditions
To form spore, what happens in bacteria?
- asymmetric cell division
- partitioning of chromosome into an internal spore (endospore)
How many endospores can a bacterium create?
1 per bacterium
Spore can germinate under what conditions?
Anaerobic
True or false: spore is contained within cell’s plasma membrane
False - they become “free” because rest of cell dies off, leaving behind the spore by itself
Clostridia (spoons)
- Spores form at the end of the cell
Clostridia is found deep in the soil, which means they are:
Obligate anaerobes
Clostridium will form spores in what kind of conditions?
Nutrient-limiting conditions
Clostridium spores are resistant to:
- dryness
- heat (boiling)
- many chemical disinfectants
“indestructable”
Clostridium spores germinate and may produce toxins under what conditions?
Anaerobic conditions (deep in soil; human tissues)
Clostridium contains a ____ toxin, which enters into cells by:
AB toxin; either endocytosis to bring in whole complex or only A enters through cytoplasmic membrane
What does A stand for in AB toxin?
Active
What does B stand for in AB toxin?
Binding
What bacteria causes tetanus?
Clostridium tetani
Where are Clostridium tetani spores found?
Ubiquitous in soil, animals/human feces
How does Clostridium tetani colonize tissue?
Wounds contaminated with feces or soil, usually by penetrating trauma (ex. nail puncturing through skin/deep tissues)
Neonatal tetanus can occur via:
unclean deliveries and cord care practices that can infect the umbilical cord
Clostridium tetani incubation time
3-21 days
What toxin does Clostridium tetani produce?
Tetanospasmin (potent neurotoxin)
True or false: many toxins are responsible for tetanus symptoms
False - only tetanospasmin is responsible for all symptoms
Tetanus toxin structure
AB structure
How does tetanus toxin travel to the CNS?
Via bloodstream or along nerves toward the spine
What does tetanospasmin do?
- Destroys proteins that regulate release of inhibitory neurotransmitters
- Enhanced and continuous involuntary muscle contraction
- Unregulated excitatory activity leads to spastic paralysis
Trismus
Lockjaw
Risus sardonicus
Sardonic smile, causes difficulty swallowing
Opisthotonos
Muscle rigidity and spasms
Spastic paralysis can lead to:
- trismus
- risus sardonicus
- opisthotonos
- seizures
- arrhythmias
- respiratory arrest –> death
How to prevent and treat Clostridium tetani
- vaccination
- debridement, clean wound
- antitoxin
- supportive care, sedation
True or false: Tetanus has no immunity
True - so toxic that not much bacteria is needed to produce symptoms, but is not enough to produce antibodies. Cannot build immunity to it or you’d already be dead
What is found in the tetanus vaccine?
Inactivated tetanus toxin; given with diphtheria and pertussis vaccines (DTaP/Tdap)
DTaP is given to:
Young children (high dose of everything)
Tdap is given to:
preteens (11-12 years old) and adults (every 10 years)
_____ is always given as a high dose in vaccines
Tetanus
Clostridium botulinum causes:
- botulism
- infant botulism
- wound botulism
What is botulism?
Life threatening paralytic illness - muscles become relaxed and don’t work
C. botulinum spores are:
Ubiquitous - on surface of vegetables used for home canning, preserves, fermented food
True or false: C. botulinum spores can survive boiling but are killed by autoclaving
True
How many toxins does C. botulinum have?
7 (A-G)
C. botulinum toxin structure
AB structure
C. botulinum toxin is a:
Neurotoxin
What does C. botulinum toxin do?
Prevents release of acetyl choline from motor neuron, stops muscle contraction - leads to flaccid paralysis
True or false: C. botulinum can be inactivated by boiling for 10 min
True but may not kill spores
_____ has potential for bioterrorism
C. botulinum (1g of toxin can kill 1 million people)
Foodborne botulism is caused by which toxins?
Toxins A and B
Foodborne botulism onset
18-38 hours; ranges 2 hours - 8 days
Symptoms reported for foodborne botulism
Headaches, dizziness, descending flaccid paralysis
Descending flaccid paralysis symptoms
- diplopia (double vision)
- difficulty swallowing and speaking, unable to move lips or tongue
- progressive difficulty breathing –> death
Also bilateral descending muscle weakness
Diagnosis for foodborne botulism
Toxin in feces or contaminated food