Anaerobic Bacteria Flashcards
What do aerobic bacteria have that anaerobic bacteria don’t to survive?
Aerobic Bacteria have: Superoxide Dismutase, Catalase, and use cytochromes.
Without these oxygen is toxic to organisms.
Common features of gram negative anaerobic bacteria?
Typically infection sites are colon, skin, and mouth. Foul smelling gas production due to fermentation. Usually from normal flora infecting other tissues.
Where does Bacteriodes Fragilis usually infect and what are it’s virulence factors?
Most common for intraabdominal infections.
Virulence factors: Polysaccharide capsule, encodes oxidative stress genes to tolerate oxygen.
What common other microbe is B. Fragilis with in intraabdominal infections?
Peptostreptococcus - Gram Positive, anaerobe
What classifies Clostridia organisms?
Gram Positive, spore forming bacilli, and anaerobic or tolerate.
When is most common to get an infection of C. Difficile?
After undergoing treatment of antibiotics, which reduce the natural flora allowing C. Difficle to expand producing toxins.
What are the toxins of C. Difficle and what do they cause?
Toxin A and Toxin B, Glucosylate Rho disrupting actin depolymerization, thus disrupting gut epithelium causing diarrhea.
What is the treatment of C. Difficle?
Metronidazole, Vancomycin, and Fluoroquinones
Where does Clostridia Perfringens typically infect and what type of clostridia is it?
Histotoxic Clostrida - typically after deep wounds that predispose for infection.
Why are deep wounds susceptible for C. Perfringens?
Due to the tissue death releasing lactate and lowering pH and host proteases breaking down dead cells that release nutrients for C. Perfringens, which release toxins causing gangrene. Treatment = Abx and Amputation
What are the two types of organisms that produce neurotoxins?
C. Botulinum and C. Tetani
What is the common mechanism of BoNT and TeNT?
They are neurotoxins that cleave SNARE proteins inhibiting release of vesicles.
How does BoNT and TeNT cause unique symptoms?
BoNT inhibits ACh release in peripheral neuron muscular junctions causing flaccid paralysis.
TeNT enters the CNS inhibiting interneurons causing spastic paralysis.
How do you become infected with C. Tetani?
Usually a wound that gets infected by a mix of organisms allowing C. Tetani to grow enough to produce toxins that spread systemically. C. Tetani is non-invasive residing at the site of infection.
What are the components of vaccines regularly given when young?
DTaP - diptheria, tetanus, and pertussis
Uppercase = full dose
Lower case = partial dose
“a” means acellular dose
