Exam 3 review sheet Flashcards
Gram positive cocci (anaerobe)
Peptostreptococcus
Gram negative bacilli (anaerobe)
Bacteriodes
Fusobacterium
Gram positive rods (anaerobes)
Clostridium
Propionibacteria
Aerobes vs. Anaerboes
AEROBES - Uses O₂ as a terminal electron acceptor; have the enzymes Superoxide Dismutase for breaking down harmful Superoxides to H₂O₂, and Catalase, for converting toxic H₂O₂ into water.
ANAEROBES - Obtain energy from fermentation or respiration using SO₄ or NO₃ as terminal electron acceptors
Obligate Anaerobes vs. Microaerophilic Anaerobes
Obligate Anaerobes usually do not have the enzymes Superoxide Dismutase and Catalase, and therefore cannot tolerate being around any amount of O₂.
Microaerophilic Anaerobes can withstand some O₂ but grow better in Anaerobic conditions
Facultative Anaerobes
Can grow in both types of environments; typically do better in O₂ environments but possess Fermentation machinery as well.
Where are anaerobes normal flora
upper respiratory tract
mouth
GI tract
genital
skin
Anaerobes are frequently involved in what type of infections?
polymicrobic infection
**(involving more than one bacterial species)
Often involving both aerobes and anaerobes
Exogenous infections
From an outside source
**Ex: food-borne botulism
**Tetanus
Endogenous infection
*Arise from sources within the body when they move from areas of normal flora into other sites
*Most infections are endogenous, from organisms inside the body
*Examples: surgery, disease, trauma
Anaerobic media Containing a reducing agents
Sodium thioglycollate
Cystine
**They absorb oxygen
Thioglycolate
*Enriched broth with hemin and vitamin K
*Supports growth of most anaerobes
**Grows at bottom of tube
**Used as backup in case plated media fails to grow
Anaerobic media is usually supplemented with what?
Supplemented with hemin, blood, and vitamin K and sodium bicarbonate (source of CO2) for fastidious organisms
Anaerobic-selective media
Anaerobic PEA
Anaerobic KV
Ways to generate anaerobic atmosphere
Gas-generating system within a closed jar or bag
Preferred to collect by needle aspiration instead of swab
*to prevent exposure to O2
Specimens that should not be cultured for anaerobes
Throat or nasopharyngeal swabs
Gingival swabs
Sputum or Bronchial washes
Gastric contents, feces, rectal swab
Characteristics of Anaerobic Infections
Foul-Smelling Discharge
Gas in the Tissues (they produce CO₂ and H₂; i.e. Gas Gangrene)
Abscess Formation - Sets up microenvironment conducive for growth
Infection is in close proximity to a Mucosal Surface
Give a basic morphology of Spirochetes
Long, thin, motile & helical bacteria
NOT seen on Gram stain
Treponema pallidum is associated with what disease?
venereal Syphilis
T pallidum subsp endemicum is associated with what disease?
Endemic syphilis aka Bejel
T.pallidum subsp pertenue is associated with what disease?
Yaws
Borrelia burgdorferi is associated with what disease?
Lyme disease
Borrelia recurrentis is associated with what disease?
Relapsing fever
Leptospira interrogans is associated with what disease?
Leptospirosis
