Actinomyces, Bacterioides, Fusobacterium Flashcards
Describe the following classes on bacteria based on O2 requirements:
Obligate anaerobe
Strict anaerobe
Moderate anaerobe
Facultative anaerobe
Obligate: kilt by normal O2 levels
Strict: dies at more than 0.5% O2 (e.g., Bacteroides, Clostridia)
Moderate: grows up to 8% O2 (e.g., Propionibacterium)
Facultative anaerobes: grow both in presence and absence of air (e.g. Enterobacteriaceae, S. aureus, Streptococcus)
Which anaerobic bacteria would you find in the intestinal tract? (name 3 types)
Bacteriodes
Clostridia spp (clostra = pasta)
Anaerobic cocci (round candies written with a big NO for no oxygen on them)
3 anaerobic bacteria you would find in the vagina include Prevotella, ___, and Peptostreptococcus
Prevotella (imagine using a vaginal cream called Prevotella)
Lactobacillus (vaginal secretions sometimes look kinda milky so there you go)
Peptostreptococcus (strep that likes peptobismal?)
Which anaerobic bacteria would you find in the oral cavity? Name 3 (hint: one of them is also in the vagina)
Anaerobic gram positive cocci
Prevotella
Fusobacterium (fuso like you’re drinking an infusion - except of bacteria)
Name 2 functions of anaerobic bacteria in the human body
Prevent colonization & infection by pathogens
Contribute to host physiology: e.g. Bacteriodes fragilis makes Vitamin K and deconjugates bile acids for us
One way that anaerobic bugs can cause disease is to first create an anaerobic environment. Describe the ways in which they can do this
Mixed infection with facultative bacteria: the usual facultative bugs that cause serious infection and destroy tissue consume a lot of O2 in the process, which leaves an anaerobic environment behind for the anaerobes to thrive
Signal host cells to increase O2 consumption
3 ways that anaerobes can evade host immunity include ___, inactivating complement and release of ___
Another way that anaerobic bacteria cause disease is to form an ___, mediated by a capsule that walls off the infection site
3 ways that anaerobes can evade host immunity include preventing phagocytosis, inactivating complement and release of toxins
Another way that anaerobic bacteria cause disease is to form an abscess, mediated by a capsule that walls off the infection site
The presence of ___, tissue necrosis (gangrene), ___ and infection near a musocal surface can all clue you into an anaerobic infection
Foul odor
Gangrene
Presence of gas
Abscess
Infection near mucosal surface/ass’d w/ malignancy
Gram stain w/ multiple morphologies
Name the gram +ve anaerobic cocci
Only one. Peptostreptococcus
There are 4 non-spore forming types of gram +ve bacteria, including Propionibacterium (aka ___), ___, Lactobacillus and ___
Propionibacterium aka Cutibacterium: causes/ass’d with acne (propioni causes acne or since now its called cutibacterium, remember acne isn’t cute)
Actinomyces
Lactobacillus
Mobiluncus (like moby-dick)
**A Lame Man is not Cute**
Which species of bacteria are gram +ve spore forming anaerobes?
Clostridium spp
Name the gran -ve anaerobic cocci
Only one. Veillonella (almost sounds like violin)
Gram negative anaerobic bacilli include ___, Fusobacterium, Prevotella and ___ (hint: the last one reminds you of the dreaded porphyrias)
Bacteroides (fragilis, thetaiotaomicron) **GI infections**
Fusobacterium. **Fusobacterium can cause oral infection**
Prevotella
Porphyromonas
Anaerobic bacteria can also be classified as endogenous or exogenous. Define this classification
Endogenous. Its on you and its in you normally, and is ass’d with abscesses
Exogenous. The exogenous bugs are generally Clostridia (b/c #spores). Can be inoculated or acquired from external environment and cause toxin-mediated disease
Where in/on the body do you find Peptostreptococcus?
What kinds of infections could be caused by this bug?
How do you Rx infections caused by this bug?
Found on skin and mucosal surface
Polymicrobial infections:
Sinusitis, pleuropulmonary infections, brain abscesses
Intraabdominal infections
Endometritis, pelvic abscesses
Soft tissue infection
Rx: Penicillin but in combo with a beta-lactamase inhibitor
Where on/in the body do you anaerobic, non-spore forming gram +ve rods?
Found on all mucosal surfaces; Cutibacterium (Propionibacterium) also found on skin (esp hair follicles)
**note that these grow slowly**
____ causes actinomycosis, which is characterized by chronic infection w/ relapsing/remitting course associated with ___, draining sinuses, ___
One feature of this infection is that it ___, which is how it can sometimes be mistaken for malignancy
Actinomyces israelii causes actinomycosis, which is characterized by chronic infection w/ relapsing/remitting course associated with abscess, draining sinuses, fibrosis
Crossing tissue planes: basically the infection spreads from tissue to tissue; part of the reason why it can also be mistaken for malignancy
Actinomyces can grow when there is ___ of the mucosal barrier
Disruption (remember in the sketchy video that this bug is ass’d with jaw trauma/dental surgery)
Which bug causes the pathology below? Name the pathology
Actinomyces_israelii
Who bug this is?
Actinomyces
How would you treat Actinomyces infection?
Penicillin G or amoxicillin
Also use tetracyclines and carbapenems (metronidazole don’t work in these bugs)
Lactobacillus can cause sepsis in ___ patients, and ___ in pts with pre-existing valve abnormalities
May cause sepsis in immunocompromised patients
May cause endocarditis in persons with underlying valve abnormalities
Who bug is this?
Lactobacillus
Cutibacterium is responsible for which skin issue? It can also cause invasive infections in patients with___
Acne
Indwelling foreign bodies (prosthetics, esp prothetic shoulders, indwelling catheters) (also neurosurgical infections)
**Apparently this bug really likes the head and neck region. The hair follicles and sebaceous glands in the head and neck region as well as those in the axilla are densely colonized with Cutibacterium**
Who bug is this?
Cutibacterium
How do you treat Cutibacterium infection? (like the serious ones)
benzoyl peroxide (topical) or tetracycline or clindamycin for acne, penicillin/beta-lactams, vancomycin for systemic disease
Who bug is this and what infection is this thing ass’d with?
Mobiluncus (found on epithelial cell borders obscured by the bugs)
Ass’d with bacterial vaginosis
How would Rx Lactobacilli infection?
penicillin or combination of antibiotics (e.g., penicillin plus an aminoglycoside); bacteria resistant to vancomycin
___ is a gram -ve anaerobic rod which can cause GI infections since its a major component of the colonic flora
Bacteroides fragilis
Bacteroides fragilis has LPS but lacks ___ activity. Its main virulence factor is a __ which prevents phagocytosis and promotes abscess formation
Bacteroides fragilis has LPS but lacks endotoxin activity. Its main virulence factor is a polysaccharide capsule which prevents phagocytosis and promotes abscess formation
**Note also the other virulence factors, and that its catalase and SOD positive**
Bacteroides fragilis infection is mainly characterized by ___ infections
How would you treat infections caused by this bug?
Bacteroides >> intraabdominal abscesses!!!
Other diseases caused by this bug:
pelvic inflammatory disease and endometritis
surgical wound infections
skin and soft tissue infections after surgery or trauma
Rx: beta-lactam/beta-lactamase inhibitor OR metronidazole plus antibiotics active against other organisms in infection
**know that this guy has a beta lactamase so it resistant to beta lactam antibiotics if you give them sans an inhibitor**
Who bug is this?
Bacteroides fragilis
Fusobacterium nucleatum is part of the normal flora of the ___, GI and genitourinary tracts
This bug mostly causes ___ infections, including infections of the head and neck
Part of normal flora of oropharynx, GI and genital tracts
Oropharyngeal infections:
Acute necrotizing ulcerative gingivitis (“trench mouth”)
Pharyngitis, tonsillitis (Vincent’s angina)
Jugular venous thrombophleitis (Lemierre’s syndrome)
Who bug is this?
Fusobacterium
Fusobacterium can cause ___ infections (hint: head and neck and tooth related)
Odontogenic infections: dental related infections of the head and neck
___ syndrome is classically caused by fusobacterium and results in thrombophlebitis of the internal jugular vein
How does this syndrome progress?
Lemierre’s syndrome is classically caused by fusobacterium and results in thrombophlebitis of the internal jugular vein
Pharyngitis >> peritonsillar abscess >> spread of bacteria through pharyngeal spaces >> thrombophlebitis of internal jugular vein
(clots can end up lodging in the lungs or other organs and cause disease there)
How do you treat Fusobacterium infections?
Beta lactam/beta-lactamase inhibitor
T/F: Cat bites are more likely to produce infection than dog bites (but you should treat empiracally in case of an animal bite anyway)
True
