Anaerobic Bacteria I and II Flashcards Preview

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Flashcards in Anaerobic Bacteria I and II Deck (22)
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1
Q

Name the Clinically important Anaerobic Gram Positive Cocci:

  • where does it colonize?
  • name of its infections
  • how is it treated
A

Peptostreptococcus

	○ Found on Skin and Mucosal Surfaces 
	○ Polymicrobial infections: sinusitis, pulmonary infections, brain abscess, endometritis, pelvic abscess, cellulitis, nec fasc, osetomyelitis 
	○ Treatment: PCN (but usually in combination therapy)
2
Q

Name the 4 clinically important Anaerobic Non Spore Forming Gram Positive Rods (GPR)?

  • where do they colonize
A

Actinomyces – A. israelli – colonize oropharynx, GI, female GU
PCN , erythromycin, c

Lactobacillus – mucosal surfaces

Mobiluncus – colonizer of the vaginal tract

Proprionibacterium – mucosa and the skin

3
Q

Actinomyces israelli -

  • Class of organism
  • manifestations
  • Macroscopic colony appearance
  • Tx
A

Anaerobic Non Spore Forming Gram Positive Rods

Cerebral

Cervico-facial – indurated lesion at angle of the mandible (“Woody firbrosis” – can be mistaken for malignancy)

Thoracic – patients with compromised gag reflex aspirate oropharyngeal content; get PNA which can penetrate into chest wall

Abdominal - appendicitis

Pelvic: classically associated with copper IUDs

“Molar tooth” appearance of the colony

Treat: PCN; erythromycin, clindamycin

4
Q

Lactobacillus

  • Class of organism
  • manifestations
  • Unique gram stain appearance
  • Tx
    what is it resistant to
A

Anaerobic Non Spore Forming Gram Positive Rods

General: usually isolates are clinically insignificant
□ Septicemia in compromised patients
□ Endocarditis in persons with valve abnormalities

Stain: Classic Appearance —- elongated GPRs

Treat: PCN (+/- aminoglycoside)
□ Resistant to vancomycin

5
Q

Mobiluncus

  • Class of organism
  • manifestations
  • Tx
    what is it resistant to
A

Anaerobic Non Spore Forming Gram Positive Rods

Colonizer of the vaginal tract

§ “Associated with bacterial vaginosis”
□ Unclear if this is the cause. May just be a marker for BV

Treatment of BV with metronidazol, which mobiluncus is resistant to

6
Q

Proprionibacterium

  • Class of organism
  • manifestations
  • unique gram strain appearance
  • Tx
    what is it resistant to
A

Anaerobic Non Spore Forming Gram Positive Rods

§ Most commonly isolated anaerobe
§ Cause of Acne

Can also cause infections with indwelling foreign hardware (valves, joints, indwelling vascular catheters)

§ Culture: clumping of short GPRs
Treat
Benzoly peroxide (topical); PCN, tetracyclines, erythromycin, clindamycin
7
Q

name the two anaerobic Gram Negative Rods

A

○ Bacteroides fragilis – colon

	○ Fusobacterium nucleatum -- oropharynx, GI, GU
8
Q

Bacteroides fragilis

    • Class of organism
  • Virulence
  • manifestation
  • Tx
    what is it resistant to ?
A

anaerobic Gram Negative Rods

  • Virulence:
    LPS but not an endotoxin
    Polysaccharide capsule prevents phagcytosis
    forms abscess

Manifestations: Abscess - (abdominal, PID, endometritis, surgical wound infections, skin and soft tissue infections)

Treat: Metronidazole + abx for other organisms

Resistance: PCN (due to beta lactamases)

9
Q

Fusobacterium nucleatum

  • Class of organism
  • unqiue appearance on gram stain?
  • manifestation
  • Tx
A

anaerobic Gram Negative Rods

Gram stain – very long thin (fusilli?) GNR

 Oropharyngeal infections:
				• Molar tooth abscess 
				• Peritonsillar abscess 
				• Perimandibular space infections: 
Can move into Pharyngeal spaces -- retro and lateral pharyngeal 

Jugular venous thrombophleitis (Lemierre’s syndrome):

tx: Beta Lactam + Beta Lactamase Inhibitor
Ampicillin - sulbactam > amoxi-clavulonate
+ Debridement of abscess

10
Q

Describe the pathenogenesis of :

Jugular venous thrombophleitis (Lemierre’s syndrome)

A

Classically caused by Fusobacterium
Pharyngitis – peritonislar abscess – pharyngeal spaces – thrombophlebitis of IJV
Clots may embolize to the lungs

11
Q

Anaerobic Spore Forming Gram Positive Rods (GPRs)

  • name the genus and the 4 clinically important species
  • What is the primary virulence factor ?
A

Genus: Clostridium

Species: C. dif, C. Perfringes, C. Tetani, C. botulinum

Virulence: Spore Forming

12
Q

Clostridium Tetani:

  • Class of organisms
  • how is it transmitted?
  • Name the Toxin? – what does it do?
  • Characteristic finding on physical exam?
A
  • Spore Froming GPR
  • Transmitted through puncture – nails, splinters, IVDU
  • Tetanus Toxin: an A-B Toxin
    B binds
    A internalized; inhibits release of GABA and Glycine
13
Q

Manifestations of Tetanus:

Diagnosis of Teatnus:

Treatment:

A

Manifestations;

Generalized Tetanus – lockjaw, opisthotosis, autonomic instability (Sweating, arrythmia, fevers, tachy), respiratory failure — SPASTIC PARALYSIS

Localized, Cephalic and Neonatal Tetanus

Diagnosis: Spastic paralysis
Opisthotosis – Pathomneuomonic with Tetanus

Treatment: Metronidazole
secondary : PCN, but this can inhibit inhibitory synapses and make things worse
Wound cleaning, airway management

14
Q

C. Botulinim

  • Class of organism
  • where is it found
  • What is the toxin and its effect
  • Characteristic finding on Physical exam
  • What are the types of botulinum illness
A

Anaerobic Spore Forming GPR
- Found in soil, sediment, vegetables, home canned foods, with alkaline pH, seafood

Botulin Toxin:

  • inhibits release of Ach at the NMJ
  • FLACID PARALYSIS

Types of illness: foodborne, wound, infant botulism, Inhalation botulism (bioterrorism)

15
Q

What are the clinical manifestations and cardinal signs of Botulism ?

  • compare to Guillane Barre
  • compare to polio
A

Botulism:
Cranial Nueropathies with symmetric descending paralyiss, progressing to resp failure
- NO FEVER
- NO SENSORY DEFICITS

Guillan Barre – ASCENDING paralysis + sensory deficits

Polio - FLaccid paralysis + FEVER

16
Q

Botulism:

  • Diagnosis
  • Treatment
A

Diagnosis: Physical Exam
Culture and Microscopy are not useful

Treatment: Metronidazole
Trivalent Botulinum anti-toxin

Keep food at acid pH and below 4C
Kill bacteria at 80C

17
Q

Clostridium Perfringes:

  • Class of organism
  • Where is found ?
  • What is unique about its culture?
  • Toxins ?
  • What disease can it cause ?
A
  • Anaerobic Spore forming GPR
  • Found in soul, water, Gi of humans and animals
  • Culture: Double zone of Hemolysis
  • Toxins: • α, β, ε, ι toxins; enterotoxin
Diseases: 
Food poisoning 
Soft tissue infection: Myonecrosis (Gas Grangrene) 
Nec fash, cellulitis 
Bacteremia 

-

18
Q

If you see SubQ emphysema on any imaging, what should you immediately think?

A

Anaerobic infection such as C. perfringes gas gangrene

19
Q

Treatment and Diagnosis of C. perfringes:
- what is characteristic about the microscopy

-Treatment

A

– will see no WBC or RBC in the infection (bc its so rapid?)

  • Treatment:
    Surgical Debridement
    ABX: PCN + Clindamycin (to inhibit toxin synthesis)
20
Q

Clostridium Dificile:

  • What class of organism
  • whwere is it found
    What are its toxins and what do they do?
    What strain is assocaited with CA c. dif colitis
A
  • Anaerobic GPR, spore forming
  • colonizes the GI tract in a small number of healthy people
  • Toxins: Enterotoxin, Cytotoxin — damage colonic tissue, form pseudomembrane plaque

NAP 1 strain

21
Q

C. Dif;
- What is the mechanism of Disease ?

  • What are the manifestations of disaese?

-

A

mechanism of Disease;

  • FQs, Clinda, and Cephalosporins can suppress the normal flora
  • Allow for overgrowth of C. Diff

Manifestations:

  • diarrhea
  • Psuedomenbranous colitis — Toxic megacolon — susceptible to perforation — sepsis and death

High relapse rate

22
Q

Diagnosis of C. dif
Treatment of C. dif
Prevention

A
- Dx: PCR Amplification of Toxin genes 
distinct Smell (tyrosine fermentation) 
  • Treatment:
  • nonsever disease: Metronidazole
  • Sever diasese: Oral Vanc +/- IV metronidazole
  • Fecal transplant

Prevention: have to wash hands
alcohol does not kill the spores