(XI) Non-Sporing Anaerobic Rods (NSA)

Question 1

Characterize (2) : Actinomyces israelii

Answer 1

(1) Gram (+) Filamentous branching rod
(2) Obligate anaerobe

Question 2

Actinomyces israelii are gram positive […] bacilli, isolated from […] in pus

Answer 2

Actinomyces israelii are gram positive branching bacilli, isolated from “sulfur granules” in pus

Question 3

Exception to NSA generalizations:

Actinomyces israelii
Clinical Presentation:
[…]

Fusobacterium necrophorum
Clinical Presentation:
[…]

Answer 3

Exception to NSA generalizations:

Actinomyces israelii
Clinical Presentation:
Actinomycosis
- Chronic draining sinuses (cervicofacial, uterine, GIT

Fusobacterium necrophorum
Clinical Presentation:
- Acute sore throat, “very sore”
- Septic thrombophlebitis

Question 4

Nearly all NSAs are sensitive to […]

Answer 4

Nearly all NSAs are sensitive to metronidazole

HH: “NS(F)s All take train (metro) HAHAHH”

Question 5

What are clinical manifestations of NSA infections?

Head & Neck:
[…]

Pleuropulmonary:
[…]

Abdominal & Pelvic
[…]

Skin & Soft Tissue
[…]

Others:
[…]

Answer 5

What are clinical manifestations of NSA infections?

Head & Neck:
- Tonsilitis, dental sepsis
- Vincent’s infection/angina (trench mouth)
- Abscess/cellulitis, Ludwig’s angina (sub-maxillary gland)
- Chronic “middle ear” and “sinus” infections
- Brain abscess (haematogenous spread from chronic ear/sinus/tooth infections

Pleuropulmonary:
- Aspiration Pneumonia
- Lung abscess
- Empyema

Abdominal & Pelvic
- Peritonitis
- Liver, pelvic abscesses
- PUO (look for hidden abscesses)

Skin & Soft Tissue
- Diabetic foot infections
- Anaerobic cellulitis including clostridial

Others:
- Male and female genital tracts
- Urinary tract (rare)
- Bone and joint (uncommon)
- Bites, punch injuries
- Bacteraemia (commonest anaerobe is B.fragilis)

Absesses everywhere!!!

Question 6

What does synergistic infections (cooperative between anaerobes and aerobes) cause?

[…]

Answer 6

What does synergistic infections (cooperative between anaerobes and aerobes) cause?

• Necrotising fasciitis
• Meleney’s syngergistic gangrene
• Fournier’s gangrene

Question 7

What is the nature of general NSA (non sporing anaerobes) infections?

[…]

Answer 7

What is the nature of general NSA (non sporing anaerobes) infections?

• Often mixed, involving aerobic species as well
• Seldom spontaneous, often involves precipitating cause (surgery, gut perforation, diabetes, cancer)
• Usually endogenous (own flora) except animal bites
• Produces disgusting smell!!!