Gram Positive Bacilli - Sporing/Non-sporing Aerobes/Anaerobes

Question 1

Sporing Aerobes: _____
Non-sporing Aerobes: _____
Sporing Anaerobes: _____
Non-sporing Anaerobes: _____

Answer 1

Bacillus
Corynebacterium, Nocardia, Listeria, Lactobacillus
Clostridium
Generalised, Actinomyces israelii, Fusobacterium necrophorum

Question 2

Virulence factors of Bacillus antracis?

Answer 2

Capsule and exotoxin (causes oedema, fatal)

Question 3

Clinical presentations of B. antracis?

Answer 3

Blood in SKIN, LUNGS, STOOL

1. Cutaneous anthrax - Local eschar with surrounding region of vesicles and oedema
2. Inhalatory anthrax - Pulmonary failure and respiratory collapse
3. Intestinal anthrax - Haemorrhagic diarrhoea
   *All can lead to septicaemia and eventual death

Question 4

Clinical presentation of B. cereus? Explain the early and late onset.

Answer 4

Food poisoning (FRIED RICE)
Rapid onset: Pre-formed toxin, causes vomiting
Late onset: Ingestion of bacteria and generation of enterotoxin in vivo, causes diarrhoea and abdominal pain

Question 5

Clinical presentation of Corynebacterium diphteriae? Separate into toxigenic and non-toxigenic strains.

Answer 5

Toxigenic: Inactivates EF2 and inhibits protein synthesis
- Local: Local pseudomembrane that expands to form bull-neck -> Laryngeal obstruction
- Distant: Myocarditis, arrhythmia, peripheral neuritis

Non-toxigenic: Pharyngitis, abscesses, invasive infections

Question 6

Clinical presentations of Nocardia asteriodes?

Answer 6

1. Opportunistic infections in immunocompromised patients (Lung infections could lead to brain abscess)
2. Madura’s foot

Question 7

Clinical presentations of Listeria?

Answer 7

1. Neonatal listeriosis and meningitis
2. Meningitis, encephalitis

Question 8

Where is Lactobacillus found?

Answer 8

Mouth, gut, and vagina (especially after puberty)

Question 9

Does Corynebacterium produce a toxin?

Answer 9

Yes, diphtheria toxin

Question 10

How is B. antracis diagnosed?

Answer 10

Pink colour on MacFadyean’s stain
+ Blood culture / Eschar Swab

Question 11

Treatment for B. anthracis?

Answer 11

Ciprofloxacin
Vaccines are limited

Question 12

Treatment for Corynebacterium?

Answer 12

Antiserum, erythromycin
Routine childhood vaccination

Question 13

Treatment for Listeria?

Answer 13

Ampicillin

Question 14

Treatment for Nocardia?

Answer 14

Cotrimoxazole

Question 15

B. antracis produce ___ spores that can spread after the ___

Answer 15

Resistant, death of the animal or is carried in bone, meat, hide

Question 16

B. cereus produce ___ spores that can ___

Answer 16

Resistant, survive high heat

Question 17

Listeria can ___ at ___ temperatures

Answer 17

Multiply, cold

Question 18

Corynebacterium ulcerans resembles ___ as _____

Answer 18

C. diphtheria, the same toxin is produced

Question 19

Corynebacterium jeikeium are ___ strains that cause ___ infections. Often infects ___ such as ______

Answer 19

Nosocomial, opportunistic, foreign implantations, valves or cannula

Question 20

Corynebacterium minutissimum causes _____. It ____ under Wood’s lamp

Answer 20

Erythrasma and occasionally invasive infections, fluoresces coral pink

Question 21

Listeria is resistant to the drug class of

Answer 21

Cephalosporins

Question 22

What will weaken the immune response to Listeria?

Answer 22

TNF inhibitors

Question 23

What exotoxin does C. perfringens produce? What does it result in?

Answer 23

Lecithinase, destroys cell membrane

Question 24

Clinical presentation of Clostridium perfringens?

Answer 24

1. Gas gangrene (local foul purulent blebs)
2. Food poisoning upon spore ingestion
3. Pigbel necrotising enteritis (Type C exotoxin)

Question 25

Treatment of C. perfringens?

Answer 25

Benzylpenicillin + Clindamycin

Question 26

Diagnosis of C. perfringens?

Answer 26

Blood culture + Nagler plate

Question 27

Clinical presentations of Clostridium difficile?

Answer 27

Antibody associated Pseudomonas Colitis -> Formation of pseudomembrane that causes obstruction Presents as foul diarrhoea (CDAD)

Question 28

When is C. difficile dangerous?

Answer 28

When broad spectrum antibiotics have been used that leads to decimation of other bacterial flora

Question 29

Treatment of C. difficile?

Answer 29

STOP ANTIBIOTICS First line: Oral metronidazole Second line: Oral vancomycin

Question 30

Clinical presentation of C. tetani?

Answer 30

Tetanus (Spastic paralysis) Tetanospasmin acts on LMNs and blocks inhibitory transmissions leading to spasmodic contractions by muscles Presents as risus sardonicus, trismus and opisthotonus

Question 31

How does Clostridium tetani look like?

Answer 31

Drumstick appearance due to large terminal spore

Question 32

Name of toxin formed by C. tetani?

Answer 32

Tetanospasmin

Question 33

Treatment of C. tetani?

Answer 33

1. HTIg to neutralise toxin 2. Clindamycin 3. Ventilator support 4. Vaccine for tetanus

Question 34

Toxin of C. botlinum?

Answer 34

Botulinum toxin

Question 35

Clinical presentation of C. botulinum?

Answer 35

Flaccid paralysis due to inhibition of NMJ conduction by preventing ACh release Presents with diplopia, ptosis and general weakness Infection with bacteria and in vivo toxin generation will cause floppy child syndrome

Question 36

Treatment of C. botulinum?

Answer 36

Antitoxin (Prevention by proper handling of food)

Question 37

Treatment of Gram Positive Generalised Anaerobes?

Answer 37

Metronidazole

Question 38

Clinical presentation of Gram Positive Generalised Anaerobes?

Answer 38

1. Mixed infections 2. Foul smelling purulent infections

Question 39

Actinomyces israeli forms ___ at _____ and _____. It is treated with ___.

Answer 39

Infection, site of trauma, spreads crossing tissue planes. Amoxicillin

Question 40

Fusobacterium necrophorum causes ___ with _____ after ____. It is treated with ___.

Answer 40

Lemierre's disease, severe septicaemia, initial sore throat. Benzylpenicillin

Question 41

Clostridium septicum causes ___ especially in ___. Commonly isolated in patients with ___.

Answer 41

Gas gangrene, neutropenic patients. Leukemia or cancer

Question 42

How does Corynebacterium diphtheriae look like in serology?

Answer 42

Chinese character appearance (Rods, branching filaments, Tinsdale medium)

Question 43

Where is Listeria Monocytogenes found?

Answer 43

Salads, cheeses, dairy

Question 44

How does Nocardia asteroides look like?

Answer 44

Branching filamentous rods

Question 45

What stain can be used for Nocardia asteroides?

Answer 45

Ziehl Neelsen

Question 46

Where is Nocardia asteroides found?

Answer 46

Soil, dirt, bad shoes

Question 47

Lactobacillus presents itself as

Answer 47

Dental caries