Spore-forming Gram-Positive Rods

Question 1

Bacillus anthracis

Answer 1

Only bacteria with an amino acid capsule
Causes anthrax
Cutaneous: exotoxin causes localized tissue necrosis “black eschar lesions”
Respiratory: “Woolsorter’s” disease
GI: rare but fatal (diarrhea)

Normal flora of sheep, goat, cattle
Encapsulated (with D-glutamic acid in capsule)
ID test: MacFaydean reaction test
Medusa head colony appearance

Question 2

Bacillus vs. Clostridium

Answer 2

Bacillus has endospore which is a specialized structure for extra resistance

Question 3

Bacillus cereus

Answer 3

Non-encapsulated, motile
Produces exotoxin
Causes food poisoning: emetic/diarrheal (fried rice)

Question 4

Bacillus subtilis

Answer 4

CM: UTI
Source of Bacitracin (wound of Margaret Tracey) which is an antibacterial cream or ointment

Question 5

Clostridium botulinum

Answer 5

Normal flora of animals
Inh. Release of Ach in skeletal muscles = paralysis
Acquired by humans through: Deep wound infection, Consumption of vacuum packed or canned foods or honey by infants

• S/S: Flaccid Paralysis (Lack of muscle tone, “Flappy baby syndrome” and Starts with facial muscles), Diaphragmatic paralysis – respiratory arrest, Diplopia, slurred speech, swallowing difficulty

Used in dermatology – Botox
Rx: Trivalent antitoxin

Question 6

Clostridium tetani

Answer 6

Normal flora of horses, dogs
CM: Tetanus
S/S: Spastic paralysis, Ricus sardonicus smile/”devil’s grin”, Opisthotonus – hyperarching of back muscles – spine may break, Lock jaw

ONLY IF SKIN IS NOT INTACT

Question 7

Clostridium perfringens

Answer 7

“Flesh eating bacteria”
CM: Gas Gangrene
S/S: Myonecrosis – liberation of foul smelling gas
ID Test: Nagler’s Test
Tx Options: Amputation-avoid spreading, Maggots – eat necrotic tissue, Hyperbaric chambers – allows O2 to penetrate for blood flow

Question 8

Clostridium difficile

Answer 8

Normal flora of colon
CM: Pseodomembranous colitis (pus-like)
S/S: bloody diarrhea, abdominal cramps, Associated with use of broad spectrum antibiotics (destroy normal Flora of intestine)

Question 9

Non-spore forming Gram positive Rods

Corynebacterium diphtheriae

Answer 9

V-shaped or palisades
“Chinese lettering”
Pleomorphic; aerobic/facultative anaerobic
Non-motile, non-encapsulated
Screening test: Schick
Lab Dx: Loeffler’s slant
Virulence: Diphtheria toxin

Question 10

Non-spore forming Gram positive Rods

Listeria monocytogenes

Answer 10

Has tumbling end-over-end motility at 22C but not at 37C
Facultative anaerobe
Catalase
Produces hemolysin
Only G(+) with endotoxin

Question 11

Non-spore forming Gram positive Rods

Propionibacterium acnes

Answer 11

More common in males due to inc. testosterone and sebum
CM: Acne
S/S: comedone (black, whiteheads)