(VII) Gram Positive Rods Aerobic (3)*Listeria monocytogenes

Question 1

Characterize (3) : Listeria monocytogenes

Answer 1

(1) Gram (+) rod
(2) Motile
(3) Catalase (+)

(Also only gram (+) with LPS)

Question 2

Listeria monocytogenes infection:

Transmission: […]

Clinical presentation:
[…]

Answer 2

Listeria monocytogenes infection:

Transmission: Food-borne (no smell. and able to multipy even in cold environment)

Clinical presentation:
Infection in Pregnant (plus foetus), neonate and immunocompromised (including elderly)
- Febrile bacteraemic sepsis
- Meningitis

Recall that listeria meningitis in neonate is early onset, similar to E coli and GBS.

Clinical Pearl : In all adults over 50 years of age and in immunocompromised patients who develop an acute meningitis, add ampicillin or co-trimozaxole to empirically cover Listeria monocytogenes !

Question 3

Listeria monocytogenes is NOT susceptible to […]

Answer 3

Listeria monocytogenes is NOT susceptible to cephalosporins

Link back to bacterial cell wall inhibitors. 1st-4th gen cephalosporins dont cover
Listeria monocytogenes
Atypicals
MRSA
Enterococci

Question 4

What is the antibiotic used in treating Listeria monocytogenes?

[…]

Answer 4

What is the antibiotic used in treating Listeria monocytogenes?

Ampicillin +/- gentamicin (rationalize therapy when Listeria is grown)