Recognized Interpretive Criteria

Exceptions to the recognized standard of CLSI M100

 

Minimum Inhibitory Concentrations
(mcg/mL)

Disk Diffusion
(zone diameter in mm)

Pathogen

S

I

R

S

I

R

Enterobacteralesa

M100 standard is recognized

Haemophilus influenzae and
parainfluenzae

M100 standard is recognized

Neisseria gonorrhoeae

M100 standard is recognized

Streptococcus pneumoniae
(meningitis)

M100 standard is recognized

-

-

-

Streptococcus pneumoniae
(non-meningitis)

M100 standard is recognized

-

-

-

Streptococcus spp β- Hemolytic Group

M100 standard is recognized

Streptococcus spp Viridans Group

M100 standard is recognized

Neisseria meningitidis

M100 standard is recognized

Anaerobes

≤1

2

≥4

-

-

-

aIncluding Salmonella spp. and Shigella spp.

S = Susceptible; I = Intermediate; R = Resistant

Susceptibility interpretive criteria recognized for Enterobacterales are based on a dose of 1 gram IV q 24h. For isolates with intermediate susceptibility, use a dose of 2 grams IV q 24h in patients with normal renal function.

For Haemophilus influenzae and parainfluenzae, susceptibility interpretive criteria recognized in CLSI M100 are based on a dose of 2 grams IV every 24 hours in patients with normal renal function.

For the bacteria listed below, susceptibility test interpretive criteria are not recognized at this time:

Acinetobacter spp

Other Non-Enterobacterales