Amoxil

[amoxicillin]

A report of "Resistant" indicates that the pathogen is not likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable; other therapy should be selected. Standardized susceptibility test procedures require the use of laboratory control microorganisms to control the technical aspects of the laboratory procedures. Standard ampicillin powder should provide the following MIC values:

Microorganism MIC (mcg/ mL)
E. coli ATCC 25922 2 to 8 E. faecalis ATCC 29212 0.5 to 2

H. influenzae ATCC 49247 d 2 to 8
S. aureus ATCC 29213 0.25 to 1

Text Continues Below

---

Using amoxicillin to determine susceptibility:
Microorganism MIC Range (mcg/ mL)
S. pneumoniae ATCC 49619 e 0.03 to 0.12

d. This quality control range is applicable to only H. influenzae ATCC 49247 tested by a broth microdilution procedure using HTM. 1

e. This quality control range is applicable to only S. pneumoniae ATCC 49619 tested by the broth microdilution procedure using cation-adjusted Mueller-Hinton broth with 2-5% lysed horse blood.

Diffusion techniques:

Quantitative methods that require measurement of zone diameters also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds.

One such standardized procedure 2 requires the use of standardized inoculum concentrations. This procedure uses paper disks impregnated with 10 mcg ampicillin to test the susceptibility of microorganisms, except S. pneumoniae, to amoxicillin. Interpretation involves correlation of the diameter obtained in the disk test with the MIC for ampicillin.
Reports from the laboratory providing results of the standard single-disk susceptibility test with a 10-mcg ampicillin disk should be interpreted according to the following criteria:

For gram-positive aerobes: Enterococcus
Zone Diameter (mm) Interpretation
. 17 Susceptible (S)
. 16 Resistant (R)
Staphylococcus f
Zone Diameter (mm) Interpretation
. 29 Susceptible (S)
. 28 Resistant (R)
-hemolytic streptococci
Zone Diameter (mm) Interpretation
. 26 Susceptible (S)
19 to 25 Intermediate (I)
. 18 Resistant (R)
NOTE: For streptococci (other than -hemolytic streptococci and S. pneumoniae), an ampicillin MIC should be determined.

Page:  << Prev | 1 | 2 | 3 | 4 | 5 | Next >>