P MICRO SENSY ABX W X Weakly sensitive

 A

In the context of an antibiotic susceptibility report, the letters usually indicate how the bacteria respond to the antibiotic:

• S = Sensitive (the antibiotic is effective)

• R = Resistant (the antibiotic is not effective)

• IE = Insufficient Evidence or Interpretive Error (uncertain, cannot interpret)

• W = Weakly sensitive or Intermediate (sometimes “Warning”) depending on the lab’s notation.

Here, for Ceftriaxone, W suggests that the bacteria may have reduced susceptibility. It’s not fully resistant, but the response may not be reliable, so it should be used with caution, possibly at higher doses, or in combination with other antibiotics.

If you want, I can make a clear table showing what each antibiotic would mean for treatment of Moraxella catarrhalis in a pediatric patient. This can make it much easier to interpret. Do you want me to do that?