Should Klebsiella oxytoca be reported as resistant to Cefotaxime?
A. In the CDS manual we state that Klebsiella oxytoca that hyper produce the K1 βlactamase should be considered resistant to Cefotaxime. However, the majority of K oxytoca are not hyper producers and are susceptible to Cefotaxime. If the organism has an inhibitory zone of ≥ 6 mm around a Cefotaxime 5 μg disc and there is no synergy between this disc and an adjacent Augmentin 60 μg or Timentin 85 μg disc, the organism is not a K1 hyper producer and can be reported as susceptible to Cefotaxime. If the organism has an inhibitory zone size of < 6 mm around a 5 μg disc or there evidence of synergy between this disc and an adjacent Augmentin 60 μg or Timentin 85 μg disc, the organism is a K1 hyper producer and should be reported as resistant to Cefotaxime.
