No abstract

Two hundred isolates of Enterobacterales were tested by Rapid Polymyxins NP for the detection of polymyxin resistance and compared to the reference test broth microdilution (BMD). The sensitivity and specificity of the NP test were 98% and the results are faster than the BMD, decreasing from approximately 24 to 2 h.

Broth microdilution (BMD), the reference method to determine bacterial susceptibility to polymyxins, is a laborious and timeconsuming technique. Policimbac® is a commercial test panel which uses lyophilized polymyxin B to determine the minimum inhibitory concentration for Gram-negative isolates. This study evaluated the performance of Policimbac® in comparison with BMD for 110 isolates. Although the Policimbac® presented a very low essential agreement, the categorical agreement with BMD was optimal. Policimbac® is an alternative approach to BMD for evaluating the susceptibility to polymyxin B.