Pathogens susceptible to tetracycline are also susceptible to omadacycline: tetracycline as a one-sided surrogate to predict omadacycline susceptible pathogens.

This study used surveillance data from a global program of clinical bacterial isolates to determine whether a tetracycline susceptible result can be used to predict an omadacycline susceptible result. Categorical agreement, very major error rates, and minor error rates were calculated for Staphylococcus aureus (MSSA and MRSA; n=38,364), S. lugdunensis (n=335), Streptococcus pneumoniae (n=11,725), S. pyogenes (n=3,390), S. anginosus group (n=622), Haemophilus spp. (n=6,419), Enterococcus faecalis (n=7,065), Klebsiella pneumoniae (n=10,313), and Enterobacter cloacae (n=4,418). Across the organisms, for which omadacycline has an FDA breakpoint established, a tetracycline susceptible result showed ≥96.3% categorical agreement in predicting an omadacycline susceptible result. The rates of very major errors were below the guideline-suggested level (<1.5%). Omadacycline retained activity against most (88.7-100% Gram-positive and 54-98.6% Gram-negative) tetracycline-resistant isolates. For laboratories that do not have the capability to perform susceptibility testing for omadacycline, one-sided surrogate testing for tetracycline can be a practical alternative.