The most frequent mutation in rrs associated with resistance to the injectable drugs is the A1401G mutation, followed by C1402T and G1484T mutations. Our assay can detect the A1401G and C1402T mutations, but it requires another set of primers to detect the G1484T mutation. Since the prevalence of the G1484T mutation is low and the resistance rate for the injectable drugs in California is also low, it may not be cost-effective to add a subassay for detection of this mutation. With a limited number of resistant isolates tested, our assay showed 100% sensitivity for detecting AMK and CAP resistance