Identification of acid-fast bacilli using pyrosequencing analysis

Pyrosequence identification of 117 isolates of acid-fast bacilli (AFB) was compared to both routine phenotypic methods and Sanger sequencing. Two (2) vendor-provided pyrosequencing primers specific for AFB were used for the study. Pyrosequence analysis correctly identified 114 (98%) of the tested 117 AFB isolates. Among the test Mycobacterium spp., 18 of 20 Mycobacterium spp. were identified correctly to the species level. All rapidly growing mycobacteria were correctly identified to species by pyrosequencing. Other slowly growing mycobacteria such as Mycobacterium tuberculosis, Mycobacterium kansasii, Mycobacterium avium–intracellulare, and others were easily identified by pyrosequencing. Only Mycobacterium simiae and Mycobacterium scrofulaceum were not identifiable by the pyrosequence method. Among the 25 Nocardia isolates, all were correctly identified to the genus level. Identification of AFB by pyrosequence analysis provides both a rapid and accurate method for this group of organisms.