Evaluation of polymerase chain reaction (PCR) for identifying Mycobacterium bovis isolates from the modified Middlebrook 7H11 agar thin layer technique

Abstract

The associated use of the modified Middlebrook 7H11 agar thin layer technique and the Polymerase Chain Reaction (PCR) assay enabled to perform the early identification of microcolonies of Mycobacterium bovis from 12th to 25th day of culture. In order to reduce the time for performing the Mycobacterium bovis identification, the combined use of these two techniques was evaluated by analyzing the microcolonies of mycobacteria at the 8th day after culturing. Until the last day of analysis, all of the PCR-positive samples already showed the microcolonies. Therefore, the early diagnosis of bovine tuberculosis is feasible, without an apparent macroscopic colonies growth.