Isolation of atypical mycobacteria from the environment in cattle herds with high and low seroprevalence to Mycobacterium avium subsp. paratuberculosis

摘要

Introduction: Testing of beef herds in Texas for paratuberculosis has identified herds with high proportions of seropositive results. In some of these herds, several atypical mycobacteria were isolated from fecal samples. The objective of this study was to investigate the association between atypical mycobacteria in the environment and 1) herds with high or low seroprevalence to Mycobacterium avium subsp. paratuberculosis (M. ptb.) as well as 2) chemical characteristics of the environment. Methods: Six beef cattle herds with a high seroprevalence for M. ptb. and three closely located herds without a previously high seroprevalence were identified in 2003. In 2004, between six and 13 environmental samples were sampled from these nine farms. Environmental samples were collected from water and soil. Soil samples were cultured using the BACTEC~R system for mycobacteria. Acid fast organisms were tested with IS900 PCR, and mycolic acid analyses using HPLC was used to characterize IS900 negative mycobacteria.