Environmental mycobacteria in soil and water on beef ranches: Association between presence of cultivable mycobacteria and soil and water physicochemical characteristics

• Published in: Veterinary microbiology 2007-09, Vol.124 (1), p.153-159
• Main Authors: Norby, Bo, Fosgate, Geoffrey T., Manning, Elizabeth J.B., Collins, Michael T., Roussel, Allen J.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Bacterial - blood; antibody detection; Bacteriology; Beef cattle; Biological and medical sciences; Bovine paratuberculosis; Cattle; cattle diseases; Cattle Diseases - epidemiology; Cattle Diseases - etiology; Colony Count, Microbial - veterinary; Cross Reactions; Cross-Sectional Studies; disease detection; disease diagnosis; environmental exposure; environmental factors; Environmental Microbiology; Environmental mycobacteria; enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Enzyme-Linked Immunosorbent Assay - veterinary; epidemiological studies; False Positive Reactions; Fundamental and applied biological sciences. Psychology; geographical variation; Hydrogen-Ion Concentration; Microbiology; mineral content; Miscellaneous; Mycobacterium - immunology; Mycobacterium - isolation & purification; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Mycobacterium avium subsp. paratuberculosis - immunology; Mycobacterium avium subsp. paratuberculosis - isolation & purification; Mycobacterium Infections - epidemiology; Mycobacterium Infections - etiology; Mycobacterium Infections - veterinary; paratuberculosis; Paratuberculosis - epidemiology; Paratuberculosis - etiology; Sensitivity and Specificity; Seroepidemiologic Studies; Soil; Soil - analysis; Soil Microbiology; Species Specificity; validity; Water; Water Microbiology
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2007.04.015

Exposure to environmental mycobacteria has been reported to be a factor contributing to false-positive results on bovine serological tests detecting antibodies to Mycobacterium avium subsp. paratuberculosis (Mptb). This study was conducted to investigate the association between recovery of mycobacteria from the environment of cattle and both (i) historically high or low seroprevalence to Mptb, and (ii) soil and water physicochemical characteristics. Eighty-two samples (soil and water) from nine beef cattle ranches in South-central and South Texas were assessed for the presence of mycobacteria. Twelve mycobacterial species were cultured from soil and water from four herds; no Mptb were detected in environmental samples. A positive culture of environmental mycobacteria from soil was significantly associated with lower pH and calcium as well as higher iron, zinc and manganese contents. Beef cattle are likely to be exposed to environmental mycobacteria that may contribute to false-positive results on ELISAs for Mptb infection. Exposure rates to these mycobacteria likely vary across small geographical areas and may be related to soil and/or water physicochemistry.