Format

Send to

Choose Destination
J Comp Pathol. 2014 Nov;151(4):410-9. doi: 10.1016/j.jcpa.2014.08.007. Epub 2014 Oct 8.

Virulence of two strains of mycobacterium bovis in cattle following aerosol infection.

Author information

1
National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA 50010, USA. Electronic address: ray.waters@ars.usda.gov.
2
National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA 50010, USA.
3
National Veterinary Services Laboratories, Veterinary Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Ames, IA 50010, USA.
4
National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA 50010, USA; Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
5
Chembio Diagnostic Systems, Inc., Medford, NY 11763, USA.

Abstract

Over the past two decades, highly virulent strains of Mycobacterium tuberculosis have emerged and spread rapidly in man, suggesting a selective advantage based on virulence. A similar scenario has not been described for Mycobacterium bovis infection in cattle (i.e. bovine tuberculosis). An epidemiological investigation of a recent outbreak of bovine tuberculosis in a USA dairy indicated that the causative strain of M. bovis (strain 10-7428) was particularly virulent, with rapid spread within the herd. In the present study, the virulence of this strain (10-7428) was directly compared in the target host with a well-characterized strain (95-1315) of relevance to the USA bovine tuberculosis eradication programme. Aerosol inoculation of 10(4) colony forming units of M. bovis 95-1315 (n = 8) or 10-7428 (n = 8) resulted in a similar distribution and severity of gross and microscopical lesions of tuberculosis as well as mycobacterial colonization, primarily affecting the lungs and lung-associated lymph nodes. Specific cell-mediated and antibody responses, including kinetics of the response, as well as antigen recognition profiles, were also comparable between the two treatment groups. Present findings demonstrate that M. bovis strains 95-1315 and 10-7428 have similar virulence when administered to cattle via aerosol inoculation. Other factors such as livestock management practices likely affected the severity of the outbreak in the dairy.

KEYWORDS:

Mycobacterium bovis; bovine tuberculosis; immunity; virulence

PMID:
25306158
DOI:
10.1016/j.jcpa.2014.08.007
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center