Pathologic findings and association of Mycobacterium bovis infection with the bovine NRAMP1 gene in cattle from herds with naturally occurring tuberculosis.
OBJECTIVE
To determine necropsy and Mycobacterium bovis culture results in cattle from herds with tuberculosis, the role of the bovine NRAMP1 gene in resistance and susceptibility to infection with M bovis, and the association between magnitude of the tuberculous lesions and various types of M bovis isolates.


METHODS
61 cattle from herds with tuberculosis in Texas and Mexico.


METHODS
61 cattle were evaluated by necropsy; 59 had positive and 2 had negative caudal fold tuberculin intradermal test (CFT) results. Thirty-three cattle with positive CFT results were genotyped to evaluate polymorphism of the 3' untranslated region of the bovine NRAMP1 gene, using single-stranded conformational analysis, 9 were resistant to M bovis with no tuberculous lesions and negative M bovis culture results, and 24 were susceptible with tuberculous lesions and positive M bovis culture results. Isolates of M bovis were analyzed by restriction fragment length polymorphism (RFLP) on the basis of IS6110 sequences and direct-repeat fingerprinting patterns.


RESULTS
21 (35.6%; 21/59) cattle with positive CFT results had tuberculous lesions or positive culture results; in addition, 1 of 2 cattle with negative CFT results had tuberculous lesions and positive culture results. Tuberculous lesions were most common in the thorax (35/63; 55.5%) and lymphoid tissues of the head (10/63; 15.9%). Tuberculous lesions varied from 1 to 11/animal; 8 of 21 (38.1%) had solitary lesions. Associations were not found between resistance or susceptibility to infection with M bovis and polymorphism in the NRAMP1 gene or between the magnitude of the lesions and various RFLP types of M bovis isolates.


CONCLUSIONS
The NRAMP1 gene does not determine resistance and susceptibility to infection with M bovis in cattle.
Barthel
R
R
Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station 77843-4467, USA.
Piedrahita
J A
JA
McMurray
D N
DN
Payeur
J
J
Baca
D
D
Suárez Güemes
F
F
Perumaalla
V S
VS
Ficht
T A
TA
Templeton
J W
JW
Adams
L G
LG
D000483:Alleles; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D027682:Cation Transport Proteins; D002417:Cattle / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D007113:Immunity, Innate / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics*; D009163:Mycobacterium bovis / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D014380:Tuberculosis, Bovine / Q000235:genetics / Q000473:pathology*; D000099173:Natural Resistance-associated Macrophage Protein 1
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D008565:Membrane Proteins; D000099173:Natural Resistance-associated Macrophage Protein 1