INVESTIGADORES
VERNA Andrea Elizabeth
artículos
Título:
Variation in the Immuno-pathological Responses of Lambs after Experimental Infection with Different Strains of Mycobacterium avium subsp. paratuberculosis
Autor/es:
A. E. VERNA, C. GARCIA-PARIENTE, M. MUNOZ, O. MORENO, J. F. GARCÝ´A-MARIN, M. I. ROMANO,
Revista:
ZOONOSES AND PUBLIC HEALTH
Referencias:
Año: 2007 vol. 54 p. 243 - 252
ISSN:
1863-1959
Resumen:
Ruminant infection by Mycobacterium avium subsp. paratuberculosis (MAP)
causes a granulomatous inflammatory response in the intestine and associated
lymph nodes. Differences either in the affected organs or in the inflammatory
infiltrate were observed between species and individuals. Such differences are
usually attributed to variations in host immune responses or to inconsistent
effects among different MAP strains. To evaluate if different MAP strains
induce different immuno-pathological responses in lambs, 28 one-month-old
individuals were divided into six groups and inoculated with different MAP
strains. Groups 1 and 2 were inoculated with two bovine strains isolated in
Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
causes a granulomatous inflammatory response in the intestine and associated
lymph nodes. Differences either in the affected organs or in the inflammatory
infiltrate were observed between species and individuals. Such differences are
usually attributed to variations in host immune responses or to inconsistent
effects among different MAP strains. To evaluate if different MAP strains
induce different immuno-pathological responses in lambs, 28 one-month-old
individuals were divided into six groups and inoculated with different MAP
strains. Groups 1 and 2 were inoculated with two bovine strains isolated in
Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
causes a granulomatous inflammatory response in the intestine and associated
lymph nodes. Differences either in the affected organs or in the inflammatory
infiltrate were observed between species and individuals. Such differences are
usually attributed to variations in host immune responses or to inconsistent
effects among different MAP strains. To evaluate if different MAP strains
induce different immuno-pathological responses in lambs, 28 one-month-old
individuals were divided into six groups and inoculated with different MAP
strains. Groups 1 and 2 were inoculated with two bovine strains isolated in
Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
causes a granulomatous inflammatory response in the intestine and associated
lymph nodes. Differences either in the affected organs or in the inflammatory
infiltrate were observed between species and individuals. Such differences are
usually attributed to variations in host immune responses or to inconsistent
effects among different MAP strains. To evaluate if different MAP strains
induce different immuno-pathological responses in lambs, 28 one-month-old
individuals were divided into six groups and inoculated with different MAP
strains. Groups 1 and 2 were inoculated with two bovine strains isolated in
Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a clinical case
affected by the same bovine strain as that of group 3. Group 5 was inoculated
with an ovine strain that was directly purified from the intestinal mucosa of a
clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral
immune responses were assessed until 150 days post-infection (dpi), when
lambs were humanely killed. Pathological studies were performed in tissues
from the intestine and lymph nodes. Lesion types and inflammatory infiltrates
were examined as indicators of pathogenicity. All the lambs infected with
bovine MAP strains showed a common lesion pattern regardless of the strain
type. Such pattern was characterized by focal lesions mainly in the mesenteric
lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the
granulomas as well as the presence of numerous giant cells. Differences in
lesion severity were observed among groups: lambs from groups 1 and 2 had
the highest number of granulomas and the largest lymph node area affected.
Lesions in animals from group 5 (infected with an ovine strain) were more
severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis
or giant cells were never detected in this group. These results indicate that the
MAP strain type induces different pathological responses in lambs.
strains E and A respectively). Group 3 was inoculated with a bovine strain
isolated in Spain obtained after a previous step of culture (patterns C1). Group
4 was inoculated with a homogenate of intestinal mucosa of a c