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Gastroinvasive Helicobacter Infection in an Ocelot (Leopardus pardalis)
J. Comp. Path. 2005, Vol. 133, 281–285
SHORT PAPER
www.elsevier.com/locate/jcpa
Gastroinvasive Helicobacter Infection in an Ocelot (Leopardus pardalis) Y. Kanou*†, D. Fukui‡, S. Yamamoto¶, T. Shibahara†, Y. Ishikawa† and K. Kadota† *Ishikari Livestock Hygiene Service Centre, 3 Hitsujigaoka, Toyohira, Sapporo 062-0045, †Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo 062-0045, ‡Asahiyama Zoological Park and Wildlife Conservation Centre, Kuranuma, Higashi-Asahikawa, Asahikawa 078-8205, and ¶Kushiro Livestock Hygiene Service Centre, 127-1 Otanoshike, Kushiro 084-0917, Japan
Summary Highly invasive Helicobacter-like organisms were found in a 19-year-old female ocelot (Leopardus pardalis) with multiple ulcers in the fundic region of the stomach. The bacteria, resembling Helicobacter heilmannii, were located largely within canaliculi or in the cytosol of parietal cells. Except in the ulcerative lesions, parietal cells were hyperplastic, while chief cells and neck mucous cells were reduced in number. The term “gastroinvasive Helicobacter-like organism” was applied. It seems probable that this organism differs from other Helicobacter organisms in pathogenicity, and possible that its behaviour in vitro would help it to evade antibacterial treatment. q 2005 Elsevier Ltd. All rights reserved. Keywords: bacterial infection; Helicobacter heilmannii; invasiveness; Leopardus pardalis; ocelot; parietal cell
In man, Helicobacter pylori infection is associated with the development of gastric diseases including chronic gastritis, ulcer, lymphoma, and adenocarcinoma (Versalovic, 2003). Several Helicobacter species have been isolated from Felidae (Fox and Lee, 1997; Schro¨der et al., 1998; Norris et al., 1999), and are linked to subclinical mild gastritis, chronic gastritis, lymphoid follicular hyperplasia, and adenocarcinoma (Eaton et al., 1993; Norris et al., 1999; Yamazaki et al., 2002). Usually, Helicobacter organisms are present at the mucosal surface and in the lumina of gastric glands (Norris et al., 1999). Some investigators, however, reported small numbers of organisms apparently in the cytoplasm of parietal cells in cats and dogs (Hermanns et al., 1995; Scanziani et al., 2001), and their exact location was shown electron microscopically to be the canaliculi (Happonen et al., 1996). Convincing
Correspondence to: T. Shibahara. 0021-9975/$ - see front matter
doi:10.1016/j.jcpa.2005.04.008
evidence of intracytoplasmic bacteria was produced in monkeys infected with H. heilmannii-like organisms (Dubois et al., 1991). A 19-year-old female ocelot (Leopardus pardalis) died one day after showing continuous bleeding from the left nostril, loss of appetite and dehydration. At necropsy, multiple ulcers were observed in the fundic gland region of the stomach. The left nasal passage was obstructed by a blood clot and the mucosa was diffusely haemorrhagic. The lungs were markedly congested, and had many white foci, 0.1 to 1.5 cm in diameter, especially in the ventral part of the left inferior lobe. For histological examination, tissue samples were collected from the nasal concha, lungs, stomach, duodenum, ileum, colon, liver, pancreas, spleen and heart. They were fixed in 10% buffered formalin, embedded in paraffin wax, sectioned at 3 mm, and stained with haematoxylin and eosin (HE). Selected paraffin wax-embedded sections were stained by the Gram, Warthin–Starry and q 2005 Elsevier Ltd. All rights reserved.
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Y. Kanou et al.
periodic acid-Schiff (PAS) methods. Sections were also examined immunohistochemically by the streptavidin–biotin–peroxidase complex (SAB) method. The primary antibodies used for immunolabelling were rabbit polyclonal antibodies to H. pylori (DAKO Corporation, Glostrup, Denmark) and rat islet amyloid polypeptide (IAPP) (Peptide Institute, Osaka, Japan), and mouse monoclonal antibody to proliferating cell nuclear antigen (PCNA) (BioGenex Laboratories, San Ramon, CA, USA); subsequent procedures were performed with an SAB kit (Nichirei Corporation, Tokyo, Japan). In addition, small blocks of formalin-fixed gastric tissue were post-fixed in 1% osmium tetroxide and embedded in epoxy resin; ultrathin sections were then stained with uranyl acetate and lead citrate, and examined by transmission electron microscopy (TEM). Histologically, in ulcerative lesions of the gastric mucosa considerable areas of the glandular tissue were destroyed, with neutrophil infiltration at the edges. In other areas of the mucosa, parietal cells showed hyperplasia (Fig. 1) and occasionally multiple nuclei (up to four), and a few were pyknotic or necrotic. By contrast, chief cells and neck mucous cells were reduced in number. Argyrophilic, Gram-negative, spiral-shaped organisms appeared to be present in most parietal cells (Figs 2 and 3), their number being much greater than in the lumen of gastric glands. Parietal cells with large numbers of bacteria also showed PASand silver-positive granules. Lymphocytes and
Fig. 1. Gastric mucosa. Mucosal thickening of the fundic region is due to hyperplastic parietal cells. HE. Bar, 50 mm.
Fig. 2. Gastric mucosa. Several spiral-shaped organisms are present in the cytoplasm of parietal cells (arrows), and a trinuclear parietal cell is observed (arrowhead). HE. Bar, 12.5 mm.
plasma cells were sparsely distributed in the lamina subglandularis. The lungs showed acute suppurative bronchopneumonia, the alveoli and bronchioles being filled with inflammatory exudate containing large numbers of neutrophils and macrophages. In the pancreas, large amounts of amyloid were deposited in nearly all the islets of
Fig. 3. Gastric mucosa. Several argyrophilic spiral-shaped organisms are present in the cytoplasm of parietal cells (arrows). Warthin-Starry. Bar, 20 mm.
Helicobacter Infection in an Ocelot
283
Fig. 4. Gastric mucosa. PCNA-positive epithelial cells are observed in the deeper part of the mucosa. Weakly positive stomach cells are visible in the lamina subglandularis (bottom). Anti-PCNA. SAB. Bar, 25 mm.
Fig. 5. Gastric mucosa. Intracytoplasmic Helicobacter-like organisms have tightly curved spiral appearances (arrows). Myelinosomes containing membranous structures are also detectable (arrowheads). TEM. Bar, 2 mm.
Langerhans, and the islet cells were few in number. There were no histological abnormalities in other organs. Immunohistochemically, the spiral-shaped bacteria were labelled by the H. pylori antibody. In the areas of parietal cell hyperplasia, PCNA-positive epithelial cells were observed not only in the proliferating neck zone but also in the deeper part of the mucosa (Fig. 4). Amyloid material was positive for IAPP. TEM of the gastric mucosa revealed apparently robust intracytoplasmic, intracanalicular and intraluminal bacteria (Fig. 5), 4.9 to 6.9 mm in length and 0.4 to 0.6 mm in diameter. They had 8 to 10 helical turns and at least four polar flagella, but were devoid of periplasmic fibres. Some parietal cells showed myelinosomes (Fig. 6) or secondary lysosomes containing membranous structures. The silver-positive granules seen histologically corresponded to the organelles visible by TEM. On the basis of morphology, Helicobacter species are divided into three types (Lockard and Boler, 1970). The organisms described here had a tightly spiralled cell body without periplasmic fibres, and fell into the category of Lockard type 3, in which Helicobacter acinonychis, H. pylori and Helicobacter heilmannii are included (Fox and Lee, 1997). The present organism closely resembled H. heilmannii, being larger than the other two. The organisms were immunolabelled by the polyclonal antiserum
against H. pylori, but this antiserum is genus-specific and not species-specific. Helicobacter-like organisms have been described in the cytoplasm of parietal cells of cats infected with H. pylori, H. felis, H. heilmannii or unclassified Helicobacter spp., apparently within canaliculi (Scanziani et al., 2001), which are deep microvillus-lined
Fig. 6. Gastric mucosa. This spiral-shaped bacterium is in direct contact with surrounding mitochondria, and is clearly intracellular. A myelinosome is also detectable. TEM. Bar, 500 nm.
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Y. Kanou et al.
invaginations and may be regarded as extensions of the glandular lumen (Stevens and Lowe, 1996). Hermanns et al. (1995) concluded that Helicobacterlike organisms in cats and dogs occurred within either dilated canaliculi or cytoplasmic vacuoles, and Happonen et al. (1996) confirmed their intracanalicular location by electron microscopy. In rhesus monkeys (Macaca mulatta), however, H. heilmannii-like organisms occurred in the cytoplasmic matrix (Dubois et al., 1991). The present bacteria showed similar but much more striking invasiveness, which might enable them to evade antibacterial treatment (Engstrand et al., 1997). In porcine intestinal adenomatosis, the affected tissue shows marked proliferation of immature epithelial cells of the intestinal crypts, and the proliferating cells contain numerous intracytoplasmic Lawsonia intracellularis organisms (Smith and Lawson, 2001). Likewise, parietal cell hyperplasia and intracytoplasmic bacteria were observed in the present case, and these features may be closely associated. Ulcerative lesions were thought to have occurred in the sites where epithelial cells injured by bacteria were more predominant than proliferating cells. After direct injection of bacteria into the cytosol of mammalian cells, most bacteria that normally reside in a vacuole are unable to replicate. In contrast, Listeria monocytogenes, Shigella flexneri and enteroinvasive Escherichia coli are able to multiply in this cellular compartment after microinjection (Goetz et al., 2001). Although bacterial division could not be confirmed in the present study, almost all intracytoplasmic organisms appeared intact, unlike H. heilmannii-like organisms within the cytoplasm of simian parietal cells (Dubois et al., 1991). The present bacteria are designated gastroinvasive Helicobacter-like organism, as they differ in invasive ability from other Helicobacter-like organisms, which show little if any invasiveness. Myelinosomes are bodies containing whorled osmiophilic membranes, and some are autolysosomes, in which cytomembranes appear to be transformed into osmiophilic membranes (Ghadially, 1997). In the present case, organelles such as smooth endoplastic reticulum and mitochondria may have been damaged by bacterial cytotoxic proteins or intracytoplasmic bacteria. Such events may be responsible for the formation of autolysosomes with membranous structures. Autophagocytic vacuoles have been induced in mammalian cells by the cytotoxin of H. pylori (Catrenich and Chestnut, 1992). Acute pneumonia was considered to be the primary cause of death of the ocelot described
here. Taking into account the gastric ulceration and chief cell depletion, the animal probably had dyspepsia; the amyloid deposition in the islets of Langerhans cells was probably due to old age (Yoshikawa et al., 1999).
Acknowledgments The authors thank Dr Y. Ando and Mr T. Fujisawa for preparation of the photomicrographs.
References Catrenich, C. E. and Chestnut, M. H. (1992). Character and origin of vacuoles induced in mammalian cells by the cytotoxin of Helicobacter pylori. Journal of Medical Microbiology, 37, 389–395. Dubois, A., Tarnawski, A., Newell, D. G., Fiala, N., Dabros, W., Stachura, J., Krivan, H. and HemanAckah, L. M. (1991). Gastric injury and invasion of parietal cells by spiral bacteria in rhesus monkeys. Are gastritis and hyperchlorhydria infectious diseases? Gastroenterology, 100, 884–891. Eaton, K. A., Radin, M. J., Kramer, L., Wack, R., Sherding, R., Krakowka, S., Fox, J. G. and Morgan, D. R. (1993). Epizootic gastritis associated with gastric spiral bacilli in cheetahs (Acinonyx jubatus). Veterinary Pathology, 30, 55–63. Engstrand, L., Graham, D., Scheynius, A., Genta, R. M. and El-Zaatari, F. (1997). Is the sanctuary where Helicobacter pylori avoids antibacterial treatment intracellular? American Journal of Clinical Pathology, 108, 504–509. Fox, J. G. and Lee, A. (1997). The role of Helicobacter species in newly recognized gastrointestinal tract diseases of animals. Laboratory Animal Science, 47, 222–255. Ghadially, F. N. (1997). Lysosomes. In: Ultrastructural Pathology of the Cell and Matrix, 4th Edit., ButterworthHeinemann, Boston, pp. 619–802. Goetz, M., Bubert, A., Wang, G., Chico-Calero, I., Vazquez-Boland, J.-A., Beck, M., Slaghuis, J., Szalay, A. A. and Goebel, W. (2001). Microinjection and growth of bacteria in the cytosol of mammalian host cells. Proceedings of the National Academy of Sciences of the United States of America, 98, 12221–12226. Happonen, I., Saari, S., Castren, L., Tyni, O., Ha¨nninen, M.-L. and Westermarck, E. (1996). Comparison of diagnostic methods for detecting gastric Helicobacterlike organisms in dogs and cats. Journal of Comparative Pathology, 115, 117–127. Hermanns, W., Kregel, K., Breuer, W. and Lechner, J. (1995). Helicobacter-like organisms: histopathological examination of gastric biopsies from dogs and cats. Journal of Comparative Pathology, 112, 307–318.
285
Helicobacter Infection in an Ocelot
Lockard, V. G. and Boler, R. K. (1970). Ultrastructure of a spiraled microorganism in the gastric mucosa of dogs. American Journal of Veterinary Research, 31, 1453– 1462. Norris, C. R., Marks, S. L., Eaton, K. A., Torabian, S. Z., Munn, R. J. and Solnick, J. V. (1999). Healthy cats are commonly colonized with “Helicobacter heilmannii” that is associated with minimal gastritis. Journal of Clinical Microbiology, 37, 189–194. Scanziani, E., Simpson, K. W., Monestiroli, S., Soldati, S., Strauss-Ayali, D. and Del Piero, F. (2001). Histological and immunohistochemical detection of different Helicobacter species in the gastric mucosa of cats. Journal of Veterinary Diagnostic Investigation, 13, 3–12. Schro¨der, H.-D., Ludwig, C., Jakob, W., Reischl, U., Stolte, M. and Lehn, N. (1998). Chronic gastritis in tigers associated with Helicobacter acinonyx. Journal of Comparative Pathology, 119, 67–73. Smith, D. G. E. and Lawson, G. H. K. (2001). Lawsonia intracellularis: getting inside the pathogenesis of proliferative enteropathy. Veterinary Microbiology, 82, 331–345.
Stevens, A. and Lowe, J. S. (1996). Alimentary tract. In: Human Histology, 2nd Edit., Mosby, London, pp. 177– 214. Versalovic, J. (2003). Helicobacter pylori. Pathology and diagnostic strategies. American Journal of Clinical Pathology, 119, 403–412. Yamazaki, Y., Aono, I., Ohya, T., Shibahara, T. and Kadota, K. (2002). Gastroduodenal adenocarcinomas and rectal adenoma in a cougar (Felis concolor) infected with Helicobacter-like organisms and spirochetes. Journal of Veterinary Medical Science, 64, 149– 153. Yoshikawa, K., Matsuura, S., Tsuchiya, T. and Kadota, K. (1999). Pancreatic endocrine carcinoma with multiple hormone production in a raccoon (Procyon lotor). Journal of Comparative Pathology, 120, 301–306.
Received; November 30th; 2004 Accepted; April 16th; 2005
SHORT PAPER
www.elsevier.com/locate/jcpa
Gastroinvasive Helicobacter Infection in an Ocelot (Leopardus pardalis) Y. Kanou*†, D. Fukui‡, S. Yamamoto¶, T. Shibahara†, Y. Ishikawa† and K. Kadota† *Ishikari Livestock Hygiene Service Centre, 3 Hitsujigaoka, Toyohira, Sapporo 062-0045, †Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo 062-0045, ‡Asahiyama Zoological Park and Wildlife Conservation Centre, Kuranuma, Higashi-Asahikawa, Asahikawa 078-8205, and ¶Kushiro Livestock Hygiene Service Centre, 127-1 Otanoshike, Kushiro 084-0917, Japan
Summary Highly invasive Helicobacter-like organisms were found in a 19-year-old female ocelot (Leopardus pardalis) with multiple ulcers in the fundic region of the stomach. The bacteria, resembling Helicobacter heilmannii, were located largely within canaliculi or in the cytosol of parietal cells. Except in the ulcerative lesions, parietal cells were hyperplastic, while chief cells and neck mucous cells were reduced in number. The term “gastroinvasive Helicobacter-like organism” was applied. It seems probable that this organism differs from other Helicobacter organisms in pathogenicity, and possible that its behaviour in vitro would help it to evade antibacterial treatment. q 2005 Elsevier Ltd. All rights reserved. Keywords: bacterial infection; Helicobacter heilmannii; invasiveness; Leopardus pardalis; ocelot; parietal cell
In man, Helicobacter pylori infection is associated with the development of gastric diseases including chronic gastritis, ulcer, lymphoma, and adenocarcinoma (Versalovic, 2003). Several Helicobacter species have been isolated from Felidae (Fox and Lee, 1997; Schro¨der et al., 1998; Norris et al., 1999), and are linked to subclinical mild gastritis, chronic gastritis, lymphoid follicular hyperplasia, and adenocarcinoma (Eaton et al., 1993; Norris et al., 1999; Yamazaki et al., 2002). Usually, Helicobacter organisms are present at the mucosal surface and in the lumina of gastric glands (Norris et al., 1999). Some investigators, however, reported small numbers of organisms apparently in the cytoplasm of parietal cells in cats and dogs (Hermanns et al., 1995; Scanziani et al., 2001), and their exact location was shown electron microscopically to be the canaliculi (Happonen et al., 1996). Convincing
Correspondence to: T. Shibahara. 0021-9975/$ - see front matter
doi:10.1016/j.jcpa.2005.04.008
evidence of intracytoplasmic bacteria was produced in monkeys infected with H. heilmannii-like organisms (Dubois et al., 1991). A 19-year-old female ocelot (Leopardus pardalis) died one day after showing continuous bleeding from the left nostril, loss of appetite and dehydration. At necropsy, multiple ulcers were observed in the fundic gland region of the stomach. The left nasal passage was obstructed by a blood clot and the mucosa was diffusely haemorrhagic. The lungs were markedly congested, and had many white foci, 0.1 to 1.5 cm in diameter, especially in the ventral part of the left inferior lobe. For histological examination, tissue samples were collected from the nasal concha, lungs, stomach, duodenum, ileum, colon, liver, pancreas, spleen and heart. They were fixed in 10% buffered formalin, embedded in paraffin wax, sectioned at 3 mm, and stained with haematoxylin and eosin (HE). Selected paraffin wax-embedded sections were stained by the Gram, Warthin–Starry and q 2005 Elsevier Ltd. All rights reserved.
282
Y. Kanou et al.
periodic acid-Schiff (PAS) methods. Sections were also examined immunohistochemically by the streptavidin–biotin–peroxidase complex (SAB) method. The primary antibodies used for immunolabelling were rabbit polyclonal antibodies to H. pylori (DAKO Corporation, Glostrup, Denmark) and rat islet amyloid polypeptide (IAPP) (Peptide Institute, Osaka, Japan), and mouse monoclonal antibody to proliferating cell nuclear antigen (PCNA) (BioGenex Laboratories, San Ramon, CA, USA); subsequent procedures were performed with an SAB kit (Nichirei Corporation, Tokyo, Japan). In addition, small blocks of formalin-fixed gastric tissue were post-fixed in 1% osmium tetroxide and embedded in epoxy resin; ultrathin sections were then stained with uranyl acetate and lead citrate, and examined by transmission electron microscopy (TEM). Histologically, in ulcerative lesions of the gastric mucosa considerable areas of the glandular tissue were destroyed, with neutrophil infiltration at the edges. In other areas of the mucosa, parietal cells showed hyperplasia (Fig. 1) and occasionally multiple nuclei (up to four), and a few were pyknotic or necrotic. By contrast, chief cells and neck mucous cells were reduced in number. Argyrophilic, Gram-negative, spiral-shaped organisms appeared to be present in most parietal cells (Figs 2 and 3), their number being much greater than in the lumen of gastric glands. Parietal cells with large numbers of bacteria also showed PASand silver-positive granules. Lymphocytes and
Fig. 1. Gastric mucosa. Mucosal thickening of the fundic region is due to hyperplastic parietal cells. HE. Bar, 50 mm.
Fig. 2. Gastric mucosa. Several spiral-shaped organisms are present in the cytoplasm of parietal cells (arrows), and a trinuclear parietal cell is observed (arrowhead). HE. Bar, 12.5 mm.
plasma cells were sparsely distributed in the lamina subglandularis. The lungs showed acute suppurative bronchopneumonia, the alveoli and bronchioles being filled with inflammatory exudate containing large numbers of neutrophils and macrophages. In the pancreas, large amounts of amyloid were deposited in nearly all the islets of
Fig. 3. Gastric mucosa. Several argyrophilic spiral-shaped organisms are present in the cytoplasm of parietal cells (arrows). Warthin-Starry. Bar, 20 mm.
Helicobacter Infection in an Ocelot
283
Fig. 4. Gastric mucosa. PCNA-positive epithelial cells are observed in the deeper part of the mucosa. Weakly positive stomach cells are visible in the lamina subglandularis (bottom). Anti-PCNA. SAB. Bar, 25 mm.
Fig. 5. Gastric mucosa. Intracytoplasmic Helicobacter-like organisms have tightly curved spiral appearances (arrows). Myelinosomes containing membranous structures are also detectable (arrowheads). TEM. Bar, 2 mm.
Langerhans, and the islet cells were few in number. There were no histological abnormalities in other organs. Immunohistochemically, the spiral-shaped bacteria were labelled by the H. pylori antibody. In the areas of parietal cell hyperplasia, PCNA-positive epithelial cells were observed not only in the proliferating neck zone but also in the deeper part of the mucosa (Fig. 4). Amyloid material was positive for IAPP. TEM of the gastric mucosa revealed apparently robust intracytoplasmic, intracanalicular and intraluminal bacteria (Fig. 5), 4.9 to 6.9 mm in length and 0.4 to 0.6 mm in diameter. They had 8 to 10 helical turns and at least four polar flagella, but were devoid of periplasmic fibres. Some parietal cells showed myelinosomes (Fig. 6) or secondary lysosomes containing membranous structures. The silver-positive granules seen histologically corresponded to the organelles visible by TEM. On the basis of morphology, Helicobacter species are divided into three types (Lockard and Boler, 1970). The organisms described here had a tightly spiralled cell body without periplasmic fibres, and fell into the category of Lockard type 3, in which Helicobacter acinonychis, H. pylori and Helicobacter heilmannii are included (Fox and Lee, 1997). The present organism closely resembled H. heilmannii, being larger than the other two. The organisms were immunolabelled by the polyclonal antiserum
against H. pylori, but this antiserum is genus-specific and not species-specific. Helicobacter-like organisms have been described in the cytoplasm of parietal cells of cats infected with H. pylori, H. felis, H. heilmannii or unclassified Helicobacter spp., apparently within canaliculi (Scanziani et al., 2001), which are deep microvillus-lined
Fig. 6. Gastric mucosa. This spiral-shaped bacterium is in direct contact with surrounding mitochondria, and is clearly intracellular. A myelinosome is also detectable. TEM. Bar, 500 nm.
284
Y. Kanou et al.
invaginations and may be regarded as extensions of the glandular lumen (Stevens and Lowe, 1996). Hermanns et al. (1995) concluded that Helicobacterlike organisms in cats and dogs occurred within either dilated canaliculi or cytoplasmic vacuoles, and Happonen et al. (1996) confirmed their intracanalicular location by electron microscopy. In rhesus monkeys (Macaca mulatta), however, H. heilmannii-like organisms occurred in the cytoplasmic matrix (Dubois et al., 1991). The present bacteria showed similar but much more striking invasiveness, which might enable them to evade antibacterial treatment (Engstrand et al., 1997). In porcine intestinal adenomatosis, the affected tissue shows marked proliferation of immature epithelial cells of the intestinal crypts, and the proliferating cells contain numerous intracytoplasmic Lawsonia intracellularis organisms (Smith and Lawson, 2001). Likewise, parietal cell hyperplasia and intracytoplasmic bacteria were observed in the present case, and these features may be closely associated. Ulcerative lesions were thought to have occurred in the sites where epithelial cells injured by bacteria were more predominant than proliferating cells. After direct injection of bacteria into the cytosol of mammalian cells, most bacteria that normally reside in a vacuole are unable to replicate. In contrast, Listeria monocytogenes, Shigella flexneri and enteroinvasive Escherichia coli are able to multiply in this cellular compartment after microinjection (Goetz et al., 2001). Although bacterial division could not be confirmed in the present study, almost all intracytoplasmic organisms appeared intact, unlike H. heilmannii-like organisms within the cytoplasm of simian parietal cells (Dubois et al., 1991). The present bacteria are designated gastroinvasive Helicobacter-like organism, as they differ in invasive ability from other Helicobacter-like organisms, which show little if any invasiveness. Myelinosomes are bodies containing whorled osmiophilic membranes, and some are autolysosomes, in which cytomembranes appear to be transformed into osmiophilic membranes (Ghadially, 1997). In the present case, organelles such as smooth endoplastic reticulum and mitochondria may have been damaged by bacterial cytotoxic proteins or intracytoplasmic bacteria. Such events may be responsible for the formation of autolysosomes with membranous structures. Autophagocytic vacuoles have been induced in mammalian cells by the cytotoxin of H. pylori (Catrenich and Chestnut, 1992). Acute pneumonia was considered to be the primary cause of death of the ocelot described
here. Taking into account the gastric ulceration and chief cell depletion, the animal probably had dyspepsia; the amyloid deposition in the islets of Langerhans cells was probably due to old age (Yoshikawa et al., 1999).
Acknowledgments The authors thank Dr Y. Ando and Mr T. Fujisawa for preparation of the photomicrographs.
References Catrenich, C. E. and Chestnut, M. H. (1992). Character and origin of vacuoles induced in mammalian cells by the cytotoxin of Helicobacter pylori. Journal of Medical Microbiology, 37, 389–395. Dubois, A., Tarnawski, A., Newell, D. G., Fiala, N., Dabros, W., Stachura, J., Krivan, H. and HemanAckah, L. M. (1991). Gastric injury and invasion of parietal cells by spiral bacteria in rhesus monkeys. Are gastritis and hyperchlorhydria infectious diseases? Gastroenterology, 100, 884–891. Eaton, K. A., Radin, M. J., Kramer, L., Wack, R., Sherding, R., Krakowka, S., Fox, J. G. and Morgan, D. R. (1993). Epizootic gastritis associated with gastric spiral bacilli in cheetahs (Acinonyx jubatus). Veterinary Pathology, 30, 55–63. Engstrand, L., Graham, D., Scheynius, A., Genta, R. M. and El-Zaatari, F. (1997). Is the sanctuary where Helicobacter pylori avoids antibacterial treatment intracellular? American Journal of Clinical Pathology, 108, 504–509. Fox, J. G. and Lee, A. (1997). The role of Helicobacter species in newly recognized gastrointestinal tract diseases of animals. Laboratory Animal Science, 47, 222–255. Ghadially, F. N. (1997). Lysosomes. In: Ultrastructural Pathology of the Cell and Matrix, 4th Edit., ButterworthHeinemann, Boston, pp. 619–802. Goetz, M., Bubert, A., Wang, G., Chico-Calero, I., Vazquez-Boland, J.-A., Beck, M., Slaghuis, J., Szalay, A. A. and Goebel, W. (2001). Microinjection and growth of bacteria in the cytosol of mammalian host cells. Proceedings of the National Academy of Sciences of the United States of America, 98, 12221–12226. Happonen, I., Saari, S., Castren, L., Tyni, O., Ha¨nninen, M.-L. and Westermarck, E. (1996). Comparison of diagnostic methods for detecting gastric Helicobacterlike organisms in dogs and cats. Journal of Comparative Pathology, 115, 117–127. Hermanns, W., Kregel, K., Breuer, W. and Lechner, J. (1995). Helicobacter-like organisms: histopathological examination of gastric biopsies from dogs and cats. Journal of Comparative Pathology, 112, 307–318.
285
Helicobacter Infection in an Ocelot
Lockard, V. G. and Boler, R. K. (1970). Ultrastructure of a spiraled microorganism in the gastric mucosa of dogs. American Journal of Veterinary Research, 31, 1453– 1462. Norris, C. R., Marks, S. L., Eaton, K. A., Torabian, S. Z., Munn, R. J. and Solnick, J. V. (1999). Healthy cats are commonly colonized with “Helicobacter heilmannii” that is associated with minimal gastritis. Journal of Clinical Microbiology, 37, 189–194. Scanziani, E., Simpson, K. W., Monestiroli, S., Soldati, S., Strauss-Ayali, D. and Del Piero, F. (2001). Histological and immunohistochemical detection of different Helicobacter species in the gastric mucosa of cats. Journal of Veterinary Diagnostic Investigation, 13, 3–12. Schro¨der, H.-D., Ludwig, C., Jakob, W., Reischl, U., Stolte, M. and Lehn, N. (1998). Chronic gastritis in tigers associated with Helicobacter acinonyx. Journal of Comparative Pathology, 119, 67–73. Smith, D. G. E. and Lawson, G. H. K. (2001). Lawsonia intracellularis: getting inside the pathogenesis of proliferative enteropathy. Veterinary Microbiology, 82, 331–345.
Stevens, A. and Lowe, J. S. (1996). Alimentary tract. In: Human Histology, 2nd Edit., Mosby, London, pp. 177– 214. Versalovic, J. (2003). Helicobacter pylori. Pathology and diagnostic strategies. American Journal of Clinical Pathology, 119, 403–412. Yamazaki, Y., Aono, I., Ohya, T., Shibahara, T. and Kadota, K. (2002). Gastroduodenal adenocarcinomas and rectal adenoma in a cougar (Felis concolor) infected with Helicobacter-like organisms and spirochetes. Journal of Veterinary Medical Science, 64, 149– 153. Yoshikawa, K., Matsuura, S., Tsuchiya, T. and Kadota, K. (1999). Pancreatic endocrine carcinoma with multiple hormone production in a raccoon (Procyon lotor). Journal of Comparative Pathology, 120, 301–306.
Received; November 30th; 2004 Accepted; April 16th; 2005