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1.
Coccidiosis due to an Isospora ohioensis-like organism was diagnosed in a 10-week-old pup. The pup had diarrhea, dehydration, and weight loss before it died 7 days after onset of clinical signs. Lesions were limited to the intestinal tract. Beginning in the distal end of the small intestine and extending through cecum and colon were mild histiocytic proliferation in the lamina propria and multifocal cryptitis. Numerous meronts and gamonts of an unidentified coccidium were in or near the lesions. Parasites were in the villous epithelium, lamina propria, and intestinal glands of the distal one-half of the small intestine, cecum, and colon. It was concluded that infection was due to an unidentified coccidium with oocysts structurally similar to those of I ohioensis.  相似文献   

2.
Enteritis induced in neonatal dogs by oral inoculation of coronavirus 1-71 was studied by virologic, histologic, histochemical, and immunofluorescent antibody methods. The enteritis, accompanied by diarrhea, developed in 4 to 7 days and was characterized by atrophy and fusion of intestinal villi and deepening of crypts, increase in cellularity of the lamina propria, flattening of epithelial cells, and discharge of goblet cells. Intra-epithelial enzyme activities generally were depressed. Specific immunofluorescent antibody reactions were present in villous epithelium of the duodenum starting on postinoculation day 2 and of the ileum on day 4. Epiehtlium of the colon showed no reaction. Virus was present in the feces for 6 to 9 days and was recovered from the small and large intestines from day 2 through day 10. The infection was not fatal and was self limiting; the diarrhea stopped between 1 and 2 weeks. The intestinal mucosa also started recovering by the end of week 1, proceeding caudally from the duodenum.  相似文献   

3.
Experiments were conducted to define the pathogenic potential of Salmonella heidelberg in weanling pigs. Oral inoculation with S heidelberg resulted in severe catarrhal enterocolitis with accumulation of large amounts of fluid in the small intestine and colon. Salmonella heidelberg was demonstrated, with fluorescence microscopy and bacteriologic cultural techniques, to colonize the ileum, to invade ileal mucosal enterocytes, and to reach mesenteric lymph nodes and extraintestinal tissues by 8 hours. In 5 pigs, intestinal loops were surgically prepared and inoculated with S heidelberg (to determine its invasiveness). Microscopically, there were atrophy of villi, erosion of enterocytes, and neutrophilic infiltration in the lamina propria. Ultrastructurally, intracellular bacteria were demonstrated in villous and cryptal enterocytes, as well as in macrophages of the lamina propria. Bacteria were morphologically intact, occurred free and membrane-bound and caused no detectable cytotoxic effect to the cell.  相似文献   

4.
Various age groups of turkeys, White Leghorn chickens, and broiler chickens were inoculated with turkey rotavirus strain Tu-2 or with chicken rotavirus Ch-2, and the development of rotavirus-induced lesions were evaluated macroscopically and microscopically (light microscopy and scanning electron microscopy). Morphometric evaluations were conducted to determine morphologic changes in the villi of infected turkeys. Macroscopic lesions that were found in turkeys, but not in chickens, consisted of pallor of the intestinal tract and distension of the cecum with frothy or nonfrothy fluid contents. Histologic lesions in turkeys consisted of basal vacuolation of enterocytes, separation of enterocytes from the lamina propria (with subsequent desquamation), villus atrophy accompanied by widening of the lamina propria, scalloping of the villus surface, fusion of the villi, and leukocytic infiltration of the lamina propria. Scanning electron microscopy indicated roughened villus surfaces, distortion of the normal morphologic features of the villi, and loss of microvilli in cells located on the tips of the villi. Most of the lesions disappeared by 8 days after inoculation. Results of the morphometric evaluations indicated that the crypt length had increased and the villus-to-crypt ratio had significantly decreased, compared with that of noninoculated control turkeys. Broilers greater than or equal to 21 days old and White Leghorn chickens greater than or equal to 35 days old had minimal leukocytic infiltration of the lamina propria and minimal loss of microvilli in cells located on the tips of the villi. The loss of microvilli was more extensive in chickens greater than or equal to 119 days old than in younger birds. Generally, turkeys 1 to 112 days old developed more severe lesions than did chickens, and lesions were more pronounced in turkeys at 112 days of age.  相似文献   

5.
Scanning electron and light microscopy were used in studies of stomach, duodenum, cranial, and caudal portions of the jejunum, ileum, cecum, and spiral colon from 18 gnotobiotic pigs. Five pigs were raised as controls and 13 were exposed at 6 days of age by oral administration of 1.6 X 10(6) colony-forming units of Escherichia coli O138:K81:NM. Infiltration of leukocytes into the mucosa of the stomach seen with the light microscope has not been previously reported. The irregular pattern of the mucosal surface of the stomach formed by the gastric pits and the mucosal extensions on the individual rugae revealed with scanning electron microscopy was different than anticipated. Sections of the ileum from control and infected pigs contained collapsed cells around the extrusion zone at the tips of the villi. These collapsed cells were more numerous in infected pigs and appeared to have sloughed from the area of the extrusion zone resulting in exposure of the lamina propria. Cecum and spinal colon were free of changes. Alterations of the mucosa of the intestinal tract of gnotobiotic pigs infected with E coli as visualized by scanning electron microscopy were considered too inconsistent to be of diagnostic significance.  相似文献   

6.
Diarrhea associated with intestinal Cryptosporidiosis in turkeys   总被引：1，自引：0，他引：1  
Turkey poults were suffering from diarrhea on a farm in which several previous grow-outs of turkeys had experienced a clinically identical problem. Upon necropsy, significant gross lesions were restricted to the gastrointestinal tract. Segments of small intestine were pale and distended with cloudy mucoid material and a few gas bubbles. The ceca contained fluid and gas. Fresh organ portions were collected and fixed in 10% neutral buffered formalin and submitted for histological processing and examination (light microscopy and scanning and transmission electron microscopy). Small (2-4 micron) basophilic bodies identified as Cryptosporidium sp. were present in enterocytes of the middle and lower small intestine. The villi were moderately atrophic, the crypts were hypertrophic, and the lamina propria was infiltrated by large numbers of lymphocytes, heterophils, and fewer macrophages and plasma cells. Numerous intraepithelial leukocytes and exocytosing inflammatory cells also were present.  相似文献   

7.
Seven adult free-ranging sika deer (Cervus nippon yesoensis) were examined by histology, immunohistochemistry and electron microscopy for intestinal spirochetal infection. Histologically epithelial and goblet cell hyperplasia and edema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the cecum and colon in 6 of the 7 deer. Numerous argyrophilic spirochetes were present in the crypts and some had invaded epithelial and goblet cells and caused degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Brachyspira (Serpulina) hyodysenteriae and B. pilosicoli. Ultrastructurally they were 6-14 microm long, 0.2-0.3 microm wide and had 4-6 coils and 13 axial filaments per cell; such features were closely similar to those in the Brachyspira species. These results showed that the spirochetes were capable of inducing enteritis in deer and this intestinal spirochete infection might already be prevalent among wild sika deer in Japan. There is a possibility that this spirochetal colitis is a new syndrome in sika deer and that the same and/or similar spirochetes have infected ruminants, including sika deer and cattle.  相似文献   

8.
Maedi visna virus (MVV) vertical transmission in sheep via infected colostrums is a very important route of infection in lambs. To verify colostral transmission and to study early viral entry in lambs, colostrum samples, and small intestine and mesenteric lymph nodes of lambs born from experimentally infected ewes were examined by histopathology, immunohistochemistry (IHC) and in situ hybridisation (ISH) studies. In particular, newborn lambs were naturally fed maternal colostrum and humanely killed at 10, 24, 48, 72, 96 h and 7 and 10 days after birth; two caesarian-derived lambs served as uninfected controls. No lesions suggestive of MVV infection were found, but marked immunoreactions for MVV capsid antigen (CA, p28) were detected in lambs fed maternal colostrum and in macrophages cultured from colostrum. IHC results in lambs suggest an initial viral absorption by intestinal epithelial cells at the tip of the villi, passage to mononuclear cells in the lamina propria and involvement of ileum Peyers' patches and mesenteric lymph nodes, with different staining patterns depending on infection times. ISH on intestinal sections of the 72 h lamb revealed the presence of proviral DNA in epithelial cells at the tip of the villi, suggesting a role for these cells in early MVV replication. The results contribute to knowledge about the pathogenesis of ovine lentivirus infection suggesting that the small intestine and mesenteric nodes are the sites of entry and propagation of MVV in lambs fed colostrums from infected ewes.  相似文献   

9.
A portion of the minute chylomicrons less than 75 nm in diameter are transcytosed from the extravascular tissue into the subepithelial blood capillaries (sBC) in the villous apices of the rat jejunum. However, the details of the transportation mechanism have not been clarified. In this study, the endothelial receptor involved in the transportation of minute chylomicrons into the sBC’s lumina was immunohistochemically and histoplanimetrically examined in intestinal villi of the rat jejunum. Immunopositivity for very low density lipoprotein (VLDL) receptor was detected on the luminal and basal surfaces of the endothelial cells of sBC in approximately 68% of those apices of jejunal villi that possessed numerous chylomicrons in the lamina propria, while VLDL receptor was detected on the endothelial cells of sBC in only approximately 8% of intestinal villi that possessed few or no chylomicrons in the lamina propria. No immunopositivity for LDL receptor was detected in the sBC of all intestinal villi. These findings suggest that VLDL receptor is expressed by the endothelial cells of the sBC in conjunction with the filling of the lamina propria of jejunal villi with many chylomicrons produced by the villous columnar epithelial cells and that the VLDL receptor mediates the transportation of minute chylomicrons, maybe VLDL, into the subepithelial portal blood from the extravascular tissue of the rat jejunal villi.  相似文献   

10.
The development of intestinal lesions caused by the porcine rotavirus were studied in six day old gnotobiotic piglets by scanning electron microscopy. The onset of diarrhea followed an incubation period of 17 to 31 hr. The first detectable lesion was observed in the ileum at 12 hr postinfection, a few hours before the onset of diarrhea. At this time enterocytes appeared swollen and began to separate from each other. Seventeen hours after the onset of diarrhea, lesions were quite severe jejunum and ileum. Enterocytes were detaching from the lamina propria leaving denuded areas. Microvilli were sparse on the cell surfaces and there was marked villous atrophy. Regeneration of ileal mucosa was evident at 4.8 days after the onset of diarrhea. Nine days after recovery from diarrhea the intestinal villi had returned to near its normal structure but there remained some evidence of mucosal damage.  相似文献   

11.
Distribution of Ia- and IgM-positive cells was compared in tissues of adult and newborn miniature pigs, using indirect immunoperoxidase and immunofluorescent techniques with monoclonal antibodies. The different distribution patterns were found mainly in adult jejunum and kidney. Both IgM- and Ia-staining were ascertained in the lamina propria between the Lieberkühn crypts and in the lymphoid follicles of the jejunum. Moreover, IgM-positive cells were demonstrated in the crypts while Ia-reaction was seen in the lamina propria of the villi. In the kidney, IgM-staining was limited to the glomeruli. On the contrary, a distinct Ia-reaction was found mainly in intertubular structures. Small differences in IgM- and Ia-positive cell distribution were also noted in the mesenteric lymph nodes and in the spleen. Developmental changes of the adult distribution patterns (chiefly that of IgM-positive cells) were found in all tissues studied at 2 days of age.  相似文献   

12.
Gross, subgross and histological lesions were studied in 103 pigs infected with transmissible gastroenteritis virus and killed at daily intervals for 14 days. Twenty-three pigs served as controls. Thirty-six pigs were given colchicine four hours prior to being killed in order to determine the mitotic activity in the gastrointestinal tract. The gross lesions consisted of dehydration, excessive milk curd in the stomach, focal hemorrhage in the submucosa of the diverticulum ventriculi of the stomach, fundic and pyloric congestion in severly dehydrated animals and thinning of the small intestinal wall. The major subgross lesion was a marked shortening of the villi in the lower duodenum, jejunum and ileum within 24 hours after exposure to the virus. Regrowth of the villi became evident on about the sixth day after infection. Histological examination of the small intestine revealed that the villus-height/crypt-depth ratio in the jejunum was reduced from 7:1 in normal pigs to less than 1:1 in infected pigs. Villous atrophy was less severe in the proximal duodenum and ileum. Cells covering the atrophic villi were flatened or cuboidal and did not have well defined brush borders. Inflammatory changes in the gastrointestinal tract were minimal at all stages of infection. Goblet cell numbers increased slightly in the recovery stage of the disease and small numbers of mononuclear cells accumulated in the lamina propria during regrowth of the villi. The number of metaphase nuclei in the small intestinal crypts of infected pigs was greater than in normal pigs.  相似文献   

13.
肠艾美耳球虫配子生殖与病理变化   总被引：2，自引：1，他引：1  
用单个肠艾美耳球虫Eimeria intestimalis Cheissin 1984卵囊感染无球虫兔,获得纯种进行研究。1.肠艾美耳球虫的配子生殖阶段寄生于空肠和回肠,此时宿主组织有较严重病变。12指肠、结肠和盲肠未见虫体,但在感染后264小时见盲肠的个别绒毛内有1～3个配子体,可能属偶然现象。2.感染后180小时发现极少数早期配子体,感染后192小时出现少量配子体寄生在空肠和回肠的绒毛和腺上皮细胞内,感染后216至264小时,绒毛上皮和腺上皮细胞内多为配子体、合子和卵囊所取代。感染后216小时出现极少量卵囊,264小时则见有大量卵囊。3.感染开始时(感染后61～73小时),回肠、空肠绒毛上皮正常;腺上皮细胞出现少量滋养体和裂殖体。96至192小时后,肠绒毛上皮和腺上皮受侵害程度渐趋严重,肠绒毛变矮,绒毛上皮及腺上皮细胞肿大变空,细胞核消失。许多腺泡塌陷。感染后216～264小时,肠绒毛受侵害最为严重,空肠和回肠绒毛萎缩或消失,变为一层矮柱或立方形上皮细胞或全无上皮细胞覆盖的绒毛。固有层均质红染,或颗粒状。肠腺塌陷,数量减少,大小不一。腺腔内见有配子体、合子或卵囊残留,部分腺泡上皮细胞再生,细胞核增生成堆。12指肠、盲肠和结肠正常。  相似文献   

14.
The small intestines of calves inoculated orally with the enteropathogenic strain of Escherichia coli 0101:K'B41',K99 were examined by electron microscopy at 3, 6, 12, 16, 21, 36, 69, 70 and 72 hours after inoculation. The challenge organism adhered to the mucosa of the distal small intestine from six hours post-inoculation. Bacteria were separated from the microvillous brush border by a gap of 200 to 300 nm in which bacterial fimbriae and the microvillous glycocalyx were seen. Bacteria never were found in epithelial cells but were present in macrophages in the lamina propria from 12 hours. At three and six hours, cytopathic changes were not seen in the small intestine, but from 12 hours epithelial cells on affected villi had blunt and thick microvilli and contained cytoplasmic inclusions. Epithelial cells were seen frequently in the process of extrusion from the villi, either singly, in small groups, or as ribbons of cells. Intervillous bridges, characteristic of villous fusion, were seen frequently from 69 hours.  相似文献   

15.
The development of the cecum and colon in the goose was investigated during the period from the 15th to 28th day of the incubation and from 1 to 30 days of age after hatching by light microscopy. By day 15 of the incubation, in the cecum and colon, the lumen was surrounded by pseudostratified epithelium. The previllous ridges appeared at 15th and 17th days of the incubation in the colon and ceca, respectively. At the base of previllous ridges, the epithelium changed into a simple prismathic epithelium at 15th and 17th days of the incubation in the colon and cecum, respectively. The villi appeared at the 21st days of the incubation. The crypts and goblet cells appeared on the first day after hatching. In the pre-hatching period, the lamina muscularis mucosa was present only in the colon. The submucosa consisted of loosely aggregated connective tissue in the pre-hatching period. In the post-hatching period, it consisted of a very thin layer of connective tissue. Its presence was only obvious where the cells of the submucosal nerve plexus or occasional large blood vessels considerably increased its thickness. The nerve plexus corresponding to the Auerbach's plexus of the mammalian intestine and submucosal nerve plexus appeared by 15th days of the incubation. From the 15th to 28th day of incubation, the tunica muscularis consisted of circular smooth muscle cells in the ceca. On the 28th day of the incubation a thinner longitudinal muscle layer added to the circular muscle layer. In the colon there was an outer longitudinal and a thicker circular muscle layer.  相似文献   

16.
OBJECTIVE: To describe spirochaetal infections in the feet and colon of cattle affected with papillomatous digital dermatitis (PDD) and colitis respectively. PROCEDURE: Eighty-two slaughtered animals were macroscopically examined for the presence of PDD. Tissues of two cattle affected with PDD were examined by histology, immunohistochemistry, electron microscopy and bacteriology for spirochaetal infection. RESULTS: Two adult cattle (a 2-year-old beef bullock and 7-year-old Holstein dairy cow) were affected with PDD. Histologically, numerous argyrophilic and gram-negative filamentous or spiral spirochaetes were found deep in the PDD lesions. Epithelial and goblet cell hyperplasia and oedema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the caecum and colon in the cattle. Numerous spirochaetes were present in the crypts and some had invaded epithelial and goblet cells, and caused their degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Treponema pallidum and Brachyspira (Serpulina) hyodysenteriae. Ultrastructurally, the intestinal spirochaetes were similar to the spirochaetes in PDD. They were 6 to 14 pm long, 0.2 to 0.3 pm wide and had 4 to 6 coils and 9 axial filaments per cell. Campylobacter species were isolated from the PDD and intestinal lesions, but spirochaetes were not. CONCLUSION: Concurrent infections with morphologically similar spirochaetal organisms may occur in the feet and colon of cattle in Japan.  相似文献   

17.
Studies of equine intestinal spirochetes have long focused on intestinal contents alone, but intestinal spirochetosis has been reported recently in a 21-month-old Thoroughbred colt in Japan. To define the clinical and pathological significances of intestinal spirochetosis in several horses, an epizootiologic survey with histologic, immunohistochemical, and ultrastructural methods was conducted for Brachyspira antigen-containing intestinal spirochetes in 12 diseased or injured Thoroughbred horses, aged from 35 days to 17 years. Brachyspira antigen-containing spirochetes were found in 7 of 12 horses (58.3%) and were more frequent in the cecum than in other parts of the bowel. It was not clear whether the infection was clinically related to diarrhea or dysentery, but histopathology revealed a close association between the bacterial infection and epithelial hyperplasia. Crypt epithelium consisted mainly of goblet cells and showed frequent mitosis throughout its length. Inflammatory cells and congestion were also present. There were numerous spirochetes in the crypts, and some invaded the cecal and colonic epithelia and underlying lamina propria. Ultrastructurally, the spirochetes were divided into 4 types. Three types were identified in degenerative epithelial cells or intracellularly. Brachyspira antigen-containing intestinal spirochetes invading the mucosa were capable of causing epithelial hyperplasia in the cecum and colon in the horses. The findings in this study will increase awareness of the importance of intestinal spirochetosis and may also be helpful for diagnosis and treatment of this condition.  相似文献   

18.
Thirty-three, 10-week-old, specific-pathogen-free pigs were randomly allotted to 3 treatment groups: group 1--intragastrically given homogenized intestinal mucosa (crude inoculum) from pigs with naturally occurring proliferative enteritis; group 2--given cultures of Campylobacter sputorum subsp mucosalis; and group 3--controls. One pig from each group was killed 4, 7, 10, 14, 18, 21, 24, 28, 31, 36, and 38 days after inoculation. The earliest intestinal lesion observed in groups 1 and 2 was leukocytic exudate within crypt lumina and focal inflammation of the surrounding lamina propria. The lesions occurred primarily over ileal aggregated lymphoid nodules (Peyer's patches). These changes were followed by focal proliferation of immature crypt epithelial cells and infiltration of increasing numbers of macrophages into the lamina propria. Campylobacter sp-like organisms were observed within the cytoplasm of affected epithelial cells by light and electron microscopies. Lesions progressed to diffuse crypt cell proliferation, elongation of crypts, and loss of villi. Mucosal necrosis was not a prominent feature.  相似文献   

19.
OBJECTIVE: To evaluate the morphologic and physiologic changes induced by Clostridium perfringens type A (alpha toxin in the ileum and colon of sheep. SAMPLE POPULATION: 16 ligated intestinal loops in 4 Merino lambs and 18 explants of ileum and colon from slaughtered lambs. PROCEDURE: alpha Toxin-induced fluid accumulation was evaluated in ligated ileal and colonic loops of sheep. Tissues were evaluated morphologically by use of gross and histologic examination. Effects of toxin on in vitro intestinal net water transport were tested in modified Ussing chambers. RESULTS: Ovine ileal and colonic loops incubated with C perfringens type A alpha toxin retained more fluid than control loops. Histologically, in the ileum of lambs inoculated with 300 LD50 of alpha toxin/mL, there was a mild to moderate multifocal infiltration of neutrophils in the lamina propria and submucosa. The colonic loops of lambs inoculated with 30 or 300 LD50 of alpha toxin/mL had excessive mucus in the lumen, a moderate amount of neutrophils mixed with mucus in the intestinal lumen, and moderate multifocal infiltration of the lamina propria and submucosa with neutrophils; the blood vessels of these layers were engorged with neutrophils. In vitro measurements of water transport also revealed inhibition of net epithelial water absorption in ileum and colon incubated with alpha toxin on the mucosal side. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicate that alpha toxin induces alterations in sheep intestine. Clostridium perfringens type A organisms that produce alpha toxin could be responsible for diseases of intestinal origin in some ruminants.  相似文献   

20.
First generation merozoites of Eimeria necatrix were found in epithelial cells of the crypts of Lieberkühn of chicks cells appeared to migrate into the lamina propria, forming nests of second generation schizonts that extended from the external muscularis to the lamina propria of the mid-villus. On the fourth and fifth days the mature schizonts, usually still within the infected cells were dishcarged into adjacent crypts. The muscularis mucosa appeared to be repaired by the formation of new, smooth muscle cells that spliced the broken ends of the ruptured muscle. 'Ghosts' of schizonts were found in the lamina propria on the sixth day after infection.  相似文献   

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