Dietary resveratrol alleviated lipopolysaccharide-induced ileitis through Nrf2 and NF-κB signalling pathways in ducks (Anas platyrhynchos).

Gram-negative bacteria contamination of feed can occur at all the stage of feed production, storage, transportation and utilization. Lipopolysaccharide (LPS) is a major toxic metabolite of Gram-negative bacteria. The aim of this study was to explore the effect of dietary resveratrol on the duck ileitis caused by LPS and its optimum addition level in diet. The results showed that LPS-induced duck ileitis with the destruction of intestinal structure, oxidative stress, mitochondrial dysfunction, inflammatory response and permeability alteration. Dietary resveratrol alleviated LPS-induced intestinal dysfunction and the increase of intestinal permeability by linearly increasing mRNA levels of tight junction protein genes (Claudin-1, Occludin-1, ZO-1) (p < 0.05) and protein expression of Claudin-1 (p < 0.01). In addition, dietary resveratrol improved the antioxidant capacity of duck ileum by reducing the production of MDA and increasing the activity of T-SOD (p < 0.01) and CAT. Lipopolysaccharide increased Keap1 at mRNA and protein level (p < 0.01) and decreased the protein level of Nrf2 (p < 0.05). Dietary resveratrol significantly downregulated expression of Keap1 and upregulated expression of Nrf2 in duck (p < 0.05). Dietary resveratrol suppressed the TLR4/NF-κB signalling pathway and the expression of its downstream genes including IKK, TXNIP, NLRP3, Caspase-1, IL-6 and IL-18. Meanwhile, the levels of inflammatory cytokines (IL-6, IL-18 and TNF-α) showed a linearly decrease (p < 0.01) with increasing dietary resveratrol level. These results demonstrated that resveratrol alleviated the LPS-induced acute ileitis of duck through Nrf2 and NF-κB signalling pathways, and the dietary resveratrol of 500 mg/kg is more efficiently.

Ultrasound and computed tomography of sacculitis and appendicitis in a rabbit.

A 9-month-old neutered male rabbit was referred for lethargy, anorexia, and gastrointestinal stasis. Routine hematology, serum biochemistry, and diagnostic imaging were performed. Computed tomography revealed a wall thickening of the sacculus rotundus and appendix, which was further confirmed on abdominal ultrasound. Full thickness biopsies were collected with histopathology diagnosing a chronic multifocal heterophilic granulomatous sacculitis and appendicitis. The patient was treated medically and at 6 weeks follow-up, clinical signs and intestinal changes had completely regressed. Inflammation of the sacculus rotundus and appendix should be considered as a cause of gastrointestinal stasis in rabbits.

Associação à positividade da Lawsonia intracellularis com a expressão clínico-patológica da infecção em suínos da região metropolitana de Bucaramanga (Santander, Colômbia) / Association to positivity of Lawsonia intracellularis with the clinical and pathologic expression of infection in swine from the metropolitan area of Bucaramanga (Santander, Colombia)

Porções de íleo terminal foram coletados de 100 suínos com sinais de doença gastrointestinal na área metropolitana de Bucaramanga, a fim de se estudar a eficiência do diagnóstico de enteropatia proliferativa suína (PPE) pela técnica de PCR aninha (PCRa) empregando sequências específicas (primers) para L. intracellularis: 16S ARN região (270pb) e sua correlação com achados clínicos e patológicos. Todas as amostras foram processadas para se determinar a associação entre positividade por PCR, os sinais clínicos, os achados de necropsia e as lesões histológicas. Cinquenta e seis por cento das amostras foram positivas para L. intracellularis pela PCRa. Só 2% exibiram resultados positivos pela técnica Warthin-Starry. Trinta e um de 100 animais com sinais de anorexia resultaram positivos para PCRa (P>0,05). Não houve associação (P<0,05) entre diarreia e queda no crescimento, bem como associação (P<0,05) entre achados anatomopatológicos e histológicos com PCRa positivas.(AU)

Fragments of terminal ileum were collected from 100 pigs at slaughter from Bucaramanga Metropolitan Area (Santander, Colombia), to study the efficacy of the diagnosis of porcine proliferative enterophaty (PPE) through the technique of nested polymerase chain reaction (PCRa), employing specific sequences (primers) for L. intracellularis: 16S ARN region (270pb) and his correlation with clinic and pathological findings. All samples were processed by standard histological methods and stained with a Warthin-Starry technique. All samples were processed to determinate the association between positive PCRa results, clinical signs and necropsy findings. 56% of the 100 samples were positive for L. intracellularis through PCRa technic. Only 2% exhibited positive results through Warthin-Starry technique. A total of 31 (100) animals with anorexic symptoms were associated with positive results from PCRa (P>,05). No associations (P<0.05) were observed between diarrhea and delayed growth. No associations (P<0.05) were observed between anatomopathological and histological findings with positive PCRa.(AU)

A novel model for studying ileitis-induced visceral hypersensitivity in goats.

BACKGROUND: Visceral hypersensitivity (VH) is a common condition in many gastrointestinal disorders such as inflammatory bowel diseases (IBDs) in human and animals. Most studies often induce Crohn's disease/colitis to investigate VH in small experimental animals. Although farm animals commonly suffer from IBDs, their VH has not been investigated so far. Because goats can suffer from Johne's disease, a naturally occurring Crohn's-like disease, they may be suitable to be used for studying the mechanism underlying VH in common intestinal disorders of large animals. In the present study, 60 healthy goats of either sex were equally divided into a 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) group and saline group. A volume of 1.2 ml of TNBS-ethanol solution (30 mg TNBS in 40 % ethanol) or an equal volume of isotonic saline was injected into the wall of the terminal ileum through laparotomy. The severity of the developing ileitis was determined according to macro- and microscopic pathologic scores and the levels of myeloperoxidase, interleukin-1ß, interleukin-6 and tumor necrosis factor-α, and VH was evaluated with visceromotor responses (VMR) to colorectal distension on days 3, 7, 14, 21 and 28. VMRs were assessed with a continuous ramp distention mode with 6 s for each pressure (20, 40, 60, 80 and 100 mmHg). RESULTS: Compared to the saline group, the TNBS-treated goats showed apparent transmural pathological changes and a significant increase (P < 0.05) in macroscopic and microscopic change scores, and levels of myeloperoxidase, interleukin-1ß, interleukin-6 and tumor necrosis factor-α in the ileum, and VMR to colorectal distension. The goats exhibited apparent ileitis at days 3 to 21, and VH at days 7 to 28 following TNBS treatment. CONCLUSION: This experiment successfully established a reproducible ileitis and VH with administration of TNBS-ethanol solution in the ileal wall of goats. This model is useful for studying the pathogenesis of the IBD and the mechanism underlying VH, and for evaluating the efficacy of new therapeutic regimens.

First molecular identification of Entamoeba polecki in a piglet in Japan and implications for aggravation of ileitis by coinfection with Lawsonia intracellularis.

Parasitic Entamoeba spp. are found in many vertebrate species including humans, as well as many livestock including pigs. In pigs, three Entamoeba spp., E. suis, and E. polecki and E. histolytica as zoonotic species, have been identified, but their pathogenicity has not been fully characterized. Here, we report the bacteriological, virological, and histopathological examination of three piglets with chronic diarrhea. Two animals appeared to be additionally infected with Lawsonia intracellularis, which caused a characteristic proliferative ileitis. In the piglet infected with Entamoeba spp., the trophozoites (approximately 10-15 µm with one nucleus in their cytoplasm) invaded into the lamina propria and the disease was worsened by the formation of ulcers and pseudomembranes. Genetic analysis identified the parasite as E. polecki (99.5% identity). Although E. polecki in humans or animals might be less pathogenic in the case of a single infection, coinfections with other pathogens including L. intracellularis may increase the severity of the disease.

Effect of Origanum vulgaris and Allium sativum extracts for the control of proliferative enteropathy in weaning pigs.

The aim of the present trial was to investigate the efficacy of Virbamix PE (Virbac SA, France) an appetite enhancer and feed flavouring material containing plant extracts of Origanum vulgaris and Allium sativum, added to the feed at one single dose in the control of proliferative enteropathy (PE) in weaning pigs, in comparison to reference treatment with tiamulin (Tiamutine 6.5 Premix/Ceva Animal Health) group and a negative control group. The trial was conducted on a farm with a previous history of ileitis outbreaks. At weaning day (25 +/- 3 days old / day 0 of the trial) a total of 288 (144 male + 144 female) piglets were selected and allocated into three experimental groups, each group comprising of four pens with 24 piglets in each pen. Group 1 (T1 group) served as negative control group (unmedicated), group T2 received medication in feed at the dose of 1 kg Virbamix PE per tonne of feed and T3 group received 32 ppm of tiamulin. Treatments lasted for six weeks (up to the age of 67 +/- 3 days), and no other antibacterial or growth promoter was added to the feed or drinking water in the same period. Administration of Virbamix PE was found to be effective for the control of PE, as shown by the reduction of prevalence of Lawsonia intracellularis in the intestine at the end of the treatment period, as determined by PCR method comparatively with the T1 group, while no significant difference was found between T2 and T3 groups. The diarrhoea score (DS) was significantly higher (P < 0.05) in the control group in comparison with T2 and T3 groups. However, no significant differences were noticed between T2 and T3 groups during the treatment period (P > 0.05). Treatment of piglets with Virbamix PE and Tiamutine 6.5 Premix resulted in significantly higher body weight and average daily gain (ADG) than in T1 group for the total treatment period (P < 0.05). Conclusively, the results of present study indicate that the use of Virbamix PE, could be an alternative and economic method for the control of PE. Moreover, the use of this product is in accordance with the contemporary consumer demands for more environmentally friendly pig production, satisfying at the same time the producer needs for increased and cost-effective performance.

Use of tylvalosin-medicated feed to control porcine proliferative enteropathy.

The effect of an oral treatment with the tartrate salt of tylvalosin on the development of proliferative enteropathy in 60 experimentally challenged pigs was studied. Thirty of the pigs were fed a diet medicated with 50 ppm tylvalosin and 30 were fed the unmedicated diet. The treated animals started to receive the medicated feed the day before they were inoculated, and continued to receive it for 14 days. The pigs' bodyweight, feed consumption and clinical signs were evaluated, and they were examined postmortem 20 days after inoculation, and samples of ileum were collected for immunohistochemistry (IHC) for Lawsonia intracellularis. Clinical signs of the disease were more evident in the untreated group than in the treated group. The average daily weight gain, average daily feed consumption and feed conversion efficiency were better in the treated group. The combined length of intestine with lesions was 2847 cm in the untreated group and 183 cm in the treated group. The tylvalosin treatment significantly reduced the level of L intracellularis infection; almost half of the treated pigs were IHC-negative compared with 3.3 per cent of the untreated pigs.

Effect of dietary inclusion of distillers dried grains with solubles on the ability of growing pigs to resist a Lawsonia intracellularis challenge.

An experiment was conducted to determine if including distillers dried grains with solubles (DDGS) in the diet of growing pigs reduces the incidence or severity of infection after a Lawsonia intracellularis challenge. Eighty 17-d-old weaned pigs were blocked by sex, ancestry, and BW and randomly allotted to 1 of 4 treatment groups: negative control (NC), unchallenged, corn-soy diet; positive control (PC), challenged, corn-soy diet; 10% DDGS diet (10D), challenged; and 20% DDGS diet (20D), challenged. Challenged pigs were orally inoculated with 1.5 x 10(9) L. intracellularis organisms after a 4-wk prechallenge feeding period. On d 21 postchallenge, pigs were euthanized, lesions of intestinal mucosa were evaluated, and ileal tissue samples were analyzed by immunohistochemistry to determine the presence and proliferation rate of L. intracellularis. Compared with unchallenged pigs, challenging pigs with L. intracellularis reduced growth rate, feed intake, and efficiency of gain (P < 0.01) and increased gauntness (P < 0.05) and diarrhea (P < 0.01). Diet did not affect growth performance postchallenge (P > 0.40). Feeding 10 or 20% DDGS diets did not reduce lesion length, prevalence, proliferation of L. intracellularis, or severity of lesions (P > 0.10). Thus, dietary inclusion of DDGS did not reduce the incidence or severity of lesions under the conditions of a severe L. intracellularis challenge used in this study.

Effect of including distillers dried grains with solubles in the diet, with or without antimicrobial regimen, on the ability of growing pigs to resist a Lawsonia intracellularis challenge.

A disease challenge experiment was conducted to determine if including 10% dried distillers grains with solubles (DDGS) in the diet, with or without antimicrobial supplementation, reduces the incidence or severity, or both, of intestinal lesions in growing pigs after an Lawsonia intracellularis challenge. One hundred 17-d-old weaned pigs were blocked by sex, ancestry, and BW and randomly allotted to 1 of 5 treatment groups: negative control, unchallenged, corn-soy diet; positive control, challenged, corn-soy diet; 10% DDGS diet, challenged; positive control with antimicrobial regimen, challenged; and 10% DDGS diet with antimicrobial regimen, challenged. For antimicrobial-supplemented treatments, diets contained 33 ppm bacitracin methylene disalicylate throughout the experiment, with chlortetracycline (Aureomycin) pulsed at 550 ppm from d 3 prechallenge to d 11 postchallenge. Challenged pigs were orally inoculated with 8.0 x 10(8) L. intracellularis organisms after a 4-wk prechallenge period. On d 21 postchallenge, pigs were euthanized, lesions of intestinal mucosa were evaluated, and ileal tissue samples were analyzed by immunohistochemistry to determine the presence and proliferation rate of L. intracellularis. Compared with other dietary treatments, feeding a diet containing 10% DDGS reduced ileum and colon lesion length and prevalence (P < 0.05) and reduced severity of lesions in the ileum (P < 0.05) and colon (P < 0.10) in challenged pigs. Compared with other challenged pigs, those fed the diet containing the antimicrobial regimen had a lower prevalence and severity of lesions in the jejunum (P < 0.05) and tended to have reduced total tract lesion length (P = 0.11). Compared with other challenged pigs, pigs on the 10% DDGS diet with antimicrobial regimen exhibited no differences in length, severity, or prevalence of lesions (P > 0.15), but fecal shedding of L. intracellularis was reduced on d 14 postchallenge (P < 0.05). No dietary effects on fecal shedding were observed by d 20 postchallenge (P > 0.10). The proportion of cells infected with L. intracellularis was reduced when DDGS (P = 0.05) or antimicrobial (P = 0.10) diets were fed. Under the conditions of this experiment, dietary inclusion of 10% DDGS appears to provide some benefit to growing pigs subjected to a moderate L. intracellularis challenge, similar to those of a currently approved antimicrobial regimen.

Effect of dietary inclusion of distillers dried grains with solubles, soybean hulls, or a polyclonal antibody product on the ability of growing pigs to resist a Lawsonia intracellularis challenge.

An experiment was conducted to determine if dietary inclusion of distillers dried grains with solubles (DDGS), soybean hulls, or soybean hulls sprayed with an egg-based, polyclonal antibody product would reduce the incidence or severity of infection, or both, in growing pigs after a Lawsonia intracellularis challenge. One hundred 17-d-old weaned pigs were blocked by sex, ancestry, and BW, and randomly allotted to 1 of 5 treatment groups: negative control, unchallenged, corn-soy diet; positive control, challenged, corn-soy diet; 20% DDGS diet (D), challenged; 5% soybean hulls diet (SH), challenged; and SH sprayed with a polyclonal antibody product diet, challenged. Challenged pigs were orally inoculated with 6.4 x 10(8) L. intracellularis organisms after a 4-wk prechallenge feeding period. On d 21 postchallenge, pigs were euthanized, lesions of intestinal mucosa were evaluated, and ileal tissue samples were analyzed by immunohistochemistry to determine the presence and proliferation rate of L. intracellularis. Challenging pigs with L. intracellularis reduced growth rate, feed intake, and efficiency of gain (P < 0.02) and increased the proportion of internal organ weights relative to BW (P < 0.01). Dietary treatment did not affect growth performance pre- or postchallenge (P > 0.10). Heart, empty stomach, and liver weights were similar among dietary treatments (P > 0.10). Weight of the large intestine as a percentage of BW was increased in D and SH pigs compared with positive control pigs (P < 0.05). Lesion length, prevalence, and severity, and fecal shedding of L. intracellularis were primarily unaffected by dietary treatment (P > 0.10), although ileal lesion length and severity observed tended to be greater in the SH sprayed with polyclonal antibody product diet vs. the D pigs (P < 0.10). Results from a previous study indicated that diet composition may affect length, severity, and prevalence of lesions caused by L. intracellularis in growing pigs subjected to a moderate challenge. However, beneficial results were not observed by feeding the dietary treatments used in this study.

First experience on the effect of in-feed lincomycin for the control of proliferative enteropathy in growing pigs.

This trial's aim was to evaluate the effect of in-feed lincomycin for the control of proliferative enteropathy (PE; also known as ileitis) in growing pigs, in which it is associated with significant morbidity levels. Investigation regarding the efficacy of this substance in growing pigs has never been carried out before in a field trial. The trial farm had a previous history of PE outbreaks. On day 1 of the trial (age of 62 +/- 1.5 days), 240 pigs were divided into two groups of 120 pigs/group which were allocated into five pens of 24 pigs each. Therefore, a randomized block design was used with two experimental groups (T1-T2) and five replicates (pens) per group. T1 group served as negative control (NC) animals which were receiving no medication and conversely T2 group received in-feed lincomycin at the dose of 110 mg/kg of feed. The treatment period lasted for 3 weeks, followed by an observation period of 4 weeks up to the age of 111 +/- 1.5 days which was the end of the grower stage. Administration of lincomycin at a dose of 110 mg/kg of feed had beneficial effects compared with the NC group. The pigs of T2 group showed significant improvement of their production parameters in terms of average daily body gain (ADG) and feed conversion ratio (FCR) not only during the treatment period (ADG: 0.515 +/- 0.050 versus 0.481 +/- 0.071 and FCR: 2.38 +/- 0.05 versus 2.56 +/- 0.08, for T2 and T1 groups respectively), but also during the remaining period until the end of the grower stage (observation period: ADG: 0.687 +/- 0.019 versus 0.646 +/- 0.044 and FCR: 2.58 +/- 0.02 versus 2.74 +/- 0.02 respectively). Other effects in the T2 group refer to the reduction of diarrhoea prevalence (mean pen diarrhoea score during the whole grower stage: 0.200 +/- 0.060 versus 0.632 +/- 0.041 respectively), morbidity rates (morbidity rates during the whole grower stage: 15.83% versus 45.00% respectively) and the reduction of Lawsonia intracellularis prevalence as shown by polymerase chain reaction diagnostic method (at the end of the treatment period: 10.0% versus 60.0% respectively). In conclusion, treatment with 110 mg lincomycin/kg of feed for 21 consecutive days had a beneficial effect on the control of PE in growing pigs.

Inhibition of TNF-alpha improves indomethacin-induced enteropathy in rats by modulating iNOS expression.

TNF-alpha, including other proinflammatory cytokines alone or in combination, induces iNOS expression and upregulates inflammatory responses. We evaluated the relationship between TNF-alpha and iNOS expression in indomethacin-induced jejunoileitis in male Sprague-Dawley rats. Rats were fed a daily dose of a phosphodiesterase inhibitor-either theophylline or pentoxifylline-for 2 days. Jejunoileitis was induced with two subcutaneous injections of indomethacin (7.5 mg/kg) 24 hr apart and theophylline or pentoxifylline continued for 12 hr or 4 days. Other rats received a single intraperitoneal injection of anti-TNF-alpha monoclonal antibody (TNF-Ab) 30-min before indomethacin. At 4 days TNF-Ab, theophylline, or pentoxifylline treatment significantly decreased indomethacin-induced ulceration, myeloperoxidase activity, and disease activity index. Although indomethacin significantly increased serum TNF-alpha and nitrate/nitrite levels over the control value as early as 12 hr, iNOS expression was detected only after 4 days. Serum IL-1beta level did not change at 12 hr but increased fourfold at 4 days. Treatment with TNF-Ab, theophylline, or pentoxifylline significantly reduced serum/tissue TNF-alpha, IL-1beta, nitrate/nitrite, and iNOS expression. The downregulation of nitrate/nitrite by these inhibitors suggests that TNF-alpha modulates iNOS expression.

Host immune status influences the development of attaching and effacing lesions in weaned pigs.

Attaching and effacing Escherichia coli (AEEC) has been associated with naturally occurring attaching and effacing (A/E) lesions in weaned pigs, and although A/E lesions have been experimentally reproduced in newborn piglets, such lesions have been much more difficult to induce in older conventional pigs. Hence, the aim of this study was to examine the effect of oral administration of dexamethasone on the development of A/E lesions in weaned pigs challenged with a porcine enteropathogenic E. coli (PEPEC) strain and to investigate the involvement of local intestinal cytokine response. Dexamethasone, given orally at a dosage of 3 mg kg of body weight(-1), significantly enhanced both the colonization of the challenge strain and the prevalence of foci of intimately adherent bacteria, resulting in extensive A/E lesions in the ileum, cecum, and colon of challenged pigs. We also confirmed the expression of both intimin and Tir by PEPEC strain ECL1001 in A/E lesions in vivo, which is, to our knowledge, the first report of the involvement of the latter proteins in any AEEC infections in vivo. Moreover, semiquantitative reverse transcription-PCR demonstrated that interleukin 1beta (IL-1beta), IL-6, IL-8, and, to a lesser extent, IL-12p40 are significantly upregulated in the ileum following challenge with strain ECL1001, whereas dexamethasone blocks such upregulation. Taken together, our results strongly suggested that host immune status influences the development of A/E lesions in weaned pigs, and it appears that IL-1beta, IL-6, IL-8, and, to a lesser extent, IL-12p40 are expressed during infection of weaned pigs by PEPEC and may contribute to the natural resistance of the host against PEPEC infection.

The influence of experimental ileitis on the neuropeptide coding of enteric neurons in the pig.

In the present study, both the ELISA test and immunohistochemical staining were used to investigate the influence of artificially induced ileitis on the chemical coding of enteric neurons in the pig. The ileum wall in experimental (E) pigs was injected in multiple sites with 4% paraformaldehyde to induce inflammation, while in the control (C) animals, the organ was injected with 0.1M phosphate buffer (pH 7.4). Three days after ileitis induction, samples of ileum wall from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM concentration (ELISA test) and the expression of these biologically active substances by the enteric neurons (immunohistochemical staining). Quantitative results showed that ileitis decreased tissue concentration of VIP, CGRP and SOM but increased tissue concentration of SP, NPY and GAL. Immunochemistry revealed that in both the experimental and control pigs, VIP-positive (VIP+) nerve fibers supplied mainly ileal blood vessels, and the labeled pericarya were located in the inner (ISP) and outer submucous plexus (OSP). SP+ and CGRP+ nerve terminals were found in both the mucous and muscular membrane, while the labeled pericarya were found in ISP, OSP and myenteric plexus (MP). In both C and E pigs, the very few nerve terminals containing NPY and SOM were located mainly in the mucous membrane. NPY- or/and SOM-immunopositive nerve cell bodies were found in ISP, OSP and MP. GAL+ nerve fibers supplied all layers of the ileum and were most numerous in the muscular membrane, while the labeled pericarya were present in all the enteric plexuses. The present results suggest that enteric neurons are highly plastic in their response to inflammation.

Cytologic diagnosis of Lawsonia intracellularis proliferative ileitis in a Japanese snow macaque (Macaca fuscata).

Diffuse ileal thickening and ileocecocolic lymphadenomegaly were observed during exploratory laparotomy in a 2-year-old male Japanese snow macaque (Macaca fuscata) that had flu-like signs and diarrhea. Cytologic examination of ileal biopsy imprints revealed many mature, mildly karyolytic neutrophils and fewer well-differentiated lymphocytes, eosinophils, macrophages, and plasma cells in a background containing amorphous, necrotic material. Tightly cohesive sheets of moderately pleomorphic epithelial cells also were seen. The cytologic diagnosis was chronic, active, mixed inflammation with atypical epithelial cells and necrosis. Histologically, the mucosal and crypt epithelium was moderately hyperplastic with a loss of goblet cells, increased mitoses, and frequent crypt abscesses. Within the lamina propria and extending into the submucosa was a marked neutrophilic infiltrate, with low numbers of lymphocytes, histiocytes, plasma cells, and eosinophils. The histologic diagnosis was chronic, diffuse, marked suppurative and lymphocytic ileitis. Warthin-Starry silver staining of the ileal biopsy and imprint specimens demonstrated numerous pleomorphic, curved bacilli consistent with Lawsonia intracellularis. Polymerase chain reaction (PCR) and immunohistochemistry confirmed the identity of the infectious agent. L intracellularis infection may be underdiagnosed because silver stain is required to visualize the organism with light microscopy and because the pathognomonic crypt hyperplasia may be complicated by secondary pathologic changes. Application of silver stain to cytologic specimens should be considered when distal intestinal lesions associated with hyperplastic epithelium, with or without inflammation, hemorrhage, or necrosis, are identified in animals with clinical signs of enteritis, especially in frequently affected species or in stressed or young animals.

Survey of porcine proliferative enteritis in the Tohoku District of Japan.

A survey of proliferative enteritis (PE) in pigs at a meat processing plant was conducted using polymerase chain reaction (PCR) testing methods. During the investigation period, 227 of 83,717 pigs brought to the meat processing plant from Iwate, Fukushima, Miyagi, Niigata, and Yamagata Prefectures displayed characteristic general pathological features in terminal ileum, including mucosal hypertrophy and reticulation of serosal surface. Of these, 179 cases were further examined in the laboratory. All cases displayed characteristic histopathological features, and the specific band of the Lawsonia intracellularis (Li) causative agent of PE in pigs was detected in 155 cases by PCR testing methods. These results suggested a general infiltration of Li in the Tohoku district.

Prevalencia de enteropatía proliferativa porcina y caracterización histopatológica de las lesiones asociadas en cerdos sacrificados en el Matadero Municipal de Medellín, Colombia / Prevalence of porcine proliferativa enteritis and histopathologycal characterization of associated lesions in slaughtered pigs of Medellín, Colombia

En el período comprendido entre julio y octubre del año 1997 se evaluaron 360 intestinos de cerdos sacrificados en el Matadero Municipal de Medellín, Colombia, con el objetivo de establecer la prevalencia de la Enteropatía Proliferativa Porcina (EPP) en el departamento de Antioquia, caracterizar las lesiones anatomopatológicas asociadas y determinar la presencia de su agente etiológico Lawsonia intracellularis. El cálculo de la muestra se efectuó de una población tabular infinita con un límite de confianza del 95 por ciento y una seguridad de ±5 por ciento. Las muestras obtenidas se sometieron a inspección macroscópica y evaluación histopatológica utilizando las coloraciones de Hematoxilina-Eosina y Warthin-Starry. El análisis de los resultados se efectuó mediante estadística descriptiva y la prueba de independencia y contingencia (chi-cuadrado). La prevalencia de EPP fue del 87.22 or ciento, determinada por la presencia de las lesiones características de la enfermedad asociadas a su agente etiológico L. intracellularis. Las formas lesionales más frecuentes fueron: Adenomatosis Intestinal en un 74.72 por ciento e Ileítis Regional en un 20.55 por ciento. Este artículo discute los hallazgos epidemiológicos y anatomopatológicos de EPP en el departamento de Antioquia y se constituye en el primer reporte del hallazgo de una bacteria como L. intracellularis diagnosticada por un método directo en Colombia.

Field evaluation of the effect of in-feed doxycycline for the control of ileitis in weaned piglets.

The aim of this trial was to evaluate the effect of in-feed doxycycline (DOXY) on the control of ileitis in weaned piglets. On a farm with a previous history of ileitis outbreaks, 288 piglets at the age of weaning (25 +/- 2 days old) were divided into four experimental groups, each group comprising three pens with 24 piglets in each pen. Non-medicated animals served as negative control (NC) group, whereas groups DOXY-50, DOXY-125 and DOXY-250 received doxycycline via feed at 50, 125 and 250 ppm, respectively. Therapy lasted for 14 days followed by an observation period of 28 days. In conclusion, administration of doxycycline at a dose rate of 125 or 250 ppm had beneficial effect compared with the NC group. in terms of the reduction of diarrhoea prevalence, the enhancement of growth performance and the reduction of prevalence of Lawsonia intracellularis in the intestine, as shown either by the PCR method or by specific histopathological examinations. Treatment with 250 ppm of doxycycline for a fortnight interval post-weaning seems to be beneficial leading to better growth rates of piglets not only during treatment period, but also throughout the whole nursery phase.

Therapeutic efficacy of water-soluble lincomycin-spectinomycin powder against porcine proliferation enteropathy in a European field study.

Controlled clinical trials to a standardised protocol were conducted into the effect of a water-soluble antibiotic on proliferative enteropathy and its causative agent (Lawsonia intracellularis) on commercial pig farms at six sites in four European countries. Clinical signs of the disease and L intracellularis-specific polymerase chain reaction (PCR)-positive pigs were detected in pens of six- to 12-week-old pigs (weighing 5 to 55 kg) immediately before each trial. Matched pens of randomised pigs were either left unmedicated (32 to 59 pigs per trial), or medicated orally with 10 mg/kg of a water-soluble combination of lincomycin and spectinomycin powder (21 and 42 mg, respectively, of antibiotic activity per litre) for either seven days (33 to 61 pigs per trial), or 14 days (33 to 61 pigs per trial), delivered via the drinking water. Investigators did not know which pens received which treatment In most of the affected pigs in each trial, diarrhoea due to L intracellularis resolved within three to seven days after the medication began, whereas most unmedicated pigs remained diarrhoeic for at least 10 days. On average the medicated pigs gained more weight than the unmedicated pigs over the 21-day trial period (P=0.01). In two trials, the absence of L intracellularis after the treatment ended was confirmed by the PCR.

Effect of peroral anti-bacterial antiserum treatment on intestinal immune parameters of germ-free piglets intragastrically infected with virulent Salmonella typhimurium or enteropathogenic E. coli.

Germ-free piglets were orally infected with either enteropathogenic E. coli 055 or a virulent strain of Salmonella typhimurium. Orally applied antiserum against E. coli protected infected animals in spite of the fact that the bacteria were consistently found in mesenteric lymph nodes and other organs. By contrast, the application of an antiserum against S. typhimurium was without any effect on the outcome of infection. The treatment with anti-bacterial antiserum prevented inflammation of ileal mucosa (TNF-alpha and heat shock protein 65 expression) only in piglets infected with E. coli. A decrease in the frequency of ileal MAC320+ cells was observed in all infected piglets treated with antiserum.