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Gastrointestinal tuberculosis (TB) is a rare manifestation of extra-pulmonary TB that is known to mimic many different gastrointestinal diseases. We present a case of an 85-year-old male patient with delayed diagnosis of gastrointestinal TB who underwent colonic resection for a cecal mass that was initially suspected to be malignant. Acid-fast staining of the surgical specimen later revealed acid-fast bacilli and multiple lymph nodes with necrotizing granulomas. The purpose of this study is to stress the importance of including gastrointestinal TB as a differential diagnosis for patients with suspected colorectal malignancy, especially when initial biopsy results do not reveal malignant features., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: This study aims to assess the clinical, radiological, and histological characteristics of Actinomyces infection identified in appendectomy specimens., Material and Methods: Between January 2013 and November 2023, 5834 patients underwent appendectomy in our clinic, and their pathology reports were retrospectively reviewed., Results: Actinomyces appendicites were reported in 14 specimens (0.23%). It was determined that appendectomy was performed in only 10 patients (71.4%), ileocecal resection was performed in two patients (14.2%) and right hemicolectomy in two patients (14.2%). The operations on five patients were performed by laparoscopy, and the operations on the other nine patients were performed by open surgery. Laparoscopy was started in three patients and converted to open surgery due to suspicion of an ileocecal mass and cecal perforation. It was found that the white blood cell count of three patients was within the normal range of reference (8-9.77mg/dL); leukocytosis was detected in other patients (10.2-18.7mg/dL). C-reactive protein was normal in one patient and high in the rest of the patients. While the first-hour erythrocyte sedimentation rate was normal in five patients, it was found to be high in the other patients. Findings on radiological imaging were reported as acute appendicitis, appendicular plastron, and ileocecal mass. As a result of the pathology findings, the patients were given oral penicillin or semi-synthetic penicillin derivatives during one month., Conclusion: Ileocecal and appendecular actinomycosis are rare, and preoperative diagnosis is difficult. A definitive diagnosis is usually made after a histopathological examination. After surgery, long-term antimicrobial treatment of the patient is possible with penicillin., (Copyright © 2024 Elsevier España, S.L.U. All rights reserved.)

Mucormycosis is a life-threatening fungal infection mostly involving the ocular region, sinuses and brain. It is mostly seen in the immunocompromised host. Gastrointestinal (GI) mucormycosis is rare and mostly present as hematemesis, abdominal pain and melena. Here, we present a case of intestinal mucormycosis who presented as cecal perforation. Surgical resection was done, and the diagnosis was made by histopathology. Our case is unique in the way that GI mucormycosis is itself a rare entity and even rarer in an immunocompetent host., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.)

Objectives: Sepsis is a severe organic dysfunction caused by an infection that affects the normal regulation of several organ systems, including the central nervous system. Inflammation and oxidative stress play crucial roles in the development of brain dysfunction in sepsis. The aim of this study was to determine the effect of a fish oil (FO)-55-enriched lipid emulsion as an important anti-inflammatory compound on brain dysfunction in septic rats., Methods: Wistar rats were subjected to sepsis by cecal ligation and perforation (CLP) or sham (control) and treated orally with FO (600 µL/kg after CLP) or vehicle (saline; sal). Animals were divided into sham+sal, sham+FO, CLP+sal and CLP+FO groups. At 24 h and 10 d after surgery, the hippocampus, prefrontal cortex, and total cortex were obtained and assayed for levels of interleukin (IL)-1β and IL-10, blood-brain barrier permeability, nitrite/nitrate concentration, myeloperoxidase activity, thiobarbituric acid reactive species formation, protein carbonyls, superoxide dismutase and catalase activity, and brain-derived neurotrophic factor levels. Behavioral tasks were performed 10 d after surgery., Results: FO reduced BBB permeability in the prefrontal cortex and total cortex of septic rats, decreased IL-1β levels and protein carbonylation in all brain structures, and diminished myeloperoxidase activity in the hippocampus and prefrontal cortex. FO enhanced brain-derived neurotrophic factor levels in the hippocampus and prefrontal cortex and prevented cognitive impairment., Conclusions: FO diminishes the negative effect of polymicrobial sepsis in the rat brain by reducing inflammatory and oxidative stress markers., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Intestinal perforation is a serious but poorly understood complication of typhoid fever. This study aims to determine the patient factors associated with postoperative morbidity and mortality., Methods: We retrospectively reviewed the records of all children presenting to our unit with typhoid intestinal perforation (TIP) between March 2009 and December 2013. The patients were grouped based on postoperative outcome status and were compared with respect to patient related variables, using chi square test. Multivariate analysis was performed using a binary logistic regression model. Significance was assigned to a p-value <0.05., Results: The records of 129 children were analyzed. There were 78 (60.5%) boys and 51 (39.5%) girls. The male/female ratio was 1.53:1. Their ages ranged from 3years to 13years (mean 8.14years; SD 2.61years). A single intestinal perforation was seen in 73.4% (94/128) of them, while 26.6% (34/128) had two or more. Mortality rate was 10.9%. Multivariate analysis showed that multiple intestinal perforations significantly predicted postoperative mortality (p=0.005) and development of postoperative fecal fistula (p=0.013), while serum albumin <32g/L was a predictor of postoperative surgical site infection (p=0.002)., Conclusion: Multiple intestinal perforations, a postoperative fecal fistula and hypoalbuminemia adversely affected outcome in our patients., Level of Evidence: III (Retrospective study). Type of study-Prognosis study., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Intestinal tuberculosis is less common than pulmonary tuberculosis. Its clinical and endoscopic features are nonspe-cific, so diagnostic suspicion must be high in order to make an early diagnosis and prevent iatrogenia. Pharmacotherapy is often effective, with an excellent clinical and endoscopic evolution. Surgical treatment is reserved for complications. We present the case of cecal tuberculosis diagnosed endoscopically; this is the second case diagnosed in a few months in our center. In this case there were no risk factors, such as recent travel, risk of contacts or inmunosupression.

The pathological diagnosis of inflammatory bowel disease (IBD) is often difficult because biopsy material may not contain pathognomonic features, making distinction between Crohn's disease, ulcerative colitis and other forms of colitides a truly challenging exercise. The problem is further complicated as several diseases frequently mimic the histological changes seen in IBD. Successful diagnosis is reliant on careful clinicopathological correlation and recognising potential pitfalls. This is best achieved in a multidisciplinary team setting when the full clinical history, endoscopic findings, radiology and relevant serology and microbiology are available. In this review, we present an up-to-date evaluation of the histopathological mimics of IBD.

Typhoid fever is caused by enteroinvasive Gram-negative organism Salmonella typhi. The well-known complications of typhoid fever are intestinal haemorrhage and perforation. In the pre-antibiotic era, these complications were quite common, but in the current antibiotic era the incidence of these complications is on the decline. We report a case of a patient with typhoid fever who developed haematochezia during the hospital stay and was found to have caecal ulcer with an adherent clot on colonoscopy. He was managed successfully with conservative measures without endotherapy and there was no rebleed.

Although tuberculosis is endemic in Tunisia, only a few cases of intestinal disease have been reported. This entity is usually associated with pulmonary tuberculosis. Any part of the gastrointestinal tract may be affected but usually with ileocaecal involvement. Diagnosis is extremely difficult because the clinical presentation is so variable. The disease frequently mimics other chronic inflammatory intra-abdominal diseases or even malignancy. We report a case of isolated colonic tuberculosis presenting as circumferential ulcerovegetative lesions in the caecal region.

Gastrointestinal tuberculosis accounts for 3% of the extrapulmonary tuberculosis with ileocaecal region being the common site of involvement up to 75%. Primary involvement of appendix is very rare and accounts for only 0.6% to 2.9% of gastrointestinal tuberculosis in the absence tubercular focus elsewhere. The pre-operative investigations usually give non-specific results. The diagnosis in most instances made only after histopathology. Here we report a case of primary appendicular tuberculosis in a patient presented with caecal perforation., (Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

Background/aim: Intestinal tuberculosis needs to be considered in the differential diagnosis when patients with intestinal pathology are encountered. Tuberculosis can mimic other disease entities like, ischemic enteritis, inflammatory bowel diseases, malignancies, intussusception etc., clinically as well as morphologically in resected intestinal specimens. We aimed to study the various clinical presentations leading to intestinal resection, with identification of different etiological factors by histopathological examination; and to illustrate, discuss and describe the various histopathological features of the lesions in these resected intestinal specimens with clinicopathological correlation., Materials and Methods: We studied 100 cases of resected intestinal specimens received during September 2002 to December 2003. We totally encountered 22 request forms with clinical suspicion of ileoceocal tuberculosis., Results: Abdominal tenderness and mass in ileoceocal region were noted in all cases. In many instances, the cases were operated for acute/subacute intestinal obstruction. Clinical and intra-operative diagnoses of tubercular enteritis, in many instances, were finally diagnosed histopathologically as ischemic enteritis (nine cases), chronic nonspecific enteritis (four cases), adenocarcinoma of the caecum, Crohn's disease, intussusception (each one case), and correctly as intestinal tuberculosis in only six cases., Conclusion: Tuberculosis can mimic various disease entities, clinically and sometimes morphologically. Vice versa is also true. An increased awareness of intestinal tuberculosis coupled with varied clinical presentations, nonspecific signs and symptoms, difficulties in diagnostic methods and need of early and specific treatment should improve the outcome for patients with this disease.

A 69-year-old female complained of persistent abdominal pain, and annular ulcers and ulcer scars were detected endoscopically in the cecum. Pathological findings included caseous granulomas with some Langhans giant cells, and Ziehl-Neelsen staining was negative. Mycobacterium gordonae (M. gordonae) was identified by the DNA-DNA hybridization method and culture (Ogawa medium) of biopsy samples from ulcerous cecal lesions. After 6 months of antibiotic therapy, ulcerous cecal lesions were healed, and no acid-fast bacteria were detected by culture of biopsy samples from scar tissue. We believe this is the first report of M. gordonae infection in the alimentary tract.

Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella spp. cecal colonization in experimentally infected broiler chickens. Egg yolk powder (EYP) was obtained by freeze-drying egg yolks containing anti-Salmonella spp. Immunoglobin Y was included in feed at 5 levels of concentration (0 to 5%). Feeds were formulated to similar nutrient levels and provided for ad libitum intake from d 1 to 28. Three days after initiation of feed treatments (d 4), chickens were co-challenged with equal numbers of Salmonella Enteritidis and Salmonella Typhimurium (2x10(6) cfu/bird). Cecal samples were recovered weekly over the experimental period (d 7 to 28) to enumerate Salmonella spp. The effect of anti-Salmonella spp. IgY feed supplementation on growth performance of infected chickens was also evaluated during the same period. In comparison with the positive control treatment (PC), treatments involving EYP (T1, T2, T3, T4, and T5), whether containing anti-Salmonella spp. IgY or not, significantly improved (P<0.05) the growth performance of challenged chickens, but without reaching the performance levels of nonchallenged chickens (NC1 and NC2). However, no link can be established between the enhancement in growth performance of challenged birds and their contamination levels by Salmonella because in-feed incorporation of EYP had no significant effect on cecal colonization by Salmonella. Furthermore, the comparison of the 5 anti-Salmonella spp. IgY concentration levels in feed did not reveal any anti-Salmonella spp. IgY concentration effect on growth performance and Salmonella cecal colonization. These results suggest that anti-Salmonella spp. IgY would undergo denaturation and degradation after their passage through the animal gastrointestinal tract and reveal that components of EYP other than specific antibodies have a beneficial effect on growth performance.

Amebiasis is uncommon in developed countries. Its clinical presentation can be variable and non-specific, and the diagnosis can be easily overlooked. Among the wide variety of clinicopathologic manifestations of the intestinal amebiasis, amebomas occur rarely, resulting from the formation of annular colonic granulation tissue, usually in the cecum or ascending colon. This report describes the case of a 65-year-old female who presented with a painful mass in the right hypochondrium and intermittent abdominal cramping, associated with defecation difficulty. Radiologic examination depicted thickening of the cecal wall and its ring-like stenosis in association with a mesenteric reaction. Because of concentric thickening of the cecal wall and the mass-like appearance, a preliminary clinical diagnosis of cecal cancer was made, and the patient was referred to the Clinic for surgical treatment. Histologic examination of the surgical specimen after segmental colectomy confirmed the diagnosis of cecal ameboma. The authors conclude that multiple granulomas of amebic trophozoites can be better recognized after PAS staining, and that the pathognomonic feature of protozoa-ingested red blood cells was also seen in the surgical specimen.

Establishment of mucosal and/or luminal colonization is the first step in the pathogenesis of many gastrointestinal bacterial pathogens. The pathogen must be able to establish itself in the face of competition from the complex microbial community that is already in place. We used culture-independent methods to monitor the colonization of the cecal mucosa of Helicobacter-free mice following experimental infection with the pathogen Helicobacter hepaticus. Two days after infection, H. hepaticus comprised a minor component of the mucosa-associated microbiota, but within 14 days, it became the dominant member of the community. Colonization of the mucosa by H. hepaticus was associated with a decrease in the overall diversity of the microbial community, in large part due to changes in evenness resulting from the relative dominance of H. hepaticus as a member of the community. Our results demonstrate that invasion of the complex gastrointestinal microbial community by a pathogenic microorganism causes reproducible and significant disturbances in the community structure. The use of non-culture-based methods to monitor these changes should lead to a greater understanding of the ecological principles that govern pathogen invasion and may lead to novel methods for the prevention and control of gastrointestinal pathogens.

Purpose: To report the imaging features of four cases of pseudo-tumoral abdominal tuberculosis in order to demonstrate diagnostic difficulties, even in endemic areas, despite expanding imaging modalities., Material and Methods: We have retrospectively reviewed four cases investigated in our hospital between 1998 and 2002. The first case concerned a 2 year and 6 month old boy admitted for a right iliac fossa mass. The other patients were 43 and 48 year old women admitted for epigastric mass and persistent epigastric pain with past history of treated tuberculosis respectively. The last was an 86 year old man investigated because progressive worsening of general health. Sonography (US) and computed tomography (CT) were performed in all four cases., Results: Involvement of the ileocaecal region was noted in three cases. Large intestinal hypervascular mass in the pediatric case, heterogeneous mass with porta hepatis lymph node in the patient with past history of treated tuberculosis, pseudotumoral caecal wall thickening in the third case. The multiloculated pattern of the epigastric mass and its location initially suggested a diagnosis of pancreatic tumor., Conclusion: Abdominal tuberculosis is rare even in endemic areas. This diagnosis must be considered when imaging modalities depict a hypervascular soft tissue mass on Doppler examination with peripheral enhancement on CT scan.

Zygomycosis occurs as an opportunistic infection following organ transplantation and immunosuppressive therapy. Gastrointestinal zygomycosis is an exceedingly rare and usually fatal presentation of this infection. We discuss the case of a renal transplant recipient who survived cecal perforation from zygomycosis. The successful treatment consisted of aggressive surgical resection, intensive course of antifungal therapy, and rapid withdrawal of anti-rejection medications.

Background & Aims: To explore the hypothesis that selective immune responses to distinct components of the intestinal microflora induce intestinal inflammation, we characterized disease kinetics and bacterial antigen-specific T-cell responses in ex germ-free interleukin 10 -/- and wild-type control mice monoassociated with Enterococcus faecalis , Escherichia coli , or Pseudomonas fluorescens ., Methods: Colitis was measured by using blinded histological scores and spontaneous interleukin 12 secretion from colonic strip culture supernatants. Interferon gamma secretion was measured from mesenteric or caudal lymph node CD4 + T cells stimulated with bacterial lysate-pulsed antigen-presenting cells. Luminal bacterial concentrations were measured by culture and quantitative polymerase chain reaction., Results: Escherichia coli induced mild cecal inflammation after 3 weeks of monoassociation in interleukin 10 -/- mice. In contrast, Enterococcus faecalis-monoassociated interleukin 10 -/- mice developed distal colitis at 10-12 weeks that was progressively more severe and associated with duodenal inflammation and obstruction by 30 weeks. Neither bacterial strain induced inflammation in wild-type mice, and germ-free and Pseudomonas fluorescens-monoassociated interleukin 10 -/- mice remained disease free. CD4 + T cells from Enterococcus faecalis- or Escherichia coli-monoassociated interleukin 10 -/- mice selectively produced higher levels of interferon gamma and interleukin 4 when stimulated with antigen-presenting cells pulsed with the bacterial species that induced disease; these immune responses preceded the onset of histological inflammation in Enterococcus faecalis -monoassociated mice. Luminal bacterial concentrations did not explain regional differences in inflammation., Conclusions: Different commensal bacterial species selectively initiate immune-mediated intestinal inflammation with distinctly different kinetics and anatomic distribution in the same host.

The purpose of our study is to emphasize the central role of ultrasound (US) in finding the cause of abdominal pain in children. Ultrasound of the lower abdomen quadrant should be considered in all cases in which the clinical signs and symptoms are not diagnostic of appendicitis. There is a wide range of clinical syndromes and diseases which can easily be diagnosed using a high resolution ultrasound with adjunct of color and power Doppler. The spectrum of abnormalities includes appendicitis, mesenteric lymphadenitis, infectious ileocecitis, Crohn's disease, intussusception, ovarian cysts, and encysted cerebrospinal fluid. One of the most common causes of acute abdominal pain in children is acute terminal ileitis (infectious ileocecitis) with mesenteric lymphadenitis. Ultrasound is the best tool to rapidly differentiate this disease from acute appendicitis, and prevent unnecessary laparotomy (Ref. 12).

Cecal pathology is commonly encountered and may represent a diagnostic challenge in patients with either acute or chronic clinical presentations. Although appendicitis accounts for the majority of surgical conditions presenting with right lower quadrant pain, readers should be aware of the broad spectrum of cecal pathologies and characteristic CT findings, which can be useful in establishing the correct diagnosis.

Candida albicans is a pleomorphic fungus with budding yeast and filamentous forms, and is a frequent cause of complicating infections in patients who are postsurgical, in shock, and have trauma. Many cases of systemic candidiasis are thought to orginate from the intestine, but it is unclear if the filament or the yeast is the more invasive form. Because C. albicans is relatively noninvasive and because mesenteric ischemia is thought to facilitate extraintestinal microbial dissemination, wild-type C. albicans CAF2 and mutant HLC54 (defective in filament formation) were orally inoculated into antibiotic-treated mice that were housed exclusively in room air, or were intermittently exposed to 10% oxygen for 1-h intervals. Both strains of C. albicans colonized the cecum in similar numbers (approximately 10(6.7)/g). C. albicans translocation to the draining mesenteric lymph nodes was not detected in mice inoculated with CAF2 (normoxic or hypoxic) or in normoxic mice inoculated with HLC54, but was detected in 33% (P < 0.01) of hypoxic mice inoculated with HLC54. Using Caco-2 and HT-29 enterocytes cultivated on plastic dishes and pretreated for 48 h in 10% oxygen, adherence of C. albicans HLC54 was decreased compared with wild-type CAF2, and hypoxia had no noticeable effect on adherence of either CAF2 or HLC54. Using enterocytes cultivated on permeable 8-microm filters, transepithelial migration of C. albicans CAF2 and HLC54 appeared similar. Thus, C. albicans HLC54 (defective in filament formation) was more invasive in hypoxic mice compared with wild-type CAF2, and host factors (e.g., mesenteric ischemia) rather than an innate ability to interact with enterocytes might play a more important role in extraintestinal dissemination of C. albicans yeast forms.

A series of benzindazole-4,9-quinones was tested for growth-inhibitory effects on Cryptosporidium parvum in vitro and in vivo. Most compounds showed considerable activity at concentrations from 25 to 100 micro M. For instance, at 25 micro M the derivatives 5-hydroxy-8-chloro-N1-methylbenz[f]-indazole-4,9-quinone and 5-chloro-N2-methylbenz[f]indazole-4,9-quinone inhibited growth of C. parvum 78-100%, and at 50 micro M seven of the 23 derivatives inhibited growth > or = 90%. The activity of the former two compounds was confirmed in a T-cell receptor alpha (TCR-alpha)-deficient mouse model of chronic cryptosporidiosis. In these mice, the mean infectivity scores (IS) in the caecum were 0.63-0.20, whereas in sham-treated mice the score was 1.44 (P < 0.05). There were similar differences in IS in the ileum, where the score for treated mice was 1.12-0.20 and that for mice receiving no drug was 1.32. There was no acute or chronic toxicity for any compound tested in vivo.

A case of a periappendiceal actinomycosis, seen in an 83-year-old woman, clinically mimicking a right ovarian neoplasm penetrating the right colon, is presented. The patient's complaints led to the discovery of a right abdominal mass. Explorative laparotomy and right hemicolectomy were done. Histological examination revealed periappendiceal actinomycotic abscesses. We discuss a possible pathogenesis and the therapeutic modalities.

Extrapulmonary tuberculosis is more frequent in hemodialysis patients than in the general population but intestinal localization is an unusual presentation of this infectious disease. We report a 60 year old patient on regular hemodialysis with intestinal tuberculosis masquerading as colon cancer. The patient presented with rectal bleeding, abdominal pain and fever and the radiological findings were compatible with ileocecal carcinoma. After surgery histological examination showed non-caseating granulomas but mycobacterial culture was not available. We performed a colonoscopy and obtained a biopsy of colonic mucosa for culture and other analyses. We identified acid-fast bacilli with Ziehl-Neelsen staining of formaldehyde preserved, paraffin-embedded tissue from the hemicolectomy and the colonic mucosal biopsy. Treatment with isoniazid, rifampicin and pyrazinamide for nine months was successful and well tolerated. Intestinal tuberculosis is a rare entity that we must keep in mind in a patient with abdominal pain, unexplained fever, digestive bleeding and particularly with a positive tuberculin reaction. When culture is not possible we can obtain intestinal samples by colonoscopy and use appropriate staining of paraffin-embedded tissues.

An 18-year-old Morgan mare was presented to the Veterinary Medical Teaching Hospital, University of Illinois, with a 10-day history of watery diarrhea, depression, and dysphagia. On admission, the animal was severely dehydrated, depressed, and unable to swallow and had no clinical signs of diarrhea. The respiratory and heart rate and body temperature were within normal limits. Following fluid therapy, the mare developed severe watery diarrhea and continued to be depressed, incoordinated, and dysphagic. The animal died on the fourth day after admission and was sent to the Laboratories of Veterinary Diagnostic Medicine for necropsy. Gross postmortem findings were consistent with an acute cerebral infarction in the right cerebral hemisphere, an acute necrotizing typhlocolitis, multifocal petechial and ecchymotic hemorrhages, enlarged and congested pars intermedia of the pituitary gland, and marked bilateral adrenocortical hyperplasia with multifocal areas of necrosis and hemorrhage. Histologic evaluation of the affected brain demonstrated an area of coagulative necrosis of the gray matter, with hemorrhage, vasculitis, and thrombosis. There were many fungal hyphae 3.5-6.0 microm, pale basophilic, septate, and occasionally branching at 45 degrees present in the arterial walls and throughout the necrotic tissue. Immunohistochemical analysis revealed Aspergillus niger as the etiologic agent responsible for the mycotic vasculitis and infarction in the brain. Bacteria culture and immunohistochemical staining of the colon and cecum failed to demonstrate specific pathogens.

We report a 44 years old male, presenting with an eight months history of right lower quadrant pain, diarrhea and weight loss. Colonoscopy showed a proliferative and ulcerated lesion in the cecum, with necrotic areas. Barium enema showed an extensive irregular stenosis with rigidity of cecum and ascending colon. The endoscopic biopsy showed numerous granulomas with giant multinucleated cells of Langhans type. A right colectomy was performed with a good postoperative evolution. Anti tuberculosis treatment was started two weeks later and was well tolerated. The patient is currently asymptomatic after two years of followup.

The present study addressed the role of IL-12 in a murine model of septic peritonitis, induced by cecal ligation and puncture (CLP). Although CLP surgery induced IL-12 production at 6 and 24 h after surgery, IL-12 immunoneutralization was clearly deleterious in this model: 54% of CLP mice receiving preimmune serum survived, whereas mice administered IL-12 antisera prior to CLP experienced a 25% survival rate. IL-12 immunoneutralization not only led to increased mortality, but also appeared to promote a shift away from IL-12 and IFN-gamma, in favor of IL-10. This cytokine shift corresponded to changes in bacterial load, as CLP mice receiving IL-12 antiserum yielded more CFUs from the peritoneal cavity at 24 h after CLP. To address the role of bacterial infection in IL-12 antiserum-induced mortality following CLP, antibiotics were administered for 4 days after surgery. Despite regular antibiotic administration, IL-12 immunoneutralization still reduced survival in CLP mice. Furthermore, histology of the ceca revealed that mice administered IL-12 antisera failed to show typical organization of the damaged cecum wall. Accordingly, Gram staining revealed bacteria within peritoneal fluids from these mice, while peritoneal fluids from CLP mice that received preimmune serum and antibiotics were free of bacteria. Altogether, these data suggested multiple important roles for IL-12 in the evolution of murine septic peritonitis.

A spiral-shaped bacterium with bipolar, single-sheathed flagella was isolated from the intestines of IL-10 (interleukin-10)-deficient (IL-10(-/-)) mice with inflammatory bowel disease. The organism was microaerobic, grew at 37 and 42 degrees C, and was oxidase and catalase positive but urease negative. On the basis of 16S rRNA gene sequence analysis and biochemical and phenotypic criteria, the organism is classified as a novel helicobacter. Cesarean section-rederived IL-10(-/-) mice without helicobacter infection did not have histological evidence of intestinal inflammation. However, helicobacter-free IL-10(-/-), SCID/NCr, and A/JNCr mice experimentally inoculated with the novel urease-negative Helicobacter sp. developed variable degrees of inflammation in the lower intestine, and in immunocompetent mice, the experimental infection was accompanied by a corresponding elevated immunoglobulin G antibody response to the novel Helicobacter sp. antigen. These data support other recent studies which demonstrate that multiple Helicobacter spp. in both naturally and experimentally infected mice can induce inflammatory bowel disease. The mouse model of helicobacter-associated intestinal inflammation should prove valuable in understanding how specific microbial antigens influence a complex disease process.

Purpose: The purpose of this article is to present a case of an uncommon opportunistic fungal infection that appears in immunologically or metabolically compromised patients and is usually fatal., Method: A 54-year-old woman with an acute lymphoblastic leukemia had acute abdominal pain with peritoneal symptoms during her hospital stay. A laparotomy was performed and a cecal infarct firmly adherent to about 30 cm of infiltrated jejunal loop was discovered., Results: Microscopic studies revealed an infiltration of the jejunal wall by abnormal lymphocytes. The cecal and ileal walls were infiltrated by leukocytes. Blood vessels were invaded by giant cells and large, unseptated, right-angle branching hyphea., Conclusions: These findings were considered typical of invasive mucormycosis of the cecum and the terminal ileum.

Hepatitis, proliferative typhlitis, and colitis were characterized in young adult and older SCID/NCr mice naturally infected with Helicobacter hepaticus. Liver lesions consisted of Kupffer, Ito, and oval cell hyperplasia along with multifocal to coalescing coagulative hepatocyte necrosis. Numerous Warthin-Starry-positive bacteria were observed in the parenchyma, and there were minimal to mild accumulations of monocytic cells and neutrophils. Proliferative typhlitis was characterized by moderate to marked mucosal epithelial cell hyperplasia with mild monocytic and neutrophilic infiltration. Minimal to mild colitis with mucosal epithelial cell hyperplasia of the colon was most marked in older mice. Comparable gastrointestinal lesions were not observed in uninfected control SCID/NCr mice. H. hepaticus was cultured from fetal viscera of 2 of 11 pups sampled late in gestation from infected SCID/NCr females, suggesting transplacental infection of H. hepaticus. As expected, most of the naturally infected SCID/NCr mice had no serum immunoglobulin G response against H. hepaticus. These findings contrast with those in infected immunocompetent A/JCr mice, which develop a significant immune response to H. hepaticus associated with prominent multifocal mononuclear cell infiltrates in the liver, with only rare bacteria observable at the periphery of inflammatory foci or in the biliary canaliculi. The results demonstrate that chronic inflammatory and proliferative lesions simultaneously affecting the liver, cecum, and colon are associated with natural infection of SCID/NCr mice with H. hepaticus and that lesions are progressive with age. Concurrent infection with H. hepaticus may confound studies that have been attributed to similar lesions due to other experimental manipulations of SCID/NCr mice.

Helicobacter bilis is a recently identified species that colonizes the intestine and liver of mice. In immunocompetent mice, infections have been associated with mild hepatitis, and in immunocompromised mice, inflammatory bowel disease has been induced by intraperitoneal inoculation of the organism. We report inoculation of 6-week-old C.B-17 scid/scid mice by gastric gavage with approximately 10(7) H. bilis colony-forming units. Groups of mice were euthanized and necropsied 12, 24, and 36 weeks after inoculation. Mild to moderate proliferative typhlitis was evident in all mice at 12 and 36 weeks after inoculation and in most mice 24 weeks after inoculation. Mild to severe chronic active hepatitis was detected in 10 of 10 male mice and 3 of 10 female mice. These results indicate that H. bilis can cause moderate to severe enterohepatic disease in immunocompromised mice.

Background: A new subline of the senescence accelerated mouse (SAM) P1/Yit strain has been established which shows spontaneous enteric inflammation under specific pathogen free (SPF) conditions., Aims: To elucidate the pathogenesis of enteric inflammation in this new subline., Methods: The SPF and germ free (GF) SAMP1/Yit strains were used. Histological, immunological, and microbiological characterisation of the mice with enteric inflammation was performed., Results: Histologically, enteritic inflammation developed as a discontinuous lesion in the terminal ileum and caecum with the infiltration of many inflammatory cells after 10 weeks of age. the activity of myeloperoxidase, and both immunolocalisation and mRNA expression of inducible nitric oxide synthase increased in the lesion. CD3-epsilon positive T cells, neutrophils, and macrophages were more numerous in the inflamed mucosa of the SAMP1/Yit strain. The GF SAMP1/Yit strain did not show any inflammation in the intestinal wall, by the age of 30 weeks, and the enteritis and caecitis developed 10 weeks after the conventionalisation of the GF SAMP1/Yit strain., Conclusion: Enteric inflammation in the ileum and caecum developed in the SAMP1/Yit strain. The pathophysiological characteristics of the disease in this mouse have some similarities to those of human inflammatory bowel disease (IBD). This mouse strain should be a useful model system for elucidating the interaction between the pathogenesis of IBD and the gut microflora.

Specific pathogen-free chicks aged 1 day were challenged per os with strains of five different species of intestinal spirochaete originally isolated from pigs or human beings. A virulent strain of Serpulina hyodysenteriae (WA 15) colonized chicks, causing retarded growth rate and histological changes, including caecal atrophy, epithelial and goblet cell hyperplasia, and crypt elongation. A further strain of S. hyodysenteriae (SA3), which was apparently avirulent for pigs, and a strain of Serpulina intermedia (889) colonized fewer chicks, caused less severe lesions and did not significantly depress growth rate. Strains of Serpulina murdochii and Brachyspira aalborgi failed to colonize or cause histological changes. Four strains of Serpulina pilosicoli (Kar, Rosie-2299 and GAP 401, isolated from human beings, and 3295, isolated from a pig) colonized chicks, and large numbers showed polar attachment to the caecal epithelium; all strains, apart from Rosie-2299, caused watery diarrhoea and wet litter, but did not significantly retard growth. Variation both in the degree of spirochaetal attachment and the resulting development of lesions was observed between S. pilosicoli strains as well as between individual chicks infected with the same strain. The study indicated that chicks may be useful in studying the pathogenicity of strains of S. hyodysenteriae, S. intermedia and S. pilosicoli.

Between January 1992 and December 1996, Serpulina-like bacteria were demonstrated in intestinal tract lesions from 37 of 88 guinea pigs submitted to the University of Ghent in Ghent, Belgium, for necropsy because of disease and death from different unknown causes. All infected animals had a history of sudden death with minimal introductory clinical signs. Occasionally, they produced yellow, slimy feces or showed nervous signs, but the condition always had a fatal outcome within 24 h. When larger colonies of guinea pigs were involved, the disease spread very rapidly unless treatment with ronidazole was initiated. Lesions consisted of a catarrhal or hemorrhagic inflammation of the colon and cecum (typhlitis). Electron microscopy demonstrated the presence of large numbers of Serpulina-like organisms adhering to the cecal mucosae of these animals. Attempts to isolate the agents failed. The organisms did not stain by an immunofluorescence technique for the detection of Serpulina hyodysenteriae. The present data provide evidence that intestinal Serpulina-like organisms can be important as a cause of disease in guinea pigs.