Emphysematous pyometra and emphysematous hepatitis caused by Klebsiella pneumoniae infection in a diabetic dog.

A 14-year-old intact female diabetic dog presented with seizures and hyperglycemic hyperosmolar syndrome. Radiographs revealed gas-filled tubular structures in the right and left caudal abdomen, raising concerns of emphysematous pyometra or small intestinal ileus. Ultrasonography played a pivotal role in confirming emphysematous pyometra, a technique previously documented only once in veterinary practice. This report also presents the first documented case of emphysematous pyometra in a diabetic dog attributed to Klebsiella pneumoniae and complicated by emphysematous hepatitis.

Opposing role of tumor necrosis factor receptor 1 signaling in T cell-mediated hepatitis and bacterial infection in mice.

UNLABELLED: Death receptor (DR) ligands such as tumor necrosis factor (TNF) have been identified as fundamental mediators of liver damage both in mouse models and in humans. While the essential site of function of DR signaling is conceivably the hepatocyte, a systematic analysis is missing. Using mice with conditional gene ablation, we analyzed the tissue-specific function of DR signaling in T cell-dependent (concanavalin A) and independent (lipopolysaccharide/galactosamine) hepatitis and in models of bacterial infection (Listeria monocytogenes, lipopolysaccharide). We report that lipopolysaccharide/galactosamine-induced liver injury depends on hepatocyte-intrinsic TNF receptor 1 (p55, TNFR1). In contrast, we show that T cell-induced hepatitis was independent of TNFR1 signaling in hepatocytes, T cells, or endothelial cells. Moreover, T cell-induced hepatitis was independent of hepatocyte-intrinsic Fas-associated protein with death domain, TNF-related apoptosis-inducing ligand receptor, or Fas signaling. Instead, concanavalin A-induced hepatitis was completely prevented in mice with myeloid-derived cell (MDC)-specific deletion of TNFR1. Significantly, however, mice lacking TNFR1 in MDCs succumbed to listeria infection, although they displayed similar sensitivity toward endotoxin-induced septic shock when compared to control mice. These results suggest that TNFR1 signaling in MDCs is a critical mediator of both the detrimental and the protective functions of TNF in T cell-induced hepatitis and bacterial infection, respectively. CONCLUSION: The critical site of action of DRs is completely dependent on the nature of hepatitis; the data specify MDCs as the essential cell type of TNFR1 function in T cell-mediated hepatitis and in the response to listeria, thereby identifying the opposing role of MDC TNFR1 in autoimmunity and bacterial infection. (Hepatology 2016;64:508-521).

Necrotizing hepatitis associated with Clostridium novyi in a pony in western Canada.

Severe icterus, peritoneal effusion, localized fibrinous peritonitis, and necrotizing hepatitis were found at necropsy of a 20-year-old female pony with a history of acute onset depression, inappetence, fever, and marked elevation in hepatic enzymes. Gross pathology, histopathology, and immunohistochemistry were compatible with a diagnosis of clostridial hepatitis caused by Clostridium novyi-group bacteria. This is believed to be the first reported case of clostridial hepatitis in an equid in Canada, and only the third report of this rare disease in North America.

Hépatite nécrosante associée àClostridium novyichez un poney de l'Ouest canadien. Un ictère grave, une effusion péritonéale, une péritonite fibrineuse localisée et une hépatite nécrosante ont été constatées chez un poney femelle âgé de 20 ans avec une anamnèse d'apparition soudaine de dépression, d'inappétence, de fièvre et d'élévations marquées des enzymes hépatiques. La pathologie clinique, l'histopathologie et l'immunohistochimie étaient compatibles avec un diagnostic d'hépatite clostridiale causée par une bactérie du groupe Clostridium novyi. On croit qu'il s'agit du premier cas signalé d'hépatite clostridiale chez un équidé au Canada et seulement le troisième rapport de cette maladie rare en Amérique du Nord.(Traduit par Isabelle Vallières).

Tyzzer's disease in foals: retrospective studies from 1969 to 2010.

Reports of 148 cases of Tyzzer's disease in foals in central Kentucky were analyzed to identify features of the disease and factors associated with it. The records indicate that Tyzzer's disease is a rapidly progressive, highly fatal hepatitis caused by Clostridium piliforme. Common clinical findings are lethargy, fever, anorexia, and icterus. Seizures, coma, and death may rapidly ensue. Laboratory findings are leukopenia, metabolic acidosis, hypoglycemia, and increased activity of hepatic enzymes. Diagnosis is primarily based on clinical signs and postmortem findings but a polymerase chain reaction (PCR) is now available to detect C. piliforme DNA in organs and feces. Disease occurred most frequently in foals between 9 and 30 days of age that were born in April to May and was associated with heavy rainfall in the spring and high protein and nitrogenous diets fed to nursing mares. The findings are consistent with the ingestion of C. piliforme in the feces of adult horses and overgrowth in the intestine of foals with a high level of nutrients in their intestine.

Maladie de Tyzzer chez les poulains : études rétrospectives de 1969 à 2010. Des rapports de 148 cas de la maladie de Tyzzer chez les poulains dans le centre du Kentucky ont été analysés pour identifier les caractéristiques de la maladie et les facteurs qui y sont associés. Les dossiers indiquent que la maladie de Tyzzer est une hépatite rapidement progressive et hautement mortelle causée par Clostridium piliforme. Les résultats cliniques fréquents sont la léthargie, la fièvre, l'anorexie et l'ictère. Des crises d'épilepsie, le coma et la mort peuvent rapidement survenir. Les résultats de laboratoire sont la leucopénie, l'acidose métabolique, l'hypoglycémie et une activité accrue des enzymes hépatiques. Le diagnostic se base principalement sur les signes cliniques et les résultats post mortem, mais une réaction d'amplification en chaîne par la polymérase (ACP) est maintenant disponible pour détecter l'ADN de C. piliforme dans les organes et les fèces. La maladie se produit le plus fréquemment chez les poulains âgés d'entre 9 et 30 jours qui sont nés en avril et en mai et elle a été associée à des pluies abondantes au printemps et à des diètes à teneur élevée en protéines et en azote données aux juments allaitantes. Les résultats sont conformes avec l'ingestion de C. piliforme dans les fèces des chevaux adultes et à la prolifération dans l'intestin des poulains ayant un niveau élevé de nutriments dans leur intestin.(Traduit par Isabelle Vallières).

Chromobacterium pathogenicity island 1 type III secretion system is a major virulence determinant for Chromobacterium violaceum-induced cell death in hepatocytes.

Chromobacterium violaceum is a Gram-negative bacterium that causes fatal septicaemia in humans and animals. C. violaceum ATCC 12472 possesses genes associated with two distinct type III secretion systems (T3SSs). One of these systems is encoded by Chromobacterium pathogenicity islands 1 and 1a (Cpi-1/-1a), another is encoded by Chromobacterium pathogenicity island 2 (Cpi-2). Here we show that C. violaceum causes fulminant hepatitis in a mouse infection model, and Cpi-1/-1a-encoded T3SS is required for its virulence. In addition, using C. violaceum strains with defined mutations in the genes that encode the Cpi-1/-1a or Cpi-2 locus in combination with cultured mammalian cell lines, we found that C. violaceum is able to induce cytotoxicity in a Cpi-1/-1a-dependent manner. Characterization of Chromobacterium-induced cytotoxicity revealed that cell lysis by C. violaceum infection involves the formation of pore structures on the host cell membrane, as demonstrated by protection by cytotoxicity in the presence of osmoprotectants. Finally, we demonstrated that CipB, a Cpi-1/-1a effector, is implicated in translocator-mediated pore formation and the ability of CipB to form a pore is essential for Chromobacterium-induced cytotoxicity. These results strongly suggest that Cpi-1/-1a-encoded T3SS is a virulence determinant that causes fatal infection by the induction of cell death in hepatocytes.

Detection of extended-spectrum-beta-lactamase-positive Escherichia coli in bile isolates from two dogs with bacterial cholangiohepatitis.

This is the first report of Escherichia coli isolates producing CTX-M-15, the predominant type of extended-spectrum ß-lactamase (ESBL) associated with clinical disease in humans in the United Kingdom, in a United Kingdom pet dog. This report also describes the first isolation of CTX-M/Tem ESBL-positive E. coli from bile in dogs with hepatobiliary disease.

Stenotrophomonas maltophilia as a causal agent of pyogranulomatous hepatitis in a buffalo (Bubalus bubalis).

A 7-year-old female buffalo (Bubalus bubalis) from a local herd in Serres, northern Greece, was presented to a private veterinary clinic with a chronic loss of appetite for 15 days. The clinical examination revealed high fever (41.5 degrees C), lethargy, yellow discoloration of skin and mucous membranes, an abdomen that appeared to be empty, hyperactive rumen motility, and tachypnea. A biochemical profile revealed an elevated total bilirubin concentration and hepatic enzyme activities, whereas globulin, creatinine, and glucose concentrations were within the reference intervals. The animal received a 12-day course of treatment with intramuscular administration of ampicillin and corticosteroids. However, no significant clinical improvement was achieved, and the buffalo was euthanized. Gross necropsy lesions included serous atrophy of adipose tissue and hepatomegaly. Microscopic lesions included necrotizing pyogranulomatous hepatitis with thrombosis, hemorrhages, edema, and fibrosis. Small, nonpigmented, bacterial colonies were harvested in pure culture from the liver and were confirmed as Stenotrophomonas maltophilia by polymerase chain reaction. The bacterium was sensitive to ciprofloxacin, enrofloxacin, colistin, polymyxin, trimethoprim/sulfamethaxazole, and chloramphenicol. In contrast, resistance to ticarcillin, piperacillin, imipenem, ceftazidime, amikacin, gentamicin, tobramycin, and tetracycline was displayed. The bacterial strain carried the L1 metallo-beta-lactamase (L1) and tet35 genes, which contribute to high-level resistance to beta-lactams and tetracycline, respectively. Although S. maltophilia is widely believed to be a contaminant, the present report suggests that the isolation, identification, and susceptibility testing of this multidrug-resistant bacterium may be of clinical importance in diagnostic samples.

Pathobiology and diagnosis of clostridial hepatitis in animals.

Clostridia can cause hepatic damage in domestic livestock, and wild and laboratory animals. Clostridium novyi type B causes infectious necrotic hepatitis (INH) in sheep and less frequently in other species. Spores of C. novyi type B can be present in soil; after ingestion, they reach the liver via portal circulation where they persist in phagocytic cells. Following liver damage, frequently caused by migrating parasites, local anaerobic conditions allow germination of the clostridial spores and production of toxins. C. novyi type B alpha toxin causes necrotizing hepatitis and extensive edema, congestion, and hemorrhage in multiple organs. Clostridium haemolyticum causes bacillary hemoglobinuria (BH) in cattle, sheep, and rarely, horses. Beta toxin is the main virulence factor of C. haemolyticum, causing hepatic necrosis and hemolysis. Clostridium piliforme, the causal agent of Tyzzer disease (TD), is the only gram-negative and obligate intracellular pathogenic clostridia. TD occurs in multiple species, but it is more frequent in foals, lagomorphs, and laboratory animals. The mode of transmission is fecal-oral, with ingestion of spores from a fecal-contaminated environment. In affected animals, C. piliforme proliferates in the intestinal mucosa, resulting in necrosis, and then disseminates to the liver and other organs. Virulence factors for this microorganism have not been identified, to date. Given the peracute or acute nature of clostridial hepatitis in animals, treatment is rarely effective. However, INH and BH can be prevented, and should be controlled by vaccination and control of liver flukes. To date, no vaccine is available to prevent TD.

Experimental acute respiratory Burkholderia pseudomallei infection in BALB/c mice.

Burkholderia pseudomallei is the causative agent of melioidosis, which is considered a potential deliberate release agent. The objective of this study was to establish and characterise a relevant, acute respiratory Burkholderia pseudomallei infection in BALB/c mice. Mice were infected with 100 B. pseudomallei strain BRI bacteria by the aerosol route (approximately 20 median lethal doses). Bacterial counts within lung, liver, spleen, brain, kidney and blood over 5 days were determined and histopathological and immunocytochemical profiles were assessed. Bacterial numbers in the lungs reached approximately 10(8) cfu/ml at day 5 post-infection. Bacterial numbers in other tissues were lower, reaching between 10(3) and 10(5) cfu/ml at day 4. Blood counts remained relatively constant at approximately 1.0 x 10(2) cfu/ml. Foci of acute inflammation and necrosis were seen within lungs, liver and spleen. These results suggest that the BALB/c mouse is highly susceptible to B. pseudomallei by the aerosol route and represents a relevant model system of acute human melioidosis.

Extrapulmonary disorders associated with Rhodococcus equi infection in foals: 150 cases (1987-2007).

OBJECTIVE: To describe frequency, types, and clinical outcomes of extrapulmonary disorders (EPDs) in foals in which Rhodococcus equi infection was diagnosed, and to identify factors determined at the time of admission that differentiated foals that developed EPDs from foals with R equi infection identified only in the lungs. DESIGN: Retrospective case series. ANIMALS: 150 foals aged 3 weeks to 6 months with a diagnosis of R equi infection. PROCEDURES: Medical records were reviewed for information on date of admission, signalment, history, clinical signs, diagnostic testing, treatment, duration of hospitalization, invoice, and outcome. For each EPD identified, further information was collected on the identification, location, treatment, and outcome of the lesion. RESULTS: Of 150 foals with R equi infections, 111 (74%) had at least 1 of 39 EPDs. Survival was significantly higher among foals without EPDs (32/39 [82%]) than among foals with EPDs (48/111 [43%]), but many EPDs were only recognized after death. Risk factors significantly associated with EPDs included referral status, duration of clinical signs prior to admission, leukocytosis, and neutrophilia. Foals with EPDs also had a higher heart rate and BUN concentration than foals without. CONCLUSIONS AND CLINICAL RELEVANCE: Practitioners should recognize that extrapulmonary manifestations of R equi occur with high prevalence affecting diverse organ systems, that multiple systems are generally affected when EPDs occur, and that suspicion of R equi infection should prompt evaluation and monitoring of extrapulmonary sites. Improved recognition of the presence of these disorders will help practitioners to better advise their clients in the treatment and outcome of foals with R equi infections.

Outbreak of tuberculosis caused by Mycobacterium bovis in golden Guernsey goats in Great Britain.

An outbreak of caprine tuberculosis caused by Mycobacterium bovis was disclosed in June 2008, affecting goats of the golden Guernsey breed kept on 10 separate smallholdings in south-west Wales and the west of England. Following the initial diagnosis at postmortem examination, 30 goats that reacted positively to the single intradermal comparative cervical tuberculin (SICCT) test, together with five in-contact animals, were euthanased and subjected to postmortem examination and mycobacterial culture. Spoligotyping and variable number tandem repeat analysis of isolates showed that they were all of the same genotype, endemic to south-west Wales. Retrospective movement tracings identified a goat herd in south-west Wales, by then completely dispersed, as the probable common source of infection. There was a perfect correlation between the SICCT test and culture results in all slaughtered goats. Grossly visible tubercular lesions were observed at postmortem examination in all but one reactor.

Systemic listeriosis in caged canaries (Serinus canarius).

The occurrence of listeriosis in 12 caged canaries is described where 50% of the birds, including the female and all of the offspring, died within 2 weeks without clinical signs. At necropsy, multifocal necrotizing and partly granulomatous hepatitis, splenitis, myocarditis, interstitial nephritis, and exudative pericarditis with intra-lesional Listeria monocytogenes were the predominant findings as shown by histopathology and immunohistochemistry. Microbiology, serology and polymerase chain reaction revealed L. monocytogenes serotype 1/2a as the causative agent. Thus listeriosis has to be considered in the differential diagnosis for granulomas associated with mycobacteriosis, yersiniosis, coligranulomatosis or fungal infections.

Multifocal granulomatous hepatitis caused by Actinobacillus pleuropneumoniae serotype 2 in slaughter pigs.

In a survey of 66 894 slaughter pigs, 11 animals from three farms were found to have multifocal granulomatous lesions in the liver, caused by Actinobacillus pleuropneumoniae serotype 2. The lesions consisted of epithelioid cells and multinucleated giant cells, with asteroid bodies and discernible gram-negative bacteria. Lymph nodes and spleen were occasionally affected. The results suggested that haematogenous spread had occurred from pre-existing pulmonary infections.

An outbreak of chlamydiosis in farmed Indopacific crocodiles (Crocodylus porosus).

An outbreak of chlamydiosis was diagnosed in hatchling and juvenile Indopacific crocodiles (Crocodylus porosus) on a crocodile farm in Papua New Guinea. The outbreak was characterised by high mortality with hepatitis and exudative conjunctivitis. The agent appears to have been introduced with live wild-caught crocodiles, which are purchased routinely by the farm. Improved quarantine procedures and treatment with tetracycline led to a rapid reduction of losses on the farm.

Canine Hepatitis Associated with Intrahepatic Bacteria in Three Dogs.

This case report describes the detection of intrahepatic bacteria in formalin-fixed paraffin-embedded histopathological sections from three dogs with neutrophilic, pyogranulomatous, or lymphoplasmacytic hepatitis and cholangiohepatitis. In each of these cases, eubacterial fluorescence in situ hybridization enabled colocalization of intrahepatic bacteria with neutrophilic and granulomatous inflammation in samples that were negative for bacteria when evaluated by routine hematoxylin and eosin histopathology augmented with histochemical stains. Positive responses to antimicrobial therapy were observed in of 2 out of 2 patients that were treated with antimicrobials. These findings suggest that eubacterial fluorescence in situ hybridization analysis of formalin-fixed paraffin-embedded histopathological sections is more sensitive than conventional histochemical stains for the diagnosis of bacteria-associated canine hepatitis.

Infectious necrotic hepatitis caused by Clostridium novyi type B in a horse: case report and review of the literature.

A 14-y-old bay Quarter Horse gelding was presented with progressive neurologic signs, elevated rectal temperature, and icterus for 3 d prior to death. Postmortem examination revealed icterus, large amounts of serosanguineous fluid in the abdominal cavity, widespread petechiae and ecchymoses in several organs, and a large, pale, and well-demarcated focus of necrosis in the liver. Histologically, there was coagulative necrosis surrounded by a rim of inflammatory cells and large numbers of gram-positive rods, which were identified as Clostridium novyi by immunohistochemistry. Liver samples tested by PCR were positive for C. novyi type B flagellin and alpha toxin genes, but negative for Clostridium haemolyticum and other clostridia. Based on postmortem findings and ancillary tests, a definitive diagnosis of infectious necrotic hepatitis (INH) was made. Mostly a disease of ruminants, also known as black disease, INH has rarely been reported in horses, and a definitive etiologic diagnosis has not been achieved previously; the etiology of all cases reported to date was identified as C. novyi but the type was not determined. Animals are predisposed to clostridial hepatitis when hepatic anaerobiosis is established. Such conditions allow germination and proliferation of bacterial spores, resulting in production and release of toxins. INH, caused by C. novyi type B, and bacillary hemoglobinuria, caused by C. haemolyticum, are mechanistically and pathologically almost indistinguishable. Because these 2 microorganisms are closely related, differentiation requires molecular tools.

Cholangitis and Cholangiohepatitis in Dogs: A Descriptive Study of 54 Cases Based on Histopathologic Diagnosis (2004-2014).

BACKGROUND: Cholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete. OBJECTIVE: To describe a population of dogs with cholangitis or cholangiohepatitis. ANIMALS: Fifty-four client-owned dogs with cholangitis or cholangiohepatitis. METHODS: Medical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer-based search and retrospectively reviewed. RESULTS: Clinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114-1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0-4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9-13.2) compared to younger dogs. CONCLUSIONS AND CLINICAL SIGNIFICANCE: Chronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.

Insights into leghorn male hepatocellular cells response to fowl adenovirus serotype 4 infection by transcriptome analysis.

Fowl adenovirus serotype 4 (FAdV-4), a member of the Aviadenovirus genus of the Adenoviridae family, causes hepatitis-hydropericardium syndrome (HHS) in chickens. It causes mortality of up to 80% in 3-6-week-old broilers, posing a substantial threat to the poultry industry. However, the specific host responses to the virus are not well understood. To better understand the interactions between the host and FAdV-4 and to explore the pathogenesis of this virus, a high-throughput RNA-seq technology was utilized with leghorn male hepatocellular (LMH) cells at 12, 24, and 48 h after FAdV-4 infection. We identified a total of 7000 differentially expressed genes (DEGs), which were enriched in a variety of biological processes and pathways using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Several immune related pathways, including Toll-like receptor (TLR) signaling pathway and cytokine-cytokine receptor interaction pathway, were activated after the FAdV-4 infection. The transcriptional data were validated by quantitative real-time PCR. The expression profiles of 10 genes involved in FAdV-4-infected chicken livers, including TLR2A, TLR3, TLR5, MyD88, IL12B, IL15, IL18, CCL20, TNFRSF21, and CD30, were consistent with RNA-seq profiles. By transfecting small interfering RNA into LMH cells, our results confirmed that MyD88 mediated FAdV-4-induced inflammation. To our knowledge, this was the first study to use transcriptome analysis to investigate host responses to FAdV-4 infection. These findings provide insights into the mechanisms of FAdV-4 pathogenesis and host-FAdV-4 interaction.

Critical roles of TRAIL in hepatic cell death and hepatic inflammation.

The TNF-related apoptosis-inducing ligand (TRAIL) induces apoptosis of tumor cells but not most normal cells. Its role in hepatic cell death and hepatic diseases is not clear. In vitro studies suggest that murine hepatocytes are not sensitive to TRAIL-induced apoptosis, indicating that TRAIL may not mediate hepatic cell death. Using two experimental models of hepatitis, we found that hepatic cell death in vivo was dramatically reduced in TRAIL-deficient mice and mice treated with a blocking TRAIL receptor. Although both TRAIL and its death receptor 5 were constitutively expressed in the liver, TRAIL expression by immune cells alone was sufficient to restore the sensitivity of TRAIL-deficient mice to hepatitis. Thus, TRAIL plays a crucial role in hepatic cell death and hepatic inflammation.