[Clinical features and prognosis of hepatosplenic candidiasis in patients with hematopathy].

Hepatosplenic candidiasis (HSC) is a rare type of candidiasis that can occur in patients with hematologic malignancies, hematopoietic stem cell transplantation. At present, there is still a lack of studies on HSC in patients with hematologic disorders. Based on The Chinese Guidelines for the Diagnosis and Treatment of Invasive Fungal Disease in Patients with Hematological Disorders and Cancers (the 6th revision), We retrospectively analyzed the clinical characteristics and prognosis of patients with HSC treated in Peking University Institute of Hematology from 2008 to 2022. Finally, eighteen patients were included, with 1 (5.6%) proven, 2 (11.1%) probable, and 15 (83.3%) possible HSC. Among them, 3 (16.7%) patients occurred after haploid hematopoietic stem cell transplantation and 15 (83.3%) patients occurred after chemotherapy. 6 (33.3%) patients had positive blood cultures, including 4 cases of Candida tropicalis and 2 cases of Candida albicans. At 4 weeks of antifungal therapy, 10 (58.8%) patients achieved partial response (PR), At 8 weeks, 1 (6.3%) patients achieved complete response and 10 (62.5%) patients achieved PR. At 6 months after diagnosis, 3 (16.7%) patients died of hematopoietic recurrence, and none of them died of HSC. As a rare fungal infection disease, HSC has a low positive rate of microbiological and histological examinations, a persistent treat cycle, and has difficulty in remission, reminding us of the need for vigilance in patients with hematopoietic disorders and persistent fever.

Therapeutic potential of rifaximin in liver diseases.

Rifaximin, derived from rifamycin, is a broad-spectrum antibiotic by inhibiting bacterial RNA synthesis. Rifaximin has a very low intestinal absorption and exerts its antimicrobial activity primarily in the intestinal tract. It regulates the gut microbiota with limited side effects systemically. Rifaximin has been recommended for the treatment of hepatic encephalopathy but some studies shed light on its medicinal effects in many other diseases. For instance, rifaximin may suppress the progression of liver fibrosis and its related complications, and ameliorate metabolic dysfunction-associated steatotic liver disease and alcohol-associated liver disease, etc. Rifaximin can also mediate anti-inflammation, antiproliferation, and proapoptotic events by activating pregnane X receptor, which is efficious in cancers such as colon cancer. In addition, some investigations have shown rifaximin may play a therapeutic role in various autoimmune and neurological disorders. However, these findings still need more real-world practices and in-depth investigations to obtain more precise indications and fully elucidate the multifaceted potentials of rifaximin.

The potential role of Akkermansia muciniphila in liver health.

Akkermansia muciniphila (A. muciniphila) is a 'star strain' that has attracted much attention in recent years. A. muciniphila can effectively regulate host metabolism, significantly affect host immune function, and play an important role in balancing host health and disease. As one of the organs most closely related to the gut (the two can communicate through the hepatic portal vein and bile duct system), liver is widely affected by intestinal microorganisms. A growing body of evidence suggests that A. muciniphila may alleviate liver-related diseases by improving the intestinal barrier, energy metabolism and regulating inflammation through its protein components and metabolites. This paper systematically reviews the key roles of A. muciniphila and its derivatives in maintaining liver health and improving liver disease.

[Box: see text].

Gut mycobiome alterations and implications for liver diseases.

Chronic liver disease and its complications are a significant global health burden. Changes in fungal communities (mycobiome), an integral component of the gut microbiome, are associated with and contribute to the development of liver disease. Fungal dysbiosis can induce intestinal barrier dysfunction and allow fungal products to translocate to the liver causing progression of disease. This review explores recent progress in understanding the compositional and functional diversity of gut mycobiome signatures across different liver diseases. It delves into causative connections between gut fungi and liver diseases. We emphasize the significance of fungal translocation, with a particular focus on fungal-derived metabolites and immune cells induced by fungi, as key contributors to liver disease. Furthermore, we review the potential impact of the intrahepatic mycobiome on the progression of liver diseases.

The gut microbiota-bile acid axis in cholestatic liver disease.

Cholestatic liver diseases (CLD) are characterized by impaired normal bile flow, culminating in excessive accumulation of toxic bile acids. The majority of patients with CLD ultimately progress to liver cirrhosis and hepatic failure, necessitating liver transplantation due to the lack of effective treatment. Recent investigations have underscored the pivotal role of the gut microbiota-bile acid axis in the progression of hepatic fibrosis via various pathways. The obstruction of bile drainage can induce gut microbiota dysbiosis and disrupt the intestinal mucosal barrier, leading to bacteria translocation. The microbial translocation activates the immune response and promotes liver fibrosis progression. The identification of therapeutic targets for modulating the gut microbiota-bile acid axis represents a promising strategy to ameliorate or perhaps reverse liver fibrosis in CLD. This review focuses on the mechanisms in the gut microbiota-bile acids axis in CLD and highlights potential therapeutic targets, aiming to lay a foundation for innovative treatment approaches.

A microbial-derived succinylated bile acid to safeguard liver health.

In this issue of Cell, Nie and co-authors report that the microbe-derived bile acid (BA) 3-succinylated cholic acid protects against the progression of metabolic dysfunction-associated liver disease. Intriguingly, its protective mechanism does not involve traditional BA signaling pathways but is instead linked to the proliferation of the commensal microbe Akkermansia muciniphila.

Microbiota and Gut-Liver Axis: An Unbreakable Bond?

The gut microbiota, amounting to approximately 100 trillion (1014) microbes represents a genetic repertoire that is bigger than the human genome itself. Evidence on bidirectional interplay between human and microbial genes is mounting. Microbiota probably play vital roles in diverse aspects of normal human metabolism, such as digestion, immune modulation, and gut endocrine function, as well as in the genesis and progression of many human diseases. Indeed, the gut microbiota has been most closely linked to various chronic ailments affecting the liver, although concrete scientific data are sparse. In this narrative review, we initially discuss the basic epidemiology of gut microbiota and the factors influencing their initial formation in the gut. Subsequently, we delve into the gut-liver axis and the evidence regarding the link between gut microbiota and the genesis or progression of various liver diseases. Finally, we summarise the recent research on plausible ways to modulate the gut microbiota to alter the natural history of liver disease.

The Progression of Microbiome Therapeutics for the Management of Gastrointestinal Diseases and Beyond.

There has been an increased ability to investigate the human microbiota through next-generation sequencing and functional assessment. This advancement has rapidly expanded our ability to study and manipulate the gastrointestinal microbiome to mitigate disease. Fecal microbiota transplantation, a therapy that broadly transfers the entire intestinal ecosystem, has been explored as a potential therapeutic in a variety of gastrointestinal, hepatic, and extraintestinal conditions. The field, however, continues to evolve, with a movement toward precision microbiome therapeutics, individualizing care for various disorders. This review will describe the use of fecal microbiota transplantation, microbiota restoration, and precision microbiome therapeutics, focusing on gastrointestinal and hepatic diseases.

Polygonatum kingianum Polysaccharides Enhance the Preventive Efficacy of Heat-Inactivated Limosilactobacillus reuteri WX-94 against High-Fat-High-Sucrose-Induced Liver Injury and Gut Dysbacteriosis.

Limosilactobacillus reuteri (L. reuteri) is an efficacious probiotic that could reduce inflammation and prevent metabolic disorders. Here, we innovatively found that Polygonatum kingianum polysaccharides (PKP) promoted proliferation and increased stability of L. reuteri WX-94 (a probiotic strain showing anti-inflammation potentials) in simulated digestive fluids in vitro. PKP was composed of galactose, glucose, mannose, and arabinose. The cell-free supernatant extracted from L. reuteri cultured with PKP increased ABTS•+, DPPH•, and FRAP scavenging capacities compared with the supernatant of the medium without PKP and increased metabolites with health-promoting activities, e.g., 3-phenyllactic acid, indole-3-lactic acid, indole-3-carbinol, and propionic acid. Moreover, PKP enhanced alleviating effects of heat-inactivated L. reuteri on high-fat-high-sucrose-induced liver injury in rats via reducing inflammation and regulating expressions of protein and genes involved in fatty acid metabolism (such as HIF1-α, FAßO, CPT1, and AMPK) and fatty acid profiles in liver. Such benefits correlated with its prominent effects on enriching Lactobacillus and short-chain fatty acids while reducing Dubosiella, Fusicatenilacter, Helicobacter, and Oscillospira. Our work provides novel insights into the probiotic property of PKP and emphasizes the great potential of the inactivated L. reuteri cultured with PKP in contracting unhealthy diet-induced liver dysfunctions and gut dysbacteriosis.

A rare case report of liver masses caused by Actinomyces species.

Actinomycosis is a rare infection caused by Actinomyces spp. Of all actinomycosis infections, only 5% of Hepatic Actinomycosis (HA) infection has been reported. This disease is often misdiagnosed as a malignancy. This case report presents a 45-year-old woman with diabetes, initially suspected of intrahepatic cholangiocarcinoma, but after careful tissue staining, we found the results supported HA infection.

Alterations in the fecal microbiota in patients with advanced cystic fibrosis liver disease after 6 months of elexacaftor/tezacaftor/ivacaftor.

BACKGROUND: Cystic fibrosis associated liver disease (CFLD) carries a significant disease burden with no effective preventive therapies. According to the gut-liver axis hypothesis for CFLD pathogenesis, dysbiosis and increased intestinal inflammation and permeability permit pathogenic bacterial translocation into the portal circulation, leading to hepatic inflammation and fibrosis. Evaluating the effect of CFTR (cystic fibrosis transmembrane conductance regulator) modulation with elexacaftor/tezacaftor/ivacaftor (ETI) may help determine the role of CFTR in CFLD and increase understanding of CFLD pathogenesis, which is critical for developing therapies. We aimed to characterize the fecal microbiota in participants with CF with and without advanced CFLD (aCFLD) before and after ETI. METHODS: This is an ancillary analysis of stool samples from participants ages ≥12 y/o enrolled in PROMISE (NCT04038047). Included participants had aCFLD (cirrhosis with or without portal hypertension, or non-cirrhotic portal hypertension) or CF without liver disease (CFnoLD). Fecal microbiota were defined by shotgun metagenomic sequencing at baseline and 1 and 6 months post-ETI. RESULTS: We analyzed 93 samples from 34 participants (11 aCFLD and 23 CFnoLD). Compared to CFnoLD, aCFLD had significantly higher baseline relative abundances of potential pathogens Streptococcus salivarius and Veillonella parvula. Four of 11 aCFLD participants had an initially abnormal fecal calprotectin that normalized 6 months post-ETI, correlating with a significant decrease in S. salivarius and a trend towards decreasing V. parvula. CONCLUSIONS: These results support an association between dysbiosis and intestinal inflammation in CFLD with improvements in both post-ETI, lending further support to the gut-liver axis in aCFLD.

Prominent role of gut dysbiosis in the pathogenesis of cystic fibrosis-related liver disease in mice.

BACKGROUND & AIMS: Cystic fibrosis-related liver disease (CFLD) is a chronic cholangiopathy that increases morbidity and mortality in patients with CF. Current treatments are unsatisfactory, and incomplete understanding of CFLD pathogenesis hampers therapeutic development. We have previously shown that mouse CF cholangiocytes respond to lipopolysaccharide with excessive inflammation. Thus, we investigated the role of the gut-liver axis in the pathogenesis of CFLD. METHODS: Wild-type (WT), whole-body Cftr knockout (CFTR-KO) and gut-corrected (CFTR-KO-GC) mice were studied. Liver changes were assessed by immunohistochemistry and single-cell transcriptomics (single-cell RNA sequencing), inflammatory mediators were analysed by proteome array, faecal microbiota by 16S ribosomal RNA sequencing and gut permeability by FITC-dextran assay. RESULTS: The livers of CFTR-KO mice showed ductular proliferation and periportal inflammation, whereas livers of CFTR-KO-GC mice had no evident pathology. Single-cell RNA sequencing analysis of periportal cells showed increased presence of neutrophils, macrophages and T cells, and activation of pro-inflammatory and pathogen-mediated immune pathways in CFTR-KO livers, consistent with a response to gut-derived stimuli. CFTR-KO mice exhibited gut dysbiosis with enrichment of Enterobacteriaceae and Enterococcus spp., which was associated with increased intestinal permeability and mucosal inflammation, whereas gut dysbiosis and inflammation were absent in CFTR-KO-GC mice. Treatment with nonabsorbable antibiotics ameliorated intestinal permeability and liver inflammation in CFTR-KO mice. Faecal microbiota transfer from CFTR-KO to germ-free WT mice did not result in dysbiosis nor liver pathology, indicating that defective intestinal CFTR is required to maintain dysbiosis. CONCLUSION: Defective CFTR in the gut sustains a pathogenic microbiota, creates an inflammatory milieu, and alters intestinal permeability. These changes are necessary for the development of cholangiopathy. Restoring CFTR in the intestine or modulating the microbiota could be a promising strategy to prevent or attenuate liver disease. IMPACT AND IMPLICATIONS: Severe cystic fibrosis-related liver disease (CFLD) affects 10% of patients with cystic fibrosis (CF) and contributes to increased morbidity and mortality. Treatment options remain limited due to a lack of understanding of disease pathophysiology. The cystic fibrosis transmembrane conductance regulator (CFTR) mediates Cl- and HCO3- secretion in the biliary epithelium and its defective function is thought to cause cholestasis and excessive inflammatory responses in CF. However, our study in Cftr-knockout mice demonstrates that microbial dysbiosis, combined with increased intestinal permeability caused by defective CFTR in the intestinal mucosa, acts as a necessary co-factor for the development of CFLD-like liver pathology in mice. These findings uncover a major role for the gut microbiota in CFLD pathogenesis and call for further investigation and clinical validation to develop targeted therapeutic strategies acting on the gut-liver axis in CF.

Longitudinal gut fungal alterations and potential fungal biomarkers for the progression of primary liver disease.

Liver disease, a major health concern worldwide, is a serious and progressive disorder. Herein, we not only established a mouse model of DEN+CCl4-induced primary liver disease but also collected clinical human samples to investigate longitudinal alterations in the gut mycobiome. As liver disease advanced, gut integrity was disrupted, and the mycobiota was disturbed in the mouse models. The metabolites associated with hepatocellular carcinoma (HCC) differed from those associated with the cirrhotic phase as follows: levels of stercobilin and aflatoxin B1 dialcohol were reduced, while levels of triterpenoids, bafilomycin A1, and DHEA were increased in the HCC group. The abundance of the phylum Chytridiomycota increased as the chronic liver disease progressed and was then replaced by the phylum Ascomycota in HCC. Based on the results from clinical human samples, the genus Candida (Ascomycota) (in humans) and the genus Kazachstania (Ascomycota) (in mice) occupied a dominant position in the HCC group, while other fungi were depleted. The increased abundance of C. albicans and depletion of S. cerevisiae may be hallmarks of the progression of liver cirrhosis to early HCC. Moreover, the administration of C. albicans and S. cerevisiae in the LC-HCC progression could accelerate or retard the progression of HCC. Therefore, gut fungi have the potential to serve as a noninvasive clinical biomarker and even a treatment method.

First Report of Campylobacter hepaticus Isolation in Laying Hens and Broiler Breeders with Spotty Liver Disease in Costa Rica.

Poultry producers in Costa Rica have informally reported a spotty liver disease-like syndrome for more than 20 yr. However, despite many attempts, the infectious agent responsible for this syndrome had not been identified. Therefore, following current knowledge of spotty liver disease diagnosis, we invited veterinarians and poultry producers to submit samples to the diagnostic laboratories of the Veterinary Medicine School, Universidad Nacional, to identify the infectious agent of this syndrome. Veterinarians and poultry producers were instructed to collect gallbladders and livers aseptically and send them for pathology examinations and bacterial cultures in less than 24 hr after collection. Samples were processed for standard histopathologic studies and cultured under aerophilic, anaerobic, and microaerophilic conditions. Campylobacter-like colonies were isolated and identified by biochemical and PCR tests. Here we report for the first time the isolation, biochemical characterization, and molecular confirmation of Campylobacter hepaticus in laying hens and broiler breeders with spotty liver disease in Costa Rica.

Nota de investigación- Primer reporte de aislamiento de Campylobacter hepaticus en gallinas de postura y reproductoras pesadas con necrosis hepática focal en Costa Rica. Los productores avícolas en Costa Rica han reportado extraoficialmente un síndrome similar a la necrosis hepática focal durante más de 20 años. Sin embargo, a pesar de muchos intentos, el agente infeccioso responsable de este síndrome no había sido identificado. Por ello, siguiendo los conocimientos actuales relacionados con la necrosis hepática focal, se invitó a los veterinarios y a los productores avícolas a enviar muestras a los laboratorios de diagnóstico de la Facultad de Medicina Veterinaria de la Universidad Nacional, para identificar el agente infeccioso de este síndrome. Se instruyó a los veterinarios y productores avícolas para recolectar vesículas biliares e hígados asépticamente y enviarlos para exámenes patológicos y para cultivos bacterianos en menos de 24 horas después de la recolección. Las muestras se procesaron para estudios histopatológicos estándar y se cultivaron en condiciones aerófilas, anaeróbicas y microaerófilas. Las colonias sugestivas de Campylobacter se aislaron e identificaron mediante pruebas bioquímicas y por PCR. Aquí se reporta por primera vez el aislamiento, caracterización bioquímica y confirmación molecular de Campylobacter hepaticus en gallinas de postura y reproductoras pesadas con la necrosis hepática focal en Costa Rica.

Campylobacter hepaticus in the Production Environment and Stagnant Water as a Potential Source of C. hepaticus Causing Spotty Liver Disease in Free-Range Laying Hens in Georgia, United States.

Spotty liver disease (SLD) has emerged as an important cause of disease in egg-producing flocks in countries such as the United Kingdom and Australia and has emerged in the United States. The organisms implicated in SLD include Campylobacter hepaticus and, more recently, Campylobacter bilis. These organisms have been found to cause focal lesions on the livers of infected birds. Campylobacter hepaticus infection results in reduced egg production, decreased feed consumption resulting in reduced egg size, and increased mortality of highly valuable hens. In the fall of 2021, birds from two flocks (A and B) of organic pasture-raised laying hens were submitted to the Poultry Diagnostic Research Center at the University of Georgia with a history suspicious of SLD. Postmortem examination of Flock A found 5/6 hens had small multifocal lesions on the liver and were PCR positive for C. hepaticus from pooled swab analysis of samples of the liver and gall bladder. Necropsy of Flock B found 6/7 submitted birds had spotty liver lesions. In pooled bile swabs, 2/7 hens from Flock B were also PCR positive for C. hepaticus. A follow-up visit to Flock A was scheduled 5 days later, as well as a visit to a flock where SLD has not been reported (Flock C), which was used as a comparative control. Samples of the liver, spleen, cecal tonsil, ceca, blood, and gall bladder were collected from six hens per house. Additionally, feed, water nipples, and environmental water (stagnant water outside the house) were collected from the affected farm and the control farm. To detect the organism, all samples collected were subjected to direct plating on blood agar and enrichment in Preston broth with incubation under microaerophilic conditions. After multiple phases of bacterial culture purification from all samples, single bacterial cultures displaying characteristics of C. hepaticus were tested by PCR to confirm identity. From Flock A, liver, ceca, cecal tonsils, gall bladder, and environmental water were PCR positive for C. hepaticus. No positive samples were detected in Flock C. After another follow-up visit, 10 wk later, Flock A was PCR positive for C. hepaticus from gall bladder bile and feces and one environmental water sample displayed a weak positive reaction for C. hepaticus. Flock C was PCR negative for C. hepaticus. To gain more knowledge about C. hepaticus prevalence, a survey of 6 layer hens from 12 different layer hen flocks between the ages of 7 to 80 wk, raised in different housing systems, were tested for C. hepaticus. The 12 layer hen flocks were culture and PCR negative for C. hepaticus. Currently, there are no approved treatments for C. hepaticus and no vaccine is available. The results of this study suggest that C. hepaticus may be endemic in some areas of the United States, and free-range laying hens may be exposed from the environment/stagnant water in areas where they range.

Campylobacter hepaticus en el ambiente de producción avícola y en el agua estancada como fuente potencial de C. hepaticus que causante de la necrosis hepática focal en gallinas ponedoras de corral en Georgia, Estados Unidos. La necrosis hepática focal (SLD, por sus siglas en inglés) se ha convertido en una causa importante de enfermedad en las parvadas productoras de huevo en países como el Reino Unido y Australia y también ha surgido en los Estados Unidos. Los organismos implicados en necrosis hepática focal incluyen Campylobacter hepaticus y, más recientemente, Campylobacter bilis. Se ha encontrado que estos organismos causan lesiones focales en el hígado de las aves infectadas. La infección por C. hepaticus da como resultado una reducción en la producción de huevos, una disminución en el consumo de alimento, lo que resulta en una reducción del tamaño de los huevos y una mayor mortalidad de gallinas de alto valor económico. En el otoño del 2021, aves de dos lotes (A y B) de gallinas de postura criadas en pastos orgánicos se enviaron al Centro de Diagnóstico e Investigación Avícolas de la Universidad de Georgia con antecedentes sospechosos de necrosis hepática focal. En el examen post mortem de la parvada A se encontró que cinco de un total de seis gallinas tenían pequeñas lesiones multifocales en el hígado y fueron positivas mediante PCR para C. hepaticus a partir de un análisis de hisopos combinados de muestras del hígado y de la vesícula biliar. La necropsia de la parvada B encontró que seis de un total de siete aves enviadas tenían lesiones hepáticas irregulares. En muestras agrupadas de bilis, dos de un total de siete gallinas de la parvada B también fueron positivas a C. hepaticus por PCR. Se programó una visita de seguimiento a la Parvada A cinco días después, así como una visita a una parvada en la que no se había reportado la presencia de necrosis hepática focal (Parvada C), que se utilizó como control para propósitos de comparación. Se recolectaron muestras de hígado, bazo, tonsilas cecales, sacos ciegos, sangre y vesícula biliar de seis gallinas por gallinero. Además, se recolectó alimento, muestras de agua de bebederos de niple y agua ambiental (agua estancada fuera de la casa) de la granja afectada y la granja de control. Para detectar el organismo, todas las muestras recolectadas se sometieron a siembra directa en agar sangre y enriquecimiento en caldo Preston con incubación en condiciones microaerófilas. Después de varias fases de purificación del cultivo bacteriano de todas las muestras, se analizaron mediante PCR los cultivos bacterianos individuales que mostraban características de C. hepaticus para confirmar la identidad. De la parvada A, el hígado, el ciego, las tonsilas cecales, la vesícula biliar y el agua ambiental dieron positivo por PCR para C. hepaticus. No se detectaron muestras positivas en la parvada C. Después una segunda visita de seguimiento, 10 semanas después, la parvada A mostró resultado positivo por PCR para C. hepaticus en la bilis de la vesícula biliar y en las heces, y una muestra de agua ambiental mostró una reacción positiva débil para C. hepaticus . La parvada C resultó negativa mediante PCR para C. hepaticus. Para obtener más conocimiento sobre la prevalencia de C. hepaticus, se realizó un muestreo incluyendo seis gallinas de postura de 12 lotes diferentes de gallinas ponedoras entre las edades de 7 a 80 semanas, criadas en diferentes sistemas de alojamiento, para detectar C. hepaticus. Las doce parvadas de gallinas de postura fueron negativas por cultivo y mediante PCR para C. hepaticus. Actualmente, no hay tratamientos aprobados para C. hepaticus y no hay vacuna disponible. Los resultados de este estudio sugieren que C. hepaticus puede ser endémico en algunas áreas de los Estados Unidos, y las gallinas de postura bajo pastoreo pueden estar expuestas al medio ambiente o al agua estancada en las áreas donde están alojadas.

Characterisation of N-linked protein glycosylation in the bacterial pathogen Campylobacter hepaticus.

Campylobacter hepaticus is an important pathogen which causes Spotty Liver Disease (SLD) in layer chickens. SLD results in an increase in mortality and a significant decrease in egg production and therefore is an important economic concern of the global poultry industry. The human pathogen Campylobacter jejuni encodes an N-linked glycosylation system that plays fundamental roles in host colonization and pathogenicity. While N-linked glycosylation has been extensively studied in C. jejuni and is now known to occur in a range of Campylobacter species, little is known about C. hepaticus glycosylation. In this study glycoproteomic analysis was used to confirm the functionality of the C. hepaticus N-glycosylation system. It was shown that C. hepaticus HV10T modifies > 35 proteins with an N-linked heptasaccharide glycan. C. hepaticus shares highly conserved glycoproteins with C. jejuni that are involved in host colonisation and also possesses unique glycoproteins which may contribute to its ability to survive in challenging host environments. C. hepaticus N-glycosylation may function as an important virulence factor, providing an opportunity to investigate and develop a better understanding the system's role in poultry infection.

Campylobacter bilis, the second novel Campylobacter species isolated from chickens with Spotty Liver Disease, can cause the disease.

Spotty Liver Disease (SLD) is a significant disease of commercial layer hens. It can cause up to 10 % flock mortalities and reduce egg production by 25 %. Campylobacter hepaticus has been identified as the main cause of the disease, although it also appears that predisposing factors, such as some form of stress, may increase the likelihood of clinical disease occurring. Recently, a newly identified species, Campylobacter bilis, was isolated from bile samples of clinical SLD affected chickens. To investigate the pathogenic potential of C. bilis two independent isolates were used in infection trials of layer hens. Within 6 days of oral challenge birds developed typical SLD liver lesions, demonstrating that both strains induced SLD. C. bilis could be recovered from all the challenged birds that developed SLD. Thus, each of the steps in Koch's postulates have been fulfilled, confirming that C. bilis is an additional cause of SLD. A PCR method was developed which can specifically detect C. bilis from samples with complex microbiota. The identification of this newly discovered Campylobacter species as a second cause of SLD and the provision of a rapid method to detect the SLD causing bacterium will help with SLD vaccine development and epidemiology, thus assisting in the control of this important disease of poultry.