Explore the vast range of titles available.

The apicomplexan parasite Babesia microti is the primary agent of human babesiosis, a malaria-like illness and potentially fatal tick-borne disease. Unlike its close relatives, the agents of human malaria, B. microti develops within human and mouse red blood cells in the absence of a parasitophorous vacuole, and its secreted antigens lack trafficking motifs found in malarial secreted antigens. Here, we show that after invasion of erythrocytes, B. microti undergoes a major morphogenic change during which it produces an interlacement of vesicles (IOV); the IOV system extends from the plasma membrane of the parasite into the cytoplasm of the host erythrocyte. We developed antibodies against two immunodominant antigens of the parasite and used them in cell fractionation studies and fluorescence and immunoelectron microscopy analyses to monitor the mode of secretion of B. microti antigens. These analyses demonstrate that the IOV system serves as a major export mechanism for important antigens of B. microti and represents a novel mechanism for delivery of parasite effectors into the host by this apicomplexan parasite.

The gut and liver are connected via the portal vein, and this relationship, which includes the gut microbiome, is described as the gut–liver axis. Hepatitis C virus (HCV) can infect the liver and cause fibrosis with chronic infection. HCV has been associated with an altered gut microbiome; however, how these changes impact metabolism across the gut–liver axis and how this varies with disease severity and time is unclear. Here we used multi-omics analysis of portal and peripheral blood, faeces and liver tissue to characterize the gut–liver axis of patients with HCV across a fibrosis severity gradient before ( n  = 29) and 6 months after ( n  = 23) sustained virologic response, that is, no detection of the virus. Fatty acids were the major metabolites perturbed across the liver, portal vein and gut microbiome in HCV, especially in patients with cirrhosis. Decreased fatty acid degradation by hepatic peroxisomes and mitochondria was coupled with increased free fatty acid (FFA) influx to the liver via the portal vein. Metatranscriptomics indicated that Anaerostipes hadrus -mediated fatty acid synthesis influences portal FFAs. Both microbial fatty acid synthesis and portal FFAs were associated with enhanced hepatic fibrosis. Bacteroides vulgatus -mediated intestinal glycan breakdown was linked to portal glycan products, which in turn correlated with enhanced portal inflammation in HCV. Paired comparison of patient samples at both timepoints showed that hepatic metabolism, especially in peroxisomes, is persistently dysregulated in cirrhosis independently of the virus. Sustained virologic response was associated with a potential beneficial role for Methanobrevibacter smithii , which correlated with liver disease severity markers. These results develop our understanding of the gut–liver axis in HCV and non-HCV liver disease aetiologies and provide a foundation for future therapies. Multi-omics analyses of gut microbiome, liver and blood samples from patients with hepatitis C infection before and after removal of the virus reveal metabolic dysregulation along the gut–liver axis.

Abstract Background Increased microbial translocation (MT) into the systemic circulation is associated with liver disease progression. Microbial translocation has yet to be completely defined in chronic hepatitis B virus (HBV) and chronic hepatitis delta virus (HDV). Methods Our aim was to characterize MT and associated immune response in chronic HBV and HDV at various stages of disease. Serum from 53 HBV, 43 HDV, and 36 healthy control (HC) subjects was obtained. Subjects were categorized by aspartate aminotransferase-to-platelet ratio index into mild (<0.5), moderate, and severe (>1.0) disease. Cytokines, microbial products, and microbial deoxyribonucleic acid (DNA) levels were assessed in a single treatment-naive time point for each patient. Next-generation sequencing identified bacterial species present within patient sera. Results The HBV and HDV subjects display higher serum concentrations of Gram-negative (G−) bacterial lipopolysaccharide and fungal beta-glucan compared with HC (all P < .01). Gram-positive (G+) bacterial peptidoglycan is higher in HBV compared to HDV and HC (both P < .0001). Within both disease cohorts, peptidoglycan correlates with interleukin (IL)-1b, IL-8, IL-12p70, and IL-13 (all Spearman’s rho >0.45; P < .05). Next-generation sequencing from 7 subjects with detectable serum bacterial DNA revealed changes in abundance of bacterial taxa and a higher proportion of Gram-positive genera in severe disease. Greater G+/G− taxa ratio is associated with higher cytokine levels and disease markers. Conclusions The HBV and HDV patients display increased translocation of bacterial and fungal products into serum. An increased proportion of Gram-positive genera is associated with disease progression. Correlations of peptidoglycan with antimicrobial cytokines suggest that particular microbial classes may contribute to systemic inflammation and possibly disease progression. HBV and HDV patients display increased bacterial and fungal product translocation into serum. Higher proportion of Gram-positive genera is associated with severe disease. Correlations of peptidoglycan with cytokines suggest particular microbial classes may contribute to systemic inflammation and disease progression.