Transfer of Carbapenem-Resistant Plasmid from Klebsiella pneumoniae ST258 to Escherichia coli in Patient

Klebsiella pneumoniae carbapenemase (KPC) 3–producing Escherichia coli was isolated from a carrier of KPC-3–producing K. pneumoniae. The KPC-3 plasmid was identical in isolates of both species. The patient's gut flora contained a carbapenem-susceptible E. coli strain isogenic with the KPC-3–producing isolate, which suggests horizontal interspecies plasmid transfer

Intestinal B cells license metabolic T-cell activation in NASH microbiota/antigen-independently and contribute to fibrosis by IgA-FcR signalling

BACKGROUND & AIMS: The progression of non-alcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS: C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH-inducing diets or standard chow for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and μMT mice (containing B cells only in the gastrointestinal tract) were fed a choline-deficient high-fat diet, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with simple steatosis, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and single-cell RNA-sequencing analysis were performed in liver and gastrointestinal tissue to characterise immune cells in mice and humans. RESULTS: Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B cells; additionally, we observed a positive correlation between IgA levels and activated FcRg+ hepatic myeloid cells, as well the extent of liver fibrosis. CONCLUSIONS: Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for the treatment of NASH. IMPACT AND IMPLICATIONS: There is currently no effective treatment for non-alcoholic steatohepatitis (NASH), which is associated with a substantial healthcare burden and is a growing risk factor for hepatocellular carcinoma (HCC). We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we show that the absence of B cells prevented HCC development. B cell-intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets for combinatorial NASH therapies against inflammation and fibrosis

Intestinal B-cells license metabolic T-cell activation in NASH microbiota/antigen-independently and contribute to fibrosis by IgA-FcR signalling

BACKGROUND & AIMS The progression of nonalcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH diets (for example, choline-deficient high-fat diet, CD-HFD) or chow diet for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and μMT mice (containing B cells only in the gastrointestinal tract) were fed a CD-HFD, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with NAFL, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and scRNA-Seq analysis were performed in liver and gastrointestinal tissue for immune cells in mice and humans. RESULTS Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen-specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B-cells and showed a positive correlation between IgA levels and activated FcRγ+ hepatic myeloid cells as well extent of liver fibrosis. CONCLUSIONS Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for treating NASH. IMPACT AND IMPLICATIONS Nonalcoholic steatohepatitis (NASH) is a chronic inflammatory condition on the rise and can lead to hepatocellular carcinoma (HCC), the 3rd most common cause of cancer-related death worldwide. Currently, there is no effective treatment for this progressive disease that correlates with a marked risk of HCC mortality and carries a substantial healthcare burden. To date, among all the solid tumours, especially in HCC, the incidence and mortality rates are almost the same, making it crucial to find curative treatments for chronic diseases, such as NASH, which highly predispose to tumorigenesis. We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we could show that the absence of B cells prevented HCC development. B-cell intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets in combinatorial NASH therapies against inflammation and fibrosis

Rudiments of insurance purchasing : a graphical state-claims analysis

Includes bibliographical references (p. 13)

Extended-Spectrum Beta-Lactamases among Enterobacter Isolates Obtained in Tel Aviv, Israel

The extended-spectrum beta-lactamase (ESBL)-producing phenotype is frequent among Enterobacter isolates at the Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. We examined the clonal relatedness and characterized the ESBLs of a collection of these strains. Clonal relatedness was determined by pulsed-field gel electrophoresis. Isoelectric focusing (IEF) and transconjugation experiments were performed. ESBL gene families were screened by colony hybridization and PCR for bla(TEM), bla(SHV), bla(CTX-M), bla(IBC), bla(PER), bla(OXA), bla(VEB), and bla(SFO); and the PCR products were sequenced. The 17 Enterobacter isolates studied comprised 15 distinct genotypes. All isolates showed at least one IEF band (range, one to five bands) whose appearance was suppressed by addition of clavulanate; pIs ranged from 5.4 to ≥8.2. Colony hybridization identified at least one family of beta-lactamase genes in 11 isolates: 10 harbored bla(TEM) and 9 harbored bla(SHV). PCR screening and sequence analysis of the PCR products for bla(TEM), bla(SHV), and bla(CTX-M) identified TEM-1 in 11 isolates, SHV-12 in 7 isolates, SHV-1 in 1 isolate, a CTX-M-2-like gene in 2 isolates, and CTX-M-26 in 1 isolate. In transconjugation experiments with four isolates harboring bla(TEM-1) and bla(SHV-12), both genes were simultaneously transferred to the recipient strain Escherichia coli HB101. Plasmid mapping, PCR, and Southern analysis with TEM- and SHV-specific probes demonstrated that a single transferred plasmid carried both the TEM-1 and the SHV-12 genes. The widespread presence of ESBLs among Enterobacter isolates in Tel Aviv is likely due not to clonal spread but, rather, to plasmid-mediated transfer, at times simultaneously, of genes encoding several types of enzymes. The dominant ESBL identified was SHV-12

HIV-1 antibody 3BNC117 suppresses viral rebound in humans during treatment interruption

Interruption of combination antiretroviral therapy in HIV-1-infected individuals leads to rapid viral rebound. Here we report the results of a phase IIa open label clinical trial evaluating 3BNC117, a broad and potent neutralizing antibody against the CD4 binding site of the HIV-1 Env protein(1), during analytical treatment interruption in 13 HIV-1-infected individuals. Participants with 3BNC117-sensitive virus outgrowth cultures were enrolled. Results show that two or four 30 mg kg(-1) 3BNC117 infusions, separated by 3 or 2 weeks, respectively, are generally well tolerated. Infusions are associated with a delay in viral rebound of 5-9 weeks after two infusions, and up to 19 weeks after four infusions, or an average of 6.7 and 9.9 weeks, respectively, compared with 2.6 weeks for historical controls (P < 0.00001). Rebound viruses arise predominantly from a single provirus. In most individuals, emerging viruses show increased resistance, indicating escape. However, 30% of participants remained suppressed until antibody concentrations waned below 20 mu g ml(-1), and the viruses emerging in all but one of these individuals showed no apparent resistance to 3BCN117, suggesting failure to escape over a period of 9-19 weeks. We conclude that the administration of 3BNC117 exerts strong selective pressure on HIV-1 emerging from latent reservoirs during analytical treatment interruption in humans