Isolation and molecular characterization of \u3ci\u3eSalmonella enterica\u3c/i\u3e serovar Enteritidis from poultry house and clinical samples during 2010

A total of 60 Salmonella enterica serovar (ser.) Enteritidis isolates, 28 from poultry houses and 32 from clinical samples, were isolated during 2010. These isolates were subjected to testing and analyzed for antibiotic resistance, virulence genes, plasmids and plasmid replicon types. To assess genetic diversity, pulsed-field gel electrophoresis (PFGE) fingerprinting, using the XbaI restriction enzyme, Multiple-Locus Variable-Number Tandem Repeat Analysis (MLVA) and plasmid profiles were performed. All isolates from poultry, and 10 out of 32 clinical isolates were sensitive to ampicillin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, sulfisoxazole, streptomycin, and tetracycline. Twenty-one of thirty-two clinical isolates were resistant to ampicillin and tetracycline, and one isolate was resistant to nalidixic acid. PFGE typing of sixty ser. Enteritidis isolates by XbaI resulted in 10e12 bands and grouped into six clusters each with similarity from 95% to 81%. The MLVA analysis of sixty isolates gave 18 allele profiles with the majority of isolates displayed in three groups, and two clinical isolates found to be new in the PulseNet national MLVA database. All isolates were positive for 12 or more of the 17 virulence genes mostly found in S. enterica (spvB, spiA, pagC, msgA, invA, sipB, prgH, spaN, orgA, tolC, iroN, sitC, IpfC, sifA, sopB, and pefA) and negative for one gene (cdtB). All isolates carried a typical 58 kb plasmid, type Inc/FIIA. Three poultry isolates and one clinical isolate carried small plasmids with 3.8, 6, 7.6 and 11.5 kb. Ten of the clinical isolates carried plasmids, with sizes 36 and 38 kb, types IncL/M and IncN, and one isolate carried an 81 kb plasmid, type IncI. Southern hybridization of a plasmid with an Inc/FIIA gene probe hybridized one large 58 kb plasmid in all isolates. Several large and small plasmids from poultry isolates were not typed by our PCR-based method. These results confirmed that PFGE fingerprinting has limited discriminatory power for ser. Enteritidis in both poultry and clinical sources. However, the plasmid and MLVA allele profiles were a useful and important epidemiology tool to discriminate outbreak strains of ser. Enteritidis from poultry and clinical samples

Bone-derived Sclerostin has endocrine actions in adipocyte precursors and pancreatic beta-cells

Osteocyte (Ot)-derived Sclerostin (Scl) has local actions in bone mediated by Lrp 4/5/6 receptors, inhibiting bone formation and stimulating bone resorption by antagonizing Wnt signaling. Emerging evidence suggests that Scl also exerts functions in distant tissues. We report here that mice with activated β-catenin in Ots (daβcatOt) and mice lacking Lrp4 in Ots (Lrp4Ot), two different genetic mouse models that exhibit high se-rum Scl, display a 2-fold increase in whole-body fat and peripheral white (WAT) and brown (BAT) adipose tissue mass. The goal of this study was to determine the contribution of Ot-derived Scl to the regulation of peripheral fat mass and glucose metabolism. To determine Scl’s contribution to the high fat phenotype, daβcatOt mice were crossed with SOST knockout mice. Deletion of SOST restored to control levels the elevated body-fat mass and WAT mass, but not BAT, in daβcatOt mice. In contrast, blockade of Scl signaling in bone via genetic deletion of Lrp4 in Ots, did not alter the elevated body fat displayed by daβcatOt mice, demonstrating that Scl actions on adi-pose tissue were not mediated by Scl actions on Ots. Consistent with direct effects of Scl on adipose tissue, treatment with recombinant Scl enhanced by 20% adipogenic differentiation of murine adipocyte precursors (preAd) in vitro, and increased the expression of mitochondrial related genes Pgc1a, Ucp1, and Prdm16 in preAds as well as in ex vivo fat organ cultures established from WAT. Further, Scl augmented mitochondrial respiration in preAds by inducing a 15% increase in maximal respiration and spare capacity, suggesting that Scl promotes adipogenesis in preAds by regulating mitochondrial oxidative phosphorylation. Both models of high serum Scl, daβcatOt and LRP4Ot mice, also were hypoglycemic and exhibited impaired glucose tolerance com-pared to control littermates. Genetic deletion of SOST restored to control values the glucose levels in blood and glucose tolerance, showing that serum Scl regulates glucose metabolism. Further, Scl fully prevented the increase in insulin mRNA expression induced by Wnt3a in rat pancreatic β-cells and decreased by 45% insulin secretion induced by high-glucose media, demonstrating that Scl acts directly on pancreatic β-cells to impair insulin production. In concert, these findings demonstrate that Scl exerts endocrine actions in fat tissues and the pancreas to regulate body composition and glucose metabolism, respectively. Further, our results provide new evidence supporting that endocrine actions of Scl mediate the crosstalk between bone and fat and the pancreas