A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

<p>Abstract</p> <p>Background</p> <p>Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with <it>Salmonella enterica </it>serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small.</p> <p>Results</p> <p>We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and <it>Salmonella</it>-resistant CBA/J mice during infection with <it>Salmonella enterica </it>serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic <it>invA </it>mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and <it>Salmonella</it>-resistant mice. Additionally we show that only a small minority of <it>Salmonellae </it>are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models.</p> <p>Conclusion</p> <p>In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models.</p

A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

<p>Abstract</p> <p>Background</p> <p>Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with <it>Salmonella enterica </it>serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small.</p> <p>Results</p> <p>We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and <it>Salmonella</it>-resistant CBA/J mice during infection with <it>Salmonella enterica </it>serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic <it>invA </it>mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and <it>Salmonella</it>-resistant mice. Additionally we show that only a small minority of <it>Salmonellae </it>are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models.</p> <p>Conclusion</p> <p>In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models.</p

Peptic Ulcer Perforation as the First Manifestation of Previously Unknown Primary Hyperparathyroidism

A patient admitted for acute abdomen was incidentally found with elevated serum calcium level. In surgery, under conservative treatment of the hypercalcemia, a perforated duodenal ulcer was found and simple closure was performed. Postoperatively, calcium level continued to rise, parathyroid hormone was elevated and ultrasonographic examination showed a lesion in the right anterior neck, while serum gastrin level was normal, thus documenting the diagnosis of primary hyperparathyroidism. Conservative treatment had no effect on calcium level and the patient was subjected to emergency neck exploration, where a large parathyroid adenoma was removed. After surgery, calcium and PTH levels were normalized and the patient was discharged on the 5th postoperative day. Peptic ulcer and its complications are usual manifestations of primary hyperparathyroidism, with or without increased gastrin level. On the other hand, cases of a perforation of peptic ulcer as the first clinical manifestation of primary hyperparathyroidism are extremely rare

Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites

A new nanocomposite architecture is reported which combines prolate spheroidal hematite nanoparticles with drug-carrying layered double hydroxide [LDH] disks in a single structure. Spindle-shaped hematite nanoparticles with average length of 225 nm and width of 75 nm were obtained by thermal decomposition of hydrothermally synthesized hematite. The particles were first coated with Mg-Al-NO3-LDH shell and then subjected to anion exchange with salicylate ions. The resulting bio-nanohybrid displayed a close structural resemblance to that of the Ring Nebula. Scanning electron microscope and transmission electron microscopy images showed that the LDH disks are stacked around the equatorial part of the ellipsoid extending along the main axis. This geometry possesses great structural tunability as the composition of the LDH and the nature of the interlayer region can be tailored and lead to novel applications in areas ranging from functional materials to medicine by encapsulating various guest molecules

Water oxidation at hematite photoelectrodes: the role of surface states

Hematite (α-Fe2O3) constitutes one of the most promising semiconductor materials for the conversion of sunlight into chemical fuels by water splitting. Its inherent drawbacks related to the long penetration depth of light and poor charge carrier conductivity are being progressively overcome by employing nanostructuring strategies and improved catalysts. However, the physical–chemical mechanisms responsible for the photoelectrochemical performance of this material (J(V) response) are still poorly understood. In the present study we prepared thin film hematite electrodes by atomic layer deposition to study the photoelectrochemical properties of this material under water-splitting conditions. We employed impedance spectroscopy to determine the main steps involved in photocurrent production at different conditions of voltage, light intensity, and electrolyte pH. A general physical model is proposed, which includes the existence of a surface state at the semiconductor/liquid interface where holes accumulate. The strong correlation between the charging of this state with the charge transfer resistance and the photocurrent onset provides new evidence of the accumulation of holes in surface states at the semiconductor/electrolyte interface, which are responsible for water oxidation. The charging of this surface state under illumination is also related to the shift of the measured flat-band potential. These findings demonstrate the utility of impedance spectroscopy in investigations of hematite electrodes to provide key parameters of photoelectrodes with a relatively simple measurement