Search

This study evaluated the effect of yeast-derived products on growth performance, gut lesion score, intestinal population ofClostridium perfringens, and local innate immunity of broiler chickens challenged withC. perfringens. One-day-old broiler chickens were randomly assigned to eight dietary treatments providing six replicate pens of 55 birds each per treatment. Dietary treatments consisted of Control diets without and withC. perfringenschallenge, and diets containing bacitracin methylene disalicylate (BMD, 55 g/tonne), nucleotides (150 g/tonne), yeast cell wall (YCW, 300 g/tonne), and a commercial product Maxi-Gen Plus (1 kg/tonne) fed to chickens challenged withC. perfringens. Diets containing 10% distillers dried grains with solubles without and withC. perfringenschallenge were also used. Birds were orally challenged withC. perfringens(108 colony-forming units (cfu)/bird) on day 14. On day 21, intestinal samples were collected for gene expression analysis. Pathogen challenge significantly (P < 0.05) impaired feed intake, body weight gain, and feed conversion ratio (FCR) shortly after the challenge (14–21 days). IncreasedC. perfringenscounts and intestinal lesion scores were observed for challenged birds except the BMD-containing diet. Over the entire trial (1–35 days), no difference in growth performance was observed except the BMD diet which improved FCR over the Control, challenged group. Birds receiving nucleotides showed increased expression of toll-like receptors and cytokines interleukin (IL)-4 and IL-18 compared to the Control, challenged group. Expression of macrophage mannose receptor and IL-18 was upregulated in birds receiving YCW. Increased expression of cytokines and receptors involved in innate immunity in broilers receiving nucleotides and YCW suggests the immunomodulatory properties of these products under pathogen challenge conditions. [ABSTRACT FROM PUBLISHER]

Virtually all life forms express short antimicrobial cationic peptides as an important component of their innate immune defenses. They serve as endogenous antibiotics that are able to rapidly kill an unusually broad range of bacteria, fungi and viruses. Consequently, considerable efforts have been expended to exploit the therapeutic potential of these antimicrobial peptides. Within the last couple of years, it has become increasingly clear that many of these peptides, in addition to their direct antimicrobial activity, also have a wide range of functions in modulating both innate and adaptive immunity. For one class of antimicrobial peptides, such as the human defensins, their primary role may even be as immunomodulators. These properties potentially provide entirely new therapeutic approaches to anti-infective therapy. [ABSTRACT FROM AUTHOR]

Advances in immunosuppressive strategies have been essential for organ transplantation becoming an established therapy for the treatment of end-stage organ failure. A global state of immunosuppression imparted by current regimens leaves the transplant recipient at a significantly increased risk for a multitude of infections. As such, recognition, prevention and treatment of infection have become primary concerns. Furthermore, as our understanding of the interaction between the innate and adaptive immune system expands, the potential for enhanced alloreactivity in the face of infection has become a topic of increasing interest. Recent studies have shown a correlation between viral infections and graft rejection. However, other categories of infection, including bacterial infections, have the potential to elicit similar immune responses. This review seeks to explore the clinical and scientific literature examining the role of bacterial infections in transplant rejection. [ABSTRACT FROM AUTHOR]