BackgroundSilver nanoparticles (AgNP) have gained much attention in recent years due to their biomedical applications, especially as antimicrobial agents. AgNP may be used in poultry production as an alternative to the use of antibiotic growth promoter. However, little is known about the impact of oral administration of AgNP on the gut microbiota and the immune system. The aim of the present study was to investigate the effects of AgNP on growth, hematological and immunological profile as well as intestinal microbial composition in broilers challenged with Campylobacter jejuni (C. jejuni).ResultsAgNP did not affect the intestinal microbial profile of birds. The body weight gain and the relative weights of bursa and spleen were reduced when supplemented with AgNP. There was no difference with respect to packed cell volume. However, the plasma concentrations of IgG and IgM were lower in birds receiving AgNP compared to the non-supplemented control group. The expression of TNF-α and NF-kB at mRNA level was significantly higher in birds receiving AgNP.ConclusionsThe application of AgNP via the drinking water in the concentration of 50 ppm reduced broiler growth, impaired immune functions and had no antibacterial effect on different intestinal bacterial groups, which may limit the applicability of AgNP against C. jejuni in broiler chickens.Electronic supplementary materialThe online version of this article (doi: 10.1186/s12917-017-1323-x) contains supplementary material, which is available to authorized users.

One of the most promising methods against drug-resistant bacteria can be surface-modified materials with biocidal nanoparticles and nanocomposites. Herein, we present a nanocomposite with silver nanoparticles (Ag-NPs) on the surface of graphene oxide (GO) as a novel multifunctional antibacterial and antifungal material. Ultrasonic technologies have been used as an effective method of coating polyurethane foils. Toxicity on gram-negative bacteria (Escherichia coli), gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis), and pathogenic yeast (Candida albicans) was evaluated by analysis of cell morphology, assessment of cell viability using the PrestoBlue assay, analysis of cell membrane integrity using the lactate dehydrogenase assay, and reactive oxygen species production. Compared to Ag-NPs and GO, which have been widely used as antibacterial agents, our nanocomposite shows much higher antimicrobial efficiency toward bacteria and yeast cells.

We have developed a sheep model to facilitate studies of the fetal programming effects of mismatched perinatal and postnatal nutrition. During the last trimester of gestation, twenty-one twin-bearing ewes were fed a normal diet fulfilling norms for energy and protein (NORM) or 50 % of a normal diet (LOW). From day 3 postpartum to 6 months (around puberty) of age, one twin lamb was fed a conventional (CONV) diet and the other a high-carbohydrate -high-fat (HCHF) diet, resulting in four groups of offspring: NORM-CONV; NORM-HCHF; LOW-CONV; LOW-HCHF. At 6 months of age, half of the lambs (all males and three females) were slaughtered for further examination and the other half (females only) were transferred to a moderate sheep diet until slaughtered at 24 months of age (adulthood). Maternal undernutrition during late gestation reduced the birth weight of LOW offspring (P, 0·05), and its long-term effects were increased adrenal size in male lambs and adult females (P, 0·05), increased neonatal appetite for fat-(P¼0·004) rather than carbohydrate-rich feeds (P,0·001) and reduced deposition of subcutaneous fat in both sexes (P,0·05). Furthermore, LOW-HCHF female lambs had markedly higher visceral:subcutaneous fat ratios compared with the other groups (P, 0·001). Postnatal overfeeding (HCHF) resulted in obesity (. 30 % fat in soft tissue) and widespread ectopic lipid deposition. In conclusion, our sheep model revealed strong pre-and postnatal impacts on growth, food preferences and fat deposition patterns. The present findings support a role for subcutaneous adipose tissue in the development of visceral adiposity, which in humans is known to precede the development of the metabolic syndrome in human adults.

The objective of the present study was to examine the effects of hydrocolloidal silver nanoparticles (Ag-nano) on microbial profile of caecum and morphology of enterocytes in duodenum of Japanese quail, as a model animal for poultry. Quails (Coturnix coturnix japonica) (10 d old) were randomly divided into four groups (15 quails each) and located into four cages for 12 days. Quails were fed with granulated diets given ad libitum and had free access to drinking water. Ag-nano were added to drinking water at concentrations of 0, 5, 15 and 25 mg/kg. At the end of the experiment, the animals were killed and samples of duodenum and caeca microflora were collected. This initial investigation demonstrated that silver nanoparticles did not influence emphatically microflora of quail caecum; however, water containing 25 mg/kg of Ag-nano significantly increased the population of lactic acid bacteria. Furthermore, Ag-nano did not show any damaging properties on enterocytes of duodenal villi.