Campylobacter jejuni is a leading human food-borne pathogen. The rapid and sensitive detection of C. jejuni is necessary for the maintenance of a safe food/water supply. In this article, we present a real-time polymerase chain reaction (PCR) assay for quantitative detection of C. jejuni in naturally contaminated poultry, milk and environmental samples without an enrichment step. The whole assay can be completed in 60 min with a detection limit of approximately 1 CFU. The standard curve correlation coefficient for the threshold cycle versus the copy number of initial C. jejuni cells was 0.988. To test the PCR system, a set of 300 frozen chicken meat samples, 300 milk samples and 300 water samples were screened for the presence of C. jejuni. 30.6% (92/300) of chicken meat samples, 27.3% (82/300) of milk samples, and 13.6% (41/300) of water samples tested positive for C. jejuni. This result indicated that the real-time PCR assay provides a specific, sensitive and rapid method for quantitative detection of C. jejuni. Moreover, it is concluded that retail chicken meat, raw milk and environmental water are commonly contaminated with C. jejuni and could serve as a potential risk for consumers in eastern China, especially if proper hygienic and cooking conditions are not maintained.

The present study was conducted in a 2 x 4 factorial arrangement in a randomized complete block (RCB) design to compare the effects of a commercial inorganic Se source (sodium selenite, SS) with a commercial organic Se source (Se-enriched yeast, SY) on tissue Se distribution and blood and whole-egg Se concentrations in laying hens. Both Se sources were added into the basal diet at 0, 0.2, 0.5, and 1.0 mg/kg of Se. Seven hundred 68 week old Rohman laying hens were fed with a basal diet containing 0.15 mg/kg DM (dry matter) of Se for 2 weeks, and then, they were allocated randomly into seven groups and were investigated for 28 days. Each group was replicated five times with five cages of four hens per cage in each replicate. During the experiment, two eggs per replicate from each treatment were collected every 7 days and blood was sampled on days 0, 14, and 28 for whole-egg and whole-blood Se analyses. At the end of the experiment, two hens per replicate from each treatment were slaughtered, and muscle (cardiac and breast muscles), liver, spleen, and kidney were sampled for the determination of Se concentrations. The results showed that the addition of Se from either source caused a significant increase in whole-egg and whole-blood Se concentrations (p < 0.01) and Se concentrations in liver, kidney, spleen, and cardiac and breast muscles (p < 0.05) of hens in comparison to the control. Both Se sources and Se levels significantly influenced (p < 0.01) Se concentrations in egg, blood, and the above-mentioned tissues. There was a more significant increase in the Se concentrations in egg (p < 0.01), spleen (p < 0.05), and breast muscle (p < 0.01) and a decrease (p < 0.01) in whole-blood and kidney from hens fed SY than those from hens fed SS. The order of Se distribution was liver > kidney > spleen > cardiac muscle > egg > blood > breast muscle, irrespective of the addition level or source. It was concluded that meat and eggs from hens fed commercial SY are a potential source of Se for humans.

The object of this study was to investigate the effect of curcumin on modulating the glutathione (GSH)-related antioxidant enzymes and antioxidant responses via NF-E2-related factor 2 (Nrf2) signaling pathway in heat-stressed broiler chickens. A total of 400 one-day-old male Arbor Acres broiler chicks was reared in an environmentally controlled room. At 21 d, broiler chicks were divided into 5 treatment groups and were fed one of 4 diets under 2 temperature conditions: 22°C + a basal diet (CON treatment); 34°C for 8 h (0900-1700) + a basal diet supplemented with 0, 50, 100, or 200 mg/kg curcumin (HS, CMN1, CMN2, and CMN3 treatments, respectively). The heat treatment lasted for 20 consecutive days. The results showed that heat stress significantly increased (P < 0.05) the weekly rectal temperature and average head and feet temperature. Compared to the HS treatment, feed conversion was significantly decreased (P < 0.05) in CMN1 and CMN2 treatments. CMN1 administration significantly improved (P < 0.05) the pH24 of muscle. The abnormal changes of serum malonaldehyde and corticosterone concentrations were prevented (P < 0.05) by curcumin. Mitochondrial GSH concentration in the liver was significantly increased (P < 0.05) in CMN1 and CMN2 treatments compared with the HS treatment. The CMN1, CMN2, and CMN3 supplementations significantly increased (P < 0.05) γ-GCL, GSH-Px, and GST activities. Curcumin significantly increased (P < 0.05) the expression of Nrf2, HO-1, and γ-GCLc in the liver as compared to the CON diet. The expression of Cu/ZnSOD and CAT were increased (P < 0.05) by feeding CMN2, respectively, as compared to the HS treatment. It was concluded that curcumin supplementation enhanced the resistance of broilers to heat stress, as evidenced by reversing the FC, increasing the GSH content and GSH-related enzyme activities, and inducing the expression of Nrf2 and Nrf2-mediated phase II detoxifying enzyme genes.

The purpose of this study was to evaluate the inhibitory activity of selenium-enriched probiotics against pathogenic Escherichia coli (E. coli) in vitro and in vivo. Escherichia coli was co-cultured in vitro with each probiotic strain individually, and a mixture of the four strains and its population was counted at various time points. We also collected a cell-free culture supernatant (CFCS) of each probiotic strain and the four-strain mix to examine their antibacterial activity, using the cylinder plate method. Results demonstrated that co-culture with probiotics significantly reduced the number of E. coli. The different sizes of the inhibition zones made by each CFCS proved that E. coli was inhibited by the metabolites of the probiotics. In vivo, Kunming mice were allocated to different groups supplemented with selenium-enriched and other probiotics. After 28 days, the mice were inoculated with pathogenic E. coli so that we could compare mortality rates and inspect other indexes of each treatment. The mortality of the group with selenium-enriched probiotics was the lowest. In addition, the organic antioxidant status improved, immunity was fortified, and the internal environment of the intestinal tract was enhanced with selenium-enriched probiotic supplementation. In conclusion, selenium-enriched probiotics can strongly antagonize pathogenic E. coli in vitro and in vivo.

Peste des petits ruminants virus (PPRV) causes high mortality in goats and sheep and the disease has shown a greatly increased geographic distribution over the last 15 years. It is responsible for serious socioeconomic problems in some of the poorest developing countries. The ability to create recombinant PPRV would provide a useful tool for investigating the biology of the virus and the pathology of disease, as well as for developing new vaccines and diagnostic methods. Here we report the first successful rescue of recombinant PPRV from a full-length cDNA clone of the virus genome. Successful recovery of PPRV was achieved by using a RNA polymerase II promoter to drive transcription of the full-length virus antigenome. We have used this technique to construct a virus expressing a tracer protein (green fluorescent protein, GFP). The recombinant virus replicated as well as the parental virus and could stably express GFP during at least 10 passages. The newly established reverse genetics system for PPRV provides a novel method for constructing a vaccine using PPRV as a vector, and will also prove valuable for fundamental research on the biology of the virus. We found that our recombinant virus allowed more rapid and higher throughput assessment of PPRV neutralization antibody titer via the virus neutralization test (VNT) compared with the traditional method.

A 35-day experiment was conducted to evaluate the effect of selenium-enriched probiotics (SP) on laying performance, egg quality, egg selenium (Se) content, and egg glutathione peroxidase (GPX) activity. Five hundred 58-week-old Rohman laying hens were randomly allotted to 5 dietary treatments of 100 each. Each treatment had 5 replicates, and each replicate had 5 cages with 4 hens per cage. The SP was supplemented to a corn-soybean-meal basal diet at 3 different levels that supplied total Se at 0.2, 0.5, and 1.0 mg/kg. The basal diet served as a blank control, while the basal diet with supplemental probiotics served as a probiotics control. The results showed that dietary SP supplementation not only increased (p < 0.05) the rate of egg laying, day egg weight, mean egg weight, egg Se content, and egg GPX activity but also decreased (p < 0.05) the feed:egg ratio and egg cholesterol content. The egg Se content was gradually increased (p < 0.05) along with the increasing level of dietary Se. The SP supplementation also slowed down (p < 0.05) the drop of Haugh units (HU) of eggs stored at room temperature. The egg GPX activity had a positive correlation (p < 0.01) with egg Se content and a negative correlation (p < 0.01) with egg HU drop. These results suggested that Se contents, GPX activity, and HU of eggs were affected by the dietary Se level, whereas the egg-laying performance and egg cholesterol content were affected by the dietary probiotics. It was concluded that this SP is an effective feed additive that combines the organic Se benefit for hen and human health with the probiotics benefit for laying hen production performance. It was also suggested that the eggs from hens fed this SP can serve as a nutraceutical food with high Se and low cholesterol contents for both healthy people and patients with hyperlipidemia, fatty liver, or cardiovascular disease.

Thirty-two wether lambs of Tan sheep were randomly assigned into four dietary treatment groups (eight per group) for an 8-wk study and then fed a basal diet deficient in Se (0.06 mg/kg) or diets supplemented to provide 0.10 mg/kg Se from sodium selenite, selenized yeast, and seleniumenriched probiotics, respectively. Blood samples were collected at d 0, 28, and 56 of the experiment and tissue samples were collected at experiment termination. Tissue and blood Se concentrations, blood glutathione peroxidase (GSH-Px) activities, and plasma interleukin levels were analyzed. The results showed that the concentrations of Se in the kidney, liver, and muscle increased in all of the supplemented groups (p < 0.01) compared with the control group. However, the Se concentrations in the kidney, liver, and muscle in the groups supplemented with Se yeast and Se-enriched probiotics were higher than those in the group supplemented with sodium selenite (p < 0.01). The activities of GSH-Px and the concentrations of Se in blood also increased in all of the supplemented groups during the period of supplementation (p < 0.01) compared with the control group. The activities of GSH-Px and the concentrations of Se in the whole blood of the lambs fed with selenized yeast and Se-enriched probiotics were higher than those of lambs fed with sodium selenite (p<0.01 or p<0.05). The concentrations of interleukin-1 and interleukin-2 in plasma significantly increased in all of the supplemented groups during the entire period of experiment (p<0.01) compared with the control group, but had no significant differences among all of the supplemented groups. In conclusion, a diet supplemented with Se for finishing lambs was able to increase the concentrations of Se in tissue and blood, activities of GSH-Px in blood, and levels of interleukins in plasma. Organic Se sources (selenized yeast and Se-enriched probiotics) were more effective than the inorganic Se source (sodium selenite) in increasing tissue and blood Se concentrations and blood GSH-Px activities of lambs. However, there were no significant differences in plasma interleukin levels of lambs between organic and inorganic Se sources.

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