For many years, yeast cell walls (YCW) and mannan oligosaccharides (MOS) have been used as alternatives to antibiotics and health feed additives to enhance the growth performance and health of food animals. In the present study, the inhibitory effects of YCWand MOS on the adhesion of enteropathogenic bacteria to intestinal epithelial cells were tested.YCW and MOS were extracted from Saccharomyces cerevisiae (XM 0315), and the morphology of YCW and MOS bound to pathogenic bacteria was observed by scanning electron microscopy (SEM). Real-time fluorescent quantitative PCR was used to quantitatively analyze the effects of YCW and MOS on the adhesion of Escherichia coli (CVCC3367) and Salmonella pullorum (CVCC520) to Caco-2 cells.The results showed that YCW inhibited E. coli and S. pullorum binding to Caco-2 cells by 95% and 74%, respectively, whereas MOS prevented E. coli and S. pullorum binding by 67% and 50%, respectively.These data suggest that YCW has a stronger ability than MOS to inhibit pathogenic bacteria from adhering to Caco-2 cells in vitro.

•Wastes produced from bacterial processes can be used as illegal feed adulterants.•Such practices are dangerous to the consumer and heighten drug resistance problems.•Here, we develop a method to monitor streptomycin and streptidine adulterants.•The combination of solid-phase extraction and UPLC–MS/MS was effective.•The method is simple, rapid, and sensitive, and does not require large sample sizes.Antibiotic industrial dregs, generated from the production of antibiotics by fermentation, are banned in China as animal feed additives. Official monitoring programs require the analysis of feeds for possible illegal use of the dregs. A rapid and sensitive method was developed for the simultaneous determination of streptomycin and streptidine as markers for streptomycin industrial dregs in pig and poultry compound feeds. After extraction with 20% aqueous trichloroacetic acid and pH adjustment, sample cleanup was performed by weak cation-exchange solid-phase extraction. UPLC–ESI–MS/MS was carried out using a hydrophilic interaction chromatography(HILIC)column to achieve separation. Quantification required matrix-matched calibrations in a linear range of 50–1000 μg kg−1; the calibration curves were linear in this range with coefficients of determination of 0.991 and 0.994 for streptomycin and streptidine, respectively. The method validity parameters—LODs (20 μg kg−1) and LOQs (50 μg kg−1), recoveries (71–78% and 75–84%, respectively), and relative reproducibility (5.4–9.6%)—satisfy the requirements of routine analysis.

β-Agonists are a group of illegal but widely used feed additives in the stockbreeding industry. In order to achieve simple-to-use, fast and high-throughput testing of this banned chemical, herein we suggest a paper-based analytical device on which a chemiluminescence diminishment method was performed. In this approach, extracts from swine hair samples as well as luminescent reagents, such as luminol and potassium periodate solution, in a low volume were applied to our device. It was found that the light emission was diminished by the β-agonists extracted from the swine hair samples. The degree of diminishment is proportional to the concentration of the β-agonists from 1.0 × 10−5 to 1.0 × 10−8 mol L−1. Also, the concentrations of solutions for chemiluminescence were optimized. The mechanism and reaction kinetics of chemiluminescence were discussed as well. The detection limit was obtained as 1.0 × 10−9 mol L−1, and recoveries from 96% to 110% were achieved, both of which suggested that our method will be favourable in field applications for swine hair samples.

β-Agonists are a group of illegal but widely used feed additives in the stockbreeding industry. In order to achieve simple-to-use, fast and high-throughput testing of this banned chemical, herein we suggest a paper-based analytical device on which a chemiluminescence diminishment method was performed. In this approach, extracts from swine hair samples as well as luminescent reagents, such as luminol and potassium periodate solution, in a low volume were applied to our device. It was found that the light emission was diminished by the β-agonists extracted from the swine hair samples. The degree of diminishment is proportional to the concentration of the β-agonists from 1.0 × 10−5 to 1.0 × 10−8 mol L−1. Also, the concentrations of solutions for chemiluminescence were optimized. The mechanism and reaction kinetics of chemiluminescence were discussed as well. The detection limit was obtained as 1.0 × 10−9 mol L−1, and recoveries from 96% to 110% were achieved, both of which suggested that our method will be favourable in field applications for swine hair samples.