Horizontal transfer of vanA between probiotic Enterococcus faecium and Enterococcus faecalis in fermented soybean meal and in digestive tract of growing pigs

Abstract

Background The aim of this study was to investigate the intergeneric transfer of vancomycin resistance gene vanA between probiotic enterococci in the fermentation progress of soybean meal and in the digestive tract of growing pigs. One vanA genotype vancomycin resistant E. faecium strain, E fm 4, and one chloramphenicol-resistant E. faecalis strain, E fs 2, were isolated from twenty-nine probiotic basis feed material / additive samples. For in vitro conjugation, E fm 4 and E fs 2 were used as starter to ferment soybean meal. For in vivo conjugation, thirty growing pigs were randomly assigned to five groups ( n = 6), treated with a basic diet, or supplemented with 10% fermented soybean meal, 1% E fm 4, 5% E fs 2 or a combination of 1% E fm 4 + 5% E fs 2 for 7 d, respectively. Fecal samples of pigs in each group were collected daily for the isolation and dynamic analysis of E fm 4, E fs 2 and transconjugants. The sequence types (STs) of E fm 4, E fs 2 and transconjugants were analyzed by multilocus sequence typing (MLST). The vanA harboring plasmid in E fm 4 and transconjugants was analyzed by S1-pulsed field gel electrophoresis (PFGE) and further verified by multiple alignments. Results The results showed that, in FSBM, transconjugants were detected 1 h after the fermentation, with a conjugation frequency of ~ 10 − 3 transconjugants / recipient. Transconjugants proliferated with E fm 4 and E fs 2 in the first 8 h and maintained steadily for 10 d till the end of the experiment. Additionally, in vivo experiment showed that transcojugants were recovered in one of six pigs in both FSBM and E fm 4 + E fs 2 groups, with conjugation frequency of ~ 10 − 5 and ~ 10 − 4 , respectively. MLST revealed the ST of E fm 4, E fs 2 and transconjugants was ST1014, ST69 and ST69, respectively. S1-PFGE confirmed the existence of the vanA -harboring, 142,988-bp plasmid, which was also a multi-drug resistant plasmid containing Tn1546 -like transposon. Conclusions The findings revealed the potential safety hazard existing in the commercial probiotic enterococci in China, because the horiz...

Supplementation of Postbiotic RI11 Improves Antioxidant Enzymes Activity, Upregulated Gut Barrier Genes and Reduced Cytokines, Acute Phase Proteins and HSP70 Gene Expression Levels in Heat-Stressed Broilers

“…As postbiotics possess the probiotic characteristics [34,39,41,44,63,64], probiotic studies can provide useful information to understand how postbiotics could improve the antioxidant capability and develop the oxidative resistance in the body under heat stress. Several studies reported that the supplementation of probiotics in the poultry diets reduced the adverse effects of oxidative stress and enhanced the antioxidant enzymes activities [57,65], which might reduce cell damages by inhibiting the production of ROS and finally improving the health of animals [66,67]. Consistent with our results, Shen, et al [68] reported that blood antioxidant capacities were significantly enhanced by the inclusion of probiotic L. plantarum in the diets and promoted growth performance in broilers.…”

Dietary Supplementation of Postbiotics Mitigates Adverse Impacts of Heat Stress on Antioxidant Enzyme Activity, Total Antioxidant, Lipid Peroxidation, Physiological Stress Indicators, Lipid Profile and Meat Quality in Broilers

“…As postbiotics possess probiotic characteristics [ 34 , 39 , 40 , 43 , 67 , 68 ], probiotic studies can provide useful information to understand how postbiotics could improve the antioxidant capability and develop the oxidative resistance in the body under heat stress. Several studies reported that the supplementation of probiotics in poultry diets reduced the adverse effects of oxidative stress and enhanced the activity of antioxidant enzymes [ 61 , 69 ], which might reduce cell damage by inhibiting the production of ROS and finally improving the health of animals [ 70 , 71 ]. Our results were consistent with Shen et al [ 72 ] who reported that blood antioxidant capacities were significantly intensified by the incorporation of probiotic L. plantarum in the diets and promoted growth performance in broilers.…”

<p>Emergence of <em>vanA</em>-Type Vancomycin-Resistant <em>Enterococcus faecium</em> ST 78 Strain with a rep2-Type Plasmid Carrying a Tn1546-Like Element Isolated from a Urinary Tract Infection in China</p>

“…According to the phylogenetic analysis, the most closely related vancomycin-resistant E. faecium strain, SC4, was found in fodder from Beijing, China with a transferable vanA-carrying plasmid. 31 In Hangzhou, the first report of vancomycin-resistant E. faecium was published in 2007 by Qu et al 20 Twenty-one vanA-carrying E. faecium isolates were obtained from inpatients among five hospitals in Hangzhou, from April 2006 to April 2007.…”