Effects of Chinese medicine herbal residues on antibiotic resistance genes and the bacterial community in chicken manure composting.

The use of livestock manure is an important way for antibiotic resistance genes (ARGs) to enter the environment, and composting is an effective method for removing ARGs from livestock manure. In this study, different volume ratios of Chinese medicinal herbal residues (CMHRs) were added to laboratory-scale chicken manure composting to evaluate their effects, if any, on the behavior of ARGs, mobile genetic elements (MGEs), and the bacterial community. At the end of the composting period, the composition of the microbial community changed. Firmicutes decreased and Bacteroidetes increased. The most striking effect was that the relative abundance of the 21 ARGs and 5 MGEs detected decreased by varying degrees in the different treatments (except for sulI and intI1). The removal rate of the ARGs increased with the increased addition of CMHRs. The correlations between transferase genes (tnpA and tnpA-02) and ARGs were significant (p < 0.05); therefore, transposons play an important role in the horizontal gene transfer of ARGs in chicken manure. The results imply that CMHRs would be an effective bulking agent for the removal of ARGs from chicken manure composting.

[Effect of Co-composting of Chicken Manure with Chinese Medicinal Herbal Residues on Antibiotic Resistance Genes].

Livestock manure is an important pathway by which antibiotic resistance genes (ARGs) enter the environment. To reduce the occurrence of antibiotic resistance genes in manures, we studied the variations of ARGs and mobile gene elements (MGEs) during the 46-day co-composting of chicken manure with Chinese medicinal herbal residues. The abundance of 100 ARGs and 5 MGEs were measured by Real-Time Quantitative PCR with 0, 3, 7, 14, 28, and 46 d co-composting. We detected 21 ARGs, 2 integrase genes (intI1 and intI2), and 3 transposase genes (tnpA-01, tnpA-02, and tnpA-03). The abundance of 5 MGEs significantly declined with co-composting time, particularly tnpA-01 and tnpA-02, which were reduced by two orders of magnitude. The abundance of aacA/aphD and aadE were significantly reduced (P<0.05) in aminoglycoside resistance genes. In ß-lactam resistance genes, the strongest relationships were demonstrated between blaOXA1 and compost days (P=0.016), and the removal rate was 78.63%. The average removal rate was 90.39% for amide resistance genes, which decreased significantly with composting time. The removal ratios were different among tetracycline resistance genes. For example, the removal ratios of tetG and tetR were 99.77% and 31.72%, respectively. The highest removal rate of qnrD was 99.89%. The removal rate of sulⅢ was as high as 99.88%, while sulⅠ showed an increasing trend. Correlations between ARGs and MGEs were significant correlation for tnpA-01 and ARGs (P<0.05). The trend of ARGs with composting time indicates that the composting of Chinese medicine residues and chicken manure can significantly reduce the abundance of ARGs, thus reducing the risk of ARGs being distributed via livestock manure application.

Electroacupuncture alleviates cerebral ischemia and reperfusion injury via modulation of the ERK1/2 signaling pathway.

Electroacupuncture (EA) has anti-oxidative and anti-inflammatory actions, but whether the neuroprotective effect of EA against cerebral ischemia-reperfusion (I/R) injury involves modulation of the extracellular regulated kinase 1/2 (ERK1/2) signaling pathway is unclear. Middle cerebral artery occlusion (MCAO) was performed in Sprague-Dawley rats for 2 hours followed by reperfusion for 24 hours. A 30-minute period of EA stimulation was applied to both Baihui (DU20) and Dazhui (DU14) acupoints in each rat (10 mm EA penetration depth, continuous wave with a frequency of 3 Hz, and a current intensity of 1-3 mA) when reperfusion was initiated. EA significantly reduced infarct volume, alleviated neuronal injury, and improved neurological function in rats with MCAO. Furthermore, high mRNA expression of Bax and low mRNA expression of Bcl-2 induced by MCAO was prevented by EA. EA substantially restored total glutathione reductase (GR), glutathione (GSH) and glutathione peroxidase (GSH-Px) levels. Additionally, Nrf2 and glutamylcysteine synthetase (GCS) expression levels were markedly increased by EA. Interestingly, the neuroprotective effects of EA were attenuated when ERK1/2 activity was blocked by PD98059 (a specific MEK inhibitor). Collectively, our findings indicate that activation of the ERK1/2 signaling pathway contributes to the neuroprotective effects of EA. Our study provides a better understanding of the regulatory mechanisms underlying the therapeutic effectiveness of EA.