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.

Quorum sensing inhibition and tobramycin acceleration in Chromobacterium violaceum by two natural cinnamic acid derivatives.

Chromobacterium violaceum, one free-living Gram-negative bacterium, is abundantly presented in tropics and sub-tropics soil and aquatic environment; it is also an opportunistic human pathogen. Here, two cinnamic acid derivatives, i.e., 4-dimethylaminocinnamic acid (DCA) and 4-methoxycinnamic acid (MCA), were identified as potential quorum sensing (QS) and biofilm inhibitors in C. violaceum ATCC12472. Both DCA (100 µg/mL) and MCA (200 µg/mL) inhibited the levels of N-decanoyl-homoserine lactone (C10-HSL) and reduced the production of certain virulence factors in C. violaceum, including violacein, hemolysin, and chitinase. Metabolomics analysis indicated that QS-related metabolites, such as ethanolamine and L-methionine, were down-regulated after treatment with DCA and MCA. Quantitative real-time polymerase chain reaction (qRT-PCR) demonstrated that DCA and MCA markedly suppressed the expression of two QS-related genes (cviI and cviR). In addition, DCA and MCA also inhibited biofilm formation and enhanced the susceptibility of biofilms to tobramycin, which was evidenced by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Our results indicated that DCA and MCA can serve as QS-based agent for controlling pathogens.Key Points • DCA and MCA inhibited QS and biofilm formation in C. violaceum.• The combination of DCA or MCA and tobramycin removed the preformed biofilm of C. violaceum. • DCA or MCA inhibited virulence factors and expressions of cviI and cviR of C. violaceum.• DCA or MCA are potential antibiotic accelerants for treating C. violaceum infection.

[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.

[Effects of Different Vegetation Types and Reclamation Years on Soil Bacterial Community Structure in Reclaimed Mine Areas].

Effects of different vegetation types (Ulmus pumila, Larix gmelinii, Armeniaca vulgaris, Picea asperata and Robinia pseudoacacia) and reclamation years (15 and 20 years) on soil bacterial community structure in reclaimed Antaibao opencast mine areas were investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and clone sequencing. For 20-year reclaimed soils, the significantly highest and lowest bacterial diversity were found in U. pumila and A. vulgaris stand, respectively, whereas no significant differences were found between the other three vegetation types. Under 15-year plantations, soil bacterial diversity index of P. asperata was significantly higher than that of R. pseudoacacia. Soil bacterial diversity index significantly increased in R. pseudoacacia planted soils but decreased in P. asperata treatment with the increase of reclaimed years. No significant change of soil bacterial community structure was observed in the same reclamation years based on the similarity coefficient analysis, cluster analysis and principal component analysis (PCA). Pearson correlation analysis demonstrated that bacterial diversity index was significantly positively correlated with soil pH. Nitrospira, Sphingomonas, Arthrobacter, Brachybacterium, Rhizobium as well as Mesorhizobium, which play important roles in the nitrogen cycle, degradation of polycyclic aromatic hydrocarbons and other organic matter, were identified by clone sequencing of the DGGE bands. Our results indicated that U. pumila and P. asperata were conducive to the recovery of soil bacterial diversity. The most dominant bacterial community from reclaimed mine soil would be beneficial for restoring wasteland contaminated soil and improving soil fertility.

Analysis on Serum Trace Element Levels of Echinococciasis Patients in Garze Tibetan Autonomous Prefecture in Sichuan, China, 2011.

In Garze Tibetan autonomous prefecture in Sichuan province, China, 41 echinococciasis patients who had received surgical treatment were recruited in the study, and 82 health persons who had lived in Garze for at least 10 years were selected as controls. The serum levels of Zn, Se and Cu of the cases and controls were detected. The results showed that most echinococciasis cases were distributed in Shiqu county (17.1%, 7/41), and only 1 case was distributed in Yajiang county (2.4%). The male to female ratio of the cases was 1:1.56. The echinococciasis patients were mainly aged 30-39 years (36.59%, 15/41). And, the cases aged 20-49 years accounted for 68.29% (28/41). Compared with health controls, the serum levels of Zn and Se of the cases significantly declined. However, the serum level of Cu of the cases had no significantly change. It was confirmed that the serum levels of Zn and Se were interrelated with the prevalence of echinococciasis.

[Effects of Different Reclaimed Scenarios on Soil Microbe and Enzyme Activities in Mining Areas].

Abstract: Ecological degradation in the mining areas is greatly aggravated in recent several decades, and ecological restoration has become the primary measure for the sustainable development. Soil microbe and enzyme activity are sensitive indices to evaluate soil quality. Ecological reconstruction was initiated in Antaibao mining area, and we tested soil physicochemical properties, microbial populations of azotobacteria, nitrifying-bacteria and denitrifying-bacteria, and enzyme activities (including sucrose, polyphenol oxidase, dehydrogenase and urease) under different regeneration scenarios. Regeneration scenarios had significant effects on soil physicochemical properties, microbial population and enzyme activities. Total nitrogen was strongly correlated with azotobacteria and nitrifying-bacteria, however, total nitrogen was not correlated with denitrifying-bacteria. Phenol oxidase activity was negatively correlated with soil organic carbon and total nitrogen, but other enzyme activities were positively correlated with soil organic carbon and total nitrogen. Principal Component Analysis ( PCA) was applied to analyze the integrated fertility index (IFI). The highest and lowest IFIs were in Robinia pseudoacacia-Pinus tabuliformis mixed forests and un-reclaimed area, respectively. R. pseudoacacia-P. tabuliformis mixed forests were feasible for reclaimed mining areas in semi-arid region Northwest Shanxi.

Intraoperative blood salvage and leukocyte depletion during liver transplantation with bacterial contamination.

BACKGROUND: Bacterial contamination is considered to be a contraindication for intraoperative blood salvage (IBS) during OLT. The aims of this study were to evaluate the efficiency of the autotransfusion device with an additional leukocyte depletion filter (LDF) for eliminating bacterial contaminations, and its clinical outcomes in terms of post-operative infections during OLT. METHODS: Forty-five patients with end-stage liver disease and cirrhotic ascites were enrolled in this study. The blood from the surgical field was collected and processed by an autotransfusion device (Cell Saver 5) and a LDF for bacteriological analysis. Among them, 12 patients with chronic severe hepatitis B received autologous transfusion for analysis of the effect on post-operative infections. RESULTS: Spontaneous bacterial peritonitis (SBP) (p < 0.05, OR = 20.1) and a long duration of operation (p < 0.01, OR = 8.3) were found to be critical risk factors for contamination. Autotransfusion devices with an additional LDF significantly eliminated bacterial contaminants from shed blood (p < 0.05). About 33% (4/12) of the patients who received autologous transfusion with salvaged and filtered erythrocytes got post-operative bacterial infection. CONCLUSIONS: Autotransfusion devices with an additional LDF could significantly eliminate bacterial contaminants of shed blood during OLT. The new mode of IBS might be a good option in reducing post-operative infections, and deserves a large-scale clinical trial.

Intraoperative blood salvage during liver transplantation in patients with hepatocellular carcinoma: efficiency of leukocyte depletion filters in the removal of tumor cells.

BACKGROUND: Intraoperative blood salvage (IBS) reduces homologous transfusion in orthotopic liver transplantation (OLT), but may carry with it the risk of reinfusing tumor cells in patients with hepatocellular carcinoma (HCC). The use of leukocyte depletion filters (LDFs) for the removal of tumor cells is rarely reported in clinical OLT. The aims of this study were to evaluate the frequency of tumor cell contamination in surgical field during OLT for HCC recipients and to investigate the efficiency of additional LDFs for eliminating tumor cells from IBS. METHODS: Thirty-two HCC patients with preoperatively elevated serum alpha-fetoprotein (AFP) underwent OLT. The blood from the surgical field was collected and processed by an autotransfusion device (Cell Saver 5), followed by 2 consecutive LDF filtrations. The HCC cells in IBS samples and filtered samples were determined using a nested RT-PCR technique to detect the AFP mRNA. RESULTS: The shed blood samples from 20 (62.5%) of the 32 HCC patients were contaminated with HCC cells and 15 of them remained positive after Cell Saver processing. Patients within the Milan or UCSF criteria were less likely to have HCC cell contamination and the contaminated HCC cells were more likely to be removed by the Cell Saver in these patients as compared to other patients (P<0.01). After filtration through an additional LDF, most cases (13/15) became negative except for those with ruptured tumors (P<0.05). CONCLUSIONS: Our results suggest that blood filtration with the LDF can efficiently remove tumor cells and the use of an additional LDF after use of the Cell Saver could markedly reduce the risk of tumor cell reintroduction during the OLT in HCC recipients with nonruptured tumors.