Urban green waste bulking agent is the major source of antimicrobial resistance genes persisted in home compost, not animal manure.

Urban green waste and food waste are often used as bulking agents to prepare home compost in combination with animal manure in urban horticulture and community gardening. Although it is known that antimicrobial resistance genes (ARGs) persist in home compost, their origins have not been determined. In addition, the factors contributing to ARGs persistence remain unclear. In this study, we aim to (i) characterize the changes in the microbiome and antimicrobial resistome during the composting process of home compost using metagenomics shotgun sequencing, (ii) identify the source of the ARGs persisted in home compost using SourceTracker, and (iii) elucidate the collective effect of compost microbiome and environmental factors, including the physicochemical properties and antibiotics concentration of home compost, in contributing to ARG persistence using Procrustes analysis, co-occurrence network analysis, variation partitioning analysis, and structural equation modeling. SourceTracker analysis indicated that urban green waste bulking agent was the major source of the persisting ARGs in home compost instead of animal manure. Procrustes analysis and co-occurrence network analysis revealed a strong association between microbiome and antimicrobial resistome. Variation partitioning analysis and structural equation modeling suggested that physicochemical properties shaped the antimicrobial resistome directly and indirectly by influencing the microbiome. Our results indicated that the persistence of ARGs in home compost might be due to the succession of microbial species from the urban green waste bulking agent, and the physicochemical properties might have defined the compost environment to shape the microbiome in the compost, thus, in turn, the persisting antimicrobial resistome.

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near PAX4.

AIMS/HYPOTHESIS: Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians. METHODS: We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations. RESULTS: We identified CDKN2A/B and four novel type 2 diabetes association signals with p < 1 × 10(-5) from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (p meta = 2.6 × 10(-8); OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (p meta = 2.3 × 10(-10)) and a population of European descent (p = 8.6 × 10(-3)). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians. CONCLUSIONS/INTERPRETATION: Our study identifies rs10229583 near PAX4 as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.

Modulation of potential respiratory pathogens by pH1N1 viral infection.

While much effort has been made to characterize influenza A pdm09 virus (pH1N1), the flu that was responsible for the fourth influenza pandemic, there is a lack of study on the composition of bacteria that lead to secondary infection. In this study, we recruited pneumonia patients with and without pH1N1 infection and characterized their oropharyngeal microbiota by the unbiased high-throughput sequencing method. While there were no significant differences in common bacterial pneumonia-causative agents (Acinetobacter and Streptococcus species), previously unreported Pseudomonas species equipped with chemotaxis and flagellar assembly genes significantly increased (>20-fold) in the pH1N1-infected group. Bacillus and Ralstonia species that also increased significantly (5-10-fold) were also found to possess similar signaling and motility genes. In contrast, no such genes were found in oral commensal Prevotella, Veillonella and Neisseria species, which decreased significantly, or in either Acinetobacter or 10 out of 21 Streptococcus species, including Streptococcus pneumoniae. Our results support the notion that pH1N1 infection provides a niche for previously unnoticed potential respiratory pathogens that were able to access the lower respiratory tract with weakened immunity.

Detection and identification of plasma bacterial and viral elements in HIV/AIDS patients in comparison to healthy adults.

A low level of CD4+ lymphocyte cells makes end-stage HIV/AIDS patients highly susceptible to microbial infections. We have adopted the next generation sequencing method to identify the spectrum of bacterial plasma and viral elements that might be present in these patients. The HIV/AIDS plasma microbiome was dominated by bacterial elements in the taxonomical order Pseudomonadales, while healthy people carried fewer bacterial DNA in the plasma. We have found that many of the bacterial elements in HIV/AIDS plasma are similar to those of the microbes found in the human gut, suggesting potential acquisition of microbial elements from the gut. The HIV/AIDS and normal plasma DNA virome shared some similarities in the presence of common ubiquitous eukaryotic viruses. The normal DNA virome was mainly composed of viruses from Anelloviridae. In contrast, the HIV/AIDS DNA virome contained a large proportion of bacteriophages, endogenous retroviruses and a non-human virus. In addition, several sequences, which might belong to novel bacteria or endogenous retroviruses, were identified. Taken together, the use of high-throughput sequencing technology in unveiling microbial metagenomics may facilitate future research in combating HIV/AIDS and its associated microbial complications.

Inhibition of c-Met downregulates TIGAR expression and reduces NADPH production leading to cell death.

c-Met represents an important emerging therapeutic target in cancer. In this study, we demonstrate the mechanism by which c-Met tyrosine kinase inhibition inhibits tumor growth in a highly invasive Asian-prevalent head and neck cancer, nasopharyngeal cancer (NPC). c-Met tyrosine kinase inhibitors (TKIs; AM7 and c-Met TKI tool compound SU11274) downregulated c-Met phosphorylation, resulting in marked inhibition of NPC cell growth and invasion. Strikingly, inhibition of c-Met resulted in significant downregulation of TP53-induced Glycolysis and Apoptosis Regulator (TIGAR) and subsequent depletion of intracellular NADPH. Importantly, overexpression of TIGAR ameliorated the effects of c-Met kinase inhibition, confirming the importance of TIGAR downregulation in the growth inhibitory activity of c-Met TKI. The effects of c-Met inhibition on TIGAR and NADPH levels were observed with two different c-Met TKIs (AM7 and SU11274) and with multiple cell lines. As NADPH provides a crucial reducing power required for cell survival and proliferation, our findings reveal a novel mechanistic action of c-Met TKI, which may represent a key effect of c-Met kinase inhibition. Our data provide the first evidence linking c-Met, TIGAR and NADPH regulation in human cancer cells suggesting that inhibition of a tyrosine kinase/TIGAR/NADPH cascade may have therapeutic applicability in human cancers.

FGF8b oncogene mediates proliferation and invasion of Epstein-Barr virus-associated nasopharyngeal carcinoma cells: implication for viral-mediated FGF8b upregulation.

The fibroblast growth factor 8b (FGF8b) oncogene is known to be primarily involved in the tumorigenesis and progression of hormone-related cancers. Its role in other epithelial cancers has not been investigated, except for esophageal cancer, in which FGF8b overexpression was mainly found in tumor biopsies of male patients. These observations were consistent with previous findings in these cancer types that the male sex-hormone androgen is responsible for FGF8b expression. Nasopharyngeal carcinoma (NPC) is a highly metastatic cancer of head and neck commonly found in Asia. It is etiologically associated with Epstein-Barr Virus (EBV) infection, inflammatory tumor microenvironment and relatively higher male predominance. Here, we reported for the first time that FGF8b is overexpressed in this EBV-associated non-hormone-related cancer of the head and neck, NPC. More importantly, overexpression of FGF8b mRNA and protein was detected in a large majority of NPC tumors from both male and female genders, in addition to multiple NPC cell lines. We hypothesized that FGF8b overexpression may contribute to NPC tumorigenesis. Using EBV-associated NPC cell lines, we demonstrated that specific knockdown of FGF8b by small interfering RNA inhibited cell proliferation, migration and invasion, whereas exogenous FGF8b stimulated these multiple phenotypes. Further mechanistic investigation revealed that in addition to NF-κB signaling (a major inflammatory signaling pathway known to be activated in NPC), an important EBV oncoprotein, the latent membrane protein 1 (LMP1), was found to be a direct inducer of FGF8b overexpression in NPC cells, whereas androgen (testosterone) has minimal effect on FGF8b expression in EBV-associated NPC cells. In summary, our study has identified LMP1 as the first viral oncogene capable of directly inducing FGF8b (an important cellular oncogene) expression in human cancer cells. This novel mechanism of viral-mediated FGF8 upregulation may implicate a new role of oncoviruses in human carcinogenesis.

Modulation by simvastatin of iberiotoxin-sensitive, Ca2+-activated K+ channels of porcine coronary artery smooth muscle cells.

BACKGROUND AND PURPOSE: Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase inhibitors) have been demonstrated to reduce cardiovascular mortality. It is unclear how the expression level of HMG CoA reductase in cardiovascular tissues compares with that in cells derived from the liver. We hypothesized that this enzyme exists in different cardiovascular tissues, and simvastatin modulates the vascular iberiotoxin-sensitive Ca2+-activated K(+) (BK(Ca)) channels. EXPERIMENTAL APPROACHES: Expression of HMG CoA reductase in different cardiovascular preparations was measured. Effects of simvastatin on BK(Ca) channel gatings of porcine coronary artery smooth muscle cells were evaluated. KEY RESULTS: Western immunoblots revealed the biochemical existence of HMG CoA reductase in human cardiovascular tissues and porcine coronary artery. In porcine coronary artery smooth muscle cells, extracellular simvastatin (1, 3 and 10 microM) (hydrophobic), but not simvastatin Na+ (hydrophilic), inhibited the BK(Ca) channels with a minimal recovery upon washout. Isopimaric acid (10 microM)-mediated enhancement of the BK(Ca) amplitude was reversed by external simvastatin. Simvastatin Na+ (10 microM, applied internally), markedly attenuated isopimaric acid (10 microM)-induced enhancement of the BK(Ca) amplitude. Reduced glutathione (5 mM; in the pipette solution) abolished simvastatin -elicited inhibition. Mevalonolactone (500 microM) and geranylgeranyl pyrophosphate (20 microM) only prevented simvastatin (1 and 3 microM)-induced responses. simvastatin (10 microM ) caused a rottlerin (1 microM)-sensitive (cycloheximide (10 microM)-insensitive) increase of PKC-delta protein expression. CONCLUSIONS AND IMPLICATIONS: Our results demonstrated the biochemical presence of HMG CoA reductase in different cardiovascular tissues, and that simvastatin inhibited the BK(Ca) channels of the arterial smooth muscle cells through multiple intracellular pathways.

Immunomodulatory effects of a traditional Chinese medicine with potential antiviral activity: a self-control study.

Traditional Chinese medicine (TCM) has been used for prevention and treatment of severe acute respiratory syndrome (SARS) in Hong Kong during the outbreak in spring 2003. We investigated the immunomodulating effects of an innovative TCM regimen derived from two herbal formulas (Sang Ju Yin and Yu Ping Feng San) for treating febrile diseases. Thirty-seven healthy volunteers were given the oral TCM regimen daily for 14 days. Peripheral venous blood samples were taken on days 0, 15 and 29 for hematology, biochemistry and immunology tests, including the measurement of blood lymphocyte subsets and plasma T-helper lymphocyte types 1 and 2 cytokines and receptor. After 3 months, 23 of the volunteers participated in a control study without TCM treatment for the same time course of blood tests. Two volunteers withdrew on day 2, due to headache and dizziness. All others remained well without any side effects. No participants showed significant changes in their blood test results, except that the T-lymphocyte CD4/CD8 ratio increased significantly from 1.31 +/- 0.50 (mean +/- SD) on day 0 to 1.41 +/- 0.63 on day 15 (p < 0.02), and reduced to 1.32 +/- 0.47 on day 29 (p < 0.05). In the control study, there were no changes in the CD4/CD8 ratio. The transient increase in CD4/CD8 ratio was likely due to the TCM intake. We postulate that the administration of the innovative TCM may have beneficial immunomodulatory effects for preventing viral infections including SARS.

Genomic characterisation of the severe acute respiratory syndrome coronavirus of Amoy Gardens outbreak in Hong Kong.

Severe acute respiratory syndrome (SARS) is a global health concern. In Hong Kong, two major outbreaks, one hospital based and the other in the Amoy Gardens apartments, were identified. The frequency of diarrhoea, admission to intensive care, and mortality differed significantly between the two outbreaks. We did genomic sequencing for viral isolates from five Amoy Gardens patients. The virus sequence was identical in four of these five patients. The sequence data from one hospital case and the four identical community cases had only three nucleotide differences. Alterations in the SARS coronavirus genome are unlikely to have caused the distinctive clinical features of the Amoy Gardens patients, and these results highlight the importance of non-viral genomic factors in this outbreak.