Bacteroides rhinocerotis sp. nov., isolated from the fresh feces of rhinoceros in Beijing Zoo.

A Gram-negative strain, anaerobic, non-motile, non-spore-forming, rod-shaped bacterial strain named as NGMCC 1.200684 T was isolated from the fresh feces of rhinoceros in Beijing Zoo. Based on 16S rRNA gene sequences, phylogenetic analysis indicated that strain NGMCC 1.200684 T belonged to the genus Bacteroides and was most strongly related to the type strain of Bacteroides uniformis ATCC 8492 T (96.88%). The G + C content of the genomic DNA was determined to be 46.62%. Between strains NGMCC 1.200684 T and B. uniformis ATCC 8492 T, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) were 93.89 and 67.60%, respectively. Strain NGMCC 1.200684 T can produce acid from fermentation of several substrates, including glucose, mannitol, lactose, saccharose, maltose, salicin, xylose, cellobiose, mannose, raffinose, sorbitol, trehalose, D-galactose, and maltotriose. The major cellular fatty acids (> 10%) were identified as anteiso-C15:0, iso-C15:0, iso-C14:0, and iso-C17:0 3-OH. The polar lipid profiles of strain NGMCC 1.200684 T were determined to contain diphosphatidyl glycerol, phosphatidylglycerol, phosphatidylethanolamine, three unknown phospholipids, and two unknown amino-phospholipids. Based on phenotypic, phylogenetic, and chemotaxonomic characteristics, a novel species of the genus Bacteroides, Bacteroides rhinocerotis sp. nov. is proposed. The type strain is NGMCC 1.200684 T (= CGMCC 1.18013 T = JCM 35702 T).

Lactococcus intestinalis sp. nov., a new lactic acid bacterium isolated from intestinal contents in Alzheimer's disease mice.

A gram-positive, facultatively anaerobic, and coccoid or ovoid-shaped bacterium designated M2458T was isolated from the intestinal contents of APPswe/PSΔE9 mouse model of Alzheimer's disease. With the polyphasic approach, the taxonomic position of the novel isolate was confirmed. Strain M2458T grew well at 37 °C on YCFA agar. Strain M2458T belongs to the family Streptococcaceae and class Bacilli, and it is closed to Lactococcus formosensis NBRC 109475T (97.59% sequence similarity) according to its 16S rRNA gene sequence. In a comparison of two housekeeping genes, rpoA and rpoB, strain M2458T was found to be well separated from Lactococcus formosensis NBRC 109475T. On the basis of whole genome sequences, the DNA G+C content was 38.29 mol%. The phylogentic analysis of the whole genome showed that a different branch was clearly formed in the phylogenetic tree of strain M2458T compared to other strains in the genus Lactococcus. A total of eight genes in strain M2458T are involved in the 'neurodegenerative disease' pathway, which involves an annotated protein (glyceraldehyde 3-phosphate dehydrogenase) involved in Alzheimer's disease. In terms of average nucleotide identity and digital DNA-DNA hybridization, strain M2458T was identified as a novel species of the genus Lacococcus. The major fatty acids (> 10% of the total fatty acids) were C18:1ω9c (39.68%), C16:0 (13.26%) and C18:1ω7c (11.52%). The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified phospholipid. As a result of its genotypic and phenotypic characteristics, strain M2458T was considered to be a new species within the genus Lactococcus; the name Lactococcus intestinalis sp. nov. has been proposed, with type strain M2458T (=JCM 35706 = CGMCC 1.60066).

Comparative Metagenomics and Metabolomes Reveals Abnormal Metabolism Activity Is Associated with Gut Microbiota in Alzheimer's Disease Mice.

A common symptom in Alzheimer's disease (AD) is cognitive decline, of which the potential pathogenesis remains unclear. In order to understand the mechanism of gut microbiota in AD, it is necessary to clarify the relationship between gut microbiota and metabolites. Behavioral tests, pathological examination, metagenomics, and metabolomics were applied to analyze the difference of gut microbiota and metabolome between APPswe/PS1ΔE9 (PAP) mice with cognitive decline and age-matched controls, and their possible correlations. Our results showed that PAP mice and health mice had different structures of the bacterial communities in the gut. The abundances and diversities of the bacterial communities in health mice were higher than in PAP mice by metagenomics analysis. The abundances of Libanicoccus massiliensis, Paraprevotella clara, and Lactobacillus amylovorus were significantly increased in PAP mice, while the abundances of Turicibacter sanguinis, Dubosiella newyorkensis, and Prevotella oris were greatly reduced. Furthermore, PAP mice possessed peculiar metabolic phenotypes in stool, serum, and hippocampus relative to WT mice, as is demonstrated by alterations in neurotransmitters metabolism, lipid metabolism, aromatic amino acids metabolism, energy metabolism, vitamin digestion and absorption, and bile metabolism. Microbiota-host metabolic correlation analysis suggests that abnormal metabolism in stool, serum, and hippocampus of PAP mice may be modulated by the gut microbiota, especially T. sanguinis, D. newyorkensis, and P. oris. Therefore, abnormal metabolism activity is associated with gut microbiota in Alzheimer's disease mice. Our results imply that modifying host metabolism through targeting gut microbiota may be a novel and viable strategy for the prevention and treatment of AD in the future.

Genome-wide identification of CBF genes and their responses to cold acclimation in Taraxacum kok-saghyz.

C-repeat binding factors (CBFs) are transcription factors that are known to play important roles in plant cold acclimation. They are highly conserved in most higher plants. Taraxacum kok-saghyz (TKS) is an herb native to China and Kazakhstan and is well-known for its production of rubber silk with industrial and economic value. To understand cold acclimation mechanisms, we conducted a genome-wide discovery of the CBF family genes in TKS and revealed ten CBF genes. A bioinformatic analysis of the CBF genes was carried out to analyze the phylogenetic relationship, protein conservative motifs, protein physicochemical properties, gene structure, promoter cis-acting elements, and the gene expression patterns under cold acclimation and control conditions. It was found that most of these genes were highly responsive at the late stage of cold acclimation, indicating that they play important roles in the cold acclimation processes of TKS. This study provides a theoretical basis for the study of the molecular functions of the CBF gene family in TKS, and a useful guidance for the genetic improvement of the cold tolerance traits of TKS and other plants, including crops.

Gut Microbiota Regulation and Their Implication in the Development of Neurodegenerative Disease.

In recent years, human gut microbiota have become one of the most promising areas of microorganism research; meanwhile, the inter-relation between the gut microbiota and various human diseases is a primary focus. As is demonstrated by the accumulating evidence, the gastrointestinal tract and central nervous system interact through the gut-brain axis, which includes neuronal, immune-mediated and metabolite-mediated pathways. Additionally, recent progress from both preclinical and clinical studies indicated that gut microbiota play a pivotal role in gut-brain interactions, whereas the imbalance of the gut microbiota composition may be associated with the pathogenesis of neurological diseases (particularly neurodegenerative diseases), the underlying mechanism of which is insufficiently studied. This review aims to highlight the relationship between gut microbiota and neurodegenerative diseases, and to contribute to our understanding of the function of gut microbiota in neurodegeneration, as well as their relevant mechanisms. Furthermore, we also discuss the current application and future prospects of microbiota-associated therapy, including probiotics and fecal microbiota transplantation (FMT), potentially shedding new light on the research of neurodegeneration.

Prophylactic subcutaneous drainage reduces post-operative incisional infections in colorectal surgeries: a meta-analysis of randomized controlled trials.

BACKGROUND: Due to lack of high-level evidences, prophylactic subcutaneous drainage has so far not been recommended in relevant guidelines as a countermeasure against incisional infections. This meta-analysis aims to clarify the efficacy of subcutaneous drainage in reducing incisional infections in colorectal surgeries. METHODS: Cochrane Library, Embase, and PubMed were searched for randomized controlled trials comparing the incidence rate of incisional infections between patients receiving prophylactic subcutaneous drainage (interventions) and those not receiving (controls) after digestive surgeries. Results from included RCTs were pooled multiple times according to different surgical types. Heterogeneity, publication bias, and certainty of evidences were estimated. RESULTS: Eight randomized controlled trials were included. Three RCTs each included patients receiving all sorts of digestive surgeries (gastrointestinal, hepatobiliary, and pancreatic); pooled incisional infection rates between the drainage group and the control group were not significantly different (RR = 0.76, 95%CI: 0.48-1.21, p = 0.25). Four RCTs included patients receiving colorectal surgeries; pooled incisional infection rate in the drainage group was significantly lower than that in the control group (RR = 0.34, 95%CI: 0.19-0.61, p = 0.0004). Four RCTs included patients receiving upper GI and/or HBP surgeries; pooled incisional infection rates in the drainage group and the non-drainage group were not significantly different (RR = 0.85, 95%CI: 0.54-1.34, p = 0.49). CONCLUSIONS: Prophylactic subcutaneous drainage significantly reduces post-operative incisional infections in colorectal surgeries but was not efficacious in digestive surgeries in general.

[Baicalein inhibits PI3K/AKT signaling pathway and induces autophagy of MGC-803 cells].

Objective To investigate the effect of baicalein (BAI) on autophagy in gastric cancer cell line MGC-803. Methods MGC-803 cells were treated with 0, 5, 15, 25, 50 µmol/L BAI for 24, 48, 72 hours. The proliferation activity of MGC-803 cells was detected by MTT assay. Acridine orange (AO) staining combined with immunofluorescence cytochemical staining was performed to observe the expression of microtubule-associated protein 1 light chain 3 (LC3) and P62 to determine autophagy in MGC-803 cells. The protein levels of LC3, P62, phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), AKT, and p-AKT were detected by Western blot analysis. Results Compared with the control group, BAI significantly inhibited the proliferation of MGC-803 cells in a time- and dose-dependent manner. BAI-treated MGC-803 cells showed a significant increase in acid lysosomes and increased LC3 expression. BAI treatment significantly decreased phosphorylation of PI3K and AKT proteins, increased the ratio of LC3-II/LC3-I and up-regulated the expression of P62 protein. Conclusion Baicalein could inhibit PI3K/AKT signaling pathway and induce autophagy in MGC-803 cells.

Cramer-rao bounds and coherence performance analysis for next generation radar with pulse trains.

We study the Cramer-Rao bounds of parameter estimation and coherence performance for the next generation radar (NGR). In order to enhance the performance of NGR, the signal model of NGR with master-slave architecture based on a single pulse is extended to the case of pulse trains, in which multiple pulses are emitted from all sensors and then integrated spatially and temporally in a unique master sensor. For the MIMO mode of NGR where orthogonal waveforms are emitted, we derive the closed-form Cramer-Rao bound (CRB) for the estimates of generalized coherence parameters (GCPs), including the time delay differences, total phase differences and Doppler frequencies with respect to different sensors. For the coherent mode of NGR where the coherent waveforms are emitted after pre-compensation using the estimates of GCPs, we develop a performance bound of signal-to-noise ratio (SNR) gain for NGR based on the aforementioned CRBs, taking all the estimation errors into consideration. It is shown that greatly improved estimation accuracy and coherence performance can be obtained with pulse trains employed in NGR. Numerical examples demonstrate the validity of the theoretical results.