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MXene, a family of two-dimensional (2D) transition metal carbides and nitrides, has intriguing electrochemical energy storage and electrocatalysis applications. Introducing the electronic metal-support interaction (EMSI) effect is one effective strategy to optimize the catalytic efficiency for MXene-based composites. However, most of the studies concentrate on optimizing the performance of metals rather than supported substrates by using this strategy. In this work, we mainly investigate the influence of an EMSI effect on the performance of the supported substrate (Ti3C2Tx MXene). Detailed scanning electrochemical microscopy and numerical simulations results reveal that the charge distribution on the Ti3C2Tx basal plane (approximate 100 nm-radius) surrounding Au nanoparticles (20 nm-radius) was significantly enhanced as a result of —O being the majority surface functional group on Ti3C2Tx that was attached to Au nanoparticle, and the related hydrogen evolution reaction (HER) activity was much better than that of the unaffected Ti3C2Tx basal plane, which even can be comparable to that of Au. This finding will be helpful for designing new strategies to enhance the overall catalytic performance of various MXene-based composites. [ABSTRACT FROM AUTHOR]

The human gut microbiome has been extensively explored, while the archaeal viruses remain largely unknown. Here, we present a comprehensive analysis of the archaeal viruses from the human gut metagenomes and the existing virus collections using the CRISPR spacer and viral signature-based approach. This results in 1279 viral species, of which, 95.2% infect Methanobrevibacteria_A, 56.5% shared high identity (>95%) with the archaeal proviruses, 37.2% have a host range across archaeal species, and 55.7% are highly prevalent in the human population (>1%). A methanogenic archaeal virus-specific gene for pseudomurein endoisopeptidase (PeiW) frequently occurs in the viral sequences (n = 150). Analysis of 33 Caudoviricetes viruses with a complete genome often discovers the genes (integrase, n = 29; mazE, n = 10) regulating the viral lysogenic-lytic cycle, implying the dominance of temperate viruses in the archaeal virome. Together, our work uncovers the unexplored diversity of archaeal viruses, revealing the novel facet of the human gut microbiome. Human gut archaeal viruses remain largely unknown. Here the authors present a bioinformatic pipeline to identify viruses of human gut archaea, revealing diversity of archaeal viruses, their hosts and their functional gene repertoire in the human gut. [ABSTRACT FROM AUTHOR]

The aim of this study was to carry out a case control study comparing the HPV genome in patients with oral cavity squamous cell carcinoma (OC-SCC) to normal patients using metagenomic shotgun sequencing. We recruited 50 OC-SCC cases which were then matched with a control patient by age, gender, race, smoking status and alcohol status. DNA was extracted from oral wash samples from all patients and whole genome shotgun sequencing performed. The raw sequence data was cleaned, reads aligned with the human genome (GRCH38), nonhuman reads identified and then HPV genotypes identified using HPViewer. In the 50 patients with OC-SCC, the most common subsite was tongue in 26 (52%). All patients were treated with primary resection and neck dissection. All but 2 tumors were negative on p16 immunohistochemistry. There were no statistically significant differences between the cases and controls in terms of gender, age, race/ethnicity, alcohol drinking, and cigarette smoking. There was no statistically significant difference between the cancer samples and control samples in the nonhuman DNA reads (medians 4,228,072 vs. 5,719,715, P value = 0.324). HPV was detected in 5 cases (10%) of OC-SCC (genotypes 10, 16, 98) but only 1 tumor sample (genotype 16) yielded a high number of reads to suggest a role in the etiology of OC-SCC. HPV was detected in 4 control patients (genotypes 16, 22, 76, 200) but all had only 1–2 HPV reads per human genome. Genotypes of HPV are rarely found in patients with oral cancer. [ABSTRACT FROM AUTHOR]

Pseudomonas phages PaGz-1 and PaZq-1, two new phages infecting Pseudomonas aeruginosa, were isolated from fresh water in Guangdong province, China. The genomes of these two phages consist of 93,975 bp and 94,315 bp and contain 175 and 172 open reading frames (ORFs), respectively. The genome sequences of PaGz-1 and PaZq-1 share 95.8% identity with a query coverage of 94%, suggesting that these two phages belong to two different species. Based on results of nucleotide sequence alignment, gene annotation, and phylogenetic analysis, we propose PaGz-1 and PaZq-1 as representative isolates of two species in the genus Pakpunavirus within the family Myoviridae. [ABSTRACT FROM AUTHOR]

Salmonella phages SenALZ1 and SenASZ3, two novel phages infecting Salmonella enterica, were isolated and analyzed. The genomes of these two phages consist of 154,811 and 157,630 base pairs (bp), with G+C contents of 44.56% and 44.74%, respectively. Fifty-nine of 199 open reading frames (ORFs) in the SenALZ1 genome, and 60 of the 204 in the SenASZ3 genome show similarity to reference sequences in the NCBI nr database that encode putative phage proteins with predicted functions. Based on the results of transmission electron microscopy (TEM) examination, complete genome sequence alignment, phylogenetic analysis, and gene annotation, we propose that these two phages are representative isolates of two new species of the genus Cba120virus, subfamily Cvivirinae, family Ackermannviridae. [ABSTRACT FROM AUTHOR]

In this study, two bacteriophage isolates, AhSzq-1 and AhSzw-1 that specifically infect Aeromonas hydrophila strain KT998822, were isolated from seawater and characterized. One-step growth curves showed that the latent period of AhSzq-1 and AhSzw-1 are 50 min and 60 min, respectively. The sequence similarities between AhSzq-1 and AhSzw-1 were 88% at the DNA and 83% at the protein level, suggesting that these two phages are representatives of two different species. The virion morphology, DNA genome size and terminal repeats of these two phages are similar to those of viruses classified as T5virus phages. Both phylogenetic analyses and proteomic comparison show that AhSzq-1 and AhSzw-1 group with members of the T5virus genus. We thus propose these two phages as representative isolates of two new species within the T5virus genus. [ABSTRACT FROM AUTHOR]

AsXd-1, a bacteriophage that infects Aeromonas salmonicida, was isolated from the wastewater of a seafood market in Shenzhen, China. The 39,014-bp genome of this phage contains 52 open reading frames (ORFs), 30 of which were found to be homologous to reference sequences that putatively encode functional phage proteins. Nine out of the remaining 22 ORFs with unknown functions were unique to AsXd-1. Gene annotation suggests that AsXd-1 has both lysogenic and lytic life cycles. Furthermore, both phylogenetic analysis based on the large subunit of terminase and genome sequence comparisons show that AsXd-1 is closely related to phages belonging to the genus Hk97virus. We thus propose AsXd-1 as a new member of the genus Hk97virus within the family Siphoviridae. [ABSTRACT FROM AUTHOR]

Increasing evidences have revealed a close interaction between the intestinal microbes and host growth performance. The shrimp (Litopenaeus vannamei) gut harbors a diverse microbial community, yet its associations with dietary, body weight and weaning age remain a matter of debate. In this study, we analyzed the effects of different dietary (fishmeal group (NC), krill meal group (KM)) and different growth stages (age from 42 day-old to 98 day-old) of the shrimp on the intestinal microbiota. High throughput sequencing of the 16S rRNA genes of shrimp intestinal microbes determined the novelty of bacteria in the shrimp gut microbiota and a core of 58 Operation Taxonomic Units (OTUs) was present among the shrimp gut samples. Analysis results indicated that the development of the shrimp gut microbiota is a dynamic process with three stages across the age according to the gut microbiota compositions. Furthermore, the dietary of KM group did not significantly change the intestinal microbiota of the shrimps compared with NC group. Intriguingly, compared to NC group, we observed in KM group that a fluctuation of the shrimp gut microbiota coincided with the shrimp body weight gain between weeks 6-7. Six OTUs associated with the microbiota change in KM group were identified. This finding strongly suggests that the shrimp gut microbiota may be correlated with the shrimp body weight likely by influencing nutrient uptake in the gut. The results obtained from this study potentially will be guidelines for manipulation to provide novel shrimp feed management approaches. [ABSTRACT FROM AUTHOR]