The complete mitochondrial genome of Paragonimus ohirai (Paragonimidae: Trematoda: Platyhelminthes) and its comparison with P. Westermani congeners and other trematodes

We present the complete mitochondrial genome of Paragonimus ohirai Miyazaki, 1939 and compare its features with those of previously reported mitochondrial genomes of the pathogenic lung-fluke, Paragonimus westermani, and other members of the genus. The circular mitochondrial DNA molecule of the single fully sequenced individual of P. ohirai was 14,818 bp in length, containing 12 protein-coding, two ribosomal RNA and 22 transfer RNA genes. As is common among trematodes, an atp8 gene was absent from the mitogenome of P. ohirai and the 50 end of nad4 overlapped with the 30 end of nad4L by 40 bp. Paragonimusohirai and four forms/strains of P. westermani from South Korea and India, exhibited remarkably different base compositions and hence codon usage in protein-coding genes. In the fully sequenced P. ohirai individual, the non-coding region started with two long identical repeats (292 bp each), separated by tRNAGlu. These were followed by an array of six short tandem repeats (STR), 117 bp each. Numbers of the short tandem repeats varied among P. ohirai individuals. A phylogenetic tree inferred from concatenated mitochondrial protein sequences of 50 strains encompassing 42 species of trematodes belonging to 14 families identified a monophyletic Paragonimidae in the class Trematoda. Characterization of additional mitogenomes in the genus Paragonimus will be useful for biomedical studies and development of molecular tools and mitochondrial markers for diagnostic, identification, hybridization and phylogenetic/epidemiological/evolutionary studies

The ribosomal transcription units of Haplorchis pumilio and H. taichui and the use of 28S rDNA sequences for phylogenetic identification of common heterophyids in Vietnam

Background: Heterophyidiasis is now a major public health threat in many tropical countries. Species in the trematode family Heterophyidae infecting humans include Centrocestus formosanus, Haplorchis pumilio, H. taichui, H. yokogawai, Procerovum varium and Stellantchasmus falcatus. For molecular phylogenetic and systematic studies on trematodes, we need more prospective markers for taxonomic identification and classification. This study provides near-complete ribosomal transcription units (rTU) from Haplorchis pumilio and H. taichui and demonstrates the use of 28S rDNA sequences for identification and phylogenetic analysis. Results: The near-complete ribosomal transcription units (rTU), consisting of 18S, ITS1, 5.8S, ITS2 and 28S rRNA genes and spacers, from H. pumilio and H. taichui from human hosts in Vietnam, were determined and annotated. Sequence analysis revealed tandem repetitive elements in ITS1 in H. pumilio and in ITS2 in H. taichui. A phylogenetic tree inferred from 28S rDNA sequences of 40 trematode strains/species, including 14 Vietnamese heterophyid individuals, clearly confirmed the status of each of the Vietnamese species: Centrocestus formosanus, Haplorchis pumilio, H. taichui, H. yokogawai, Procerovum varium and Stellantchasmus falcatus. However, the family Heterophyidae was clearly not monophyletic, with some genera apparently allied with other families within the superfamily Opisthorchioidea (i. e. Cryptogonimidae and Opisthorchiidae). These families and their constituent genera require substantial re-evaluation using a combination of morphological and molecular data. Our new molecular data will assist in such studies. Conclusions: The 28S rDNA sequences are conserved among individuals within a species but varied between genera. Based on analysis of 40 28S rDNA sequences representing 19 species in the superfamily Opisthorchioidea and an outgroup taxon (Alaria alata, family Diplostomidae), six common human pathogenic heterophyids were identified and clearly resolved. The phylogenetic tree inferred from these sequences again confirmed anomalies in molecular placement of some members of the family Heterophyidae and demonstrates the need for reappraisal of the entire superfamily Opisthorchioidea. The new sequences provided here supplement those already available in public databases and add to the array of molecular tools that can be used for the diagnosis of heterophyid species in human and animal infections

Synthesis of cuprous oxide nanocubes combined with chitosan nanoparticles and its application to p-nitrophenol degradation

For the first time, cuprous oxide nanocubes (Cu2O NCBs) were successfully combined with chitosan nanoparticles (CS NPs) to generate Cu2O NCBs/CS NPs composites material with highly optical property and photocatalytic activity using a simple and eco-friendly synthetic approach at room temperature for 30 min. The synthesized Cu2O NCBs NPs/CS NPs were determined characterizations by Ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X – ray Diffraction (XRD),  Transmission Electron Microscope (TEM) and Energy-dispersive X-ray spectroscopy (EDX). Results show that the Cu2O NCBs/CS NPs composites have an average particle size of ~3-5 nm; in which, Cu2O has the form of nanocubes (Cu2O NCBs) with size ~3-4 nm and chitosan nanoparticles with spherical shape (CS NPs) with size ~4-5 nm. In addition, the percent (%) composition of elements present in Cu2O NCBs/CS NPs composites material have been obtained respective: Cu (23.99%), O (38.18%), and C (33.61%). Moreover, Cu2O NCBs/CS NPs composites material was also investigated for photocatalytic activity applied in p-nitrophenol degradation. The obtained results showed that the catalytic capability of Cu2O NCBs/CS NPs for p-nitrophenol reduction reached the highest efficiency >55% in the treatment time of 25 min, and this efficiency was higher than that result of using ZnO@chitosan nanoparticles (ZnO@CS NPs) catalyst under the same conditions for comparison

A METHOD TO IMPROVE THE TIME OF COMPUTING BETWEENNESS CENTRALITY IN SOCIAL NETWORK GRAPH

The Betweenness centrality is an important metric in the graph theory and can be applied in the analyzing social network. The main researches about Betweenness centrality often focus on reducing the complexity. Nowadays, the number of users in the social networks is huge. Thus, improving the computing time of Betweenness centrality to apply in the social network is neccessary. In this paper, we propose the algorithm of computing Betweenness centrality by reduce the similar nodes in the graph in order to reducing computing time. Our experiments with graph networks result shows that the computing time of the proposed algorithm is less than Brandes algorithm. The proposed algorithm is compared with the Brandes algorithm [3] in term of execution time

Cloning and expression of gene FanC-2NT encoding K99-2NT fimbrial antigen of enterotoxigenic Escherichia coli from diarrheic post-weaning piglets

Background and Purpose: The K99 (F5) is one pilus adhesin that mediates the attachment of enterotoxigenic E. coli (ETEC) strains to small intestines to cause to diarrhea in piglets, lambs and newborn calves. In this work, we carried out cloning and expression of the mature peptide of FanC subunit, K99 fimbriae, one of the most common adhesive antigens in E. coli. Materials and Methods: E. coli 2NT strain was isolated from fecal samples of post-weaning piglets with diarrhea. The coding sequence of the mature peptide of K99-2NT subunit was isolated by PCR amplification and cloned into pGEM®-T Easy vector for sequencing using fluorescent dideoxy-terminator method. Expression of K99-2NT protein which was inserted into pET200/D-TOPO vector induced with IPTG. The PCR product and expression level of protein was examined by agarose gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. Results and Conclusions: We cloned and expressed successfully the mature peptide of K99 subunit with molecular weight of approximately 17.5 kDa from E. coli 2NT strain (named K99-2NT). Nucleotide sequence of the K99-2NT subunit coding region of fanC-2NT gene is 477 bp in length and is 99% similarity with that of fanC gene (accession no: M35282). Highest expression level occurred after 12 h of induction with 0.75 mM IPTG at 37oC. This subunit antigen will be tested for immune response of rat in the next time

Antibacterial Nanocomposites Based on Fe 3

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions

Environmental Pollution of Heavy Metals in a Vietnamese Informal E-waste Processing Village

Inappropriate handlings of informal e-waste processing have increasingly become a global environmental and public health issue of concern. This study was conducted to quantify the concentrations of five heavy metals found in the environmental media at an exposed village and a reference village in Northern Vietnam. The correlations between a pair of the heavy metals found in a medium, and between a pair of the environmental media was found. The results showed that drinking water was safe for heavy metal exposure in both studied villages. However, at the exposed village, the levels of the heavy metals found in indoor soil were, in descending order, Pb (678.42 ± 846.11 mg kg-1) > Ni (148.77± 163.80 mg kg-1) > Cr (61.99 ± 42.50 mg kg-1) > As (7.62 ± 3.33 mg kg-1) > Cd (6.34 ± 12.39 mg kg-1). The levels of Pb, Cd, Cr, and Ni in indoor soil and surface dust in the exposed village were significantly higher than those in the reference village at p<0.001. The average concentrations of Pb, Cd, Cr, Ni and As in indoor soil were 3.57, 8.78, 1.90, 4.41, and 1.08 times, respectively, higher than those in outdoor soil at p<0.001. The levels of Pb and Cd found in indoor soil at the exposed village were 9.69 and 3.17 time, respectively, higher than the maximum allowable limits in Vietnam. Significant correlations between the pairs of the heavy metals in a medium and between the pair of the environmental media was found at the exposed village. This finding suggested that inappropriate activities conducted at an informal e-waste processing facility could be a major contributor to the heavy metal contaminations. This study highlighted the importance of release mitigation of a hazardous heavy metal from an informal e-waste processing facility to prevent its potential effects on human health

SECONDARY METABOLITES FROM MICROMONOSPORA SP. (G044)

In the course of our screening program, the EtOAc extract of a Micromonospora sp. (strain G044) from sponge Tethya aurantium of the sea of Côtô - Thanh Lân exhibited antimicrobial activity against Enterococcus faecalis, Bacillus cereus and Candida albicans. In this paper, we reported the isolation and structural elucidation of six secondary metabolites Cyclo-(Pro-Trp) (1), Cyclo-(Pro-Met) (2), Cyclo-(Pro-Val) (4), N-acetyltryptamine (3), uridine (5), and 2-phenylacetic acid (6) from the cultures broth of Micromonospora sp. (strain G044). The structures of 1 – 6 were determined by analyses of MS and 2D NMR data. All compounds were evaluated for their antimicrobial activity against a panel of clinically significant microorganisms. Compound 1 inhibited Escherichia coli with a MIC value of 128 µg/ml

Prevalence of carbapenem resistance and its potential association with antimicrobial use in humans and animals in rural communities in Vietnam

Background Vietnam and Southeast Asia are hotspots for antimicrobial resistance; however, little is known on the prevalence of carriage of carbapenem resistance in non-hospitalized humans and in animals. Carbapenem-resistant Enterobacteriaceae (CRE), particularly Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP) and also Acinetobacter baumannii (CRAB) are emerging threats worldwide. Methods We investigated healthy humans (n = 652), chickens (n = 237), ducks (n = 150) and pigs (n = 143) in 400 small-scale farms in the Mekong Delta of Vietnam. Samples (rectal swabs, faecal swabs) were investigated for carriage of CRE/CRAB and were further characterized phenotypically and genotypically. Results In the Mekong Delta of Vietnam, the prevalence of CRE isolates in human rectal swabs was 0.6%, including 4 CREC and 1 CRKP. One pig was infected with CREC (prevalence 0.7%). CRAB was isolated from chickens (n = 4) (prevalence 2.1%) and one duck (prevalence 0.7%). CRKP was isolated from a human who was also colonized with CREC. The CRKP strain (ST16), from an 80 year-old person with pneumonia under antimicrobial treatment, genetically clustered with clinical strains isolated in a hospital outbreak in southern Vietnam. The prevalence of CRE was higher among humans that had used antimicrobials within 90 days of the sampling date than those had not (4.2% versus 0.2%) (P = 0.005). All CRE/CRAB strains were MDR, although they were susceptible to colistin and neomycin. The carbapenemase genes identified in study strains were blaNDM and blaOXA. Conclusions The finding of a CRKP strain clustering with previous hospital outbreak raises concerns about potential transmission of carbapenem-resistant organisms from hospital to community settings or vice-versa

Chemical constituents from fruits of Hydnocarpus hainanensis Merr. (Flacourtiaceae) in Vietnam

Five compounds were isolated from the fruits of Hydnocarpus hainanensis Merr. Sleum. (Flacourtiaceae). Their structures were determined by spectroscopic analysis including MS and NMR. The isolates were identified as taraktophyllin (1), hydnocarpic acid (2), 3,4-dihydroxybenzyl alcohol (3), 3,4-dihydroxybenzoic acid (4) and 3-hydroxy-4-methoxybenzoic acid (5)