Salmonella Newport: Genetic Diversity and Phylogenetic Analysis

Salmonella enterica subsp. enterica causes over 99% of human salmonellosis. Salmonella Newport has ranked in the top three Salmonella serotypes associated with foodborne outbreaks in the United States. S. Newport is ubiquitous in the environment. S. Newport consisted of three lineages. It is necessary to investigate and determine the evolution relationship between S. Newport and to identify the genetic diversities of this emerging foodborne pathogen. Whole genome sequencing has played important roles in food safety and public health providing the most accurate information for phylogenetic analysis and more comprehensive picture for comparative genomics. Total 26 S. Newport strains from diverse sources and geographic locations were selected and conducted pyrosequencing to obtain 16-24 × coverage of draft genomes. More than 140,000 SNPs were identified to construct parsimony tree. Phylogenetic analysis indicated that S. Newport was divided into two major groups, lineages II and III. Lineage II was further grouped into three subgroups, IIA, IIB, and IIC. Lineage III strains showed close relationship to each other. Moreover, lineages II and III displayed divergent distance. Comparative genomics identified the region around mutS as potential biomarkers to distinguish these two lineages, including ste fimbrial operon, transposase, and cas genes. Salmonella pathogenicity islands (SPIs) play essential roles in virulence, metabolism, and host adaptations in Salmonella. Due to the significant roles of SPI-5 and SPI-6, the genetic diversities in these two gene clusters may contribute to the various activities in different strains. Both indels and mutations were identified in SPI-5, including two large insertions with over 40 kb encoding phage genes and 146 single nucleotide polymorphisms (SNPs). The phylogenetic tree of SPI-5 genes showed that lineages II and III contained divergent distances. SPI-6 was not identified in Asian strains in subgroup IIA, indicating the potential differences in virulence and host adaptations. S. Newport multidrug resistant strains have been clinical important issue in the United States. Plasmids contributed to the MDR phenotypes. The common genetic characterizations of these strains could be help to understand the prevalence of MDR strains. In the current study, all MDR strains belonging to one node in IIC and contained unfunctional CRISPR systems

Organic Sulphur Transfers in Coke Oven Gas via Noncatalytic Partial Oxidation

The organic sulfur transformation was studied during coke oven gas to produce syngas via noncatalytic partial oxidation. The concentration of CS2 and thiophene was examined in syngas by sulfide detector. For comparison, the sulfur transfer was also studied in coke oven gas under dry and hydrous conditions. When the ratio of O2 / Gas was 0.32, complete thiophene and about 83% of CS2 in feed gas could be transformed via noncatalytic partial oxidation in the dry condition. It was mainly because of burner nozzle unique structure forming local hyperthemia, which benefited OH, O free radical and active atoms. During steam transforming to produce syngas, the ratio of water to carbon was less than 3, a higher ratio of O2/Gas favored sulfur transformation. However, compared to dry feed, transforming rate of CS2 and thiophene was decreased. This indicates that the steam added was disadvantageous to the transformation of organic sulphur during the production of syngas by noncatalytic partial oxidation, steam and mass H2S in feed gas, resulting in the decrease of local hyperthermia temperature and the formation of organic sulfu

A recombinant avian antibody against VP2 of infectious bursal disease virus protects chicken from viral infection

【Abstract】A stable cell-line was established that expressed the recombinant avian antibody (rAb) against the infectious bursal disease virus (IBDV). rAb exhibited neutralization activity to IBDV-B87 strain in DF1 cells. The minimum rAb concentration required for inhibition of the cytopathic effect (CPE) was 1.563 μg/mL. To test the efficacy of rAb, a 168-h cohabitation challenge experiment was performed to transmit the disease from the chickens challenged with vvIBDV (HLJ0504 strain) to three test groups of chickens, i.e. (1) chickens treated with rAb, (2) chickens treated with yolk antibody, and (3) non-treatment chickens. The survival rates of chickens treated with rAb, yolk antibody and without treatment were 73%, 67% and 20%, respectively. Another batch of chickens was challenged with IBDV (BC6/85 strain) and then injected with rAb (1.0 mg/kg) 6, 24 and 36 h post-challenge. Non-treatment chickens had 100% morbidity, whereas those administered with rAb exhibited only 20% morbidity. Morbidity was evaluated using clinical indicators and bursal histopathological section. This study provides a new approach to treating IBDV and the rAb represents a promising candidate for this IBDV therapy.This research was supported by Heilongjiang province project of applied technology research and development (2013GC13C105) and The National Natural Science Fund biologic science base improve program of research training and capacity (J1210069/J0124)

Characterization of internalin genes in Listeria monocytogenes from food and humans, and their association with the invasion of Caco-2 cells

Internalins are surface proteins that are utilized by Listeria monocytogenes to facilitate its invasion into human intestinal epithelial cells. The expression of a full-length InlA is one of essential virulence factors for L. monocytogenes to cross the intestinal barrier in order to invade epithelial cells.https://doi.org/10.1186/s13099-019-0307-

Selective Release of Hydrophobic and Hydrophilic Cargos from Multi-Stimuli-Responsive Nanogels

Highly stable multi-stimuli-responsive nanogels for selective release of simultaneously encapsulated hydrophobic and hydrophilic cargos in a spatiotemporally controlled manner are demonstrated here. The nanogel is composed of hydrophilic pH- and thermoresponsive poly­(2-(dimethylamino)­ethyl methacrylate) (PDMAEMA) and hydrophobic photocleavable <i>o</i>-nitrobenzyl (ONB) linkage. The hydrophobic cargos were noncovalently encapsulated into lipophilic interiors of the nanogels, while the hydrophilic cargos were chemically linked to the nanogel precursor polymer PDMAEMA through a redox-cleavable disulfide junction. For these dual-loaded nanogels, hydrophobic cargos can be released in response to temperature, pH, and UV light, while the hydrophilic cargos can be released in response to redox reagent. The stimuli-selective release of hydrophobic and hydrophilic cargos affords the system with great potential applications in combination chemotherapy, tissue engineering, anticorrosion, and smart nanoreactors

Linking Vegetation Diversity and Soils on Highway Slopes: A Case Study of the Zhengzhou–Xinxiang Section of the Beijing–Hong Kong–Macau Highway

The rapid development of highways has caused a series of ecological problems, the restoration of which is an important part of highway construction. However, most related studies have focused only on the early stages of slope restoration. The present study investigated the Zhengzhou–Xinxiang section of the Beijing–Hong Kong–Macau Highway, which has been restored over more than 20 years, examining nine representative vegetation communities within this section and investigating their species diversity and soil physicochemical properties. Redundancy analysis and the grey correlation degree model were used to determine the relationship and coupling mechanism between vegetation diversity and soil physiochemical properties. The results showed some differences in the diversity of different vegetation communities and soil physicochemical properties; vegetation diversity was mainly influenced by organic material, total and available nitrogen, total and available phosphorus, slope, available potassium, and soil bulk density. Overall, environmental factors had a strong correlation with the Simpson dominance index and a weak correlation with the species richness index. The degree of coordination between vegetation community diversity and the soil coupling of the road slope remained on low and medium levels. Artificial vegetation restoration can regulate water and fertilizer resources and promote the restoration of highway slope vegetation