Detection and Molecular Identification of Salmonella Pathogenic Islands and Virulence Plasmid Genes of Salmonella in Xuzhou Raw Meat Products.

ABSTRACT: Virulence genes expressed in Salmonella are a primary contributing factor leading to the high morbidity and mortality of salmonellosis in humans. The pathogenicity of Salmonella is mainly determined by the specific virulence factors that it carries. These factors also confer greater virulence and play a role in infection of a host and transmission of disease, and most Salmonella enterica can cause cross-infections between humans and animals. In this study, 265 samples in total were collected from a farmer's market and two supermarkets in Xuzhou, Jiangsu province, China, including 205 pork samples and 60 chicken samples. The suspected Salmonella isolates were isolated and identified using microbiological and molecular methods, and the confirmed isolates were used for serovar analysis and antimicrobial susceptibility testing. The virulence genes of Salmonella pathogenic islands (SPIs) and Salmonella virulence plasmids (Spv) in Salmonella-positive isolates were subsequently detected. Salmonella was isolated from 29.0% of samples, and all isolates were confirmed by PCR targeting the stn gene. Among the Salmonella isolates, resistance was most frequently observed against ciprofloxacin (84.4%), followed by tetracycline (71.4%) and streptomycin (68.8%). Resistance to amoxicillin-clavulanic acid (6.3%) and aztreonam (5%) was less commonly detected. The presence of the following virulence genes was determined by specific PCRs: hilA (SPI-1), sifA (SPI-2), misL (SPI-3), siiE (SPI-4), sopB (SPI-5), and spvC. The detection rate for SPI-1 to SPI-5 was 93.5, 87.0, 97.4, 97.4, and 97.4%, respectively. In addition, the detection rate of the spvC gene was 96.1%. Except for sopB (94.7%), all isolates of the dominant serovar S. enterica subsp.. enterica serovar Enteritidis contained all virulence genes from SPI-1 to SPI-5. This study demonstrated the epidemiological status of Salmonella in raw meat products in Xuzhou, and the complex antibiotic resistance and high isolation rate of virulence genes observed reveal many potential risks of which the findings presented herein will provide orientation to improve public health safeguards.

Hypoxia-inducible lipid droplet-associated (HILPDA) facilitates the malignant phenotype of lung adenocarcinoma cells in vitro through modulating cell cycle pathways.

BACKGROUND: Hypoxia-inducible lipid droplet-associated (HILPDA) is considered to have tumorigenic activity, but its function in lung adenocarcinoma (LUAD) is rarely known. This work aimed to assess the regulatory functions as well as the in-depth mechanism of HILPDA in LUAD. METHODS: The expression of HILPDA in LUAD tissues was analyzed based on TCGA database, and then qRT-PCR was performed to confirm the HILPDA expression in LUAD cell lines. Kaplan-Meier analysis was used to measure the correlation of HILPDA expression and overall survival in patients with LUAD. Then, Cell-Counting Kit-8 (CCK-8), colony formation and transwell assays were performed to detect cell proliferation, invasion and migration. Moreover, the pathways closely related to the high HILPDA expression was analyzed by Kyoto Encyclopedia of genes and Genomes (KEGG) analysis. The levels of Cell cycle pathway-related proteins were assessed using western blotting. RESULTS: Herein, we revealed that HILPDA was expressed at high levels in LUAD tissues and cell lines, and LUAD patients with the higher HILPDA expression presented the shorter survival time. Down-regulation of HILPDA in Calu-3 cells can retard cell proliferation, migration and invasion as well as arrest cells in the G1 phase, whereas overexpression of HILPDA in A549 cells presented a marked promotion on these phenotypes. Moreover, we surveyed that knockdown of HILPDA restrained the activation of cell cycle pathway, while up-regulation of HILPDA led to opponent outcomes. CONCLUSIONS: In summing, HILPDA may act as an oncogenic factor in LUAD cells via modulating cell cycle pathway, which represent a novel biomarker of tumorigenesis in LUAD patients.

MicroRNA-18a-5p mitigates oxygen-glucose-deprivation/reoxygenation-induced injury through suppression of TLRs/NF-κB signaling by targeting TLR8 in PC12 cells.

This work aimed to assess the role of TLR8 in cerebral I/R injury and its in-depth pathogenesis. Bioinformatics analysis indicated that TLR8 was up-regulated in patients with ischemic stroke than that in healthy control, and miR-18a-5p was the upstream regulatory of TLR8. Then, the rat pheochromocytoma PC12 cells were exposed in oxygen-glucose-deprivation/reoxygenation (OGD/R) conditions to construct a model in vitro. The functional experiments indicated that OGD/R can decline the viability and elevate the apoptosis of PC12 cells, while up-regulation of miR-18a-5p can alleviate OGD/R-induced cell injury. Notably, overexpression of TLR8 reverses the miR-18a-5p-mediated protection on OGD/R-induced cells injury. Finally, we found that up-regulation of miR-18a-5p obviously declined the protein levels of TLR4 and TLR7 as well as the phosphorylation of NF-κB, while overexpression of TLR8 canceled the decrease caused by miR-18a-5p up-regulation. In summing, our results illustrated that miR-18a-5p/TLR8 axis can mitigate OGD/R-induced cells injury through TLRs and NF-κB pathway.

Targeted delivery of extracellular matrix protected against neurologic defects after focal ischemia reperfusion in rats.

Ischemic stroke is one of the leading causes of morbidity and mortality worldwide and characterized by defective angiogenesis. The functional sequences (RGDs, GRGDSPASSPISC) derived from fibronectin have been confirmed to augment angiogenesis in vivo and in vitro. However, delivery of peptides into the brain parenchyma has been hampered by the presence of the blood-brain barrier (BBB). We fused RGDs with penetratin (Antp) derived from Drosophila antennapedia homeodomain protein to improve the penetration of peptides through BBB into ischemic hemisphere. We found Antp-RGDs successfully not only penetrate the SH-SY5Y cells but also penetrated through BBB into ischemic hemisphere by intraperitoneal injection. In addition, application of Antp-RGDs to the focal cerebral ischemic reperfusion injury in rats resulted in the reduction of cerebral ischemic volume and the improvement of neurologic score according to the 21-point score. We further demonstrated that activation of phosphorylation-extracellular-signal related kinase 1/2 (p-ERK 1/2) and upregulation of gene VEGF resulted from post-treatment with Antp-RGDs 2 hours after reperfusion onset might at least partly contribute to the benefic changes after focal cerebral ischemic reperfusion injury in rats. Our data suggested that Antp-RGDs may serve as an attractive therapeutic intervention for treating ischemic stroke.