Yangyang Wang

Shiga toxin-producing Escherichia coli (STEC) causes a wide spectrum of diseases including hemorrhagic colitis and hemolytic uremic syndrome (HUS). Previously, we developed a rapid, sensitive, and potentially portable assay that identified STEC by detecting Shiga toxin (Stx) using a B-cell based biosensor platform. We applied this assay to detect Stx2 present in food samples that have been implicated in previous STEC foodborne outbreaks (milk, lettuce, and beef). The STEC enrichment medium, modified Tryptone Soy Broth (mTSB), inhibited the biosensor assay, but dilution with the assay buffer relieved this effect. Results with Stx2a toxoid-spiked food samples indicated an estimated limit of detection (LOD) of ≈4 ng/mL. When this assay was applied to food samples inoculated with STEC, it was able to detect 0.4 CFU/g or 0.4 CFU/mL of STEC at 16 h post incubation (hpi) in an enrichment medium containing mitomycin C. Importantly, this assay was even able to detect STEC strains that were high expressors of Stx2 at 8 hpi. These results indicate that the STEC CANARY biosensor assay is a rapid and sensitive assay applicable for detection of STEC contamination in food with minimal sample processing that can complement the current Food Safety Inspection Service (US) methodologies for STEC.

Shiga-toxin-producing Escherichia coli (STEC) causes a wide spectrum of diseases including hemorrhagic colitis and hemolytic uremic syndrome (HUS). The current Food Safety Inspection Service (FSIS) testing methods for STEC use the Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) protocol, which includes enrichment, cell plating, and genomic sequencing and takes time to complete, thus delaying diagnosis and treatment. We wanted to develop a rapid, sensitive, and potentially portable assay that can identify STEC by detecting Shiga toxin (Stx) using the CANARY (Cellular Analysis and Notification of Antigen Risks and Yields) B-cell based biosensor technology. Five potential biosensor cell lines were evaluated for their ability to detect Stx2. The results using the best biosensor cell line (T5) indicated that this biosensor was stable after reconstitution with assay buffer covered in foil at 4 °C for up to 10 days with an estimated limit of detection (LOD) of ≈0.1–0.2 ng/mL for days up to day 5 and ≈0.4 ng/mL on day 10. The assay detected a broad range of Stx2 subtypes, including Stx2a, Stx2b, Stx2c, Stx2d, and Stx2g but did not cross-react with closely related Stx1, abrin, or ricin. Additionally, this assay was able to detect Stx2 in culture supernatants of STEC grown in media with mitomycin C at 8 and 24 h post-inoculation. These results indicate that the STEC CANARY biosensor developed in this study is sensitive, reproducible, specific, rapid (≈3 min), and may be applicable for surveillance of the environment and food to protect public health.

Naringenin (NR) is a kind of flavonoid which plays a great role in the treatment of autism spectrum disorder (ASD). However, the underlying mechanism of NR in treating ASD still remains unclear. This study used network pharmacology and molecular docking to examine the potential targets and pharmacological mechanism of NR on ASD. Targets related to NR were screened from Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP), Encyclopedia of Traditional Chinese Medicine Database (ETCM), Traditional Chinese Medicine Integrated Database (TCMID), PharmaMapper database, and targets related to ASD were screened from Online Mendelian Inheritance In Man (OMIM), Disgenet, GeneCards, Therapeutic Target Database (TTD), Drugbank, and ETCM. Screened of the intersected gene targets. Then, we used the protein–protein interaction (PPI) networks to construct a PPI network and used Network Analyzer plug-in to perform topological analysis to screen out the core target. We used Metascape platform to perform gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and used Chem draw, Pymol, AutoDock 1.5.6 software for molecular docking verification with core targets. A total of 149 targets of NR and 1594 potential targets of ASD were screened, and 43 intersected targets and 8 key targets were obtained and screened. A total of 176 GO items were obtained by GO enrichment analysis (P < .05), 153 entries on biological process (BP), 12 entries on BP and 11entries on cell composition (CC) were included. A total of 100 signaling pathways were obtained by KEGG pathway enrichment screening (P < .05).The pathways that are closely related to the pathogenesis of ASD are estrogen signaling, thyroid hormone signaling pathway, prolactin signaling pathway, and endocrine resistance pathway. Molecular docking results showed that NR had the best docking activity with the core target CASP3, and had good binding ability with AKT1, ESR1, ACTB and MAPK3. Taken together, our findings support that NR exerts therapeutic effects on ASD with multi-target, and multi-pathway characteristics, which provides a preliminary theoretical basis for clinical trials. The mechanism of anti-oxidative stress response, anti-apoptosis, regulation of cell growth and metabolism, anti-inflammatory, balance hormone levels may be important for the therapeutic effect.

The Salmonella CANARY Zephyr assay is designed to provide rapid and reliable detection of Salmonella enterica from various types of environmental surfaces, including stainless steel, silicone rubber, high density polyethylene (HDPE), and glazed ceramic. The assay is using cell- and immuno-based CANARY technology and tested on Smiths Detection’s Zephyr platform. The objective of this validation study was to evaluate the Salmonella CANARY Zephyr assay for its inclusivity/exclusivity, matrix study for 4 claimed environmental surfaces, consistency/stability, and robustness. The Salmonella CANARY Zephyr assay was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual (BAM) Chapter 5 “Salmonella” using an unpaired study design for environmental surfaces including stainless steel, silicone rubber, HDPE, and glazed ceramic (1” x 1” test area). For the inclusivity and exclusivity evaluation, the Salmonella CANARY Zephyr assay correctly identified 101 out of 102 target organism isolates (with 1 strain of S. enterica subsp. indica not detected) and excluded all 33 non-target strains that were analyzed. For matrix study, the Salmonella CANARY Zephyr assay demonstrated no statistically significant differences between presumptive and confirmed results or between candidate and reference method results. Probability of detection (POD) analysis of the Salmonella CANARY Zephyr method on robustness and product consistency/stability (lot-to-lot) study demonstrated no statistically significant differences. The Salmonella CANARY Zephyr assay is an effective method for the detection of Salmonella enterica from various environmental surfaces including stainless steel, silicone rubber, HDPE, and glazed ceramic. The Salmonella CANARY Zephyr assay allows for rapid and sensitive detection of Salmonella enterica on environmental surfaces. It only takes less than 5 minutes to prepare sample and 1 minute for instrument running/reading.

To investigate the association between small ubiquitin-related modifier-1 (SUMO-1) gene rs6709162, rs7599810, rs7580433 polymorphism and non-syndromic oral clefting (NSOC). Our study consisted of 208 Ningxia NSOC patients, their parents (189 fathers and 176 mothers), 172 nuclear families (patients and their parents), and 284 normal controls. DNA was extracted and polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) was used to identify rs6709162, rs7599810, rs7580433 genotypes of the samples. The data was analyzed by case-control analysis, family based associated test (FBAT), and transmission disequilibrium test (TDT). Case-control study found that TT genotype's frequency was significantly different in cleft lip and cleft palate group compared with the control group at rs7599810 of SUMO-1 (P=0.01, P=0.01). TDT test showed that rs7599810's T allele had over-transmitted (P=0.00) in cleft lip and palate group. FBAT analysis revealed that distribution of rs7599810's TT genotype and T allele was significantly different (P=0.00, P=0.00). TDT test showed that rs6709162's C allele in cleft palate and cleft lip and palate patients had over-transmitted (P=0.00, P=0.01). rs7580433's G allele in cleft lip group had over-transmitted (P=0.05). SUMO-1 gene polymorphism is associated with NSOC.

A novel carbendazim-degrading actinobacterium, designated djl-6-2^T, was isolated from the sludge of a carbendazim wastewater treatment facility in Jiangsu province, China. The morphological and chemotaxonomic properties of the isolate were typical of members of the genusRhodococcus. Strain djl-6-2^Tformed a coherent cluster withRhodococcus qingshengiidjl-6^T,Rhodococcus baikonurensisDSM 44587^T,Rhodococcus erythropolisDSM 43066^TandRhodococcus globerulusDSM 43954^Tin 16S rRNA gene sequence analysis. The results of DNA–DNA hybridization with the above strains (27.7, 19.3, 18.6 and 10.6 % relatedness, respectively), in combination with differences in biochemical and physiological properties, suggest that strain djl-6-2^Tshould be classified within a novel species of the genusRhodococcus, for which the nameRhodococcus jialingiaesp. nov. is proposed, with djl-6-2^T(=DSM 45257^T=CCTCC AB 208292^T) as the type strain.