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

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Functional Characterization of a Putative RNA Demethylase ALKBH6 in Arabidopsis Growth and Abiotic Stress Responses

RNA methylation and demethylation, which is mediated by RNA methyltransferases (referred to as “writers”) and demethylases (referred to as “erasers”), respectively, are emerging as a key regulatory process in plant development and stress responses. Although several studies have shown that AlkB homolog (ALKBH) proteins are potential RNA demethylases, the function of most ALKBHs is yet to be determined. The Arabidopsis thaliana genome contains thirteen genes encoding ALKBH proteins, the functions of which are largely unknown. In this study, we characterized the function of a potential eraser protein, ALKBH6 (At4g20350), during seed germination and seedling growth in Arabidopsis under abiotic stresses. The seeds of T-DNA insertion alkbh6 knockdown mutants germinated faster than the wild-type seeds under cold, salt, or abscisic acid (ABA) treatment conditions but not under dehydration stress conditions. Although no differences in seedling and root growth were observed between the alkbh6 mutant and wild-type under normal conditions, the alkbh6 mutant showed a much lower survival rate than the wild-type under salt, drought, or heat stress. Cotyledon greening of the alkbh6 mutants was much higher than that of the wild-type upon ABA application. Moreover, the transcript levels of ABA signaling-related genes, including ABI3 and ABI4, were down-regulated in the alkbh6 mutant compared to wild-type plants. Importantly, the ALKBH6 protein had an ability to bind to both m6A-labeled and m5C-labeled RNAs. Collectively, these results indicate that the potential eraser ALKBH6 plays important roles in seed germination, seedling growth, and survival of Arabidopsis under abiotic stresses

Nitrogen removal efficiency of some bacterial strains isolated from seawater in Thua Thien Hue, Vietnam

Background: Nitrifying bacteria in aquaculture environments are capable of removing toxic nitrogen compounds such as ammonium and nitrite. Using these indigenous microbial resources can improve shrimp production.Methods: Screening method was used to isolate aerobic strains of nitrifying bacteria. Species identification for these isolates was done by biomolecular method based on 16S rDNA gene sequence. Ammonium, nitrite and nitrate concentrations from the culture were determined by spectrophotometry at the appropriate wavelength. Temperature, pH, dissolved oxygen and salinity were measured by specialized equipment. Formation and development of flocs during shrimp culture were determined based on their volume and weight. A trial of shrimp nursery was carried out on a small scale with 0.5 m3 tanks containing diluted seawater to 16-18‰ salinity at a density of 400 individual/m3 for 24 days on April 2019. Results: This study isolated two strains of Pseudomonas (BF01 and BF03) and one strain of Cupriavidus oxalaticus BF02 from seawater in Thua Thien Hue province, Vietnam. These bacterial isolates have shown ability to remove nitrogen compounds such as ammonium, nitrite and nitrate in culture medium. Formation and development of flocs were found in trials of shrimp nursery with diluted seawater containing the isolates. Some water quality parameters (temperature, pH, dissolved oxygen, salinity, ammonium and nitrite) were kept at a safe level and juvenile shrimp grown normally during culture.Conclusion: The observations on the water quality and basic growth parameters of juvenile shrimp in the two treatments, diluted seawater and diluted seawater with commercial microbial products, showed that there were no significant differences between them with p = 0.05. This proves that three isolates have played an important role in shrimp nursery.   Keywords: Cupriavidus oxalaticus; Floc; Litopenaeus vanamei; Nitrifying-denitrifying bacteria; Pseudomonas sp.

Non-pyrogenic highly pure magnetosomes for efficient hyperthermia treatment of prostate cancer

We report the fabrication of highly pure magnetosomes that are synthesized by magnetotactic bacteria (MTB) using pharmaceutically compatible growth media, i.e., without compounds of animal origin (yeast extracts), carcinogenic, mutagenic, or toxic for reproduction (CMR) products, and other heavy metals than iron. To enable magnetosome medical applications, these growth media are reduced and amended compared with media commonly used to grow these bacteria. Furthermore, magnetosomes are made non-pyrogenic by being extracted from these micro-organisms and heated above 400 °C to remove and denature bacterial organic material and produce inorganic magnetosome minerals. To be stabilized, these minerals are further coated with citric acid to yield M-CA, leading to fully reconstructed chains of magnetosomes. The heating properties and anti-tumor activity of highly pure M-CA are then studied by bringing M-CA into contact with PC3-Luc tumor cells and by exposing such assembly to an alternating magnetic field (AMF) of 42 mT and 195 kHz during 30 min. While in the absence of AMF, M-CA are observed to be non-cytotoxic, they result in a 35% decrease in cell viability following AMF application. The treatment efficacy can be associated with a specific absorption rate (SAR) value of M-CA, which is relatively high in cellular environment, i.e., SARcell = 253 ± 11 W/gFe, while being lower than the M-CA SAR value measured in water, i.e., SARwater = 1025 ± 194 W/gFe, highlighting that a reduction in the Brownian contribution to the SAR value in cellular environment does not prevent efficient tumor cell destruction with these nanoparticles. KEY POINTS : • Highly pure magnetosomes were produced in pharmaceutically compatible growth media • Non-pyrogenic and stable magnetosomes were prepared for human injection • Magnetosomes efficiently destroyed prostate tumor cells in magnetic hyperthermia. Keywords: Alternating magnetic field; Cancer; Hyperthermia; Magnetosome; Magnetotactic bacteria; Nanotechnology

Coordinated Expression of Cytosolic and Chloroplastic Glutamine Synthetase During Reproductive Stage and Its Impact in GS1 RNAi Transgenic Rice

To understand the reallocation of organic nitrogen from leaf to the flower head of rice, the role of glutamine synthetase (GS) was investigated by characterizing GS1 RNAi transgenic rice, which revealed a significant reduction in panicle number and number of seeds per panicle. We observed the expression of GS isotypes at transcriptional and protein levels in flag leaves, leaf sheaths and panicles at three different flower development stages. The mRNA expression of GS1;1 was clearly suppressed in flag leaves, especially at the flowering stage. GS1 protein was barely detectable in flag leaves until the flowering stage, while GS1 protein was compromised in the leaf sheath and panicle, with transient expression of GS2 protein at the flowering stage. The glutamine level in transgenic plants was significantly reduced in both flag leaves and panicles, but ammonium was highly accumulated. The level of other amino acids, including aspartate and asparagine, tended to be higher in RNAi transgenic plants than the wild type plants during the reproductive stage. In addition, accumulation of toxic ammonium in panicles with low glutamine level might have caused low seed-setting in the transgenic rice. These results indicated that nitrogen reallocation was critical for panicle development, and that multiple GS isotypes functioned cooperatively to complete the rice life cycle when leaf nitrogen was remobilized to the developing reproductive organs. Keywords: ammonium, grain yield, RNA interference, panicle development, nitrogen reallocation, rice, glutamine synthase, flowering stag

MỘT SỐ ĐẶC ĐIỂM CÓ LỢI CỦA CHỦNG Weissella cibaria HN07 PHÂN LẬP TỪ HỆ TIÊU HÓA TÔM CHÂN TRẮNG (Litopenaeus vannamei)

Lactic acid bacteria (LAB) are used as digestive and immune stimulant probiotics and are suitable alternatives to conventional antibiotics in aquaculture systems. In this study, we determine the antagonistic ability of Vibrio parahaemolyticus and some biochemical characteristics of the Weissella cibaria HN07 strain isolated from the digestive system of white-leg shrimp (Litopenaeus vannamei). Accordingly, bacterial strain HN07 has a strong antagonistic ability against V. parahaemolyticus K5 with an antibacterial diameter of 21 mm. Through sequencing the 16S rRNA gene, we determined that strain HN07 is Weissella cibaria. The results of antibiotic resistance tests show that Weissella cibaria HN07 is sensitive to ampicillin and chloramphenicol but resistant to sulfonamides and kanamycin antibiotics. At the same time, the results show that Weissella cibaria HN07 does not dissolve blood cells on the Blood agar medium containing 5% sheep blood. Therefore, Weissella cibaria HN07 is a safe bacterial strain and a potential microorganism to produce probiotics applied in the prevention and treatment of AHPND on white-leg shrimp.Vi khuẩn lactic (Lactic Acid bacteria – LAB) được sử dụng làm chế phẩm sinh học kích thích tiêu hóa, miễn dịch và là lựa chọn thay thế phù hợp cho thuốc kháng sinh thông thường trong hệ thống nuôi trồng thủy sản. Nghiên cứu này xác định khả năng đối kháng Vibrio parahaemolyticus và một số đặc điểm sinh hóa của chủng Weissella cibaria HN07 được phân lập từ hệ tiêu hóa của tôm chân trắng (Litopenaeus vannamei). Theo đó, chủng vi khuẩn HN07 có khả năng đối kháng mạnh với V. parahaemolyticus K5 với đường kính kháng khuẩn đạt 21 mm. Thông qua giải trình tự gen 16S rRNA, chúng tôi xác định chủng HN07 là Weissella cibaria. Kết quả thử khả năng kháng kháng sinh cho thấy Weissella cibaria HN07 nhạy cảm với ampicilin và chloramphenicol nhưng lại kháng các loại kháng sinh thuộc nhóm sulfonamides và kanamycin. Đồng thời, kết quả cũng cho thấy Weissella cibaria HN07  không làm tan tế bào máu trên môi trường Blood agar chứa 5% máu cừu. Vì vậy, Weissella cibaria HN07 là chủng vi khuẩn an toàn và cũng là chủng vi sinh vật tiềm năng để sản xuất chế phẩm sinh học ứng dụng trong phòng trị bệnh AHPND trên tôm chân trắng

Innovative Virtual Screening of PD-L1 Inhibitors: The Synergy of Molecular Similarity, Neural Networks, and GNINA Docking

Immune checkpoint inhibitors have garnered significant attention in oncological research over recent years. A plethora of studies have elucidated that inhibitors targeting the Programmed Death-Ligand 1 (PD-L1) play a pivotal role in circumventing the evasion mechanisms of cancer cells against the immune system. This study aimed to develop an integrated screening model combining an Artificial Neural Network (ANN), Molecular Similarity (MS) assessments, and GNINA 1.0 molecular docking, targeting PD-L1 inhibitors. A database of 2044 substances with known PD-L1 inhibitory activity was compiled from Google Patents and used to enhance molecular similarity evaluations and train the machine learning model. For retrospective validation of the docking procedure, the human PD-L1 protein, with the Protein Data Bank (PDB) ID: 5N2F, was employed as a control. In this phase of the study, 15,235 compounds from the DrugBank database were subjected to a series of screening processes: initially through medicinal chemistry filters, followed by MS assessments, the ANN model, and culminating with molecular docking using GNINA 1.0. The decoy generation yielded promising outcomes, evidenced by an AUC-ROC 1NN value of 0.52 and Doppelganger scores with a mean of 0.24 and a maximum of 0.346, indicating a high resemblance of the decoys to the active set. For MS, the AVALON emerged as the most effective fingerprint for similarity searching, demonstrating an Enrichment Factor (EF) of 1% at 10.96%, an AUC-ROC of 0.963, and an optimal similarity threshold of 0.32. The ANN model demonstrated superior performance in cross-validation, achieving an average precision of 0.863±0.032 and an F1 score of 0.745±0.039, outperforming both the Support Vector Classifier (SVC) and Random Forest (RF) models, albeit not significantly. In external validation, the ANN model maintained its superiority with an average precision of 0.851 and an F1 score of 0.790. GNINA 1.0, employed for molecular docking, was validated through redocking and retrospective control, achieving an AUC of 0.975, with a critical cnn_pose_score threshold of 0.73. From the initial 15,235 compounds, 128 were shortlisted using the MS and ANN models. Further screening through GNINA 1.0 identified 22 potential candidates, among which (3S)-1-(4-acetylphenyl)-5-oxopyrrolidine-3-carboxylic acid emerged as the most promising, with a cnn_pose_score of 0.79, a PD-L1 inhibitory probability of 70.5%, and a Tanimoto coefficient of 0.35

XÁC ĐỊNH SỰ CÓ MẶT CỦA CÁC GEN ĐỘC TỐ Ở CÁC CHỦNG Vibrio GÂY BỆNH HOẠI TỬ GAN TỤY CẤP TÍNH TRÊN TÔM THẺ CHÂN TRẮNG TẠI THỪA THIÊN HUẾ

Acute hepatopancreatic necrosis disease (AHPND) is a disease caused by bacteria, with the death ratio up to 100% in the population of Litopenaeus vannamei and Penaeus monodon, and causes great economic losses to many shrimp‐producing countries in Asia. Previous studies have shown that not all strains of Vibrio can cause AHPND because they contain different toxin genes, such as pirAvp, pirBvb, tlh, trh, and tdh. In this study, we evaluate the presence of several toxic genes on Vibrio isolates from Thua Thien Hue province and analyze the sequence of these genes. The results show that in 14 Vibrio strains carrying pirABvp gene, the tlh and toxR genes occur in 14/14 and 7/14 strains, respectively, while none of them have the two genes of trh and tdh. Analyzing the sequence of four DNA fragments shows that these genes have high similarity (98–100%) compared with the genes announced on the Genbank. Genes pirAvp and pirBvp are less different, while tlh and toxR genes are more different. The results could be used for further studies in the production of bioproducts for the prevention and treatment of acute hepatopancreatic necrosis disease in shrimp.Bệnh hoại tử gan tụy cấp tính (Acute Hepatopancreatic Necrosis Disease – AHPND) là một bệnh do vi khuẩn gây ra. Bệnh này dẫn đến tỷ lệ chết lên đến 100% trong quần thể tôm thẻ chân trắng, tôm sú và gây những tổn thất kinh tế đáng kể cho ngành nuôi tôm ở nhiều nước châu Á. Các nghiên cứu trước đây cho thấy không phải chủng Vibrio nào cũng có khả năng gây bệnh do chúng mang các gen độc tố khác nhau. Chúng tôi đã đánh giá sự có mặt của các gen độc tố trên các chủng Vibrio phân lập tại Thừa Thiên Huế đồng thời phân tích trình tự các gen này. Kết quả cho thấy trong 14 chủng Vibrio mang gen pirABvp nghiên cứu, gen tlh xuất hiện ở tất cả các chủng, gen toxR xuất hiện ở 7/14 chủng trong khi đó các gen trh và tdh không xuất hiện trong các chủng vi khuẩn Vibrio phân lập được. Giải trình tự đoạn chỉ thị các gen độc tố cho thấy các gen này đều có độ tương đồng khá cao (98–100%) so với các gen đã công bố trên ngân hàng gen, trong đó 2 gen pirAvp và pirBvp ít sai khác còn các gen tlh và toxR có sự sai khác nhiều hơn. Đây là cơ sở để thực hiện các nghiên cứu tiếp theo trong việc sản xuất các chế phẩm phòng và trị bệnh hoại tử gan tụy cấp tính trên tôm

Plasma cell-free DNA: a potential biomarker for early prediction of severe dengue

Background: Considerable progress has been made in dengue management, however the lack of appropriate predictors of severity has led to huge number of unwanted admissions mostly decided on the grounds of warning signs. Apoptosis related mediators,among others, are known to correlate with severe dengue (SD) although no predictive validity is established. The objective of this study was to investigate the association of plasma cell-free DNA (cfDNA) with SD, and evaluate its prognostic value in SD prediction at acute phase. Methods: This was a hospital-based prospective cohort study conducted in Vietnam.All the recruited patients were required to be admitted to the hospital and were strictly monitored for various laboratory and clinical parameters(including progression to SD) until discharged. Plasma samples collected during acute phase (6-48 h before defervescence) were used to estimate the level of cfDNA. Results: Of the 61 dengue patients,SD patients (n = 8)developed shock syndrome in 4.8 days (95% CI 3.7-5.4) after the fever onset. Plasma cfDNA levels before the defervescence of SD patients were significantly higher than the non-SD group (p = 0.0493). From the receiver operating characteristic (ROC) curve analysis, a cut-off of > 36.9 ng/mL was able to predict SD with a good sensitivity (87.5%), specificity (54.7%), and area under the curve (AUC) (0.72, 95% CI 0.55-0.88; p = 0.0493).Conclusions: Taken together, these findings suggest that cfDNA could serve as a potential prognostic biomarker of SD. Studies with cfDNA kinetics and its combination with other biomarkers and clinical parameters would further improve the diagnostic ability for SD