Dual-Specificity Phosphatase 4 Promotes Malignant Features in Colorectal Cancer Through Cyclic-AMP Response Element Binding Protein/Protein Kinase CAMP-Activated Catalytic Subunit Beta Activation.

INTRODUCTION: Previous studies have demonstrated that Dual-specificity phosphatase 4 (DUSP4) plays an important role in the progression of different tumor types. However, the role and mechanism of DUSP4 in colorectal cancer (CRC) remain unclear. AIMS: We investigate the role and mechanisms of DUSP4 in CRC. METHODS: Immunohistochemistry was used to investigate DUSP4 expression in CRC tissues. Cell proliferation, apoptosis and migration assays were used to validate DUSP4 function in vitro and in vivo. RNA-sequence assay was used to identify the target genes of DUSP4. Human phosphokinase array and inhibitor assays were used to explore the downstream signaling of DUSP4. RESULTS: DUSP4 expression was upregulated in CRC tissues relative to normal colorectal tissues, and DUSP4 expression showed a significant positive correlation with CRC stage. Consistently, we found that DUSP4 was highly expressed in colorectal cancer cells compared to normal cells. DUSP4 knockdown inhibits CRC cell proliferation, migration and promotes apoptosis. Furthermore, the ectopic expression of DUSP4 enhanced CRC cell proliferation, migration and diminished apoptosis in vitro and in vivo. Human phosphokinase array data showed that ectopic expression of DUSP4 promotes CREB activation. RNA-sequencing data showed that PRKACB acts as a downstream target gene of DUSP4/CREB and enhances CREB activation through PKA/cAMP signaling. In addition, xenograft model results demonstrated that DUSP4 promotes colorectal tumor progression via PRKACB/CREB activation in vivo. CONCLUSION: These findings suggest that DUSP4 promotes CRC progression. Therefore, it may be a promising therapeutic target for CRC.

Safety and efficacy of multi-target TKI combined with nivolumab in check-point inhibitor-refractory patients with advanced NSCLC: a prospective, single-arm, two-stage study.

BACKGROUND: Resistance to immune checkpoint inhibitors (ICIs) represents a major unmet medical need in non-small cell lung cancer (NSCLC) patients. Vascular endothelial growth factor (VEGF) inhibition may reverse a suppressive microenvironment and recover sensitivity to subsequent ICIs. METHODS: This phase Ib/IIa, single-arm study, comprised dose-finding (Part A) and expansion (Part B) cohorts. Patients with ICIs-refractory NSCLC were enrolled to receive anlotinib (a multi-target tyrosine kinase inhibitor) orally (from days 1 to 14 in a 21-day cycle) and nivolumab (360 mg every 3 weeks, intravenously) on a 21-day treatment cycle. The first 21-day treatment cycle was a safety observation period (phase Ib) followed by a phase II expansion cohort. The primary objectives were recommended phase 2 dose (RP2D, part A), safety (part B), and objective response rate (ORR, part B), respectively. RESULTS: Between November 2020 and March 2022, 34 patients were screened, and 21 eligible patients were enrolled (6 patients in Part A). The RP2D of anlotinib is 12 mg/day orally (14 days on and 7 days off) and nivolumab (360 mg every 3 weeks). Adverse events (AEs) of any cause and treatment-related AEs (TRAEs) were reported in all treated patients. Two patients (9.5%) experienced grade 3 TRAE. No grade 4 or higher AEs were observed. Serious AEs were reported in 4 patients. Six patients experienced anlotinib interruption and 4 patients experienced nivolumab interruption due to TRAEs. ORR and disease control rate (DCR) was 19.0% and 76.2%, respectively. Median PFS and OS were 7.4 months (95% CI, 4.3-NE) and 15.2 months (95% CI, 12.1-NE), respectively. CONCLUSION: Our study suggests that anlotinib combined with nivolumab shows manageable safety and promising efficacy signals. Further studies are warranted. TRIAL REGISTRATION: NCT04507906 August 11, 2020.

Foodborne Pathogenic Bacteria: Prevalence and Control-Volume I.

From the farm to the dining table, foodborne pathogenic bacteria can contaminate food at any stage of the food production, processing, delivery, preparation, and consumption chain, posing a critical threat to the safety of food systems worldwide [...].

Dissemination of IncC plasmids in Salmonella enterica serovar Thompson recovered from seafood and human diarrheic patients in China.

Salmonella Thompson is a prevalent foodborne pathogen and a major threat to food safety and public health. This study aims to reveal the dissemination mechanism of S. Thompson with co-resistance to ceftriaxone and ciprofloxacin. In this study, 181 S. Thompson isolates were obtained from a retrospective screening on 2118 serotyped Salmonella isolates from foods and patients, which were disseminated in 12 of 16 districts in Shanghai, China. A total of 10 (5.5 %) S. Thompson isolates exhibited resistance to ceftriaxone (MIC ranging from 8 to 32 µg/mL) and ciprofloxacin (MIC ranging from 2 to 8 µg/mL). The AmpC ß-lactamase gene blaCMY-2 and plasmid-mediated quinolone resistance (PMQR) genes of qnrS and qepA were identified in the 9 isolates. Conjugation results showed that the co-transfer of blaCMY-2, qnrS, and qepA occurred on the IncC plasmids with sizes of ∼150 (n = 8) or ∼138 (n = 1) kbp. Three typical modules of ISEcp1-blaCMY-2-blc-sugE, IS26-IS15DIV-qnrS-ISKpn19, and ISCR3-qepA-intl1 were identified in an ST3 IncC plasmid pSH11G0791. Phylogenetic analysis indicated that IncC plasmids evolved into Lineages 1, 2, and 3. IncC plasmids from China including pSH11G0791 in this study fell into Lineage 1 with those from the USA, suggesting their close genotype relationship. In conclusion, to our knowledge, it is the first report of the co-existence of blaCMY-2, qnrS, and qepA in IncC plasmids, and the conjugational transfer contributed to their dissemination in S. Thompson. These findings underline further challenges for the prevention and treatment of Enterobacteriaceae infections posed by IncC plasmids bearing blaCMY-2, qnrS, and qepA.

Rationale and design of a multicenter, randomized phase II trial of durvalumab with or without multitarget tyrosine kinase inhibitor as maintenance treatment in extensive-stage small-cell lung cancer patients (DURABLE study).

INTRODUCTION: Durvalumab is a check-point inhibitor against programmed death ligand-1 (PD-L1), and anlotinib is a new orally administered multitarget tyrosine kinase inhibitor (TKI). Both agents have been approved in China. Preclinical and clinical trials have suggested that antiangiogenic therapy has the potential to alleviate immunosuppression and showed synergetic effect when combined with ICIs. However, it is unclear that whether this combination is effective when initiated as maintenance treatment in ES-SCLC patients. METHODS: This is a multicenter, randomized, phase II study. A total of 64 eligible patients who do not experience disease progression after four cycles platinum-based chemotherapy combined with durvalumab will be randomized to durvalumab with anlotinib or durvalumab alone until disease progression, withdrawal of consent, or unacceptable toxicity. The primary endpoint is PFS (from randomization); secondary endpoint was OS and PFS (from diagnosis), objective response rate (ORR); disease control rate (DCR) and duration of response (DOR), safety and tolerability assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. DISCUSSION: We conduct a phase II study to investigate the safety and efficacy of durvalumab combined with anlotinib as maintenance treatment in ES-SCLC patients.

Prevalence, antimicrobial resistance, and genetic characteristics of Staphylococcus aureus isolates in frozen flour and rice products in Shanghai, China.

Staphylococcus aureus is widely recognized as a highly hazardous pathogen that poses significant threats to food safety and public health. This study aimed to assess the prevalence, antimicrobial resistance, and genetic characteristics of S. aureus isolates recovered from 288 frozen flour and rice product samples in Shanghai, China, between September 2019 and May 2020. A total of 81 S. aureus isolates were obtained, representing 25 sequence types (STs), with ST7 being the most prevalent (17.28%, n = 14). The majority of S. aureus isolates (85.19%, n = 69) carried at least one enterotoxin gene, with the seg gene being the most frequently detected (51.85%, n = 42). Additionally, 12 isolates (14.81%) were identified as methicillin-resistant S. aureus (MRSA) through mecA gene detection. Notably, this study reported the presence of an ST398 MRSA isolate in frozen flour and rice products for the first time. All MRSA isolates displayed multidrug resistance, with the highest resistance observed against cefoxitin (100.00%), followed by penicillin (91.67%) and erythromycin (66.67%). Genomic analysis of the 12 MRSA isolates revealed the presence of twenty distinct acquired antimicrobial resistance genes (ARGs), eight chromosomal point mutations, and twenty-four unique virulence genes. Comparative genome analysis indicated close genetic relationships between these MRSA isolates and previously reported MRSA isolates from clinical infections, highlighting the potential transmission of MRSA through the food chain and its implications for public health. Significantly, the identification of three plasmids harboring ARGs, insertion sequences (ISs), the origin of transfer site (oriT), and the relaxase gene suggested the potential for horizontal transfer of ARGs via conjugative plasmids in S. aureus. In conclusion, this study revealed significant contamination of retail frozen flour and rice products with S. aureus, and provided essential data for ensuring food safety and protecting public health.

Houttuynia cordata Thunb repairs steroid-induced avascular necrosis of the femoral head through regulating NF-κB signaling pathway.

To investigate the influences of Houttuynia cordata Thunb (HCT) in steroid-induced avascular necrosis of the femoral head (SANFH), we conducted a comprehensive study evaluating the effects of HCT on various aspects. Cell Counting Kit-8 assay was used to examine bone marrow stem cells (BMSCs) cell viability. Flow cytometry and lactate dehydrogenase detection assay were conducted to determine cell apoptosis. The levels of apoptosis-related proteins, osteogenic-related markers, inflammatory factors, and nuclear factor kappa B (NF-κB) pathway-associated proteins were determined via western blotting. Hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were utilized to verify the effects of HCT in SANFH rats. Our findings revealed that HCT could enhanced cell viability and arrested cell apoptosis in dexamethasone (Dex)-treated BMSCs. Dex increased the levels of cleaved caspase-3, Bcl2-associated X, interleukin (IL)-1ß, IL-18, IL-6, p65, and inhibitor of NF-κB kinase ß (IKKß), while this promoting trend was weakened by HCT. Moreover, pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB signaling pathway) further increased the inhibitory role of apoptosis and the levels of IL-1ß, IL-18, and IL-6 and the promotional effect of the levels of RUNX2 and ALP in Dex-treated BMSCs. The in-vivo assays showed that HCT decreased the percentage of empty lacunae, apoptosis, and the levels of IL-1ß, IL-18, IL-6, p65, and IKKß in SANFH rats. In conclusion, our study demonstrated that HCT relieved SANFH, which might be possibly achieved by NF-κB pathway.

A randomized double-blind trial of TQB2450 with or without anlotinib in pretreated driver-negative non-small cell lung cancer.

OBJECTIVE: Immune monotherapy as second-line treatment confers only modest survival benefit on non-small cell lung cancer (NSCLC) patients with no mutated driver genes, necessitating combination treatment strategies. This phase Ib trial investigated the efficacy and safety of anti-PD-L1 antibody TQB2450 plus antiangiogenic drug anlotinib for NSCLC. MATERIALS AND METHODS: Pretreated stage IIIB or IV NSCLC patients with wild-type EGFR/ALK and minimally one measurable lesion were randomized 1:1:1 to receive TQB2450 1200 mg plus placebo, or TQB2450 1200 mg plus anlotinib 10 or 12 mg. The primary outcome was progression-free survival (PFS) and the secondary outcomes included objective response rate (ORR). RESULTS: Thirty-three patients received TQB2450 plus placebo and 34 patients each received TQB2450 plus anlotinib 10 mg and 12 mg. At the data cutoff, the median PFS was 8.7 months (95% CI 6.1-17.1) in the TQB2450 plus anlotinib group and 2.8 months (95% CI 1.4-4.7) in the TQB2450 only group. The ORR reached 30.9% (95% CI 20.2%-43.3%) in the TQB2450 plus anlotinib group and was 3.0% (95% CI 0.1%-15.8%) in the TQB2450 only group. In patients with PD-L1 ≥ 1%, the ORR was 50.0% (95% CI 33.4%-66.6%) for TQB2450 plus anlotinib and 5.3% (95% CI 0.1%-26.0%) for TQB2450 plus placebo. No new safety signals were observed. CONCLUSION: Anlotinib plus TQB2450 demonstrated promising antitumor activities in advanced NSCLC patients without EGFR and ALK alterations and the toxicities were overall manageable. The study findings support the continued development of TQB2450 plus anlotinib for advanced NSCLC patients without driver gene alterations.

Exploring Possible Ways to Enhance the Potential and Use of Natural Products through Nanotechnology in the Battle against Biofilms of Foodborne Bacterial Pathogens.

Biofilms enable pathogenic bacteria to survive in unfavorable environments. As biofilm-forming pathogens can cause rapid food spoilage and recurrent infections in humans, especially their presence in the food industry is problematic. Using chemical disinfectants in the food industry to prevent biofilm formation raises serious health concerns. Further, the ability of biofilm-forming bacterial pathogens to tolerate disinfection procedures questions the traditional treatment methods. Thus, there is a dire need for alternative treatment options targeting bacterial pathogens, especially biofilms. As clean-label products without carcinogenic and hazardous potential, natural compounds with growth and biofilm-inhibiting and biofilm-eradicating potentials have gained popularity as natural preservatives in the food industry. However, the use of these natural preservatives in the food industry is restricted by their poor availability, stability during food processing and storage. Also there is a lack of standardization, and unattractive organoleptic qualities. Nanotechnology is one way to get around these limitations and as well as the use of underutilized bioactives. The use of nanotechnology has several advantages including traversing the biofilm matrix, targeted drug delivery, controlled release, and enhanced bioavailability, bioactivity, and stability. The nanoparticles used in fabricating or encapsulating natural products are considered as an appealing antibiofilm strategy since the nanoparticles enhance the activity of the natural products against biofilms of foodborne bacterial pathogens. Hence, this literature review is intended to provide a comprehensive analysis of the current methods in nanotechnology used for natural products delivery (biofabrication, encapsulation, and nanoemulsion) and also discuss the different promising strategies employed in the recent and past to enhance the inhibition and eradication of foodborne bacterial biofilms.

Regulation of Staphylococcus aureus Virulence and Application of Nanotherapeutics to Eradicate S. aureus Infection.

Staphylococcus aureus is a versatile pathogen known to cause hospital- and community-acquired, foodborne, and zoonotic infections. The clinical infections by S. aureus cause an increase in morbidity and mortality rates and treatment costs, aggravated by the emergence of drug-resistant strains. As a multi-faceted pathogen, it is imperative to consolidate the knowledge on its pathogenesis, including the mechanisms of virulence regulation, development of antimicrobial resistance, and biofilm formation, to make it amenable to different treatment strategies. Nanomaterials provide a suitable platform to address this challenge, with the potential to control intracellular parasitism and multidrug resistance where conventional therapies show limited efficacy. In a nutshell, the first part of this review focuses on the impact of S. aureus on human health and the role of virulence factors and biofilms during pathogenesis. The second part discusses the large diversity of nanoparticles and their applications in controlling S. aureus infections, including combination with antibiotics and phytochemicals and the incorporation of antimicrobial coatings for biomaterials. Finally, the limitations and prospects using nanomaterials are highlighted, aiming to foster the development of novel nanotechnology-driven therapies against multidrug-resistant S. aureus.

Correlation Analysis between GlpQ-Regulated Degradation of Wall Teichoic Acid and Biofilm Formation Triggered by Lactobionic Acid in Staphylococcus aureus.

Staphylococcus aureus biofilms are a serious problem in the food industry. Wall teichoic acid (WTA) is crucial in S. aureus biofilm formation. Overexpression of the WTA-hydrolyzing enzyme glycerophosphoryl diester phosphodiesterase (GlpQ), induced by lactobionic acid (LBA), may be related to biofilm formation. We investigated the relationship between the regulation on GlpQ degradation of WTA by LBA and S. aureus biofilm formation. LBA minimum inhibitory concentration for S. aureus was 12.5 mg/mL. Crystal violet staining revealed the LBA-mediated inhibition of S. aureus adhesion and biofilm formation. RT-qPCR revealed the repressed expression of adhesion-related genes by LBA. Scanning electron microscopy revealed the obvious disruption of S. aureus surface structure, confirming the repression of S. aureus adhesion and biofilm formation by LBA. Native-PAGE results suggested that the WTA content of S. aureus was reduced under the inhibition of LBA. Additionally, LBA induced the overexpression of glpQ. Combined with our previous work, these results suggest that glpQ is induced in S. aureus to function in WTA degradation with the addition of LBA, resulting in decreased WTA content and subsequent reduction of adhesion and biofilm formation. The findings provide new insight into the degradation mechanism of S. aureus WTA and indicate the potential of LBA as an anti-biofilm agent.

Efficacy and safety of first-line anlotinib-based combinations for advanced non-small cell lung cancer: a three-armed prospective study.

Background: The evidence of combined therapies of multi-target agents in first-line treatment of advanced non-small cell lung cancer (NSCLC) was limited. This study aimed to evaluate the safety and efficacy of anlotinib combined with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), chemotherapy, or immune checkpoint inhibitor (ICI) in advanced NSCLC. Methods: This open-label, three-arm, prospective study (NCT03628521) enrolled untreated locally advanced/metastatic NSCLC patients. Patients with EGFR mutation NSCLC received anlotinib and erlotinib (cohort A). Patients without EGFR/ALK/ROS1 mutation received anlotinib combined with carboplatin plus pemetrexed/gemcitabine (cohort B), or sintilimab (cohort C). The primary outcomes were safety and objective response rate (ORR). The secondary endpoints included progression-free survival (PFS), disease control rate (DCR), and overall survival (OS). Treatments were performed for at least 2 cycles and efficacy was evaluated every 2 cycles using RECIST version 1.1. Safety was assessed throughout the study. Results: A total of 30, 30, and 22 patients were enrolled in cohorts A, B, and C, respectively. There were 3 patients did not complete the treatment in cohort A. In cohorts A and B, ≥ grade 3 treatment-related adverse events (TRAEs) occurred in 77.3% and 60.0% of patients, respectively. The most common TRAEs were rash (10.0%) and decreased platelet count (30.0%) in cohorts A and B, respectively. The ORRs were 92.9% and 60.0% in cohorts A and B, respectively, and DCRs were 96.4% and 96.7%, respectively. The ORR and incidence of ≥ grade 3 TRAEs of cohort C were, which 72.7% and 54.5%, which had been published previously. Median PFSs [95% confidence interval (CI)] were 21.6 (15.6 to 24.9), 13.0 [10.5 to not estimated (NE)], and 15.6 (12.9 to NE) months in cohorts A, B, and C, respectively. Median OS was 28.1 (95% CI: 21.82 to NE) months in cohort B. The 24-month OS rates in cohorts A and C were 87.1% and 83.9%, respectively. Conclusions: Anlotinib-based combinations with EGFR-TKI, chemotherapy, and ICI are well-tolerated and encouraging as first-line therapies for advanced NSCLC, which could be verified in future studies. Anlotinib-based combination might provide multiple choices for first-line treatment in patients with advanced NSCLC.

Ethanol at Subinhibitory Concentrations Enhances Biofilm Formation in Salmonella Enteritidis.

The survival of Salmonella Enteritidis in the food chain is relevant to its biofilm formation capacity, which is influenced by suboptimal environmental conditions. Here, biofilm formation pattern of this bacterium was assessed in the presence of ethanol at sub-minimal inhibitory concentrations (sub-MICs) by microtiter plate assays, cell characteristic analyses, and gene expression tests. It was observed that ethanol at subinhibitory concentrations (1/4 MIC, 2.5%; 1/2 MIC, 5.0%) was able to stimulate biofilm formation in S. Enteritidis. The OD595 value (optical density at 595 nm) used to quantify biofilm production was increased from 0.14 in control groups to 0.36 and 0.63 under 2.5% and 5.0% ethanol stresses, respectively. Ethanol was also shown to reduce bacterial swimming motility and enhance cell auto-aggregation ability. However, other cell characteristics such as swarming activity, initial attachment and cell surface hydrophobicity were not remarkedly impacted by ethanol. Reverse transcription quantitative real-time PCR (RT-qPCR) analysis further revealed that the luxS gene belonging to a quorum-sensing system was upregulated by 2.49- and 10.08-fold in the presence of 2.5% and 5.0% ethanol, respectively. The relative expression level of other biofilm-related genes (adrA, csgB, csgD, and sdiA) and sRNAs (ArcZ, CsrB, OxyS, and SroC) did not obviously change. Taken together, these findings suggest that decrease in swimming motility and increase in cell auto-aggregation and quorum sensing may result in the enhancement of biofilm formation by S. Enteritidis under sublethal ethanol stress.

Global Spread of MCR-Producing Salmonella enterica Isolates.

Colistin resistance in bacteria has become a significant threat to food safety and public health, and its development was mainly attributed to the plasmid-mediated mcr genes. This study aimed to determine the global prevalence and molecular characteristics of mcr-producing Salmonella enterica isolates. A total of 2279 mcr-producing Salmonella genomes were obtained from the public database, which were disseminated in 37 countries from five continents worldwide, including Asia, Europe, America, Australia, and Africa. Human samples (39.5%; 900/2279) were the predominant sources of mcr-producing Salmonella isolates, followed by foods (32.6%), animals (13.7%), and environment (4.4%). Furthermore, 80 Salmonella serotypes were identified, and Typhimurium and 1,4,[5],12:i:- were the predominant serotypes, accounting for 18.3% and 18.7%, respectively. Twenty mcr variants were identified, and the most common ones were mcr-9.1 (65.2%) and mcr-1.1 (24.4%). Carbapenems-resistance gene blaNDM-1 and tigecycline-resistance gene tet(X4) were identified in one isolate, respectively. Phylogenetic results indicated that mcr-producing Salmonella fell into nine lineages (Lineages I-IX), and Salmonella Typhimurium, 1,4,[5],12:i:- and 4,[5],12:i:- isolates from different countries were mixed in Lineages I, II and III, suggesting that international spread occurred. These findings underline further challenges for the spread of Salmonella-bearing mcr genes.

International Spread of Tet(X4)-Producing Escherichia coli Isolates.

Tigecycline resistance in bacteria has become a significant threat to food safety and public health, where the development of which is attributed to plasmid-mediated tet(X4) genes. In this study, the genomes of 613 tet(X4)-producing Escherichia coli (E. coli) isolates, available from public databases, are evaluated to determine their international prevalence and molecular characterization. These E. coli isolates have been disseminated in 12 countries across Asia and Europe. It was found that pigs and their products (n = 162) were the most common vehicle, followed by humans (n = 122), chickens (n = 60), and the environment (n = 49). Carbapenems-resistant genes blaNDM-5 (1.3%) and blaNDM-1 (0.2%) were identified, as well as colistin-resistant genes mcr-1.1 (12.6%) and mcr-3.1 (0.5%). It was noted that the tigecycline-resistant gene cluster tmexC-tmexD-toprJ1 was identified in seven (1.1%) isolates. Phylogenomic results indicated that tet(X4)-producing E. coli isolates fell into seven lineages (lineages I, II, III, IV, V, VI, and VII), and international spread mainly occurred in Asian countries, especially China, Pakistan, Singapore, and Malaysia. Four forms of tet(X4) transposon units were found, including the I-type (IS26-tet(X4)-ISCR2), II-type (ΔIS1R-tet(X4)-ISCR2), III-type (ISCR2-tet(X4)-ISCR2), and IV-type (ISCR2-tet(X4)-ΔISCR2). These findings underline further challenges for the spread of E. coli bearing tet(X4) gene.

Phylogenomic Analysis of Salmonella enterica Serovar Indiana ST17, an Emerging Multidrug-Resistant Clone in China.

Salmonella enterica serovar Indiana (S. Indiana) is an extremely expanded foodborne pathogen in China in recent years. This study aimed to elucidate the national prevalence and phylogenomic characterization of this pathogen in China. Among 5, 287 serotyped Salmonella isolates collected during 2002 to 2018, 466 S. Indiana isolates were found in 15 provinces, and 407 were identified to be ST17, and the rest were ST2040. Among 407 ST17 isolates, 372 (91.4%) were multidrug resistant, and 366 (89.9%) were resistant to ciprofloxacin, 235 (57.7%) were further resistant to ceftriaxone. Phylogenomic analysis revealed that ST17 isolates were classified into four clades (I, II, III and IV), which appeared in international clonal dissemination. ST17 isolates from China fell into Clade IV with part of isolates from the United Kingdom, the United States, South Korea, and Thailand, suggesting their close genetic relationship. Mutations in quinolone resistance-determining regions (QRDR) of GyrA and ParC, and plasmid-mediated quinolone resistance (PMQR) genes aac(6')-Ib-cr, oqxAB, and qnrS as well as extended spectrum ß-lactamases (ESBL) genes blaCTX-M, blaOXA, and blaTEM in isolates from Clade IV were much higher than those from other three clades. Various blaCTX-M subtypes (blaCTX-M-65, blaCTX-M-55, blaCTX-M-27, blaCTX-M-14, and blaCTX-M-123) with ISEcp1, IS903B, ISVsa5, and IS1R were found in ST17 isolates, especially Tn1721 containing ΔISEcp1-blaCTX-M-27-IS903B in P1-like bacteriophage plasmids. These findings on the prevalent and genomic characterization for the S. Indiana multidrug-resistant ST17 clone in China, which have not been reported yet, provide valuable insights into the potential risk of this high-resistant clone. IMPORTANCE Fluoroquinolones and cephalosporins are the primary choices for severe salmonellosis treatment. S. Indiana has become one of the most prevalent serovars in breeding poultry and poultry meats in China in recent years. ST17 was recognized as the leading epidemiological importance in S. Indiana because of its high-level resistance to the most of common antibiotics, including ciprofloxacin and ceftriaxone. However, the prevalence and phylogenomic characterization of ST17 isolates are unclear. Here, we did a retrospective screening on a large scale for S. Indiana in China, and performed its phylogenomic analysis. It was found that ST17 isolates had extensive spread in 15 provinces of China and became a multidrug-resistant clone. The international spread of the ST17 isolates was observed among several countries, especially China, the United Kingdom, and the United States. Our study emphasized the importance of surveillance of a high-resistant S. Indiana ST17 clone to combat its threat to public health.

A New BCN Compound with Monoclinic Symmetry: First-Principle Calculations.

In this study, we predicted and investigated a new light-element compound B-C-N in Pm phase, denoted as Pm-BCN, using density functional theory. Pm-BCN is mechanically, dynamically, and thermodynamically stable. The elastic moduli of Pm-BCN are larger than those of other B-C-N and light-element compounds, such as P213 BN, B2C3, P4/m BN, Pnc2 BN, and dz4 BN. By studying the mechanical anisotropy of elastic moduli, we proved that Pm-BCN is a mechanically anisotropic material. In addition, the shear anisotropy factors A2 and ABa of Pm-BCN are smaller than those of the seven B-C-N compounds mentioned in this paper. Pm-BCN is a semiconductor material with an indirect and wide band gap, suggesting that Pm-BCN can be applied in microelectronic devices.

Rationale and design of a phase II trial of dacomitinib in advanced non-small cell lung cancer patients with uncommon epidermal growth factor receptor mutations: a prospective and single arm study (DANCE study).

BACKGROUND: Dacomitinib is a second-generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). ARCHER-1050 showed that this agent can improve progression-free survival and overall survival in advanced non-small cell lung cancer patients with sensitive EGFR mutation compared to gefitinib. However, it is unclear whether dacomitinib is effective in patients with sensitizing uncommon EGFR mutations in exon 18-21. The aim of this study is to investigate the safety and efficacy of dacomitinib in these patients. METHODS: This is a single arm, prospective, open label and phase II trial. Sample size will be calculated by a minimax two-stage design method based on the following parameters: α = 0.075, 1-ß = 0.9, P0 = 0.20, P1 = 0.45 and a dropout rate of 10%. A total of 30 eligible patients will be included. Patients will receive continuous oral therapy with dacomitinib (45 mg/day) until disease progression, withdrawal of consent, or unacceptable toxicity, whichever occurs first. The primary endpoint is objective response rate (ORR) per RECIST version 1.1, as assessed by investigators' review. The second endpoint is disease control rate (DCR), PFS, OS, and safety. DISCUSSION: We conduct a single arm, phase II study to investigate the safety and efficacy of dacomitinib in advanced NSCLC patients with sensitizing uncommon EGFR mutations. The results of the DANCE study will provide new data regarding efficacy and safety of these patients. TRIAL REGISTRATION: NCT04504071.

DsrA Modulates Central Carbon Metabolism and Redox Balance by Directly Repressing pflB Expression in Salmonella Typhimurium.

Bacterial small RNAs (sRNAs) function as vital regulators in response to various environmental stresses by base pairing with target mRNAs. The sRNA DsrA, an important posttranscriptional regulator, has been reported to play a crucial role in defense against oxidative stress in Salmonella enterica serovar Typhimurium, but its regulatory mechanism remains unclear. The transcriptome sequencing (RNA-seq) results in this study showed that the genes involved in glycolysis, pyruvate metabolism, the tricarboxylic acid (TCA) cycle, and NADH-dependent respiration exhibited significantly different expression patterns between S. Typhimurium wild type (WT) and the dsrA deletion mutant (ΔdsrA strain) before and after H2O2 treatment. This indicated the importance of DsrA in regulating central carbon metabolism (CCM) and NAD(H) homeostasis of S. Typhimurium. To reveal the direct target of DsrA action, fusion proteins of six candidate genes (acnA, srlE, tdcB, nuoH, katG, and pflB) with green fluorescent protein (GFP) were constructed, and the fluorescence analysis showed that the expression of pflB encoding pyruvate-formate lyase was repressed by DsrA. Furthermore, site-directed mutagenesis and RNase E-dependent experiments showed that the direct base pairing of DsrA with pflB mRNA could recruit RNase E to degrade pflB mRNA and reduce the stability of pflB mRNA. In addition, the NAD+/NADH ratio in WT-ppflB-pdsrA was significantly lower than that in WT-ppflB, suggesting that the repression of pflB by DsrA could contribute greatly to the redox balance in S. Typhimurium. Taken together, a novel target of DsrA was identified, and its regulatory role was clarified, which demonstrated that DsrA could modulate CCM and redox balance by directly repressing pflB expression in S. Typhimurium. IMPORTANCE Small RNA DsrA plays an important role in defending against oxidative stress in bacteria. In this study, we identified a novel target (pflB, encoding pyruvate-formate lyase) of DsrA and demonstrated its potential regulatory mechanism in S. Typhimurium by transcriptome analysis. In silico prediction revealed a direct base pairing between DsrA and pflB mRNA, which was confirmed in site-directed mutagenesis experiments. The interaction of DsrA-pflB mRNA could greatly contribute to the regulation of central carbon metabolism and intracellular redox balance in S. Typhimurium. These findings provided a better understanding of the critical roles of small RNA in central metabolism and stress responses in foodborne pathogens.