Clonal transmission of blaIMP-4-carrying ST196 Klebsiella pneumoniae isolates mediated by IncN plasmid in China.

OBJECTIVES: To investigate the clinical and molecular epidemiological characteristics of blaIMP-4-carrying Klebsiella pneumoniae in a tertiary hospital in China. METHODS: 10 Carbapenem Resistant K. pneumoniae (CRKP) isolates with blaIMP-4 gene were collected. Molecular characteristics were analyzed using whole-genome sequencing. Plasmid conjugation experiment was used to analyze the conjugation of plasmids. We compared and analyzed K. pneumoniae carrying blaIMP-4 on NCBI with the strains in this study. RESULTS: All 10 CRKP isolates with blaIMP-4 were collected from 10 adult patients in the respiratory intensive care unit. These strains were only sensitive to polymyxins and tigecycline due to simultaneously carrying multiple resistance genes, such as blaOKP-A-5, fosA, oqxA and oqxB. Notably, R29 harbored two carbapenemase genes (blaNDM-1 and blaIMP-4). These strains had similar drug-resistant phenotypes and drug-resistant genes, all belonging to ST196. Additionally, the patients had spatiotemporal intersection during hospitalization, suggesting that these strains had clonal transmission, but they belonged to different clonal clusters from the blaIMP-4-positive K. pneumoniae currently published on NCBI. Among the 10 strains, blaIMP-4 was located on the IncN plasmid, and 6 strains had successfully transferred the plasmid to the recipient strain EC600 through plasmid conjugation. CONCLUSIONS: The blaIMP-4-positive ST196 CRKP had clonal distribution in the respiratory ICU, which was mediated by IncN plasmid. Consequently, there should be increased monitoring of carbapenem-resistant strains in clinical settings to prevent and control of its transmission.

Pangenome analysis of Shewanella xiamenensis revealed important genetic traits concerning genetic diversity, pathogenicity and antibiotic resistance.

BACKGROUND: Shewanella xiamenensis, widely distributed in natural environments, has long been considered as opportunistic pathogen. Recently, significant changes in the resistance spectrum have been observed in S. xiamenensis, due to acquired antibiotic resistance genes. Therefore, a pan-genome analysis was conducted to illuminate the genomic changes in S. xiamenensis. RESULTS: Phylogenetic analysis revealed three major clusters and three singletons, among which close relationship between several strains was discovered, regardless of their host and niches. The "open" genomes with diversity of accessory and strain-specific genomes took advantage towards diversity environments. The purifying selection pressure was the main force on genome evolution, especially in conservative genes. Only 53 gene families were under positive selection pressure. Phenotypic resistance analysis revealed 21 strains were classified as multi-drug resistance (MDR). Ten types of antibiotic resistance genes and two heavy metal resistance operons were discovered in S. xiamenensis. Mobile genetic elements and horizontal gene transfer increased genome diversity and were closely related to MDR strains. S. xiamenensis carried a variety of virulence genes and macromolecular secretion systems, indicating their important roles in pathogenicity and adaptability. Type IV secretion system was discovered in 15 genomes with various sequence structures, indicating it was originated from different donors through horizontal gene transfer. CONCLUSIONS: This study provided with a detailed insight into the changes in the pan-genome of S. xiamenensis, highlighting its capability to acquire new mobile genetic elements and resistance genes for its adaptation to environment and pathogenicity to human and animals.

Molecular characterization of extensively drug-resistant hypervirulent Pseudomonas aeruginosa isolates in China.

BACKGROUND: Recently, extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) isolates have been increasingly detected and posed great challenges to clinical anti-infection treatments. However, little is known about extensively resistant hypervirulent P. aeruginosa (XDR-hvPA). In this study, we investigate its epidemiological characteristics and provide important basis for preventing its dissemination. METHODS: Clinical XDR-PA isolates were collected from January 2018 to January 2023 and identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry; antibiotic susceptibility testing was performed by broth microdilution method, and minimum inhibitory concentrations (MICs) were evaluated. Virulence was evaluated using the Galleria mellonella infection model; molecular characteristics, including resistance genes, virulence genes, and homology, were determined using whole-genome sequencing. RESULTS: A total of 77 XDR-PA strains were collected; 47/77 strains were XDR-hvPA. Patients aged > 60 years showed a significantly higher detection rate of XDR-hvPA than of XDR-non-hvPA. Among the 47 XDR-hvPA strains, 24 strains carried a carbapenemase gene, including blaGES-1 (10/47), blaVIM-2 (6/47), blaGES-14 (4/47), blaIMP-45 (2/47), blaKPC-2 (1/47), and blaNDM-14 (1/47). ExoU, exoT, exoY, and exoS, important virulence factors of PA, were found in 31/47, 47/47, 46/47, and 29/47 strains, respectively. Notably, two XDR-hvPA simultaneously co-carried exoU and exoS. Six serotypes (O1, O4-O7, and O11) were detected; O11 (19/47), O7 (13/47), and O4 (9/47) were the most prevalent. In 2018-2020, O4 and O7 were the most prevalent serotypes; 2021 onward, O11 (16/26) was the most prevalent serotype. Fourteen types of ST were detected, mainly ST235 (14/47), ST1158 (13/47), and ST1800 (7/47). Five global epidemic ST235 XDR-hvPA carried blaGES and showed the MIC value of ceftazidime/avibactam reached the susceptibility breakpoint (8/4 mg/L). CONCLUSIONS: The clinical detection rate of XDR-hvPA is unexpectedly high, particularly in patients aged > 60 years, who are seemingly more susceptible to contracting this infection. Clonal transmission of XDR-hvPA carrying blaGES, which belongs to the global epidemic ST235, was noted. Therefore, the monitoring of XDR-hvPA should be strengthened, particularly for elderly hospitalized patients, to prevent its spread.

Case Report: Successful treatment of advanced hepatocarcinoma with the PD-1 inhibitor Camrelizumab.

Primary liver cancer is characterized by closely related with chronic liver inflammation, thereby reversing hypoxic immunosuppressive microenvironment of tumor cell growth by immunotherapy drug is a potentially effective strategy. Camrelizumab is an anti-PD-1 antibody being developed by Jiangsu Hengrui Pharmaceuticals Co., Ltd. We reported a case of an adult critical Chinese patient with primary hepatocellular carcinoma and lung metastasis completely responding to Camrelizumab, most of the lesions were stable and no new lesions occurred after 1-year treatment, which provides us to reconsider the therapeutic effect of Camrelizumab on such patients. Camrelizumab had a safety profile for the patient in our case report, except for the occurrence of RCCEP. This case provides the evidence of the effective antitumor activity and manageable toxicities of Camrelizumab for patients with advanced hepatocellular carcinoma, which was the first application as far as we know.

WNT ligands in non-small cell lung cancer: from pathogenesis to clinical practice.

Non-small cell lung cancer (NSCLC) is the malignant tumor with the highest morbidity and leading cause of death worldwide, whereas its pathogenesis has not been fully elucidated. Although mutations in some crucial genes in WNT pathways such as ß-catenin and APC are not common in NSCLC, the abnormal signal transduction of WNT pathways is still closely related to the occurrence and progression of NSCLC. WNT ligands (WNTs) are a class of secreted glycoproteins that activate WNT pathways through binding to their receptors and play important regulatory roles in embryonic development, cell differentiation, and tissue regeneration. Therefore, the abnormal expression or dysfunction of WNTs undoubtedly affects WNT pathways and thus participates in the pathogenesis of diseases. There are 19 members of human WNTs, WNT1, WNT2, WNT2b, WNT3, WNT3a, WNT4, WNT5a, WNT5b, WNT6, WNT7a, WNT7b, WNT8a, WNT8b, WNT9a, WNT9b, WNT10a, WNT10b, WNT11 and WNT16. The expression levels of WNTs, binding receptors, and activated WNT pathways are diverse in different tissue types, which endows the complexity of WNT pathways and multifarious biological effects. Although abundant studies have reported the role of WNTs in the pathogenesis of NSCLC, it still needs further study as therapeutic targets for lung cancer. This review will systematically summarize current research on human WNTs in NSCLC, from molecular pathogenesis to potential clinical practice.

Biosynthesis of Silver Nanoparticles Using the Biofilm Supernatant of Pseudomonas aeruginosa PA75 and Evaluation of Their Antibacterial, Antibiofilm, and Antitumor Activities.

Purpose: As an under-explored biomaterial, bacterial biofilms have a wide range of applications in the green synthesis of nanomaterials. The biofilm supernatant of Pseudomonas aeruginosa PA75 was used to synthesize novel silver nanoparticles (AgNPs). BF75-AgNPs were found to possess several biological properties. Methods: In this study, we biosynthesized BF75-AgNPs using biofilm supernatant as the reducing agent, stabilizer, and dispersant and investigated their biopotential in terms of antibacterial, antibiofilm, and antitumor activities. Results: The synthesized BF75-AgNPs demonstrated a typical face-centered cubic crystal structure; they were well dispersed; and they were spherical with a size of 13.899 ± 4.036 nm. The average zeta potential of the BF75-AgNPs was -31.0 ± 8.1 mV. The BF75-AgNPs exhibited strong antibacterial activities against the methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase Escherichia coli (ESBL-EC), extensively drug-resistant Klebsiella pneumoniae (XDR-KP), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA). Moreover, the BF75-AgNPs had a strong bactericidal effect on XDR-KP at 1/2 × MIC, and the expression level of reactive oxygen species (ROS) in bacteria was significantly increased. A synergistic effect was observed when the BF75-AgNPs and colistin were used for the co-treatment of two colistin-resistant XDR-KP strains, with fractional inhibitory concentration index (FICI) values of 0.281 and 0.187, respectively. Furthermore, the BF75-AgNPs demonstrated a strong biofilm inhibition activity and mature biofilm bactericidal activity against XDR-KP. The BF75-AgNPs also exhibited a strong antitumor activity against melanoma cells and low cytotoxicity against normal epidermal cells. In addition, the BF75-AgNPs increased the proportion of apoptotic cells in two melanoma cell lines, and the proportion of late apoptotic cells increased with BF75-AgNP concentration. Conclusion: This study suggests that BF75-AgNPs synthesized from biofilm supernatant have broad prospects for antibacterial, antibiofilm, and antitumor applications.

Metagenomic analysis reveals the short-term influences on conjugation of blaNDM-1 and microbiome in hospital wastewater by silver nanoparticles at environmental-related concentration.

Hospital wastewater contains large amounts of antibiotic-resistant bacteria and serves as an important reservoir for horizontal gene transfer (HGT). However, the response of the microbiome in hospital wastewater to silver remains unclear. In this study, the short-term impacts of silver on the microbiome in hospital wastewater were investigated by metagenome next-generation sequencing. The influence of silver on the conjugation of plasmid carrying blaNDM-1 was further examined. Our results showed that in hospital wastewater, high abundances of antibiotic resistance genes (ARGs) were detected. The distribution tendencies of certain ARG types on chromosomes or plasmids were different. Clinically important ARGs were identified in phage-like contigs, indicating potential transmission via transduction. Pseudomonadales, Enterobacterales, and Bacteroidales were the major ARG hosts. Mobile genetic elements were mainly detected in plasmids and associated with various types of ARGs. The binning approach identified 29 bins that were assigned to three phyla. Various ARGs and virulence factors were identified in 14 and 11 bins, respectively. MetaCHIP identified 49 HGT events. The transferred genes were annotated as ARGs, mobile genetic elements, and functional genes, and they mainly originated from donors belonging to Bacteroides and Pseudomonadales. In addition, 20 nm AgNPs reduced microbial diversity and enhanced the relative abundance of Acinetobacter. The changes induced by 20 nm AgNPs included increases in the abundances of ARGs and genes involved lipid metabolism pathway. Conjugation experiments showed that Ag+ and 20 nm AgNPs caused 2.38-, 3.31-, 4.72-, and 4.57-fold and 1.46-, 1.61-, 3.86-, and 2.16-fold increases in conjugation frequencies of plasmid with blaNDM-1 at 0.1, 1, 10, and 100 µg/L, respectively. Our findings provide insight into the response of the microbiome in hospital wastewater to silver, emphasize the adaptation capability of Acinetobacter inhabiting hospitals against adverse environments, and highlight the promotion of silver for antibiotic resistance.

LRP5 Promotes Gastric Cancer via Activating Canonical Wnt/ß-Catenin and Glycolysis Pathways.

The overactivation of canonical Wnt/ß-catenin pathway is one of the main cascades for the initiation, progression, and recurrence of most human malignancies. As an indispensable coreceptor for the signaling transduction of the canonical Wnt/ß-catenin pathway, LRP5 is up-regulated and exerts a carcinogenic role in most types of cancer. However, its expression level and role in gastric cancer (GC) has not been clearly elucidated. The current work showed that LRP5 was overexpressed in GC tissues and the expression of LRP5 was positively associated with the advanced clinical stages and poor prognosis. Ectopic expression of LRP5 enhanced the proliferation, invasiveness, and drug resistance of GC cells in vitro, and accelerated the tumor growth in nude mice, through activating the canonical Wnt/ß-catenin signaling pathway and up-regulating aerobic glycolysis, thus increasing the energy supply for GC cells. Additionally, the expression of LRP5 and glycolysis-related genes showed an obviously positive correlation in GC tissues. By contrast, the exact opposite results were observed when the endogenous LRP5 was silenced in GC cells. Collectively, these results not only reveal the carcinogenic role of LRP5 during GC development through activating the canonical Wnt/ß-catenin and glycolysis pathways, but also provide a valuable candidate for the diagnosis and treatment of human GC.

Comprehensive analysis of lncRNAs as biomarkers for diagnosis, prognosis, and treatment response in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most common histological type of renal carcinoma and has a high recurrence rate and poor outcome. Accurate patient risk stratification based on genetic markers can help to identify the high-risk patient for early and further treatments and would promote patient survival. Long non-coding RNAs (lncRNAs) have attracted widespread attention as biomarkers for early diagnosis, treatment, and prognosis because of their high specificity and sensitivity. Here, we performed a systematic search in NCBI PubMed and found 44 lncRNAs as oncogenes, 18 lncRNAs as tumor suppressors, 199 lncRNAs as diagnostic biomarkers, 62 lncRNAs as prognostic biomarkers, and 3 lncRNAs as predictive biomarkers for ccRCC. We also comprehensively discuss the biological functions and molecular regulatory mechanisms of lncRNAs in ccRCC. Overall, the present study is a systemic analysis to assess the expression and clinical value of lncRNAs in ccRCC, and lncRNAs hold promise to be diagnostic, prognostic, and predictive biomarkers.

Long Noncoding RNA NEAT1 Promotes Proliferation and Invasion via Targeting miR-181a-5p in Non-Small Cell Lung Cancer.

Long noncoding RNAs (lncRNAs) have been implicated in various biological processes and pathological conditions, including tumorigenesis. However, the exact roles of NEAT1 and its underlying mechanisms in non-small cell lung cancer (NSCLC) remain largely unclear. In the present study, lncRNA NEAT1 was detected to be significantly upregulated in NSCLC tissues and closely associated with advanced TNM stages, lymph node metastasis, distant metastasis, and poor prognosis. Further experiments revealed that lncRNA NEAT1 silencing inhibited cell proliferation and invasion in vitro. In addition, mechanistic analysis showed that lncRNA NEAT1 upregulated the miR-181a-5p-targeted gene HMGB2 through acting as a competitive "sponge" of miR-181a-5p. In conclusion, our study suggested that lncRNA NEAT1 plays an oncogenic role in NSCLC progression and provides potential mechanisms by which lncRNA NEAT1 contributes to this disease.

Expression of basic fibroblast growth factor, CD31, and α-smooth muscle actin and esophageal cancer recurrence after definitive chemoradiation.

There is cumulative evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. The aims of this study were to analyze the expression of basic fibroblast growth factor (FGF-2), CD31, and α-smooth muscle actin (SMA) in esophageal cancer patients and to establish their significance as indicators of disease recurrence after definitive chemoradiation (CRT). Protein expressions of FGF-2, CD31, and SMA were evaluated by immunohistochemistry and Western blot analysis in 70 patients, 20 with esophageal squamous cell carcinoma (ESCC) and 50 with locally recurrent ESCC after definitive CRT. Twenty matched normal esophageal squamous epithelium were also studied as controls. Esophageal cancer tissues showed positive expression of FGF-2, CD31, and SMA; in contrast, FGF-2 expression was not detected and only little staining for CD31 and SMA was noted in normal epithelium. Protein levels of FGF-2, CD31, and SMA were significantly elevated in recurrent ESCC. Among the patients with locally recurrent disease, expression of FGF-2 and SMA was notably high in whom the tumor recurred locally within 24 months after definitive CRT. The 2- and 5-year local recurrence-free survival rate was 15.4 % and 0 in patients with high FGF-2 expression, compared with 45.8 and 33.3 % in those who expressed low FGF-2, respectively (P = 0.005). Of patients who expressed high SMA, the 2- and 5-year local recurrence-free survival rate was 21.7 and 8.7 %, respectively, compared to those with low SMA expression which was 37.0 and 22.2 %, respectively (P = 0.016). Overexpression of FGF-2 and SMA is associated with local recurrence and reduced recurrence-free survival after definitive CRT for ESCC. The data also suggest that targeting stromal cells may be an attractive approach for esophageal cancer therapy strategies.

Expression profile of apoptosis-related genes potentially explains early recurrence after definitive chemoradiation in esophageal squamous cell carcinoma.

Definitive chemoradiation is a curative treatment option for patients with locoregional esophageal squamous cell carcinoma (ESCC) who are not suitable for surgical resection, but many tend to develop local recurrence. The purpose of the study was to investigate factors affecting local recurrence of the tumor. Seventy-two patients with stage II-III thoracic ESCC who received definitive concurrent chemoradiation (CRT) and completely responded to the treatment were enrolled into this study. The case patients were 49 patients who recurred locally within 24 months after definitive CRT and 23 patients who did not have a local recurrence within 24 months were considered as controls. We investigated whether dysregulation of apoptosis-related genes was associated with early tumor recurrence. Quantitative real-time polymerase chain reaction showed upregulation of BCLAF1 and downregulation of BAG4, CARD6, IGF1R, and TNF in the tissues of case patients, as compared with controls. Among the patients with recurrent ESCC, those with tumors which exhibited more than twofold upregulated BCLAF1 and more than twofold downregulated BAG4 and TNF had a decreased time interval to local recurrence. Three gene pairs of the downregulated genes showed a significant correlation with local recurrence: BAG4 and CARD6, BAG4 and TNF, CARD6, and TNF. The patients with T3-4 disease and those with tumor >3 cm in length had a trend toward early local recurrence, though the associations were not reached statistical significance. Upregulation of BCLAF1 and downregulation of BAG4 and TNF was independently associated with early local recurrence in multivariate analysis (P < 0.05). This study supports the involvement of apoptosis-related genes in early tumor recurrence after definitive chemoradiation in patients with stage II-III thoracic ESCC.

Core-shell structured α-Fe2O3@TiO2 nanocomposites with improved photocatalytic activity in the visible light region.

The core-shell structured Fe2O3@TiO2 nanocomposites prepared via a heteroepitaxial growth route using the Fe2O3 spindle as a hard template display improved photocatalytic degradation activity for Rhodamine B dye under visible light irradiation. The ratio of α-Fe2O3 : TiO2 in the α-Fe2O3@TiO2 core-shell nanocomposites can be tuned by etching the α-Fe2O3 core via controlling the concentration of HCl and etching time. An appropriate concentration of the Fe2O3 core could effectively induce a transition of the optical response from the UV to the visible region and decrease the recombination rate of photogenerated electrons and the holes of the core-shell structured catalyst, greatly contributing to the enhancement of visible light response and visible light photocatalytic activity of the Fe2O3@TiO2 catalysts. It is revealed that the optical response and photocatalytic performance of the core-shell α-Fe2O3@TiO2 nanocomposites can be tuned by adjusting the molar ratio of Fe2O3 : TiO2 of the α-Fe2O3@TiO2 nanocomposites. The α-Fe2O3@TiO2 core-shell nanocomposite with an optimal molar ratio of 7% for Fe2O3 : TiO2 exhibits the best photocatalytic performance under visible light irradiation. It is shown that the Fe2O3/TiO2 heterojunction structure is responsible for the efficient visible-light photocatalytic activity. As the concentration of Fe2O3 is high, Fe(3+) ions will act as recombination centres of the photogenerated electrons and holes. The present core-shell Fe2O3@TiO2 nanoparticles displaying enhanced photodegradation activity could find potential applications as photocatalysts for the abatement of various organic pollutants.