Isolation and characterization of three novel lytic phages against K54 serotype carbapenem-resistant hypervirulent Klebsiella pneumoniae.

The emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) has driven us to explore alternative treatments for the limitation of antimicrobial agents. Lytic phages are considered a promising alternative treatment for CR-hvKP infection. In this study, we reported three novel lytic phages, vB_KpnA_SCNJ1-Z, vB_KpnS_SCNJ1-C, and vB_KpnM_SCNJ1-Y, against a CR-hvKP strain SCNJ1, and they possess genomes of double-stranded DNA with a size of 43,428 bp, 46,039 bp, and 50,360 bp, respectively. Phylogenetic analysis demonstrated that vB_KpnA_SCNJ1-Z belongs to the family Autographiviridae within the class Caudoviricetes, while vB_KpnS_SCNJ1-C and vB_KpnM_SCNJ1-Y are unclassified Caudoviricetes. The phages showed a narrow host range only lysing 1 of 50 tested clinical bacterial strains. The one-step growth curves and stability results showed that the phages displayed relatively short latency periods, with broad pH (pH 3-14) and thermal stabilities (20-60°C). The phages showed significant inhibition of the biofilm formation by SCNJ1 and strong antibacterial activity in vitro. In the mouse model, we demonstrated that administration of a single phage or phage cocktail significantly reduced bacteria loads in the lung, liver, and spleen, and effectively rescued mice from the infection of the SCNJ1 strain, with a survival rate of 70-80%. These findings suggested the three phages have great potential as an alternative therapy with favorable stability and strong antibacterial activity both in vivo and in vitro for the treatment of CR-hvKP infection.

Case report: Transcatheter tricuspid valve intervention using K-Clip™ system after prior Kay's annuloplasty.

The K-Clip™ system is emerging as an alternative to correct tricuspid regurgitation (TR) for patients with high surgical risk. However, patients with recurrent severe tricuspid regurgitation after prior Kay's annuloplasty are not generally deemed to be candidates for K-Clip™ implantation. Herein, we report a case of a 63-year-old woman with recurrent symptomatic torrential tricuspid regurgitation 5 years after double valve replacement with Kay's annuloplasty of the tricuspid valve. The K-Clip™ was successfully implanted, and the severity of tricuspid regurgitation and dimensions of tricuspid annulus achieved significant reduction. In conclusion, K-Clip™ can still be feasible and effective for patients with prior Kay's annuloplasty. However, indications become more rigorous, and evaluation should be more comprehensive.

Genetic analysis of resistance and virulence characteristics of clinical multidrug-resistant Proteus mirabilis isolates.

Objective: Proteus mirabilis is the one of most important pathogens of catheter-associated urinary tract infections. The emergence of multidrug-resistant (MDR) P. mirabilis severely limits antibiotic treatments, which poses a public health risk. This study aims to investigate the resistance characteristics and virulence potential for a collection of P. mirabilis clinical isolates. Methods and results: Antibiotic susceptibility testing revealed fourteen MDR strains, which showed high resistance to most ß-lactams and trimethoprim/sulfamethoxazole, and a lesser extent to quinolones. All the MDR strains were sensitive to carbapenems (except imipenem), ceftazidime, and amikacin, and most of them were also sensitive to aminoglycosides. The obtained MDR isolates were sequenced using an Illumina HiSeq. The core genome-based phylogenetic tree reveals the high genetic diversity of these MDR P. mirabilis isolates and highlights the possibility of clonal spread of them across China. Mobile genetic elements SXT/R391 ICEs were commonly (10/14) detected in these MDR P. mirabilis strains, whereas the presence of resistance island PmGRI1 and plasmid was sporadic. All ICEs except for ICEPmiChn31006 carried abundant antimicrobial resistance genes (ARGs) in the HS4 region, including the extended-spectrum ß-lactamase (ESBL) gene blaCTX-M-65. ICEPmiChn31006 contained the sole ARG blaCMY-2 and was nearly identical to the global epidemic ICEPmiJpn1. The findings highlight the important roles of ICEs in mediating the spread of ARGs in P. mirabilis strains. Additionally, these MDR P. mirabilis strains have great virulence potential as they exhibited significant virulence-related phenotypes including strong crystalline biofilm, hemolysis, urease production, and robust swarming motility, and harbored abundant virulence genes. Conclusion: In conclusion, the prevalence of MDR P. mirabilis with high virulence potential poses an urgent threat to public health. Intensive monitoring is needed to reduce the incidence of infections by MDR P. mirabilis.

Type 2 diabetes has a protective causal association with thoracic aortic aneurysm: a Mendelian randomization study.

BACKGROUND: Observational studies have reported an inverse association of type 2 diabetes (T2D) with thoracic aortic aneurysm (TAA). However, the causality of the association has not been established yet. The present study aims to clarify the causal relationship between T2D and TAA via a Mendelian randomization (MR) approach. METHODS: Causality of associations were assessed using a two-sample MR framework. Genome-wide association study (GWAS) summary statistics were obtained for T2D, glycated hemoglobin (HbA1c), fasting glucose (FG) and fasting insulin (FI) as exposures, and TAA, ascending aortic diameter (AAoD) and descending aortic diameter (DAoD) as outcomes. Four different methods (inverse variance weighted [IVW], weight median, MR-Egger and MR-PRESSO) were used to calculate causal estimates. Heterogeneity and horizontal pleiotropy were assessed using Cochran Q test and MR-Egger regression intercept, respectively. RESULTS: Genetically predicted T2D was inversely associated with the risk of TAA (OR: 0.931, 95% CI 0.870 to 0.997, p = 0.040, IVW method) and AAoD (Beta: -0.065, 95%CI -0.099 to - 0.031, p = 1.7e-04, IVW method), but not with DAoD (p > 0.05). Genetically predicted FG level was inversely associated with AAoD (Beta: -0.273, 95% CI -0.396 to -0.150, p = 1.41e-05, IVW method) and DAoD (Beta: -0.166, 95% CI -0.281 to -0.051, p = 0.005, IVW method), but not with TAA (p > 0.05). The effect of genetically predicted HbA1c and FI on TAA, AAoD and DAoD did not reach statistical significance (p > 0.05). CONCLUSIONS: Genetic predisposition to T2D decreases the risk of TAA. Genetically predicted T2D is inversely associated with AAoD, but not with DAoD. Genetically predicted FG level was inversely associated with AAoD and DAoD.

Genomic characterisation of a blaKPC-2- and mcr-10-co-harbouring Enterobacter kobei isolate with high-level resistance to colistin and carbapenems.

OBJECTIVES: The emergence and spread of colistin resistance in carbapenem-resistant Enterobacteriaceae pose a serious threat to human and animal health. This work aimed to characterise the genetic features of antimicrobial resistance of the carbapenem- and colistin-resistant Enterobacter kobei strain SCLZS19, isolated from hospital sewage, by using whole genome sequencing. METHODS: Antimicrobial susceptibility tests were performed using the disk diffusion method. Whole genome sequencing of SCLZS19 was carried out on the HiSeq 2000 combined with PacBio RSII platforms. Sequence type, plasmid incompatibility types, resistance genes, and insertion elements were identified using multilocus sequence typing, PlasmidFinder, ResFinder, and ISfinder, respectively. Conjugation assays were performed using both broth- and filter-based methods with the azide-resistant Escherichia coli J53 as the recipient. The function of the mcr-9-like variant was determined by gene cloning. RESULTS: E. kobei SCLZS19 had a 4 862 177-bp circular chromosome and nine circular plasmids ranging in size from 4120 bp to 282 472 bp. It carried 11 antibiotic resistance genes, and 10 of them were located on plasmids. The colistin resistance gene mcr-10 was located on a 118 766-bp non-transferable IncF (Y3:A-:B-) plasmid. The carbapenemase gene blaKPC-2 was carried by a self-transmissible IncP6 plasmid, which is epidemic in China. In addition, SCLZS19 also carried an mcr-9-like variant on a IncHI2 (ST1) plasmid. The cloning assay showed that the mcr-9-like variant did not mediate colistin resistance in E. coli DH5α. CONCLUSION: The findings highlight that carbapenem- and colistin-resistant Enterobacterales from water environments may serve as a reservoir for clinically significant antibiotic resistance genes, and continuous surveillance is required.

A new class A beta-lactamase gene blaCAE-1 coexists with blaAFM-1 in a novel untypable plasmid in Comamonas aquatica.

Antimicrobial resistance, especially carbapenem resistance, poses a serious threat to global public health. Here, a carbapenem-resistant Comamonas aquatica isolate SCLZS63 was recovered from hospital sewage. Whole-genome sequencing showed that SCLZS63 has a 4,048,791-bp circular chromosome and three plasmids. The carbapenemase gene blaAFM-1 is located on the 143,067-bp untypable plasmid p1_SCLZS63, which is a novel type of plasmid with two multidrug-resistant (MDR) regions. Notably, a novel class A serine ß-lactamase gene, blaCAE-1, coexists with blaAFM-1 in the mosaic MDR2 region. Cloning assay showed that CAE-1 confers resistance to ampicillin, piperacillin, cefazolin, cefuroxime, and ceftriaxone, and elevates the MIC of ampicillin-sulbactam two-fold in Escherichia coli DH5α, suggesting that CAE-1 functions as a broad-spectrum ß-lactamase. Amino acid sequences analysis suggested that blaCAE-1 may originate from Comamonadaceae. The blaAFM-1 in p1_SCLZS63 is located in a conserved structure of ISCR29-ΔgroL-blaAFM-1-ble-ΔtrpF-ΔISCR27-msrB-msrA-yfcG-corA. Comprehensive analysis of the blaAFM-bearing sequences revealed important roles of ISCR29 and ΔISCR27 in the mobilization and truncation of the core module of blaAFM alleles, respectively. The diverse passenger contents of class 1 integrons flanking the blaAFM core module make the complexity of genetic contexts for blaAFM. In conclusion, this study reveals that Comamonas may act as an important reservoir for antibiotics-resistance genes and plasmids in the environment. Continuous monitoring for the environmental emergence of antimicrobial-resistant bacteria is needed to control the spread of antimicrobial resistance.

Photocontrolled Release of Carbendazim from Photocaged Molecule.

Carbendazim (MBC) is a high-efficient and broad-spectrum fungicide, but excessive residues caused by its improper use have caused health toxicity and environmental pollution. It is an irresistible trend to find green, safe, accurate and controllable release technology of MBC. To achieve the purpose of safe and efficient use of MBC, photolabile protecting group was used to realize the controllable release. This study aimed to covalently link MBC and 6-nitropiperonyl alcohol (NP) to synthesize photocaged molecule NP-MBC. The photodegradation test showed that NP-MBC could effectively release MBC under ultraviolet light. The antifungal activity of NP-MBC showed significant difference against Rhizoctonia solani, Sclerotinia sclerotiorum and Fusarium graminearum before and after irradiation, and the effects on mycelial morphology are different. The hyphae morphology of R. solani and F. graminearum changed significantly, and mycelia were severely damaged. The hyphae surface of former was swollen and broken, and the latter was collapsed and shriveled after NP-MBC light treatment. NP-MBC could realize the light-controlled release of MBC, and the antifungal activity before and after irradiation was significantly different, which provides an effective way to release MBC.

Inadvertently Swallowed Needle Pierced the Pulmonary Artery in an Adult.

BACKGROUND: Esophageal foreign body (FB) is usually seen in children, prisoners, or patients with psychiatric disorders, most of which can be removed with endoscope. CASE PRESENTATION: We herein report a mentally normal adult inadvertently swallowing a needle, which pierced through the esophagus into the adventitia of pulmonary artery. Computed tomography angiography confirmed its specific location, and urgently, surgical removal was performed after the endoscopic attempt. The patient recovered well and was discharged without any complication of the esophageal perforation. CONCLUSION: Surgical treatment should be carried out aggressively if the esophageal FB is out of reach for endoscopic removal or if complications cannot be resolved endoscopically.

Low expression of ESR1 correlates with ascending aortic dilation and acute type A aortic dissection.

BACKGROUND: The common genetic signatures of ascending aortic dilation and acute type A aortic dissection (AAAD) remained unclear. This study aims to investigate the role of ESR1 in ascending aortic dilation and AAAD via a multi-omics approach combining transcriptome-wide association study (TWAS) and mRNA expression profiles. METHODS: The TWAS analysis was performed by integrating expression quantitative trait loci (eQTL) data of aorta and the GWAS dataset of ascending aortic diameter using the FUSION software. Joint/Conditional Analysis was used to screen conditionally independent genes from TWAS significant regions. mRNA expression profiles were used to confirm the differential expression of ESR1 in ascending aortic dilation and AAAD. An independent mRNA expression profile dataset was used to validate the diagnostic efficiency of ESR1 expression on thoracic aortic aneurysm (TAA). Gene set enrichment analysis (GSEA) was utilized to explore the potential molecular function of ESR1 in mouse aorta. Immune infiltration analysis was performed to evaluate the association between ESR1 and immune infiltration in AAAD. RESULTS: ESR1 was among the top 10 most significant genes identified by TWAS of ascending aortic diameter (Z score = -7.3, PTWAS = 3.30 × 10-13). mRNA expression profiles confirmed the low expression of ESR1 both in ascending aortic dilation (PmRNA = 0.0361) and AAAD (PmRNA = 0.0142). The diagnostic efficiency of peripheral blood ESR1 expression on TAA was further validated by an independent mRNA expression profile dataset. GSEA showed that GO terms and KEGG pathways mainly involved in metabolism and oxidoreductase activity were enriched in aortic tissue of ERα knockout mice. The immune infiltration ration of naive CD8 + T cells was significantly lower in AAAD compared with normal aorta, and was positively correlated with ESR1 expression. CONCLUSION: Low expression of ESR1 is associated with ascending aortic dilation and AAAD. Peripheral blood ESR1 expression may be a novel diagnostic biomarker of TAA. ESR1 expression is positively correlated with immune infiltration ration of naive CD8 + T cells in AAAD.

Genomic characteristics of clinical multidrug-resistant Proteus isolates from a tertiary care hospital in southwest China.

Multidrug-resistant (MDR) Proteus, especially those strains producing extended-spectrum ß-lactamases (ESBL) and carbapenemases, represents a major public health concern. In the present work, we characterized 27 MDR Proteus clinical isolates, including 23 Proteus mirabilis, three Proteus terrae, and one Proteus faecis, by whole-genome analysis. Among the 27 isolates analyzed, SXT/R391 ICEs were detected in 14 strains, and the complete sequences of nine ICEs were obtained. These ICEs share a common backbone structure but also have different gene contents in hotspots and variable regions. Among them, ICEPmiChn2826, ICEPmiChn2833, ICEPmiChn3105, and ICEPmiChn3725 contain abundant antibiotic resistance genes, including the ESBL gene bla CTX-M-65. The core gene phylogenetic analysis of ICEs showed their genetic diversity, and revealed the cryptic dissemination of them in Proteus strains from food animals and humans on a China-wide scale. One of the isolates, FZP3105, acquired an NDM-1-producing MDR plasmid, designated pNDM_FZP3105, which is a self-transmissible type 1/2 hybrid IncC plasmid. Analysis of the genetic organization showed that pNDM_FZP3105 has two novel antibiotic resistance islands bearing abundant antibiotic resistance genes, among which bla NDM-1 is located in a 9.0 kb ΔTn125 bracketed by two copies of IS26 in the same direction. In isolates FZP2936 and FZP3115, bla KPC-2 was detected on an IncN plasmid, which is identical to the previously reported pT211 in Zhejiang province of China. Besides, a MDR genomic island PmGRI1, a variant of PmGRI1-YN9 from chicken in China, was identified on their chromosome. In conclusion, this study demonstrates abundant genetic diversity of mobile genetic elements carrying antibiotic resistance genes, especially ESBL and carbapenemase genes, in clinical Proteus isolates, and highlights that the continuous monitoring on their transmission and further evolution is needed.

Mechanosensitive Channel PIEZO1 Senses Shear Force to Induce KLF2/4 Expression via CaMKII/MEKK3/ERK5 Axis in Endothelial Cells.

Shear stress exerted by the blood stream modulates endothelial functions through altering gene expression. KLF2 and KLF4, the mechanosensitive transcription factors, are promoted by laminar flow to maintain endothelial homeostasis. However, how the expression of KLF2/4 is regulated by shear stress is poorly understood. Here, we showed that the activation of PIEZO1 upregulates the expression of KLF2/4 in endothelial cells. Mice with endothelial-specific deletion of Piezo1 exhibit reduced KLF2/4 expression in thoracic aorta and pulmonary vascular endothelial cells. Mechanistically, shear stress activates PIEZO1, which results in a calcium influx and subsequently activation of CaMKII. CaMKII interacts with and activates MEKK3 to promote MEKK3/MEK5/ERK5 signaling and ultimately induce the transcription of KLF2/4. Our data provide the molecular insight into how endothelial cells sense and convert mechanical stimuli into a biological response to promote KLF2/4 expression for the maintenance of endothelial function and homeostasis.

Tricuspid Annulus Dilation in Patients With Combined Functional Tricuspid Regurgitation and Left-Heart Valvular Disease: Does Septal Annulus Not Dilate?

Background: This study aimed to investigate the course of tricuspid annulus dilation in functional tricuspid regurgitation with varied severities by direct intraoperative assessment. Methods: A total of 317 patients who underwent left heart surgery and concomitant tricuspid repair were divided into three groups according to the severity of the functional tricuspid regurgitation (mild, moderate and severe). Demographic and echocardiographic data were collected. The length of each tricuspid annulus segment was measured intraoperatively. The risk factors for preoperative severe functional tricuspid regurgitation and its postoperative recurrence were identified, and the impact of each tricuspid annulus segment on postoperative recurrence was compared. Results: In the course of tricuspid annulus dilation, the posterior annulus dilated 17% (group 1: 33.31 ± 6.94 mm vs. group 2: 35.56 ± 7.63 vs. group 3: 38.98 ± 8.70, p < 0.01), the anterior annulus dilated 13.4% (group 1: 36.71 ± 6.30 mm vs. group 2: 38.21 ± 8.35 vs. group 3: 41.63 ± 9.20, p < 0.01), and the septal annulus dilated 11.4% (group 1: 38.11 ± 5.28 mm vs. group 2: 39.76 ± 6.90 vs. group 3: 42.46 ± 7.50, p < 0.01). Tricuspid annulus circumference index (p < 0.01) independently correlated with preoperative severe tricuspid regurgitation and postoperative recurrence. When patients were grouped based on the length of each segment, the septal annulus demonstrated significantly higher sensitivity (p < 0.001) to postoperative recurrence than the anterior (p = 0.085) or posterior annulus (p = 0.262). Conclusions: This study revealed that each segment of tricuspid annulus could dilate in functional tricuspid regurgitation and highlighted the potential benefits of septal annulus plication in tricuspid annuloplasty, which may aid in the development of a methodology for prosthetic ring annuloplasty.

Genomic characterization of a carbapenem-resistant Citrobacter freundii cocarrying blaKPC-2 and blaNDM-1.

OBJECTIVES: Citrobacter freundii is an important opportunistic pathogen, and carbapenem-resistant strains pose a significant challenge to public health. Here we report the genetic features of antimicrobial resistance genes of a carbapenem-resistant C. freundii SCLZS47 from hospital sewage by using whole genome sequencing. METHODS: Antimicrobial susceptibility was determined by the broth microdilution method. Whole genomic sequences of SCLZS47 were obtained by using the HiSeq 2000 combined with PacBio RSII platforms. Plasmid incompatibility types, resistance genes, and insertion elements were identified using the PlasmidFinder, ResFinder, and ISfinder, respectively. RESULTS: SCLZS47 has a circular chromosome and three resistance plasmids, and it carries 23 known ARGs. Among them, blaCMY-135 and three copies of blaCTX-M-14 are located on the chromosome. Sixteen ARGs are clustered in two accessory modules of a multidrug resistance (MDR) plasmid, and homologous recombination and transposition events contribute to the formation of these MDR regions. Carbapenemase genes blaKPC-2 and blaNDM-1 are carried by a pCKPC18-1-like plasmid and a pNDM-HN380-like plasmid, respectively. Conjugation experiments indicated that both KPC-2- and NDM-1-encoding plasmids are transmissible. CONCLUSION: Analysis of the genetic features of resistance genes would help to better understand their transmission mechanisms and dynamics in bacterial community, which has significant clinical implications.

Minimally Invasive Isolated Tricuspid Valve Repair After Left-Sided Valve Surgery: A Single-Center Experience.

Background: Tricuspid regurgitation after left-sided valve surgery was associated with terrible outcomes and high perioperative mortality for surgical treatment. In current years, minimally invasive isolated tricuspid valve repair is increasingly performed in our institution to address tricuspid regurgitation. Methods: Thirty-seven consecutive patients with previous left-sided valve surgery underwent minimally invasive isolated tricuspid valve repair in our institution between November 2017 and December 2020. Twenty-nine patients(78.4%) were women and the mean age of patients was 58.4 ± 8.5 years. Follow-up was 100% complete with a mean follow-up time of 17.2 ± 9.5 months. Results: Both the in-hospital and 30-day mortalities were 2.7%. The overall NYHA class had improved significantly during the follow-up (p < 0.001). The grade of TR had decreased before discharge (p < 0.001) and during the follow-up (p < 0.001) compared with the preoperative level although severe TR was recurrent in one patient. Conclusions: Minimally invasive isolated tricuspid valve repair has acceptable early and midterm outcomes, may be the preferred surgical option to address tricuspid regurgitation after previous left-sided valve surgery when it is feasible.