Branching of High-Current Relativistic Electron Beam in Porous Materials

Propagation of high-current relativistic electron beam (REB) in plasma is relevant to many high-energy astrophysical phenomena as well as applications based on high-intensity lasers and charged-particle beams. Here, we report a new regime of beam-plasma interaction arising from REB propagation in medium with fine structures. In this regime, the REB cascades into thin branches with local density a hundred times the initial value and deposits its energy 2 orders of magnitude more efficiently than that in homogeneous plasma, where REB branching does not occur, of similar average density. Such beam branching can be attributed to successive weak scatterings of the beam electrons by the unevenly distributed magnetic fields induced by the local return currents in the skeletons of the porous medium. Results from a model for the excitation conditions and location of the first branching point with respect to the medium and beam parameters agree well with that from pore-resolved particle-in-cell simulations.

Lipid peroxidation in diamond supported bilayers

Lipid peroxidation is a process that occurs in cells when they are exposed to oxidative stress. During the process reactive oxygen species attack lipids within the lipid bilayers of cells. Since the products of lipid peroxidation are toxic and carcinogenic, it is important to understand where and how it occurs with nanoscale resolution. The radical intermediates of this process are particularly interesting since they are causing chain reactions damaging large parts of the lipid membranes in cells. However, they are also difficult to measure for the state of the art because they are short lived and reactive. Here, we study the lipid peroxidation of three artificial lipid bilayers on a diamonds substrate that can be used to study lipid peroxidation. In particular, we present a diamond quantum sensing method called T₁-relaxometry that allows for in situ measurements and imaging of radical intermediates of lipid peroxidation in these membranes.

Distributed Filtering for Semi-Markov-Type Sensor Networks With Hybrid Sojourn-Time Distributions-A Nonmonotonic Approach

This article examines the distributed filtering problem for a general class of filtering systems consisting of distributed time-delayed plant and filtering networks with semi-Markov-type topology switching (SMTTS). The SMTTS implies the topology sojourn time can be a hybrid function of different types of probabilistic distributions, typically, binomial distribution used to model unreliable communication links between the filtering nodes and Weibull distribution employed to depict the cumulative abrasion failure. First, by properly constructing a sojourn-time-dependent Lyapunov-Krasovski function (STDLKF), both time-varying topology-dependent filter and topology-dependent filter are designed. Second, a novel nonmonotonic approach with less design conservatism is developed by relaxing the monotonic requirement of STDLKF within each topology sojourn time. Moreover, an algorithm with less computational effort is proposed to generate a semi-Markov chain from a given Markov renewal chain. Simulation examples, including a microgrid islanded system, are presented to testify the generality and elucidate the practical potential of the nonmonotonic approach.

Comparative genomics revealed that Vibrio furnissii and Vibrio fluvialis have mutations in genes related to T6SS1 and T6SS2

The type VI secretion system (T6SS) is important for interbacterial competition and virulence in Vibrio species. It is generally agreed that T6SS provides a fitness advantage to Vibrios. Some Vibrio species possess one, while others possess two T6SSs. Even within the same Vibrio species, different strains can harbor a variable number of T6SSs. Such is the case in V. fluvialis, an opportunistic human pathogen, that some V. fluvialis strains do not harbor T6SS1. This study found that Amphritea, Marinomonas, Marinobacterium, Vibrio, Photobacterium, and Oceanospirillum species have genes encoding V. fluvialis T6SS1 homologs. The cladogram of T6SS1 genes suggested that these genes appeared to be horizontally acquired by V. fluvialis, V. furnissii, and some other Vibrio species, when compared with the species tree. Codon insertions, codon deletions, nonsense mutations, and the insertion sequence are found in many genes, such as clpV1, tssL1, and tssF1, which encode structure components of T6SS1 in V. furnissii and V. fluvialis. Codon deletion events are more common than codon insertion, insertion sequence disruption, and nonsense mutation events in genes that encode components of T6SS1. Similarly, codon insertions and codon deletions are found in genes relevant to T6SS2, including tssM2, vgrG2 and vasH, in V. furnissii and V. fluvialis. These mutations are likely to disable the functions of T6SSs. Our findings indicate that T6SS may have a fitness disadvantage in V. furnissii and V. fluvialis, and the loss of function in T6SS may help these Vibrio species to survive under certain conditions.

[Prognostic factors for non-small cell lung cancer patients with central nervous system metastasis with positive driver genes]

Objective: To investigate the prognostic factors of patients with central nervous system (CNS) metastatic non-small cell lung cancer (NSCLC) with positive driver genes. Methods: The clinical data of 103 patients with CNS metastatic NSCLC admitted to Beijing Tongren Hospital from January 2016 to December 2020 were retrospectively analyzed, and the patients were divided into positive driver gene group (patients with driver genes mutation and receiving corresponding targeted therapy) and negative driver gene group. Cox univariate and multivariate regression analyses were performed to identify the factors affecting patients' prognosis, and the receiver operating characteristic curve (ROC) was used to compare the predictive ability of 4 scoring systems [recursive partitioning analysis (RPA) classes, diagnosis-specific graded prognostic assessment (DS-GPA) index, basic score for brain metastasesn (BS-BM) and (lung-molecular graded prognostic assessment (lung-mol GPA)]on patients' prognosis. Results: Among the 103 patients, 48 were males and 55 were females, and aged (64.6±9.7) years old. The median survival time of the 103 patients was 24.0 (95%CI: 20.0-28.0) months, the median survival time of the 59 patients in the positive driver gene group was 33.0 (95%CI: 23.4-42.6) months, the median survival time of the 44 patients in the negative driver gene group was 17.0 (95%CI: 14.4-19.6) months, and the difference was statistically significant (χ²=24.69, P<0.001). The results of Cox multivariate analysis showed that the negative driver genes (HR=3.788, 95%CI: 1.951-7.301, P=0.001), Karnofsky performance status (KPS) score<70 (HR=2.613, 95%CI: 1.185-5.761, P=0.017) and neutrophil-to-lymphocyte ratio (NLR)>3.22 (HR=2.714, 95%CI: 1.157-6.365, P=0.022) were independent risk factors affecting the prognosis of patients with CNS metastatic NSCLC. KPS score<70 (HR=3.719, 95%CI: 1.165-11.876, P=0.027) and no radiotherapy (HR=2.032, 95%CI: 1.033-11.364, P=0.041) were independent risk factors affecting the prognosis of patients with CNS metastatic NSCLC with positive driver genes. ROC curve analysis showed that the area under curve (AUC) value of lung-mol GPA was the highest among the 4 scoring systems (AUC=0.843, 95%CI: 0.731-0.956, P<0.001), and the AUC value of the lung-mol GPA combined scoring system (AUC=0.904, 95%CI: 0.816-0.991, P<0.001) was higher than lung-mol GPA. Conclusions: A low KPS score and no cranial radiation therapy are independent risk factors for the prognosis of patients with CNS metastatic NSCLC with positive driver genes; the lung-mol GPA joint scoring system is more conducive to the prognostic assessment of patients with CNS metastatic NSCLC with positive driver genes.

[Cardiac magnetic resonance-feature tracking technique can assess cardiac function and prognosis in patients with myocardial amyloidosis]

OBJECTIVE

To quantitatively assess cardiac functions in patients with cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance-feature tracking (CMR-FT) technique and evaluate the prognostic value of CMR-FT in patients with CA.

METHODS

We retrospectively collected the data from 31 CA patients with systemic amyloidosis confirmed by Congo red staining and serum immunohistochemistry after extracardiac tissue biopsy undergoing CMR at our hospital from March, 2013 to June, 2021.Thirty-one age and gender matched patients with asymmetric left ventricular wall hypertrophy and 31 healthy individuals without organic or functional heart disease served as the controls.Radial, circumferential and longitudinal strains and strain rates of the left ventricle at the global level and in each myocardial segment (basal, middle and apical) were obtained with CMR-FT technique and compared among the 3 groups.The predictive value of myocardial strains and strain rates for all-cause mortality in CA patients was analyzed using a stepwise COX regression model.

RESULTS

The left ventricular volume, myocardial mass, ejection fraction and cardiac output differed significantly among the groups (P < 0.05).Except for apical longitudinal strain, the global and segmental strains were all significantly lower in CA group than in HCM group (P < 0.05).The global and segmental strains were all significantly lower in CA group than in the healthy individuals (P < 0.05).The basal strain rates in the 3 directions were significantly lower in CA group than in the healthy individuals (P < 0.05), but the difference in apical strain rates was not statistically significant between the two groups.Multivariate stepwise COX analysis showed that troponin T (HR=1.05, 95%CI: 1.01-1.10, P=0.017) and middle peak diastolic circumferential strain rate (HR=6.87, 95%CI: 1.52-31.06, P=0.012) were strong predictors of death in CA patients.

CONCLUSION

Strain and strain rate parameters derived from CMR-FT based on cine sequences are new noninvasive imaging markers for assessing cardiac impairment in CA and cardiac function changes in HCM, and provide independent predictive information for all-cause mortality in CA patients.

Insertion sequences mediate clinical ST34 monophasic Salmonella enterica serovar Typhimurium plasmid polymorphism

Hybrid plasmids can combine the genetic elements of multiple plasmids, with the potential to carry a variety of antibiotic resistance genes and virulence genes, causing a great public health concern. Hybrid plasmids formed by fusion events may further exacerbate the spread of antibiotic resistance genes as well as plasmid evolution. Salmonella enterica serovar 4,[5],12:i:- is a monophasic variant of S. Typhimurium, which is one of the major causes of foodborne disease outbreaks worldwide. To assess the risk of transmission due to plasmid structure changes, we investigated the structural diversity of plasmids in two S. 4,[5],12:i:- isolates. Nanopore long-read sequencing was performed for plasmid comparison between original plasmids (donor isolates) and reorganized plasmids. We found that the IncHI2-IncHI2A multidrug resistance (MDR) plasmids in S. 4,[5],12:i:- possessed high plasticity, and could undergo recombination with other plasmids to form fusion plasmids of different sizes. Plasmid structural polymorphisms were mainly mediated by insertion sequences such as IS26 and ISPa40, and led to the rearrangement of the plasmid internal structures. To the best of our knowledge, this is the first report of the fusion of the IncHI2-IncHI2A and IncB/O/K/Z plasmids in S. 4,[5],12:i:- mediated by IS26. In addition, we also found that the mcr-1 gene was able to generate duplication during conjugation. Polymorphic changes in MDR plasmids during conjugation may further reduce the choice of clinical therapeutic agents. Therefore, continuous monitoring regarding plasmid polymorphic changes during transmission in both in vitro and in vivo is urgently needed to decipher the MDR plasmid evolution.

Genomic and functional analysis of high-level tigecycline resistant Klebsiella michiganensis co-carrying tet(X4) and tmexCD2-toprJ2 from pork

Tigecycline plays an important role in the clinical treatment of infections caused by multidrug-resistant pathogens. The emergence of plasmid-mediated tigecycline resistance genes tet(X) and tmexCD1-tmexJ1 has been reported in a variety of animal and animal-derived foods, and have the potential spread to humans, seriously limiting the choice of clinical medication. Herein, three ST92 Klebsiella michiganensis isolates co-harboring tet(X4) and tmexCD2-toprJ2 were collected from pork samples in Jiangsu Province, China. These K. michiganensis isolates were all multidrug-resistant isolates. Genome analysis showed that tmexCD2-toprJ2 and tet(X4) were located on IncFIB(K) and IncX1 plasmids, respectively. The IncFIB(K) plasmid pMX581-77k is a novel tmexCD2-toprJ2-bearing plasmid. Worryingly, there were only a small number of SNPs between K. michiganensis isolated from pork in this study and K. michiganensis from human sources, with the possibility of clonal transmission. In addition, tet(X4) and tmexCD2-toprJ2 in K. michiganensis were able to stabilize in the absence of antibiotics. The growth curve indicated that the tmexCD2-toprJ2-positive plasmid imposed a burden on the growth of host bacteria. Interestingly, we found that the high-level resistance phenotype to tigecycline in these K. michiganensis isolates was mainly mediated by tet(X4). However, both tet(X4) and tmexCD2-toprJ2 expression were significantly elevated when host bacteria were exposed to tigecycline. This study systematically investigated K. michiganensis co-carrying tet(X4) and tmexCD2-toprJ2, emphasizing the importance for continuous surveillance of tigecycline-resistant K. michiganensis in animal-derived foods.

IncHI1 plasmids mediated the tet(X4) gene spread in Enterobacteriaceae in porcine

The tigecycline resistance gene tet(X4) was widespread in various bacteria. However, limited information about the plasmid harboring the tet(X4) gene spread among the different species is available. Here, we investigated the transmission mechanisms of the tet(X4) gene spread among bacteria in a pig farm. The tet(X4) positive Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Enterobacter hormaeche were identified in the same farm. The whole genome sequencing (WGS) analysis showed that the K. pneumoniae belonged to ST727 (n = 11) and ST3830 (n = 1), E. cloacae and E. hormaeche belonged to ST524 (n = 1) and ST1862 (n = 1). All tet(X4) genes were located on the IncHI1 plasmids that could be conjugatively transferred into the recipient E. coli C600 at 30°C. Moreover, a fusion plasmid was identified that the IncHI1 plasmid recombined with the IncN plasmid mediated by ISCR2 during the conjugation from strains B12L to C600 (pB12L-EC-1). The fusion plasmid also has been discovered in a K. pneumoniae (K1L) that could provide more opportunities to spread antimicrobial resistance genes. The tet(X4) plasmids in these bacteria are derived from the same plasmid with a similar structure. Moreover, all the IncHI1 plasmids harboring the tet(X4) gene in GenBank belonged to the pST17, the newly defined pMLST. The antimicrobial susceptibility testing was performed by broth microdilution method showing the transconjugants acquired the most antimicrobial resistance from the donor strains. Taken together, this report provides evidence that IncHI1/pST17 is an important carrier for the tet(X4) spread in Enterobacteriaceae species, and these transmission mechanisms may perform in the environment.

Complete Genetic Analysis of Plasmids Carrying Multiple Resistance, Virulence, and Phage-Like Genes in Foodborne Escherichia coli Isolate

Bacterial antimicrobial resistance, especially phenotypic resistance to multiple drugs (MDR), has posed a serious threat to public health worldwide. To clarify the mechanism of transmission of multidrug resistance encoding plasmids in Enterobacterales, all seven plasmids of an Escherichia coli (E. coli) strain 1108 obtained from a chicken meat sample were extracted and sequenced by Illumina Nextseq 500 and MinION platforms. Plasmids in strain 1108 possessed 16 known antimicrobial resistance genes, with p1108-NDM (~97K) being the most variable plasmid. The multidrug resistance region of p1108-NDM was punctuated by eight IS26 insertion sequences; thus, four MDR regions were found in the backbone of this plasmid. The plasmid p1108-MCR (~65K) was found to lack the ISApl1 element and harbor the blaCTX-M-64-ISEcp1 transposition unit. Moreover, the ISEcp1-blaCMY-2 transposition unit was found in plasmid p1108-CMY2 (~98K), whereas plasmid p1108-emrB (~102K) was associated with resistance to erythromycin (emrB) and streptomycin (aadA22). p1108-IncY (96K) was a phage P1-like plasmid, while p1108-IncFIB (~194K) was found to harbor a virulence region similar to ColV plasmids, and they were found to encode a conserved conjugative transfer protein but harbor no resistance genes. Finally, no mobile element and resistant genes were found in p1108-ColV (~2K). Carriage of mcr-1-encoding elements in carbapenemase-producing Escherichia coli will potentially render all antimicrobial treatment regimens ineffective. Enhanced surveillance and effective intervention strategies are urgently needed to control the transmission of such multidrug resistance plasmids. IMPORTANCE Antimicrobial resistance (AMR) has been increasingly prevalent in agricultural and clinical fields. Understanding the genetic environment involved in AMR genes is important for preventing transmission and developing mitigation strategies. In this study, we investigated the genetic features of an E. coli strain (1108) isolated from food product and harboring 16 AMR genes, including blaNDM-1 and mcr-1 genes encoding resistance to last line antibiotics, meropenem, and colistin. Moreover, this strain also carried virulence genes such as iroBCDEN, iucABCD, and iutA. Our findings confirmed that multiple conjugative plasmids that were formed through active recombination and translocation events were associated with transmission of AMR determinants. Our data warrant the continuous monitoring of emergence and further transmission of these important MDR pathogens.

Association of APP gene polymorphisms and promoter methylation with essential hypertension in Guizhou: a case-control study

BACKGROUND

Single-nucleotide polymorphisms (SNPs) and DNA methylation are crucial regulators of essential hypertension (EH). Amyloid precursor protein (APP) mutations are implicated in hypertension development. Nonetheless, studies on the association of APP gene polymorphism and promoter methylation with hypertension are limited. Therefore, this case-control aims to evaluate the genetic association of APP gene polymorphism and promoter methylation with EH in Guizhou populations.

OBJECTIVE AND METHODS

We conducted a case-control study on 343 EH patients and 335 healthy controls (including Miao, Buyi, and Han populations) in the Guizhou province of China to analyze 11 single-nucleotide polymorphisms (rs2040273, rs63750921, rs2211772, rs2830077, rs467021, rs368196, rs466433, rs364048, rs364051, rs438031, rs463946) in the APP gene via MassARRAY SNP. The MassARRAY EpiTYPER was employed to detect the methylation levels of the promoters.

RESULTS

In the Han population, the rs2211772 genotype distribution was significantly different between disease and control groups (χ² = 6.343, P = 0.039). The CC genotype reduced the risk of hypertension compared to the TT or TC genotype (OR 0.105, 95%CI 0.012-0.914, P = 0.041). For rs2040273 in the Miao population, AG or GG genotype reduced the hypertension risk compared with the AA genotype (OR 0.533, 95%CI 0.294-0.965, P = 0.038). Haplotype TCC (rs364051-rs438031-rs463946) increased the risk of EH in Guizhou (OR 1.427, 95%CI 1.020-1.996, P = 0.037). Each 1% increase in CpG_19 (- 613 bp) methylation level was associated with a 4.1% increase in hypertension risk (OR 1.041, 95%CI 1.002-1.081, P = 0.039). Each 1% increase in CpG_1 (- 296 bp) methylation level was associated with an 8% decrease in hypertension risk in women (OR 0.920, 95%CI 0.860-0.984, P = 0.015). CpG_19 significantly correlated with systolic blood pressure (r = 0.2, P = 0.03). The methylation levels of CpG_19 in hypertensive patients with rs466433, rs364048, and rs364051 minor alleles were lower than that with wild-type alleles (P < 0.05). Moreover, rs467021 and rs364051 showed strong synergistic interaction with EH (χ² = 7.633, P = 0.006). CpG_11, CpG_19, and rs364051 showed weak synergistic interaction with EH (χ² = 19.874, P < 0.001).

CONCLUSION

In summary, rs2211772 polymorphism and promoter methylation level of APP gene may be linked to EH in Guizhou populations. Our findings will provide novel insights for genetic research of hypertension and Alzheimer's disease.

[Expression and clinical significance of plasma methylated SEPT 9 gene in patients with primary liver cancer]

Objective: To investigate the expression and clinical significance of plasma methylated SEPT9 (mSEPT9) gene in patients with primary liver cancer. Methods: 393 cases who visited our hospital from May 2016 to October 2018 were selected. Among them, 75 cases were in the primary liver cancer (PLC) group, 50 cases were in the liver cirrhosis (LC) group, and 268 cases were in the healthy control group (HC). The three groups' positive rates of mSEPT9 expression in the peripheral plasma were detected by the polymerase chain reaction (PCR) fluorescent probe method. The correlational clinical features of liver cancer were analyzed. At the same time, the electrochemiluminescence detection method was used to compare the AFP positive rate. Statistical analysis was conducted using chi-square tests or continuity-corrected chi-square tests. Results: 367 cases actually had valid samples. There were 64, 42, and 64 cases in the liver cancer group, cirrhosis group, and healthy control group, respectively. Among them, 34 cases of liver cancer were verified from pathological tissues. The positive rate of plasma mSEPT9 was significantly higher in the liver cancer group than that in the liver cirrhosis and healthy control groups [76.6% (49/64), 35.7% (15/42), and 3.8% (10/261), respectively], and the differences were statistically significant (χ (2) = 176.017, P < 0.001). The sensitivity of plasma mSEPT9 detection (76.6%) was significantly better in liver cancer (76.6%) than that of AFP patients (54.7%), and the difference was statistically significant (χ (2) = 6.788, P < 0.01). Compared with the single detection, the sensitivity and specificity of plasma mSEPT9 combined with AFP were significantly improved (89.7% vs. 96.3%, respectively). Patients with liver cancer aged≥50 years, with clinical stage II or above, and those with pathological signs of moderate to low differentiation had higher levels of plasma mSEPT9 positive expression, and the differences were statistically significant (χ (2) = 6.41, 9.279, 6.332, P < 0.05). During the follow-up period, the survival time of liver cancer patients with positive plasma mSEPT9 expression was significantly shorter than that of those with negative expression (310 ± 26 days vs. 487 ± 59 days, respectively), with statistically significant differences (Log Rank P = 0.039). Conclusion: In China, the positive rate of plasma mSEPT9 detection in liver cancer patients is higher than that of AFP in relation to age, clinical stage, and degree of tissue differentiation; additionally, it has certain survival predictive values. As a result, detecting this gene has important clinical significance and potential clinical application value in the non-invasive diagnosis and prognosis assessment of patients with primary liver cancer.

[Analysis of efficacy and safety of a new endoscopic anastomosis clip in the treatment of defects after endoscopic full-thickness resection]

Objective: To investigate the efficacy and safety of a new endoscopic anastomosis clip in the treatment of defects after endoscopic full-thickness resection (EFTR). Methods: Retrospective cohort study. Fourteen patients [4 males and 10 females, aged (55.9±8.2) years (45-69 years)] with gastric submucosal tumors underwent EFTR at the First Affiliated Hospital of Soochow University were included from December 2018 to January 2021. Patients were divided into new anastomotic clamp group (n=6) and nylon ring combined with metal clips group (n=8). Preoperative endoscopic ultrasound examinations were required to all patients to evaluate the wound condition. The size of the defect, operation time required for wound closure, success rate of closure, postoperative gastric tube placement time, postoperative hospital stay, incidence of complications, preoperative and postoperative serological indexes were compared between the two groups. All patients were followed up after the operation, among which the general endoscopy was reviewed in the first month after the operation, and the telephone and questionnaire follow-up were used in the second, third, sixth month and one year after the operation to evaluate the therapeutic effect of the new endoscopic anastomosis clip and nylon rope combined with metal clip after the EFTR operation. Results: Both groups successfully completed EFTR and were successfully closed. There was no significant difference between the age, tumor diameter and defect diameter of the two groups (all P>0.05). Compared with the nylon ring combined with metal clip group, the operation time of the new anastomotic clip group was shortened [(5.0±1.8) minutes vs (35.6±10.2) minutes, P<0.001]. The operation time was shortened [(62.2±12.5) minutes vs (92.5±0.2) minutes, P=0.007]. Postoperative fasting time decreased [(2.8±0.8) days vs (4.9±1.1) days, P=0.002]. The hospital stay after operation was also shortened [(5.2±0.8) days vs (6.9±1.5) days, P=0.023]. The total intraoperative bleeding volume decreased [(20.00±5.48) ml vs (35.63±14.75) ml, P=0.031]. The patients in both groups received endoscopic examination 1 month after operation, and there was no delayed perforation and bleeding after operation. There was no obvious symptoms of discomfort. Conclusion: The new anastomotic clamp is suitable for the treatment of full-thickness gastric wall defects after EFTR, and shows advantages of shorter operation, less bleeding, and fewer postoperative complications.

Clonal outbreak of NDM-1 producing Enterobacter hormaechei belonging to high-risk international clone ST78 with the coexistence of tmexCD2-toprJ2 and mcr-9 in China

The emergence of the carbapenem-resistant Enterobacter cloacae complex (CR-ECC) has posed significant challenges to the clinical treatment of healthcare-associated infections globally. Herein, we report the clonal outbreak of NDM-1-producing Enterobacter hormaechei with the coexistence of tmexCD2-toprJ2 and mcr-9 in China. During the outbreak (January 2018-December 2021), a total of fifteen non-repetitive multidrug-resistant E. hormaechei strains were obtained from thirteen patients in a tertiary hospital. The 15 E. hormaechei strains belonged to the high-risk international clone ST78 and co-harbored tmexCD2-toprJ2 and bla_NDM-1, of which 12 E. hormaechei strains carried the mcr-9 gene. Whole-genome sequencing analysis revealed that tmexCD2-toprJ2 and bla_NDM-1 coexisted on the IncFIB/IncFII type plasmid, which could be transferred to E. coli J53 by conjugation and had a significant effect on host fitness. The mcr-9 gene is located between two insertion sequences, IS903B and IS1R, but lacks the two-component system regulatory genes qseBC, which might be the reason for all mcr-9-positive E. hormaechei strains remained susceptible to colistin. Besides, the expression of mcr-9 is not inducible in strains confirmed by colistin induction assays. Furthermore, the phylogenetic analysis illustrated the silent spread and rapid evolution of mcr-9-carrying E. hormaechei worldwide. Collectively, this study enriched the epidemiological and genomic characterization of the coexistence of tmexCD2-toprJ2 and mcr-9 in ST78 CR-ECC isolates and demonstrated that they could prolong clonal dissemination in a tertiary hospital in China. Hence, continuous epidemiological surveillance and molecular characterization of CR-ECC should be conducted to monitor the evolution of CR-ECC around the world.

Comprehensive Analysis of Antimicrobial, Heavy Metal, and Pesticide Residues in Commercial Organic Fertilizers and Their Correlation with Tigecycline-Resistant tet(X)-Variant Genes

With the issue of the antimicrobial additive ban in feed in Chinese animal husbandry, it is important to determine the potential drivers of the spread of the newly discovered tigecycline-resistant tet(X)-variant genes. Here, we investigated the correlations between residues of heavy metals, antimicrobials, and pesticides and the relative abundance of tet(X)-variant genes in 94 commercial organic-fertilizer samples collected from 9 Chinese provinces. A total of 5 heavy metals (mercury, lead, arsenic, chromium, and cadmium), 10 antimicrobials, and 18 pesticides were detected. The tet(X)-variant genes, including tet(X)/(X2), tet(X3), tet(X4), tet(X5), and tet(X6) were detected in 39 (41.5%) samples. Although tet(X)-variant-carrying bacteria were not isolated from these samples, the tet(X4)-carrying plasmids could be captured by exogenous Escherichia coli. Correlation analysis revealed that heavy metals, other than antimicrobials, showed a significant positive association with the relative abundance of the tet(X)-variant genes, especially tet(X3) and tet(X4) (R = 0.346 to 0.389, P < 0.001). The correlation was attributed to the coselection of the tet(X3)/tet(X4) gene on the same plasmid and the conjugation-promoting effect of tet(X3)/tet(X4)-carrying plasmids by subinhibitory concentrations of heavy metals. The heavy metals increased the permeability of the bacterial outer membrane and upregulated the transcription of type IV secretion system (T4SS)-encoding genes on tet(X)-variant-carrying plasmids, therefore enhancing the bacterial conjugation rates. Taken together, our findings have indicated that heavy metals may play an important role in spreading tet(X)-variant genes within the animal manure-related environment. IMPORTANCE An antimicrobial resistance gene (ARG) is considered a novel contaminant for the environment. Most animal feces are usually made into commercial organic fertilizers in China and will pose a threat to the farmland soil and agricultural product if fertilizers harboring clinically significant antimicrobial-resistant (AMR) genes are applied on farmland. This study has indicated that heavy metals may play an important role in the transmission of transferable tigecycline resistance genes [tet(X3) and tet(X4)]. The mechanism was that heavy metals posed a coselection effect of the tet(X3)/tet(X4) gene on the same plasmid and could increase the conjugation ability of tet(X3)/tet(X4)-carrying plasmids. The conjugation-promoting concentrations of heavy metals are lower than the maximal limits defined in the national standard for fertilizers, indicating a high transmission risk of tet(X3)/tet(X4) genes within the animal manure-related environment. The findings in this study will provide scientific evidence for the future development of effective measures to reduce AMR dissemination.

Aeromonas spp. from hospital sewage act as a reservoir of genes resistant to last-line antibiotics

BACKGROUND

Aeromonas species are opportunistic pathogens distributed widely in the ecosystem. They are known to be capable of acquiring antibiotic resistance genes, including those encoding proteins against last-line antibiotics, such as the tmexCD-toprJ, mcr and carbapenemase genes. We investigated the genomic and phenotypic characteristics of tmexCD-toprJ-positive Aeromonas strains collected from human, animals, and water samples, particularly those from hospital wastewater in China.

METHODS

Samples were collected from living animals, meat, water and human. Aeromonas strains in these samples were isolated in selective media. Antimicrobial resistance profiles of all Aeromonas strains were tested by the broth microdilution method. The presence of tmexCD-toprJ was verified by polymerase chain reaction (PCR). All tmexCD-toprJ-positive (n = 36) and selected tmexCD-toprJ-negative (n = 18) Aeromonas strains were subjected to whole genome sequencing. Carriage of antimicrobial resistance genes, the genetic environment of tmexCD-toprJ and genetic diversity of tmexCD-toprJ-positive Aeromonas strains were determined by bioinformatics analysis. Phylogenetic tree of the Aeromonas strains was built by using the Harvest Suite.

FINDINGS

Among the 636 Aeromonas strains isolated from different sources, 36 were positive for tmexCD-toprJ, with the highest prevalence of tmexCD-toprJ being found in fishes (8.8%, 95 CI% 3.6-17.2%), followed by hospital wastewater (6.5%, 95 CI% 4.3-9.3%), river water (2.0%, 0.1-10.9) and duck (1.2%, 95 CI% 3.6-17.2%). All tmexCD-toprJ-positive Aeromonas strains carried multiple antimicrobial resistance genes and exhibited resistance to different classes of antibiotics. Co-existence of tmexCD-toprJ, mcr and bla_KPC-2 were identified in 21 strains. The tmexCD-toprJ-positive Aeromonas strains were genetically diverse and found to belong to four different species that could be clustered into three major lineages. The tmexCD-toprJ gene clusters were predominantly located in the chromosome (35/36) of Aeromonas spp., with only one strain carrying the plasmid-borne tmexCD-toprJ cluster. The tmexCD-toprJ genes were associated with seven different types of genetic environments, each of which carried distinct types of mobile elements that may be responsible for mediating transmission of this gene cluster.

Enterobacteriaceae genome-wide analysis reveals roles for P1-like phage-plasmids in transmission of mcr-1, tetX4 and other antibiotic resistance genes

P1 -like phage-plasmids (PPs) are important gene vehicles in isolated pathogens. In this study, we conducted genome-wide and cross-species analysis of antimicrobial resistance genes (ARGs) from 35 ARG-positive P1-like PPs. LS-BSR analysis reveal that P1-like PPs had in common 7 highly variable regions and carried 48 different ARG subtypes. The most prevalent gene groups were the colistin resistance gene mcr-1 and a class 1 integron. Analysis of the flanking sequences of mcr-1 indicated an "IS30-mcr-1-ORF-IS30" as the core cluster. In particular, we found an mcr-1- and bla_CTX-M-55-coharboring large fusion P1-like PP. Also, tet(X4) was detected and flanking sequences indicated tet(X4)-bearing cluster can formed a larger size fusion plasmid mediated a wider spread via IS26 hotspots. Overall, this study demonstrated that P1-like PPs can not only mobilize a large number of ARGs in variable regions but also form larger hybrid P1-like PPs that would increase their ability to spread antimicrobial resistance.

Determining the gluonic gravitational form factors of the proton

The proton is one of the main building blocks of all visible matter in the Universe¹. Among its intrinsic properties are its electric charge, mass and spin². These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics^3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering². An example is the highly precise measurement of the electric charge radius of the proton⁶. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton^7,8 from our measurement. We used a variety of models^9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics¹². This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

Anterolateral thigh flap with a central hole for the repair of extensive oral defects in patients treated for chemotherapy-induced trismus

Trismus is a rare complication of chemotherapy. The usefulness of a modified anterolateral thigh (ALT) flap for the repair of extensive oral defects in patients treated for chemotherapy-induced trismus was evaluated. Between 2019 and 2021, three patients with chemotherapy-induced trismus underwent scar excision. A thinned ALT flap with a central hole was designed to repair the resultant oral mucosal defects. The patients were followed up for a mean 9.3 months (range 4-18 months). The mean pre- and intraoperative maximum inter-incisal opening (MIO) was 0.7 cm (range 0-2.0 cm) and 3.6 cm (range 3.4-3.7 cm), respectively, indicating a significant operative effect. MIO at the latest follow-up was 2.4 cm (range 1.5-3.5 cm). All of the flaps survived without complications. All patients achieved a good diet and were satisfied with the aesthetics. Thorough excision of the perioral scar and restoration with a modified ALT flap achieved satisfactory mouth opening and cosmetic effects in patients with chemotherapy-induced trismus.

Long intergenic non-protein coding RNA 00858 participates in the occurrence and development of esophageal squamous cell carcinoma through the activation of the FTO-m6A-MYC axis by recruiting ZNF184

OBJECTIVES

We aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m⁶A-MYC axis.

METHODS

Expression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted.

RESULTS

LINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice.

CONCLUSIONS

LINC00858 modulated MYC m⁶A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.

The Prevalence of Plasmid-Mediated Colistin Resistance Gene mcr-1 and Different Transferability and Fitness of mcr-1-Bearing IncX4 Plasmids in Escherichia coli from Pigeons

The prevalence of colistin-resistant bacteria limited the usage of colistin in the treatment of clinical multidrug-resistant Gram-negative bacterial infections. Here, we aimed to investigate the prevalence and molecular characterization of mcr-1-carrying isolates from pigeons close to humans following the ban on the use of colistin as an animal feed additive in China. Methods, including PCR, antimicrobial susceptibility testing, conjugation experiments, plasmid replicon typing, genome sequencing, bioinformatics analysis, measurement of growth curves, competition experiments, and plasmid stability assays were used to identify and characterize mcr-1-positive isolates. In total, 45 mcr-1-positive E. coli isolates were acquired from 100 fecal samples, and MICs of colistin ranged from 4 to 8 mg/L. The prevalence of mcr-1-positive E. coli isolates from pigeons was mainly mediated by IncX4 plasmids (39/45), including transferable mcr-1-bearing IncX4 plasmids with fitness advantage in 21 isolates, and nontransferable mcr-1-bearing IncX4 plasmids with fitness disadvantage in 18 isolates. There is a similar structure among the 6 mcr-1-bearing nontransferable IncX4 plasmids and 10 mcr-1-bearing transferable IncX4 plasmids in 16 E. coli isolates that have been sequenced. Plasmid transferability evaluation indicated that the same IncX4 plasmid has different transferability in different E. coli isolates. In conclusion, this study demonstrates that pigeons could act as potential reservoirs for the spread of mcr-1-positive E. coli in China. Transferability of IncX4 plasmids may be influenced by host chromosome in the same bacterial species. Additional research on the factors influencing the transferability of IncX4 plasmids in different bacterial hosts is required to help combat antimicrobial resistance. IMPORTANCE The emergence of plasmid-mediated colistin resistance gene mcr-1 incurs great concerns. Since the close proximity of pigeons with humans, it is significant to understand the prevalence and molecular characterization of mcr-1-positive isolates in pigeons, to provide a rationale for controlling its spread. Here, we found that the prevalence of mcr-1-positive E. coli from pigeons was mainly mediated by IncX4 plasmids. However, different transferability and fitness of mcr-1-bearing IncX4 plasmids in E. coli were observed, which demonstrated that transferability of IncX4 plasmids could be affected not only by genes on plasmids, but also by chromosomal factors in the same bacterial species. Our finding provided a new insight on studying the factors influencing the transferability of plasmids.

Characterization of a Conjugative Hybrid Plasmid Coharboring blaKPC-2 and blaIMP-4 in a Klebsiella quasipneumoniae Clinical Isolate

Generation of hybrid MDR plasmids accelerated the evolution and transmission of resistance genes. In this study, we characterized a bla_KPC-2- and bla_IMP-4-coharboring conjugative hybrid plasmid constituted of an IncHI5 plasmid-like region, an IncFII(Yp)/IncFIA plasmid-like region, and a KPN1344 chromosome-like region from a clinical ST852-KL18 Klebsiella quasipneumoniae strain. The bla_IMP-4 gene was captured by a novel integron In1965, and the bla_KPC-2 gene was located on a new non-Tn4401 group I NTE_KPC element. Both bla_KPC-2- and bla_IMP-4-containing genetic architectures were distinguished from classical structures, highlighting the constant evolution of these genetic elements. IMPORTANCE The emergence of carbapenem-resistant Enterobacterales (CRE) that coexpress serine- and metallo-carbapenemases is a severe threat to the efficacy of ceftazidime-avibactam (CZA), which has been proven to be extremely effective against KPC-producing Enterobacterales strains. Our study described the cooccurrence of KPC-2, a serine β-lactamase, and IMP-4, a metallo-β-lactamase (MBL), on a conjugative hybrid plasmid from a clinical carbapenem-resistant K. quasipneumoniae strain, and it revealed an alternative route for IncHI5 plasmid to evolve by recombining with other plasmids to form a hybrid plasmid. Moreover, this hybrid plasmid can be transferred into other Klebsiella species and stably persist during passage. The propagation of two important carbapenemase genes with a new genetic background using well-evolved plasmids in the clinical setting promotes the emergence of superbugs that require careful monitoring.

Population genomic analysis reveals the emergence of high-risk carbapenem-resistant Escherichia coli among ICU patients in China

OBJECTIVES

The increasing incidence of carbapenem-resistant Enterobacterales (CRE) mediated nosocomial infections has caused a significant public health burden globally. Currently, the prevalence and genomic characteristics of carbapenem-resistant Escherichia coli (CREC) in patients admitted to the intensive care unit (ICU) are unknown.

METHODS

Herein, we present a nationwide genomic investigation of CREC isolates among ICU patients in China in 2018 and 2020. In total, 113 CREC isolates were identified from 1105 samples in 25 hospitals, and investigated with phenotyping and genomics approaches.

RESULTS

Carbapenemases were produced in 94.69% (107/113) of CREC isolates, which comprise KPC-2 (n = 53, 49.53%), NDM (n = 51, 47.66%), IMP-4 (n = 2, 1.87%), and OXA-181 (n = 1, 0.93%). Notably, CREC isolates co-carrying mcr-9 and bla_NDM-5 or tet(X4) and bla_NDM-5 were first identified in clinical settings. The carbapenemase genes of most isolates were located on the plasmids. The bla_KPC gene was mainly mediated by IncFII plasmids (n = 37, 69.81%), and bla_NDM was located on the IncX3 plasmid (n = 36, 70.59%). CREC isolates belonged to diverse sequence types (STs) of which ST131 was the most prevalent bla_KPC-positive CREC isolates (34/113, 30.09%), while bla_NDM was associated with ST617 and ST410 isolates, thereby indicating that multiple CREC clones spread in Chinese ICU patients.

CONCLUSIONS

This study highlights the emerging threat of high-risk CREC isolates such as ST131 circulating in the ICU in China. Hence, stringent monitoring of such high-risk clones should be performed.

Polymorphism of NOS3 gene and its association with essential hypertension in Guizhou populations of China

OBJECTIVE

A case-control study was conducted to evaluate the relationship between endothelial nitric oxide synthase (NOS3) gene polymorphism and essential hypertension in the Han, Miao, and Buyi populations in Guizhou China.

METHODS

DNA was collected from the blood samples of 353 essential hypertension patients and 342 healthy controls from Guizhou province of China. Eight polymorphisms of the NOS3 gene were genotyped using the Sequenom MassARRAY platform. For genetic analysis, SPSS 26.0, Haploview, SNPStats, SHEsis, and MDR were utilized.

RESULTS

All SNPs (rs11771443, rs1808593, rs753482, rs3918186, rs3918188, rs3918227, rs7830, and rs891512) satisfied the Hardy-Weinberg equilibrium test (P > 0.05). The allele and genotype frequencies of rs7830 and rs1808593 in case-control groups demonstrated significant differences (P < 0.05). Compared to the TT genotype of rs1808593, the TG or GG genotype reduced the risk of hypertension in the Miao population (OR = 0.410, 95% CI: 0.218-0.770, P = 0.006). Compared to the GG or GT genotype of rs7830, the TT genotype increased the risk of hypertension in the overall populations (OR = 1.716, 95%CI: 1.139-2.586, P = 0.010). The CATT (rs3918227-rs391818186-rs1808593-rs7830) haplotype was a risk factor for hypertension in the Miao and Han populations (OR = 1.471, 95%CI: 1.010-2.143, P = 0.044 and OR = 1.692, 95%CI: 1.124-2.545, P = 0.011). The CAGG haplotype in the Miao population was a protective factor against hypertension (OR = 0.555, 95%CI: 0.330-0.934, P = 0.025). The rs3918188, rs1808593, and rs7830 in the Miao population showed an interaction effect on hypertension (P < 0.001). The rs11771443, rs3918188, and rs7830 in the Buyi and Han populations showed an interaction effect on hypertension (P = 0.013 and P < 0.001).

CONCLUSION

The single nucleotide polymorphisms rs1808593 and rs7830 of NOS3 gene are associated with essential hypertension in Guizhou ethnic populations.

[Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region]

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.