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Lou, X.

Publications and source records attributed to Lou, X..

At least 19 recordsLinked to original sources

Decoding and Targeting Coordinated CDKN1A and CDKN2A Senescence Programs in ECM-Dominant Cardiovascular Pathologies

Cellular senescence is a hallmark of aging and an emerging therapeutic target; however, its role as a context-specific driver of disease remains incompletely defined, and senolytic therapies have shown inconsistent clinical benefit. Here, we identify extracellular matrix (ECM)-dominant pathologies as a major class of senescence-driven disease, characterized by inflammation, matrix degeneration, and progressive tissue dysfunction. Using integrated single-cell transcriptomics, spatial profiling, and multiplex imaging across human specimens and murine models, we demonstrate that senescent fibroblasts, rather than canonical myofibroblasts, constitute the principal disease-driving cell state in myxomatous mitral valve disease (MMVD) and related conditions. These cells exhibit coordinated CDKN1A inflammatory and CDKN2A ECM-remodeling programs that form a feed-forward circuit linking immune activation to matrix disorganization and functional decline. Senescence extends beyond fibroblasts to endothelial and immune compartments, establishing a multicellular senescent milieu that reinforces intercellular crosstalk and disease progression. Senolytic treatment (dasatinib plus quercetin or fisetin) restores ECM architecture and improves cardiac function, outperforming pathway-specific anti-inflammatory and antifibrotic approaches. Cross-disease analyses further reveal conservation of this coordinated CDKN1A/CDKN2A senescence programs across multiple ECM-dominant cardiovascular diseases, including aortic aneurysm and calcific valve disease. Notably, in vivo single-cell transcriptomic profiling following multiple senolytic treatments provides whole-transcriptome resolution of context-dependent cellular responses. Collectively, these findings establish context-specific senescence as a central organizing mechanism in ECM-dominant diseases and support a shift from generalized anti-aging strategies toward precision senolytic prevention or therapy. Given that valvular and aortic diseases affect millions and increase markedly with age to a prevalence comparable to major cancers, these results indicate a potential solution to a substantial and underrecognized clinical burden.

Cell Biology↗

Cross-Species Multi-Omics Profiling Identifies Conserved Activated Valvular Interstitial Cell Population Driving Myxomatous Mitral Valve Degeneration

BackgroundPrimary mitral regurgitation resulting from mitral valve prolapse can lead to life-threatening complications, including arrhythmias, heart failure, and sudden cardiac death. Mitral valve prolapse is classically associated with myxomatous mitral valve degeneration, characterized by leaflet thickening, extracellular matrix disorganization, and progressive structural remodeling. Valvular interstitial cells, the predominant stromal population within the valve, maintain extracellular matrix homeostasis; however, their molecular heterogeneity, and state-specific contributions to disease pathogenesis remain incompletely defined. MethodsUsing a fibrillin-1 deficient mouse model and human tissue specimens we integrated single-cell RNA sequencing with spatial transcriptomic profiling to construct a comprehensive atlas of cellular composition and extracellular matrix organization across normal mitral valves, sporadic mitral valve prolapse, and Marfan syndrome-associated mitral valve prolapse. ResultsAnalyses revealed spatially organized cellular niches and substantial heterogeneity within the valvular interstitial cell population. Across murine and human datasets, we identified a conserved activated valvular interstitial cell population enriched for profibrotic extracellular matrix remodeling programs and preferentially localized to mechanically vulnerable leaflet tip regions. This population exhibited coordinated upregulation of collagen- and matrix-associated genes, metabolic signatures consistent with enhanced mitochondrial activity, and transcriptional features suggesting fibro-inflammatory signaling. ConclusionsWe identified a transcriptionally and spatially distinct activated valvular interstitial cell state conserved across species and disease etiologies that is strongly implicated in fibrotic remodeling during myxomatous mitral valve degeneration and provides a candidate therapeutic target.

molecular biology↗

Parkinsonism Reversal and Dopaminergic Resilience: Lessons from a Rotenone-induced Parkinson's Disease Model

Parkinsons disease (PD) is a progressive neurodegenerative disorder characterized by profound loss of dopaminergic (DA) neurons, yet the underlying mechanism remains incompletely defined. Mitochondrial toxins can induce acute degeneration of DA neurons and Parkinsonism-like phenotypes in animal models, and epidemiological studies have linked pesticide exposure to increased PD risk; however, the long-term effects of pesticide exposure remain elusive. Here, we examined both the acute and long-term effects of rotenone exposure in mice to understand PD onset, progression, and recovery. A 21-day regimen of rotenone intraperitoneal injections (2.5 mg/kg/day) induced robust Parkinsonism-like deficits by the 4th week, including impaired locomotion, increased anxiety-like behaviors, and deficits in motor balancing and coordination. These behavioral abnormalities were accompanied by pronounced reduction in tyrosine hydroxylase (TH) expression and selective loss of DA neurons in the substantia nigra pars compacta (SNc). Unexpectedly, these functional impairments fully resolved by 12 months, and rotenone-treated mice behaved equally well as age-matched controls. In parallel, the TH expression and DA neuron density in SNc were restored to control levels. Together, these longitudinal results demonstrate that chronic rotenone injection induces robust but reversible Parkinsonism in the acute phase, with limited long-term consequence on Parkinsonism upon toxin cessation. These findings contrast with the prevailing view that environmental pesticide exposure irreversibly drives PD and instead they reveal a substantial resilience and adaptive capacity of the nigrostriatal dopaminergic system in vivo. HighlightsO_LIChronic rotenone exposure in mice induces robust Parkinsonism-like behaviors in both motor and non-motor domains. C_LIO_LISNc dopaminergic neurons are reduced by [~]40% at the acute phase within 4 weeks. C_LIO_LIBoth motor and non-motor deficits are fully recovered by 12 months. C_LIO_LIPD-like pathological changes in the SNc are resolved by 12 months. C_LI Infographics O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=166 SRC="FIGDIR/small/695709v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@570654org.highwire.dtl.DTLVardef@160b285org.highwire.dtl.DTLVardef@16846c7org.highwire.dtl.DTLVardef@fec0df_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

NAD+ hydrolase Sarm1 is a key driver of synapse degeneration and memory loss in Alzheimer's disease

Synapse degeneration is a hallmark of neurodegenerative diseases1-3, including Parkinsons and Alzheimers disease (AD). Synapse loss has been known for decades as the strongest correlate with cognition and disease progression in AD patients4-8, but the molecular mechanisms that drive synapse degeneration remain elusive. Here, we identify Sarm1, a new class of NAD+ hydrolase required for Wallerian degeneration of periphery nerves after injuries9-12, as the key mediator of synaptic degeneration in AD brains. Sarm1 knockout largely reversed synapse loss, amyloid-{beta} (A{beta}) burden, and cognitive decline in 5XFAD mice. We found that Sarm1 is enriched in synaptic terminals and becomes activated in synaptic dystrophies adjacent to A{beta} plaques, leading to synapse degeneration and subsequent neuroinflammation. Sarm1 deletion in the AD mice prevented synaptic dystrophies and rescued short-term and long-term synaptic plasticity. Further, Sarm1 deletion protected synapses from C1q tagging and phagocytosis, and C1q-MERTK signaling in complement cascades 7,13-15 was significantly reduced. The reduced synapse degeneration, in turn, broke the feed-forward loop of "glia activation-neuroinflammation-A{beta} deposition". These data suggest that Sarm1 plays a key role in driving synapse degeneration in AD before C1q-tagging and phagocytic clearance, and targeting Sarm1 may offer a novel intervention to attenuate synapse degeneration and memory loss in AD. HighlightO_LISarm1 is enriched at presynaptic dystrophies and correlated with A{beta}. C_LIO_LIGenetic deletion of Sarm1 prevents synapse degeneration in AD. C_LIO_LISarm1 depletion is sufficient to reverse synaptic dysfunction and memory loss. C_LIO_LISarm1 depletion reduces A{beta} burden and neuroinflammation C_LIO_LIC1q--MERTK axis acts downstream of synaptic Sarm1 activation. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/695860v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@bd6b12org.highwire.dtl.DTLVardef@1c089e5org.highwire.dtl.DTLVardef@19d35fborg.highwire.dtl.DTLVardef@431364_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Spatial epigenomic niches underlie glioblastoma cell state plasticity

IDH-wildtype glioblastoma (GBM) is an aggressive brain tumor with poor survival and few therapeutic options. Transcriptionally-defined cell states coexist in GBM and occupy defined regions of the tumor. Evidence indicates that GBM cell states are plastic, but it remains unclear if they are determined by the underlying epigenetic state and/or by microenvironmental factors. Here, we present spatially-resolved epigenomic profiling of human GBM tissues that implicate chromatin structure as a key enabler of cell plasticity. We report two epigenetically-defined and spatially-nested tumor niches. Each niche activates short-range molecular signals to maintain its own state and, surprisingly, long-range signals to reinforce the state of the neighboring niche. The position of a cell along this gradient-like system of opposing signals determines its likelihood to be in one state or the other. Our results reveal an intrinsic system for cell plasticity that is encoded in the chromatin profiles of two adjacent niches that dot the topological architecture of GBM in cartesian space.

genomics↗

APV-Sankey: A Comprehensive Toolbox for Aptamer Screening and Visualization

Aptamers, short single-stranded DNA or RNA molecules, have gained prominence as molecular recognition elements in diagnostics and therapeutics. Screening high-performance aptamers from SELEX process is tough due to limited library diversity, PCR bias, and low library enrichment efficiency. The enriched highest frequency sequences often do not have the highest affinity or specificity. Thus, we developed APV-Sankey, a novel and versatile toolbox designed for the rapid aptamer screening and visualization of the enrichment process. Its key feature is the innovative use of Sankey charts for interactive and informative visualizations. These charts facilitate tracing the evolution of K-mers (K-mer is just a sequence of k characters in a string) across SELEX rounds, aiding in the identification and selection of high-affinity sequences containing K-mers while excluding high-frequency sequences without affinity. Besides integrating essential functions for aptamer analysis, we also developed advanced methods including K-mer concatenation and K-mer evolution, combined with Sankey chart visualizations. Using this toolbox to analyze experimentally screened sequences, we successfully identified high-performance candidate aptamers of rapamycin and thrombin.

bioinformatics↗

Enzymatic Degrading Chlorophenol Wastewater by Mixed Strains of Immobilized White Rot Fungi

To address chlorophenol wastewater pollution, immobilized mixed white rot fungi (WRF) strain microsphere was designed as a solid degradation agent, using lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac) to degradating the wastewater. Considering the diverse physical and chemical properties of the fungal sphere, the immobilization agent formula is optimized and comprehensive environmental factor design response surface analysis are implemented to determine the delivery conditions. Consequently, the 2,4-DCP treatment rate and extracellular enzyme activity for a 1:1 encapsulation of T. versicolor and P. sajor-caju significantly outperform those of individual strains. Using polyvinyl alcohol (PVA), sodium alginate (SA), and biochar as carriers, with sodium dihydrogen phosphate solution as crosslinker and SiO2/zeolite as additives, immobilizing mixed bacteria yielded a high-quality solid agent. This achieved a 99.33% 2,4-DCP degradation rate over 96 hours, with optimal dosage, pH, and initial 2,4-DCP concentration at 11.5 g/L, 5.5, and 40 mg/L. The degradation of 2,4-DCP by WRF selectively removes adjacent chlorine atoms to produce 4-CP, enhancing the dechlorination efficiency. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=94 SRC="FIGDIR/small/611973v1_ufig1.gif" ALT="Figure 1"> View larger version (65K): org.highwire.dtl.DTLVardef@1653067org.highwire.dtl.DTLVardef@4cc31dorg.highwire.dtl.DTLVardef@19daa33org.highwire.dtl.DTLVardef@1115c5_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Spatial dynamics of mammalian brain development and neuroinflammation by multimodal tri-omics mapping

The ability to spatially map multiple layers of the omics information over different time points allows for exploring the mechanisms driving brain development, differentiation, arealization, and alterations in disease. Herein we developed and applied spatial tri-omic sequencing technologies, DBiT ARP-seq (spatial ATAC-RNA-Protein-seq) and DBiT CTRP-seq (spatial CUT&Tag- RNA-Protein-seq) together with multiplexed immunofluorescence imaging (CODEX) to map spatial dynamic remodeling in brain development and neuroinflammation. A spatiotemporal tri-omic atlas of the mouse brain was obtained at different stages from postnatal day P0 to P21, and compared to the regions of interest in the human developing brains. Specifically, in the cortical area, we discovered temporal persistence and spatial spreading of chromatin accessibility for the layer-defining transcription factors. In corpus callosum, we observed dynamic chromatin priming of myelin genes across the subregions. Together, it suggests a role for layer specific projection neurons to coordinate axonogenesis and myelination. We further mapped the brain of a lysolecithin (LPC) neuroinflammation mouse model and observed common molecular programs in development and neuroinflammation. Microglia, exhibiting both conserved and distinct programs for inflammation and resolution, are transiently activated not only at the core of the LPC lesion, but also at distal locations presumably through neuronal circuitry. Thus, this work unveiled common and differential mechanisms in brain development and neuroinflammation, resulting in a valuable data resource to investigate brain development, function and disease.

neuroscience↗

Using split protein reassembly strategy to optically control PLD enzymatic activity

Phospholipase D (PLD) and phosphatidic acid (PA) play a spatio-temporal role in regulating diverse cellular activities. Although current methodologies enable optical control of the subcellular localization of PLD and by which influence local PLD enzyme activity, the overexpression of PLD elevates the basal PLD enzyme activity and further leads to increased PA levels in cells. In this study, we employed a split protein reassembly strategy and optogenetic techniques to modify superPLD (developed by Jeremy Baskin group). We splited this variants into two HKD domains and fused these domains with optogenetic and chemogenetic elements and by which we achieved control of the two HKD interaction and then restored the PLD enzymatic activity.

cell biology↗

Optogenetic strategies for optimizing the performance of biosensors of membrane phospholipids in live cells

High-performance biosensors play a crucial role in elucidating the intricate spatiotemporal regulatory roles and dynamics of membrane lipids. However, enhancing their sensitivity and substrate-detecting capabilities remains a significant challenge. Here, we presented optogenetic-based strategies to optimize phospholipid biosensors. These strategies involved pre-sequestering unbound probes in the cell nucleus to minimize background signals in the cytoplasm. These stored probes could be released from the nucleus in response to blue light according to experimental requirements. Furthermore, we employed optically-controlled phase separation to generate punctate probes that amplified signals and facilitated the visualization of phospholipids in cells. These improved phospholipid biosensors hold great potential for enhancing our understanding of the spatiotemporal dynamics and regulatory roles of membrane lipids in live cells and this methodological insights might be valuable for developing other high-performance biosensors.

cell biology↗

Integration of microbial and chemical synthesis for the efficient production of plitidepsin, a promising anticancer and antiviral agent

Plitidepsin, a marine-derived anticancer medicine, is being tested in phase III clinical trials for treating COVID-19. However, the current supply of plitidepsin relies on laborious chemical synthesis processes. Here, we present a new approach that combines microbial and chemical synthesis to produce plitidepsin. We screened a Tistrella strain library to identify a high-yield didemnin B producer, and then introduced a second copy of the didemnin biosynthetic gene cluster into its genome, resulting in the highest yield of didemnin B reported in the literature. Next, we developed two straightforward chemical strategies to convert didemnin B to plitidepsin, one of which involved a one-step synthetic route giving over 90% overall yield. We also synthesized two new didemnin analogues and assessed their anticancer and antiviral activities. Our findings offer a practical and sustainable solution for producing plitidepsin and its derivatives, potentially expediting didemnin drug development.

synthetic biology↗

Single-Cell RNA-seq of Heart Reveals Intercellular Communication Drivers of Myocardial Fibrosis in Diabetic Mice

Diabetes-induced cardiomyopathy is characterized by myocardial fibrosis as a main pathology. In-depth study of cardiac heterogeneity and cell-to-cell interactions will help to reveal the pathogenesis of diabetic myocardial fibrosis and provide potential targets for the treatment of this disease. Here, we insighted into the intercellular communication drivers underlying myocardial fibrosis in mouse heart with high-fat-diet (HFD)/streptozotocin (STZ)-induced diabetes at single-cell resolution. Intercellular and protein-protein interaction networks of fibroblasts and macrophages, endothelial cells, as well as fibroblasts and epicardial cells reveal critical changes in ligand-receptor interactions such as Pdgf(s)-Pdgfra and Efemp1-Egfr, which promote the development of a profibrotic microenvironment during diabetes progression and confirm that specific inhibition of Pdgfra axis can significantly improve diabetic myocardial fibrosis. We further identified the phenotypically distinct Hrchi and Postnhi fibroblast subpopulations that are associated with pathological extracellular matrix remodeling, of which Hrchi fibroblasts are the most profibrogenic under diabetic conditions. Finally, we validated the role of Itgb1 hub gene mediated intercellular communication drivers of diabetic myocardial fibrosis in Hrchi fibroblasts, and confirmed the result by AAV9-mediated Itgb1 knockdown in the heart of diabetic mice. In summary, cardiac cell mapping provides novel insights into intercellular communication drivers underlying pathological extracellular matrix remodeling during diabetic myocardial fibrosis.

cell biology↗

In vitro activity of ertapenem against Neisseria gonorrhoeae clinical isolates with decreased susceptibility or resistance to extended spectrum cephalosporins in Nanjing, China (2013-2019)

ObjectiveNeisseria gonorrhoeae isolates collected in Nanjing, China, that possessed decreased susceptibility (or resistance) to extended spectrum cephalosporins (ESCs), were examined for susceptibility to ertapenem and their sequence types determined. MethodsCeftriaxone and cefixime minimum inhibitory concentrations (MICs) [&ge;] 0.125 mg/L and [&ge;] 0.25 mg/L, respectively, were first determined in 259 strains isolated between 2013 and 2019 and then MICs of ertapenem were measured using the antimicrobial gradient epsilometer test (Etest). Genetic determinants of ESC resistance and multi-antigen sequence typing (NG-MAST) were also determined to analyze associations with ertapenem susceptibility. ResultsAll isolates displayed ertapenem MICs between 0.006 mg/L-0.38 mg/L; the overall MIC50 and MIC90 were 0.032 mg/L and 0.125 mg/L. 44 (17.0%) isolates displayed ertapenem MICs of [&ge;] 0.125 mg/L; 10 (3.9%) had MICs [&ge;] 0.25 mg/L. The proportion of isolates with ertapenem MICs [&ge;] 0.125 mg/L increased from 4.0% in 2013, to 20.0% in 2019 ({chi}2= 24.144, P<0.001; Chi square test for linear trend). The penA mosaic allele was present in a significantly higher proportion of isolates with ertapenem MICs [&ge;] 0.125 mg/L compared to isolates with MICs [&le;] 0.094 mg/L) (97.7% vs. 34.9%, respectively; {chi}2=58.158, P<0.001). ST5308 was the most prevalent NG-MAST type (8.5%); ST5308 was also significantly more common among isolates with ertapenem MICs [&ge;] 0.125 mg/L vs. isolates with MICs [&le;] 0.094mg/L (22.7% and 5.6% respectively; {chi}2=13.815, P=0.001). ConclusionsErtapenem may be effective therapy for gonococcal isolates with decreased susceptibility or resistance to ESCs and isolates with identifiable genetic resistance determinants.

microbiology↗

In vitro efficacy of gentamicin against multidrug-resistant Neisseria gonorrhoeae: synergy of three gentamicin antimicrobial combinations

ObjectivesTo determine in vitro activities of gentamicin alone and in combination with ceftriaxone, ertapenem and azithromycin against multidrug-resistant (MDR) N. gonorrhoeae isolates. Methods407 isolates from Nanjing, China, obtained in 2016 and 2017, had minimum inhibitory concentrations (MICs) determined for gentamicin using the agar dilution method. Antimicrobial combinations were also tested in 97 MDR strains using the antimicrobial gradient epsilometer test (Etest); results ranging from synergy to antagonism were interpreted using the fractional inhibitory concentration (FICI). ResultsAll 407 gonococcal isolates were susceptible to gentamicin. MICs ranged from 2 mg/L to 16 mg/L. Synergy was demonstrated in 16.5%(16/97), 27.8%(27/97) and 8.2%(8/97) MDR strains when gentamicin was combined with ceftriaxone [geometric mean (GM) FICI; 0.747], ertapenem (GM FICI; 0.662) and azithromycin (GM FICI; 1.021), respectively. No antimicrobial antagonism was observed with any combination. The three antimicrobial combinations were indifferent overall. The overall GM MICs of gentamicin were reduced by 2.63-, 3.80- and 1.98-fold when tested in combination with ceftriaxone, ertapenem and azithromycin, respectively. The GM MICs of the three antimicrobials by themselves were reduced by 3-, 2.57- and 1.98-fold respectively, when each was tested in combination with gentamicin. No antimicrobial antagonism was observed with any combination. ConclusionsGentamicin alone was effective in vitro against MDR N. gonorrhoeae and in combination with ceftriaxone, ertapenem or azithromycin. Combination testing of resistant strains, overall, showed lower effective MICs against gentamicin itself and each of the three antimicrobials when used in combination with gentamicin.

microbiology↗

Hydrogel-coating improves the in-vivo stability of electrochemical aptamer-based biosensors

The ability to track the levels of specific molecules, such as drugs, metabolites, and biomarkers, in the living body, in real time and for long durations would improve our understanding of health and our ability to diagnose, treat and monitor disease. To this end, we are developing electrochemical aptamer-based (E-AB) biosensors, a general platform supporting high-frequency, real-time molecular measurements in the living body. Here we report that the addition of an agarose hydrogel protective layer to E-AB sensors significantly improves their baseline stability when deployed in the complex, highly time-varying environments found in vivo. The improved stability is sufficient that these hydrogel-protected sensors achieved good baseline stability when deployed in situ in the veins, muscles, bladder, or tumors of living rats without the use of the drift correction approaches traditionally required in such placements. Finally, this improved stability is achieved without any significant, associated "costs" in terms of detection limits, response times, or biocompatibility.

bioengineering↗

A Probabilistic and Anisotropic Failure Metric for Ascending Thoracic Aortic Aneurysm Risk Stratification

Experimental studies have shown that aortic wall tensile strengths in circumferential and longitudinal directions are different (i.e., anisotropic), and vary significantly among patients with aortic aneurysm. To assess aneurysm rupture and dissection risk, material failure metric of the aortic wall needs to be accurately defined and determined. Previously such risk assessment methods have largely relied on deterministic or isotropic failure metric. In this study, we develop a novel probabilistic and anisotropic failure metric for risk stratification of ascending thoracic aortic aneurysm (ATAA). To this end, uniaxial tensile tests were performed using aortic tissue samples of 84 ATAA patients, from which a joint probability distribution of the anisotropic wall strengths was obtained. Next, the anisotropic failure probability (FP) based on the Tsai-Hill (TH) failure criterion was derived. The novel FP metric, which incorporates uncertainty in the anisotropic failure properties, can be evaluated after the aortic wall stresses are computed from patient-specific biomechanical analysis. For method validation, "ground-truth" risks of additional 41 ATAA patients were numerically-reconstructed using corresponding CT images and tissue testing data. Performance of different risk stratification methods (e.g., with and without patient-specific hyperelastic properties) was compared using p-value and receiver operating characteristic (ROC) curve. The results show that: (1) the probabilistic FP metric outperforms the deterministic TH metric; and (2) patient-specific hyperelastic properties can help to improve the performance of probabilistic FP metric in ATAA risk stratification.

bioengineering↗

Susceptibility trends of zoliflodacin against multidrug-resistant Neisseria gonorrhoeae clinical isolates in NanJing, China (2014-2018)

Previously, we reported potent activity of a novel spiropyrimidinetrione, zoliflodacin, against N. gonorrhoeae isolates from symptomatic men in Nanjing, China, collected in 2013. Here, we investigated trends of susceptibilities of zoliflodacin in 986 gonococcal isolates collected from men between 2014 and 2018. N. gonorrhoeae isolates were tested for susceptibility to zoliflodacin and seven other antibiotics. Mutations in gyrA, gyrB, parC and parE genes were determined by PCR and DNA sequencing. The MIC of zoliflodacin for N. gonorrhoeae ranged from [&le;]0.002 to 0.25 mg/L; the overall MIC50s and MIC90s were 0.06 mg/L and 0.125mg/L in 2018, increasing two-fold from 2014. However, the percent of isolates with lower zoliflodacin MICs declined in each year sequentially while the percent with higher MICs increased yearly (P[&le;]0.00001). All isolates were susceptible to spectinomycin but resistant to ciprofloxacin (MIC [&ge;]1 g/ml); 21.2% (209/986) were resistant to azithromycin ([&ge;]1 g/ml), 43.4% (428/986) were penicillinase-producing (PPNG), 26.9% (265/986) tetracycline-resistant (TRNG) and 19.4% (191/986) were multi-drug resistant (MDR) isolates. Among 143 isolates with higher zoliflodacin MICs (0.125-0.25 mg/L), all had quinolone resistance associated double or triple mutations in gyrA; 139/143 (97.2%) also had mutations in parC. There were no D429N/A and/or K450T mutations in GyrB identified in the 143 isolates with higher zoliflodacin MICs; a S467N mutation in GyrB was identified in one isolate. We report that zoliflodacin has excellent in vitro activity against clinical gonococcal isolates, including those with high-level resistance to ciprofloxacin, azithromycin and extended spectrum cephalosporins.

microbiology↗

Rapid development of an inactivated vaccine for SARS-CoV-2

The COVID-19 pandemic caused by SARS-CoV-2 has brought about an unprecedented crisis, taking a heavy toll on human health, lives as well as the global economy. There are no SARS-CoV-2-specific treatments or vaccines available due to the novelty of this virus. Hence, rapid development of effective vaccines against SARS-CoV-2 is urgently needed. Here we developed a pilot-scale production of a purified inactivated SARS-CoV-2 virus vaccine candidate (PiCoVacc), which induced SARS-CoV-2-specific neutralizing antibodies in mice, rats and non-human primates. These antibodies potently neutralized 10 representative SARS-CoV-2 strains, indicative of a possible broader neutralizing ability against SARS-CoV-2 strains circulating worldwide. Immunization with two different doses (3g or 6 g per dose) provided partial or complete protection in macaques against SARS-CoV-2 challenge, respectively, without any antibody-dependent enhancement of infection. Systematic evaluation of PiCoVacc via monitoring clinical signs, hematological and biochemical index, and histophathological analysis in macaques suggests that it is safe. These data support the rapid clinical development of SARS-CoV-2 vaccines for humans. One Sentence SummaryA purified inactivated SARS-CoV-2 virus vaccine candidate (PiCoVacc) confers complete protection in non-human primates against SARS-CoV-2 strains circulating worldwide by eliciting potent humoral responses devoid of immunopathology

microbiology↗