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1.
Cell Mol Life Sci ; 81(1): 221, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38763964

RESUMO

In females, the pathophysiological mechanism of poor ovarian response (POR) is not fully understood. Considering the expression level of p62 was significantly reduced in the granulosa cells (GCs) of POR patients, this study focused on identifying the role of the selective autophagy receptor p62 in conducting the effect of follicle-stimulating hormone (FSH) on antral follicles (AFs) formation in female mice. The results showed that p62 in GCs was FSH responsive and that its level increased to a peak and then decreased time-dependently either in ovaries or in GCs after gonadotropin induction in vivo. GC-specific deletion of p62 resulted in subfertility, a significantly reduced number of AFs and irregular estrous cycles, which were same as pathophysiological symptom of POR. By conducting mass spectrum analysis, we found the ubiquitination of proteins was decreased, and autophagic flux was blocked in GCs. Specifically, the level of nonubiquitinated Wilms tumor 1 homolog (WT1), a transcription factor and negative controller of GC differentiation, increased steadily. Co-IP results showed that p62 deletion increased the level of ubiquitin-specific peptidase 5 (USP5), which blocked the ubiquitination of WT1. Furthermore, a joint analysis of RNA-seq and the spatial transcriptome sequencing data showed the expression of steroid metabolic genes and FSH receptors pivotal for GCs differentiation decreased unanimously. Accordingly, the accumulation of WT1 in GCs deficient of p62 decreased steroid hormone levels and reduced FSH responsiveness, while the availability of p62 in GCs simultaneously ensured the degradation of WT1 through the ubiquitin‒proteasome system and autophagolysosomal system. Therefore, p62 in GCs participates in GC differentiation and AF formation in FSH induction by dynamically controlling the degradation of WT1. The findings of the study contributes to further study the pathology of POR.


Assuntos
Hormônio Foliculoestimulante , Células da Granulosa , Folículo Ovariano , Proteína Sequestossoma-1 , Ubiquitinação , Proteínas WT1 , Animais , Hormônio Foliculoestimulante/metabolismo , Hormônio Foliculoestimulante/farmacologia , Feminino , Proteínas WT1/metabolismo , Proteínas WT1/genética , Camundongos , Folículo Ovariano/metabolismo , Folículo Ovariano/efeitos dos fármacos , Células da Granulosa/metabolismo , Células da Granulosa/efeitos dos fármacos , Proteína Sequestossoma-1/metabolismo , Proteína Sequestossoma-1/genética , Camundongos Endogâmicos C57BL , Autofagia/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Humanos , Camundongos Knockout
2.
Anal Chem ; 96(29): 11932-11941, 2024 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-38984509

RESUMO

Oxidative stress, characterized by an imbalance between oxidative and antioxidant processes, results in excessive accumulation of intracellular reactive oxygen species. Among these responses, the regulation of intracellular hydroxyl radicals (•OH) and glutathione (GSH) is vital for physiological processes. Real-time in situ monitoring these two opposing bioactive species and their redox interactions is essential for understanding physiological balance and imbalance. In this study, we developed a dual-site fluorescence chemosensor OG-3, which can independently image both exogenous and endogenous •OH and GSH in separate channels both within cells and in vivo, eliminating issues of spatiotemporal inhomogeneous distribution and cross-interference. With its imaging capabilities of monitoring •OH-GSH redox, OG-3 elucidated two different pathways for ferroptosis induction: (i) inhibition of system xc- to block cystine uptake (extrinsic pathway) and (ii) GPX4 inactivation, leading to the loss of antioxidant defense (intrinsic pathway). Moreover, we assessed the antiferroptotic function and effects of ferroptosis inhibitors by monitoring •OH and GSH fluctuations during ferroptosis. This method provides a reliable platform for identifying potential ferroptosis inhibitors, contributing to our understanding of relevant metabolic and physiological mechanisms. It shows potential for elucidating the regulation of ferroptosis mechanisms and investigating further strategies for therapeutic applications.


Assuntos
Ferroptose , Corantes Fluorescentes , Glutationa , Radical Hidroxila , Oxirredução , Ferroptose/efeitos dos fármacos , Glutationa/metabolismo , Glutationa/análise , Humanos , Radical Hidroxila/metabolismo , Animais , Corantes Fluorescentes/química , Camundongos , Imagem Óptica
3.
Fish Shellfish Immunol ; 150: 109611, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38734119

RESUMO

During virus-host co-evolution, viruses have developed multiple strategies to dampen IFN response and prevent its antiviral activity in host cells. To date, the interactions between host IFN response and the immune evasion strategies exploited by fish iridoviruses still remain largely uncertain. Here, a potential immune evasion protein candidate of Singapore grouper iridovirus (SGIV), VP82 (encoded by SGIV ORF82) was screened and its roles during viral replication were investigated in detail. Firstly, VP82 overexpression dramatically decreased IFN or ISRE promoter activity and the transcription levels of IFN stimulated genes (ISGs) stimulated by grouper cyclic GMP-AMP synthase (EccGAS)/stimulator of interferon genes (EcSTING), TANK-binding kinase 1 (EcTBK1), IFN regulatory factor 3 (EcIRF3)and EcIRF7. Secondly, Co-IP assays indicated that VP82 interacted with EcIRF3 and EcIRF7, but not EcSTING and EcTBK1, which was consistent with the co-localization between VP82 and EcIRF3 or EcIRF7. Furthermore, VP82 promoted the degradation of EcIRF3 and EcIRF7 in a dose-dependent manner via the autophagy pathway. Finally, VP82 overexpression accelerated SGIV replication, evidenced by the increased transcriptions of viral core genes and viral production. Moreover, the antiviral action of EcIRF3 or EcIRF7 was significantly depressed in VP82 overexpressed cells. Together, VP82 was speculated to exert crucial roles for SGIV replication by inhibiting the IFN response via the degradation of IRF3 and IRF7. Our findings provided new insights into understanding the immune evasion strategies utilized by fish iridovirus through IFN regulation.


Assuntos
Infecções por Vírus de DNA , Doenças dos Peixes , Proteínas de Peixes , Fator Regulador 3 de Interferon , Fator Regulador 7 de Interferon , Ranavirus , Proteínas Virais , Animais , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/imunologia , Fator Regulador 3 de Interferon/metabolismo , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/metabolismo , Fator Regulador 7 de Interferon/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Proteínas de Peixes/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Infecções por Vírus de DNA/imunologia , Infecções por Vírus de DNA/veterinária , Ranavirus/fisiologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Imunidade Inata/genética , Interferons/genética , Interferons/imunologia , Interferons/metabolismo , Evasão da Resposta Imune , Bass/imunologia , Bass/genética , Replicação Viral , Proteínas de Peixe-Zebra , Fatores Reguladores de Interferon
4.
Fish Shellfish Immunol ; 145: 109349, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38184183

RESUMO

Singapore grouper iridovirus (SGIV), belonging to genus Ranavirus, family Iridoviridae, is a highly pathogenic agent and causes heavy economic losses in the global grouper aquaculture. Recent studies demonstrated that SGIV infection attenuated antiviral immune and inflammatory response induced by poly (I:C) in vitro. However, little was known about the potential functions of the immune regulatory proteins encoded by SGIV. Here, we identified the detailed roles of VP20 and clarified the potential mechanism underlying its immune regulatory function during SGIV infection. Our results showed that VP20 was an IE gene, and partially co-localized with Golgi apparatus and lysosomes in grouper cells. Overexpression of VP20 enhanced SGIV replication, demonstrated by the increase in the transcription levels of viral core genes and the protein synthesis of MCP. Reporter gene assays showed that SGIV VP20 overexpression significantly reduced the IFN promoter activity induced by poly (I:C), grouper stimulator of interferon genes (EcSTING) and TANK-binding kinase 1 (EcTBK1). Consistently, the transcription levels of IFN related genes were significantly decreased in VP20 overexpressing cells compared to those in control cells. Co-IP assay and confocal microscopy observations indicated that VP20 co-localized and interacted with EcTBK1 and EcIRF3, but not EcSTING. In addition, VP20 was able to degrade EcIRF3 and attenuate the antiviral action of EcIRF3, while had no effect on EcTBK1. Together, SGIV VP20 was speculated to promote viral replication through attenuating the IFN response mediated by TBK1-IRF3 in vitro. Our findings provided new insights into the immune regulatory function of SGIV encoded unknown proteins.


Assuntos
Bass , Infecções por Vírus de DNA , Doenças dos Peixes , Iridovirus , Ranavirus , Animais , Interferons , Ranavirus/fisiologia , Imunidade Inata/genética , Singapura , Sequência de Aminoácidos , Proteínas de Peixes/genética , Alinhamento de Sequência
5.
Environ Sci Technol ; 58(4): 2069-2077, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38237036

RESUMO

Earthworms accumulate organic pollutants to form earthworm tissue-bound residues (EBRs); however, the composition and fate of EBRs in soil remain largely unknown. Here, we investigated the fate of tetrabromobisphenol A (TBBPA)-derived EBRs in soil for 250 days using a 14C-radioactive isotope tracer and the geophagous earthworm Metaphire guillelmi. The EBRs of TBBPA in soil were rapidly transformed into nonextractable residues (NERs), mainly in the form of sequestered and ester-linked residues. After 250 days of incubation, 4.9% of the initially applied EBRs were mineralized and 69.3% were released to extractable residues containing TBBPA and its transformation products (TPs, generated mainly via debromination, O-methylation, and skeletal cleavage). Soil microbial activity and autolytic enzymes of earthworms jointly contributed to the release process. In their full-life period, the earthworms overall retained 24.1% TBBPA and its TPs in soil and thus prolonged the persistence of these pollutants. Our study explored, for the first time, the composition and fate of organic pollutant-derived EBRs in soil and indicated that the decomposition of earthworms may release pollutants and cause potential environmental risks of concern, which should be included in both environmental risk assessment and soil remediation using earthworms.


Assuntos
Poluentes Ambientais , Oligoquetos , Bifenil Polibromatos , Poluentes do Solo , Animais , Solo/química
6.
BMC Musculoskelet Disord ; 25(1): 303, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641788

RESUMO

BACKGROUND: Osteoarthritis (OA) is a common orthopedic disorder, and its incidence has been increasing among young adults in recent years. The purpose of this study is to investigate the global, regional, and national trends in OA burden and variation among individuals aged 30 to 44 from 1990 to 2019. METHODS: Data on the incidence, prevalence, and years lived with disability (YLDs) related to OA were sourced from the Global Burden of Disease Study 2019 among individuals aged 30 to 44. These measures were stratified by gender, region, country, and socio-demographic index (SDI). Additionally, we analyzed YLDs attributable to risk factors. RESULTS: In 2019, there were a total of 32,971,701 cases of OA among individuals aged 30 to 44 years worldwide, with an additional 7,794,008 new incident cases reported. OA of the knee was the primary contributor to both incidence and prevalence rates over the past three decades. From 1990 to 2019, both males and females in countries with high SDI and high-middle SDI showed upward trends in age-standardized incidence, prevalence, and YLDs rates. In 2019, the United States of America had the highest age-standardized incidence, prevalence, and YLDs rates. Elevated body-mass index (BMI) was found to be the most prevalent risk factor for osteoarthritis-related YLDs. Age-standardized YLDs rates were positively associated with SDI. CONCLUSIONS: OA remains a significant disease burden on individuals aged 30 to 44, with modifiable risk factors such as unhealthy lifestyle and obesity representing key targets for future interventions aimed at reducing the impact of this condition on younger generations.


Assuntos
Carga Global da Doença , Osteoartrite , Masculino , Feminino , Adulto Jovem , Humanos , Saúde Global , Osteoartrite/diagnóstico , Osteoartrite/epidemiologia , Prevalência , Efeitos Psicossociais da Doença , Incidência , Anos de Vida Ajustados por Qualidade de Vida
7.
J Dairy Sci ; 107(7): 4658-4669, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38310957

RESUMO

Enteric CH4 produced from dairy cows contributes to the emission of greenhouse gases from anthropogenic sources. Recent studies have shown that the selection of lower CH4-emitting cows is possible, but doing so would be simpler if performance measures already recorded on farm could be used, instead of measuring gas emissions from individual cows. These performance measures could be used for selection of low emitting cows. The aim of this analysis was to quantify how much of the between-cow variation in CH4 production can be explained by variation in performance measures. A dataset with 3 experiments and a total of 149 lactating dairy cows with repeated measures was used to estimate the between-cow variation (the variation between cow estimates) for performance and gas measures from GreenFeed (C-Lock, Rapid City, SD). The cow estimates were obtained with a linear mixed model with the diet within period effect as a fixed effect and the cow within experiment as a random effect. The cow estimates for CH4 production were first regressed on the performance and gas measures individually, and then performance and CO2 production measures were grouped in 3 subsets for principal component analysis and principal component regression. The variables that explained most of the between-cow variation in CH4 production were DMI (R2 = 0.44), among the performance measures, and CO2 production (R2 = 0.61), among gas measures. Grouping the measures increased the R2 to 0.53 when only performance measures were used, and to 0.66 when CO2 production was added to the significant performance measures. We found the marginal improvement to be insufficient to justify the use of grouped measures rather than an individual measure because the latter simplifies the model and avoids over-fitting. Investigation of other measures that can be explored to increase explanatory power of between-cow variation in CH4 production is briefly discussed. Finally, the use of residual CH4 as a measure for CH4 efficiency could be considered by using either DMI or CO2 production as the sole predicting variables.


Assuntos
Dieta , Lactação , Metano , Metano/biossíntese , Metano/metabolismo , Animais , Bovinos , Feminino , Dieta/veterinária , Leite/química , Leite/metabolismo , Ração Animal , Dióxido de Carbono/análise
8.
Front Cell Infect Microbiol ; 14: 1410921, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015336

RESUMO

Objective: The emergence of clinical Klebsiella pneumoniae strains harboring acrAB-tolC genes in the chromosome, along with the presence of two repetitive tandem core structures for bla KPC-2 and bla CTX-M-65 genes on a plasmid, has presented a significant clinical challenge. Methods: In order to study the detailed genetic features of K. pneumoniae strain SC35, both the bacterial chromosome and plasmids were sequenced using Illumina and nanopore platforms. Furthermore, bioinformatics methods were employed to analyze the mobile genetic elements associated with antibiotic resistance genes. Results: K. pneumoniae strain SC35 was found to possess a class A beta-lactamase and demonstrated resistance to all tested antibiotics. This resistance was attributed to the presence of efflux pump genes, specifically acrAB-tolC, on the SC35 chromosome. Additionally, the SC35 plasmid p1 carried the two repetitive tandem core structures for bla KPC-2 and bla CTX-M-65, as well as bla TEM-1 with rmtB, which shared overlapping structures with mobile genetic elements as In413, Tn3, and TnAs3. Through plasmid transfer assays, it was determined that the SC35 plasmid p1 could be successfully transferred with an average conjugation frequency of 6.85 × 10-4. Conclusion: The structure of the SC35 plasmid p1 appears to have evolved in correlation with other plasmids such as pKPC2_130119, pDD01754-2, and F4_plasmid pA. The infectious strain SC35 exhibits no susceptibility to tested antibioticst, thus effective measures should be taken to prevent the spread and epidemic of this strain.


Assuntos
Antibacterianos , Cromossomos Bacterianos , Infecções por Klebsiella , Klebsiella pneumoniae , Plasmídeos , beta-Lactamases , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Plasmídeos/genética , beta-Lactamases/genética , Infecções por Klebsiella/microbiologia , Antibacterianos/farmacologia , Cromossomos Bacterianos/genética , Humanos , Testes de Sensibilidade Microbiana , Sequências Repetitivas Dispersas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
9.
Int J Nanomedicine ; 19: 651-671, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38269254

RESUMO

Background: Polyvinyl alcohol/Chitosan hydrogel is often employed as a carrier because it is non-toxic, biodegradable, and has a three-dimensional network structure. Meanwhile, Magnesium-doped nano-hydroxyapatite(Mg-nHA) demonstrated high characterization to promote the osteogenic differentiation of bone marrow derived mesenchymal stem cell(BMSCs). Therefore, in order to develop a porous hydrogel scaffold for the application of bone tissue engineering, an appropriate-type Mg-nHA hydrogel scaffold was developed and evaluated. Methods: A composite hydrogel containing magnesium-doped nano-hydroxyapatite (Mg-nHA/PVA/CS) was developed using a magnetic stirring-ion exchange method and cyclic freeze-thaw method design, with polyvinyl alcohol and chitosan as the main components. Fourier transform infrared spectra (FTIR), electron energy dispersive spectroscopy (EDS), X-ray photoelectron spectrometer (XPS) and scanning electron microscopy (SEM) were employed to analyze the chemical structure, porosity, and elemental composition of each hydrogels. The equilibrium swelling degree, moisture content, pH change, potential for biomineralization, biocompatibility, the osteogenic potential and magnesium ion release rate of the composite hydrogel were also evaluated. Results: SEM analysis revealed a well-defined 3D spatial structure of micropores in the synthesised hydrogel. FTIR analysis showed that doping nanoparticles had little effect on the hydrogel's structure and both the 5% Mg-nHA/PVA/CS and 10% Mg-nHA/PVA/CS groups promoted amide bond formation. EDS observation indicated that the new material exhibited favourable biomineralization ability, with optimal performance seen in the 5% Mg-nHA/PVA/CS group. The composite hydrogel not only displayed favourable water content, enhanced biocompatibility, and porosity (similar to human cancellous bone), but also maintained an equilibrium swelling degree and released magnesium ions that created an alkaline environment around it. Additionally, it facilitated the proliferation of bone marrow mesenchymal stem cells and their osteogenic differentiation. Conclusion: The Mg-nHA/PVA/CS hydrogel demonstrates significant potential for application in the field of bone repair, making it an excellent composite material for bone tissue engineering.


Assuntos
Quitosana , Humanos , Durapatita , Osteogênese , Magnésio , Álcool de Polivinil , Hidrogéis
10.
Phytochemistry ; 218: 113951, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38096962

RESUMO

Inubritanolides C and D (1 and 2), two exo sesquiterpenoid [4 + 2] adducts with unprecedented interconverting conformations of twist-chair and chair, together with two previously undescribed endo [4 + 2] dimers (3 and 4) were discovered from Inula britannica flowers. Dimers 1 and 2 have an undescribed carbon skeleton comprising of eudesmanolide and guaianolide units with the linkage mode of C-11/C-1' and C-13/C-3' via a Diels-Alder cycloaddition reaction. Their structures were elucidated using 1D/2D NMR, X-ray diffraction, ECD, and variable-temperature NMR experiments. Dimer 2 displayed a strong inhibitory effect on breast cancer cells by promoting lipid ROS production, showing its potential as ferroptosis inducer.


Assuntos
Asteraceae , Ferroptose , Inula , Sesquiterpenos , Inula/química , Conformação Molecular , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Estrutura Molecular
11.
Med Image Anal ; 91: 102999, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37862866

RESUMO

Coronary CT angiography (CCTA) is an effective and non-invasive method for coronary artery disease diagnosis. Extracting an accurate coronary artery tree from CCTA image is essential for centerline extraction, plaque detection, and stenosis quantification. In practice, data quality varies. Sometimes, the arteries and veins have similar intensities and locate closely, which may confuse segmentation algorithms, even deep learning based ones, to obtain accurate arteries. However, it is not always feasible to re-scan the patient for better image quality. In this paper, we propose an artery and vein disentanglement network (AVDNet) for robust and accurate segmentation by incorporating the coronary vein into the segmentation task. This is the first work to segment coronary artery and vein at the same time. The AVDNet consists of an image based vessel recognition network (IVRN) and a topology based vessel refinement network (TVRN). IVRN learns to segment the arteries and veins, while TVRN learns to correct the segmentation errors based on topology consistency. We also design a novel inverse distance weighted dice (IDD) loss function to recover more thin vessel branches and preserve the vascular boundaries. Extensive experiments are conducted on a multi-center dataset of 700 patients. Quantitative and qualitative results demonstrate the effectiveness of the proposed method by comparing it with state-of-the-art methods and different variants. Prediction results of the AVDNet on the Automated Segmentation of Coronary Artery Challenge dataset are avaliabel at https://github.com/WennyJJ/Coronary-Artery-Vein-Segmentation for follow-up research.


Assuntos
Algoritmos , Vasos Coronários , Humanos , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Angiografia Coronária/métodos , Angiografia por Tomografia Computadorizada/métodos , Processamento de Imagem Assistida por Computador/métodos
12.
Sci Bull (Beijing) ; 69(8): 1122-1136, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38302330

RESUMO

In a growing follicle, the survival and maturation of the oocyte largely depend on support from somatic cells to facilitate FSH-induced mutual signaling and chemical communication. Although apoptosis and autophagy in somatic cells are involved in the process of FSH-induced follicular development, the underlying mechanisms require substantial study. According to our study, along with FSH-induced antral follicles (AFs) formation, both lysine-specific demethylase 1 (LSD1) protein levels and autophagy increased simultaneously in granulosa cells (GCs) in a time-dependent manner, we therefore evaluated the importance of LSD1 upon facilitating the formation of AFs correlated to autophagy in GCs. Conditional knockout of Lsd1 in GCs resulted in significantly decreased AF number and subfertility in females, accompanied by marked suppression of the autophagy in GCs. On the one hand, depletion of Lsd1 resulted in accumulation of Wilms tumor 1 homolog (WT1), at both the protein and mRNA levels. WT1 prevented the expression of FSH receptor (Fshr) in GCs and thus reduced the responsiveness of the secondary follicles to FSH induction. On the other hand, depletion of LSD1 resulted in suppressed level of autophagy by upregulation of ATG16L2 in GCs. We finally approved that LSD1 contributed to these sequential activities in GCs through its H3K4me2 demethylase activity. Therefore, the importance of LSD1 in GCs is attributable to its roles in both accelerating autophagy and suppressing WT1 expression to ensure the responsiveness of GCs to FSH during AFs formation.


Assuntos
Células da Granulosa , Folículo Ovariano , Feminino , Autofagia/genética , Hormônio Foliculoestimulante/farmacologia , Células da Granulosa/metabolismo , Folículo Ovariano/metabolismo , Transdução de Sinais , Animais , Camundongos
13.
Front Cell Infect Microbiol ; 13: 1324846, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274736

RESUMO

Background: Today, the blaNDM gene is widely distributed on several plasmids from a variety of Gram-negative bacteria, primarily in transposons and gene cassettes within their multidrug-resistant (MDR) regions. This has led to the global dissemination of the blaNDM gene. Methods: The determination of class A beta-lactamase, class B and D carbapenemases was performed according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). Antimicrobial susceptibility testing was performed using both the BioMerieux VITEK2 system and antibiotic paper diffusion methods. Plasmid transfer was then evaluated by conjugation experiments and plasmid electroporation assays. To comprehensively analyze the complete genome of K. pneumoniae strain F11 and to investigate the presence of mobile genetic elements associated with antibiotic resistance and virulence genes, Nanopore and Illumina sequencing platforms were used, and bioinformatics methods were applied to analyze the obtained data. Results: Our findings revealed that K. pneumoniae strain F11 carried class A beta-lactamase and classes B+D carbapenemases, and exhibited resistance to commonly used antibiotics, particularly tigecycline and ceftazidime/avibactam, due to the presence of relevant resistance genes. Plasmid transfer assays demonstrated successful recovery of plasmids pA_F11 and pB_F11, with average conjugation frequencies of 2.91×10-4 and 1.56×10-4, respectively. However, plasmids pC_F11 and pD_F11 failed in both conjugation and electroporation experiments. The MDR region of plasmid pA_F11 contained rare In1765, TnAs2, and TnAs3 elements. The MDR2 region of plasmid pB_F11 functioned as a mobile genetic "island" and lacked the blaNDM-1 gene, serving as a "bridge" connecting the early composite structure of bleMBL and blaNDM-1 to the recent composite structure. Additionally, the MDR1 region of plasmid pB_F11 comprised In27, TnAs1, TnAs3, and Tn2; and plasmid pC_F11 harbored the recent composite structure of bleMBL and blaNDM-1 within Tn3000 which partially contained partial Tn125. Conclusion: This study demonstrated that complex combinations of transposons and integron overlaps, along with the synergistic effects of different drug resistance and virulence genes, led to a lack of effective therapeutic agents for strain F11, therefore its dissemination and prevalence should be strictly controlled.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , Klebsiella pneumoniae/genética , Plasmídeos/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Infecções por Klebsiella/microbiologia , Testes de Sensibilidade Microbiana
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