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BACKGROUND: Circular RNAs (circRNAs) appear to be important modulators in ovarian cancer. We aimed to explore the role and mechanism of circ_0025033 in ovarian cancer. METHODS: qRT-PCR was conducted to determine circ_0025033, hsa_miR-370-3p, and SLC1A5 mRNA expression. Functional experiments were conducted, including Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, tube formation, xenograft tumor model assay, western blot analysis of protein levels, and analysis of glutamine metabolism using commercial kits. Their predicted interaction was confirmed using dual-luciferase reporter and RNA pull-down. RESULTS: circ_0025033 was upregulated in ovarian cancer; its knockdown induced proliferation, invasion, angiogenesis, glutamine metabolism, and apoptosis in vitro, and blocked tumor growth in vivo. circ_0025033 regulated ovarian cancer cellular behaviors via sponging hsa_miR-370-3p. In parallel, SLC1A5 might abolish the anti-ovarian cancer role of hsa_miR-370-3p. Furthermore, circ_0025033 affected SLC1A5 via regulating hsa_miR-370-3p. CONCLUSION: circ_0025033 might promote ovarian cancer progression via hsa_miR-370-3p/SLC1A5, providing an interesting insight into ovarian cancer tumorigenesis.
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MicroARNs , Neoplasias Ováricas , ARN Circular , Femenino , Humanos , Sistema de Transporte de Aminoácidos ASC/genética , Sistema de Transporte de Aminoácidos ASC/metabolismo , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Glutamina/genética , Glutamina/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Antígenos de Histocompatibilidad Menor , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , ARN MensajeroRESUMEN
BACKGROUND: Opportunistic pathogens are important for clinical practice as they often cause antibiotic-resistant infections. However, little is documented for many emerging opportunistic pathogens and their biological characteristics. Here, we isolated a strain of extended-spectrum ß-lactamase-producing Enterobacteriaceae from a patient with a biliary tract infection. We explored the biological and genomic characteristics of this strain to provide new evidence and detailed information for opportunistic pathogens about the co-infection they may cause. RESULTS: The isolate grew very slowly but conferred strong protection for the co-infected cephalosporin-sensitive Klebsiella pneumoniae. As the initial laboratory testing failed to identify the taxonomy of the strain, great perplexity was caused in the etiological diagnosis and anti-infection treatment for the patient. Rigorous sequencing efforts achieved the complete genome sequence of the isolate which we designated as AF18. AF18 is phylogenetically close to a few strains isolated from soil, clinical sewage, and patients, forming a novel species together, while the taxonomic nomenclature of which is still under discussion. And this is the first report of human infection of this novel species. Like its relatives, AF18 harbors many genes related to cell mobility, various genes adaptive to both the natural environment and animal host, over 30 mobile genetic elements, and a plasmid bearing blaCTX-M-3 gene, indicating its ability to disseminate antimicrobial-resistant genes from the natural environment to patients. Transcriptome sequencing identified two sRNAs that critically regulate the growth rate of AF18, which could serve as targets for novel antimicrobial strategies. CONCLUSIONS: Our findings imply that AF18 and its species are not only infection-relevant but also potential disseminators of antibiotic resistance genes, which highlights the need for continuous monitoring for this novel species and efforts to develop treatment strategies.
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Coinfección/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Enterobacteriaceae/genética , Regulación Bacteriana de la Expresión Génica/genética , beta-Lactamasas/metabolismo , Antibacterianos/farmacología , Sistema Biliar/microbiología , Técnicas de Cocultivo , Enterobacteriaceae/citología , Enterobacteriaceae/patogenicidad , Enterobacteriaceae/ultraestructura , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Klebsiella pneumoniae/patogenicidad , Microscopía Electrónica de Rastreo , Filogenia , ARN no Traducido/genética , ARN no Traducido/metabolismo , RNA-Seq , Transcriptoma/genética , Secuenciación Completa del Genoma , beta-Lactamasas/genéticaRESUMEN
The complete 284,628bp sequence of pH11, an IncHI2 plasmid, was determined through single-molecule, real-time (SMRT) sequencing. Harbored by a clinical Klebsiella pneumoniae strain H11, and isolated in Beijing, this plasmid contains multiple antibiotic resistance genes, including catA2, aac(6')-Ib, strB, strA, dfrA19, blaTEM-1, blaSHV-12, sul1, qacE delta 1, ereA, arr2, and aac3. The aac(6')-Ib is carried by a class I integron. Plasmid pH11 also carries several genes associated with resistance to heavy metals, such as tellurium, mercury, cobalt, zinc, nickel, copper, lead and cadmium. This plasmid exhibits numerous characteristics, including HipBA and RelBE toxin-antitoxin systems, two major transfer (Tra) regions closely related to those of Salmonella enterica serovar plasmid pRH-R27, a type II restriction modification system (EcoRII R-M system), several methyltransferases and methylases and genes encoding Hha and StpA. These characteristics suggest that pH11 may adapt to various hosts and environments. Multiple insertion sequence elements, transposases, recombinases, resolvases and integrases are scattered throughout pH11. The presence of these genes may indicate that horizontal gene transfer occurs frequently in pH11 and thus may facilitate the dissemination of antimicrobial resistance determinants. Our data suggest that pH11 is a chimera gradually assembled through the integration of different horizontally acquired DNA segments via transposition or homologous recombination.
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Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Metales Pesados/toxicidad , Plásmidos/genética , Secuencia de Bases , ADN Bacteriano/genética , Proteínas de Unión al ADN/genética , Transferencia de Gen Horizontal , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación , Metiltransferasas/genética , Pruebas de Sensibilidad Microbiana , Retroelementos/genética , Análisis de Secuencia de ADNRESUMEN
The construction of marine ranching is a concrete practice to fulfil the strategic objective of China's maritime power. The shortage of funds has turned into an important issue to be resolved urgently in the modernization of marine ranching. This study constructs a supply chain system, involving a leading enterprise of marine ranching with short funds and a retailer, and introduces the government guidance fund to solve the issue of capital shortage. Then, we discuss the supply chain financing decision under two different power structure modes, and analyze the product environmental attribute (the product's environmental friendliness and the environmental enrichment) and the guiding effect of government investment on the operation of different modes. The research shows that: (1) The wholesale price of products is mainly influenced by the dominant position of the marine ranching leading enterprise. Furthermore, the wholesale price and the marine ranching company's profits increase with the growth of the product environmental attribute. (2) The retailer's profit and the supply chain system's profit are mainly affected by the dominant power of the retailer and are positively correlated with the product environmental attribute. In addition, the supply chain system's overall profits are negatively related to the guiding effect of government investment.
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PURPOSE: Radiation-induced lung injury limits the implementation of radiotherapy plans and severely impairs the quality of life. Crocetin has the capability to protect against radiation. This study is aimed at estimate the preventive effect and mechanism of crocetin on acute radiation induced lung injury. METHODS AND MATERIALS: In this study, we offer a strategy for radiation-induced lung injury by using crocetin, an extract of gardenia fruit. Histopathology, transcriptomics, flow cytometry, and other methods have served to examine the effect and mechanism of crocetin on acute radiation-induced lung injury. RESULTS: Crocetin effectively alleviates radiation-induced alveolar wall thickening and alveolar destruction. The number of normal alveoli and lung structure of mice is well protected by the prevention of crocetin. It is found that crocetin inhibits necroptosis to achieve effective radioprotection by down regulating the Tnfrsf10b gene in vitro. CONCLUSION: Crocetin inhibits necroptosis through transcriptional regulation of the Tnfrsf10b gene, thereby preventing radiation-induced lung injury. This work may provide a new strategy for the prevention of lung radiation injury by the extract from Chinese herbal medicine.
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Lesión Pulmonar Aguda , Gardenia , Traumatismos por Radiación , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/prevención & control , Animales , Carotenoides , Frutas/química , Gardenia/química , Pulmón , Ratones , Extractos Vegetales/análisis , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Calidad de Vida , Traumatismos por Radiación/tratamiento farmacológico , Traumatismos por Radiación/prevención & control , Vitamina A/análogos & derivadosRESUMEN
OBJECTIVES: Klebsiella pneumoniae carbapenemase (KPC) has spread across the world. The present study focused on exploring the sequences of two new KPC-harbouring plasmids in K. pneumoniae. METHODS: Eighteen KPC-harbouring K. pneumoniae isolates were collected from a tertiary teaching hospital in 2014 in Fujian, China, among which two new KPC-harbouring plasmids (pF77 and pF5) we identified. The characteristics of the plasmids and the isolates carrying them were investigated in detail. RESULTS: The two KPC-harbouring plasmids (pF5 and pF77) carried the antimicrobial resistance genes blaKPC-2, blaCTX-M-65, blaSHV-12, catA2 and fosA3. Detailed sequence comparison revealed that the two plasmids might have evolved from recombination of the previously reported plasmids pKP1034 and pCT-KPC, which were considered to evolve from ancestor plasmids pHN7A8, pKPC-LK30 and pKPHS2. Plasmids pF5 and pF77 were non-conjugative and were mainly identified in sequence type 11 (ST11) K. pneumoniae isolates. Additionally, 4-55 core single nucleotide polymorphisms (SNPs) were identified in each pair of sequenced isolates that carried the identified plasmids. CONCLUSION: Plasmids pF5 and pF77 as well as the previously reported plasmids pKP1034 and pCT-KPC were all detected in 2013-2014 in South China and were carried by ST11 K. pneumoniae isolates. SNP analysis indicated high similarity of the sequenced isolates. Therefore, spread of the group of plasmids may be due to an outbreak of clonal dissemination of ST11 KPC-producing K. pneumoniae. This study also highlights the importance of plasmid analysis in the surveillance and control of antibiotic resistance spread in clinical isolates.
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Infecciones por Klebsiella , Klebsiella pneumoniae , Proteínas Bacterianas , China , Electroforesis en Gel de Campo Pulsado , Humanos , Klebsiella pneumoniae/genética , Plásmidos/genética , beta-Lactamasas/genéticaRESUMEN
The EXO70 gene is a vital component of the exocytosis complex and participates in biological processes ranging from plant cell division to polar growth. There are many EXO70 genes in plants and their functions are extensive, but little is known about the EXO70 gene family in cotton. Here, we analyzed four cotton sequence databases, identified 165 EXO70 genes, and divided them into eight subgroups (EXO70A-EXO70H) based on their phylogenetic relationships. EXO70A had the most exons (≥11), whereas the other seven each had only one or two exons. Hence, EXO70A may have many important functions. The 84 EXO70 genes in Asian and upland cotton were expressed in the roots, stems, leaves, flowers, fibers, and/or ovules. Full-length GhEXO70A1-A cDNA was homologously cloned from upland cotton (Gossypium hirsutum, G. hirsutum). Subcellular analysis revealed that GhEXO70A1-A protein was localized to the plasma membrane. A yeast two-hybrid assay revealed that GhEXO70A1-A interacted with GhEXO84A, GhEXO84B, and GhEXO84C. GhEXO70A1-A silencing significantly altered over 4000 genes and changed several signaling pathways related to metabolism. Thus, the EXO70 gene plays critical roles in the physiological functions of cotton.
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Genes de Plantas , Gossypium/genética , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , TranscriptomaRESUMEN
BACKGROUND: Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) poses distinct clinical challenges due to extensively drug resistant (XDR) phenotype, and sequence type (ST) 11 is the most dominant blaKPC-2-bearing CP-Kp clone in China. The purpose of this current retrospective study was to explore the genetic factors associated with the success of XDR CP-Kp ST11 strains circulated in the intensive care unit (ICU) of a Chinese tertiary hospital. METHODS: Six ST11 XDR CP-Kp strains were identified between May and December 2014 and validated by minimum inhibitory concentration examination, polymerase chain reaction, and pyrosequencing. The six ST11 XDR CP-Kp, as well as three multi-drug resistant (MDR) and four susceptible strains, were sequenced using single-molecule real-time method. Comprehensively structural and functional analysis based on comparative genomics was performed to identify genomic characteristics of the XDR ST11 CP-Kp strains. RESULTS: We found that ST11 XDR blaKPC-2-bearing CP-Kp strains isolated from inpatients spread in the ICU of the hospital. Functionally, genes associated with information storage and processing of the ST11 XDR CP-Kp strains were more abundant than those of MDR and susceptible strains, especially genes correlative with mobile genetic elements (MGEs) such as transposons and prophages. Structurally, eleven large-scale genetic regions taken for the unique genome in these ST11 XDR CP-Kp strains were identified as MGEs including transposons, integrons, prophages, genomic islands, and integrative and conjugative elements. Three of them were located on plasmids and eight on chromosomes; five of them were with antimicrobial resistance genes and eight with adaptation associated genes. Notably, a new blaKPC-2-bearing ΔΔTn1721-blaKPC-2 transposon, probably transposed and truncated from ΔTn1721-blaKPC-2 by IS903D and ISKpn8, was identified in all six ST11 XDR CP-Kp strains. CONCLUSION: Our findings suggested that together with clonal spread, MGEs identified uniquely in the ST11 XDR CP-Kp strains might contribute to their formidable adaptability, which facilitated their widespread dissemination in hospital.
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Infecciones por Klebsiella , Preparaciones Farmacéuticas , Antibacterianos , Proteínas Bacterianas , China , Electroforesis en Gel de Campo Pulsado , Hospitales , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Estudios Retrospectivos , beta-Lactamasas/genéticaRESUMEN
Reducing human reliance on energy-inefficient cooling methods such as air conditioning would have a large impact on the global energy landscape. By a process of complete delignification and densification of wood, we developed a structural material with a mechanical strength of 404.3 megapascals, more than eight times that of natural wood. The cellulose nanofibers in our engineered material backscatter solar radiation and emit strongly in mid-infrared wavelengths, resulting in continuous subambient cooling during both day and night. We model the potential impact of our cooling wood and find energy savings between 20 and 60%, which is most pronounced in hot and dry climates.
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In this paper, we report a mid-wave infrared (MWIR) and long-wave infrared (LWIR) dual-band photodetector capable of voltage-controllable detection band selection. The voltage-tunable dual-band photodetector is based on the multiple stacks of sub-monolayer (SML) quantum dots (QDs) and self-assembled QDs. By changing the photodetector bias voltages, one can set the detection band to be MWIR, or LWIR or both with high photodetectivity and low crosstalk between the bands.
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Engineering heterogeneous micro-mechano-microenvironments of extracellular matrix is of great interest in tissue engineering, but spatial control over mechanical heterogeneity in three dimensions is still challenging given the fact that geometry and stiffness are inherently intertwined in fabrication. Here, we develop a layer-by-layer three-dimensional (3D) printing paradigm which achieves orthogonal control of stiffness and geometry by capitalizing on the conventionally adverse effect of oxygen inhibition on free-radical polymerization. Controlled oxygen permeation and inhibition result in photo-cured hydrogel layers with thicknesses only weakly dependent to the ultraviolet exposure dosage. The dosage is instead leveraged to program the crosslink density and stiffness of the cured structures. The programmable stiffness spans nearly an order of magnitude (E ~ 2-15 kPa) within the physiologically relevant range. We further demonstrate that extracellular matrices with programmed micro-mechano-environments can dictate 3D cellular organization, enabling in vitro tissue reconstruction.
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Microambiente Celular , Matriz Extracelular , Impresión Tridimensional , Ingeniería de Tejidos , Músculo Liso Vascular/citología , OxígenoRESUMEN
OBJECTIVE: The current investigation explores whether extended-spectrum ß-lactamase (ESBL) genes exist in clinical non-ESBL-producing Klebsiella pneumoniae isolates. METHODS: A total of 202 clinical isolates with non-ESBL-producing K. pneumoniae were collected from southern and middle of China. Thirteen ß-lactamase genes (blaSHV, CTX-M, TEM, OXA-2, OXA-10, VEB, PER, SFO, GES, CSP, TLA, BEL, and IBC) were screened by PCR and their identity confirmed by sequencing of PCR products. The ESBL-producing phenotype of the isolates that carried ESBL genes was tested and confirmed in 9 of the 18 isolates by a double-disc synergy test. The sequences upstream of ESBL genes of isolates with ESBL-producing genotype (+)/phenotype (-) were also subjected to PCR and sequencing. The ESBL genes and their upstream regions were cloned into Escherichia coli DH5α for functional evaluation. RESULTS: A total of 8.9% (18/202) isolates carried ESBL genes. All of them harbored only one ESBL gene, including 33.3% (6/18) blaSHV and 66.7% (12/18) blaCTX-M. Among the isolates carrying ESBL genes, nine isolates were confirmed as ESBL phenotype (-). The ESBL genotype (+)/phenotype (-) isolates had blaSHV-27,38,41,42 (66.7%, 6/9) and blaCTX-M-3,15,24 (33.3%, 3/9). The upstream gene sequences, including promoters of these unexpressed ESBL genes, were intact without any mutations or spacers and effective among eight strains. The ISEcp1 element in the upstream region was not found in one isolate carrying an unexpressed blaCTX-M-15 gene. CONCLUSIONS: Clinical non-ESBL-producing K. pneumoniae isolates could carry ESBL genes with intact promoter, but without the correlated phenotype. Specific silencing mechanisms may play an important role in regulating ESBL gene expression. This kind of isolates has the potential to transfer their ESBL genes to other bacteria with effective promoters, resulting in ESBL phenotype.
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Antibacterianos/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , beta-Lactamasas/genética , Escherichia coli/genética , Humanos , Infecciones por Klebsiella/microbiología , Pruebas de Sensibilidad Microbiana/métodosRESUMEN
Bacterial isolate X39 was isolated from a community-acquired pneumonia patient in Beijing, China. A phylogenetic tree based on rpoB genes and average nucleotide identity data confirmed that isolate X39 belonged to Klebsiella variicola. The genome of K. variicola X39 contained one circular chromosome and nine plasmids. Comparative genomic analyses with other K. variicola isolates revealed that K. variicola X39 contained the most unique genes. Of these unique genes, many were prophages and transposases. Many virulence factors were shared between K. variicola X39 and Klebsiella pneumoniae F1. The pathogenicity of K. variicola X39 was compared with that of K. pneumoniae F1 in an abdominal infection model. The results indicated that K. variicola X39 was less virulent than typical clinical K. pneumoniae F1. The genome of K. variicola X39 also contained some genes involved in plant colonization, nitrogen fixation, and defense against oxidative stress. GFP-labeled K. variicola X39 could colonize maize as an endophytic bacterium. We concluded that K. variicola X39 was a kingdom-crossing strain.
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The highly refractory nature of cervical cancer to chemotherapeutic drugs and its epithelial-to-mesenchymal transition (EMT) are the key reasons contributing to the poor prognosis of this disease. Golgi Membrane Protein 1 (GOLM1), a protein involved in the trafficking of proteins through the Golgi apparatus, has been shown to be oncogenic in a variety of human cancers. Herein, we found GOLM1 was markedly up-regulated in cervical cancer and GOLM1 down-expression enhanced the anti-tumor effect of methotrexate. By performing mechanistic studies using both in vitro and in vivo models, we found that GOLM1 could target matrix metallopeptidase 13 (MMP13), a member of the MMPs, and regulate the EMT process. Moreover, altered EMT progression compromised the chemotherapy-enhancing effects of GOLM1 knock-down. Finally, we found significantly higher levels of GOLM1 and MMP13 in cervical cancer tissues compared with adjacent noncancerous tissues, and this was also associated with poor cervical cancer patients' prognosis. Taken together, our results suggest that the GOLM1/MMP13/EMT axis is an important factor involved in regulating methotrexate in cervical cancer, and highlights the potential of novel GOLM1-based clinical modalities as a therapeutic approach in cervical cancer patients.
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Passive radiative cooling draws heat from surfaces and radiates it into space as infrared radiation to which the atmosphere is transparent. However, the energy density mismatch between solar irradiance and the low infrared radiation flux from a near-ambient-temperature surface requires materials that strongly emit thermal energy and barely absorb sunlight. We embedded resonant polar dielectric microspheres randomly in a polymeric matrix, resulting in a metamaterial that is fully transparent to the solar spectrum while having an infrared emissivity greater than 0.93 across the atmospheric window. When backed with a silver coating, the metamaterial shows a noontime radiative cooling power of 93 watts per square meter under direct sunshine. More critically, we demonstrated high-throughput, economical roll-to-roll manufacturing of the metamaterial, which is vital for promoting radiative cooling as a viable energy technology.
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AIMS: This work investigated the relative strengths of different blaSHV promoter-associated sequences and their regulation function in blaSHV expression and ß-lactam resistance. METHODS: Recombinant plasmids with the promoter-associated sequences (P-W, P-S, P-IS, and P-WPD), tac promoter, and combined fragments of promoter and blaSHV were separately constructed and transformed into Escherichia coli DH5α. The relative strengths of the promoters indicated by the intensities of green fluorescent protein and the mRNA expression levels of blaSHV were compared. The minimum inhibitory concentration and extended spectrum ß-lactamase phenotypes were evaluated. RESULTS: The relative strengths were ranked as P-tac > P-WPD > P-IS > P-S > P-W. The mRNA expression and ß-lactam resistance levels of the different promoter-associated sequence groups were generally consistent with the strength rank, but the extent of gfp and blaSHV mRNA levels varied significantly in each group. The ß-lactam resistance levels were inconsistent with the strength rank in certain blaSHV groups. In relation to the different promoter-associated sequences, blaSHV-ESBLs displayed significantly different change modes of ß-lactam resistance compared with blaSHV-non-ESBLs. CONCLUSION: The mRNA expression and ß-lactam resistance of the blaSHV showed consistencies and inconsistencies with the strengths of the promoter-associated sequences. The mechanisms accounting for these discrepancies need further investigation.
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Regulación Bacteriana de la Expresión Génica , Klebsiella pneumoniae/genética , Regiones Promotoras Genéticas , Resistencia betalactámica/genética , beta-Lactamasas/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Secuencia de Bases , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/genética , Genes Bacterianos , Genotipo , Pruebas de Sensibilidad Microbiana , Fenotipo , Plásmidos/genética , ARN Mensajero/genética , beta-Lactamas/farmacologíaRESUMEN
AIMS: The aim of this project was to explore the different CTX-M expression levels occurring from a single conserved promoter with different spacer sequences, the variation of which is hypothesized to be a key factor in fluctuating levels of CTX-M. METHODS: The blaCTX-M promoter fragments with five different spacer sequences were amplified, sequenced and cloned into the pUA66 expression vector carrying the green fluorescent protein (GFP) gene. The expression of blaCTX-M in the transconjugants was analyzed using fluorescence microscopy, flow cytometry and qRT-PCR. RESULTS: The promoters of all the blaCTX-M genes were provided by ISEcp1 and were extremely conserved. The promoter-associated spacer sequences varied from 42 to 127 bp and variations in GFP expression in the five transconjugants were observed. A nucleic acid deletion and point mutation were detected in the spacer sequences by variations in which the expression of blaCTX-M was influenced. CONCLUSION: The different spacer sequences have a significant impact on the activity of the conserved promoter. The shorter spacer sequence between the conserved promoter and the blaCTX-M gene does not specifically enhance the expression of blaCTX-M, contrary to previous reports. The expression of blaCTX-M may be regulated by changes in promoter activity caused by diverse spacer sequences.
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Expresión Génica , Regiones Promotoras Genéticas , beta-Lactamasas/biosíntesis , beta-Lactamasas/genética , Citometría de Flujo , Perfilación de la Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/análisis , Proteínas Fluorescentes Verdes/genética , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/aislamiento & purificación , Microscopía Fluorescente , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
BACKGROUND: The extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance. Previous studies have focused on the resistance genes in ESBL-producing strains, and the resistance-associated genetic environment of non-ESBL-producing strains has been ignored until now. Here, we investigated the occurrence and characteristics of non-ESBL-producing K. pneumoniae, which potentially carries unexpressed resistance genes. METHODS: K. pneumoniae strains were collected from five medical institutions in China from February 2010 to August 2013. The VITEK-2 ESBL detection system was used as a primary screen to identify the ESBL-producing phenotype, and the three primary types of ESBL-associated genes (CTX, SHV, and TEM) were detected by polymerase chain reaction (PCR) to confirm the strains presenting with a non-ESBL-producing phenotype. mRNA expression in the non-ESBL-producing strains was further screened by reverse-transcription PCR (RT-PCR) to validate their transcriptional efficiency. RESULTS: Out of 224 clinically isolated antibiotic-sensitive K. pneumoniae strains with a non-ESBL-producing phenotype, 5 (2.2%) were identified to carry inactivated ESBL blaSHV genes with intact upstream promoter regions and resistance gene sequences. Interestingly, three of the five antibiotic-sensitive K. pneumoniae strains containing ESBL blaSHV genes still exhibited mRNA transcription of blaSHV, while the other two exhibited no mRNA transcription. CONCLUSION: These findings suggest that inactivated ESBL genes exist in non-ESBL-producing antibiotic-sensitive K. pneumoniae strains, which have the potential to transform the strain into an ESBL phenotype if an inappropriate application or overdose of antibiotics is implemented during clinical management.
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Antibacterianos/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , beta-Lactamasas/genética , China , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad MicrobianaRESUMEN
OBJECTIVE: To assess the heritability of serum uric acid in adult, using the classic twin design. METHODS: Adult Twins were recruited from the Qingdao Twin Registry. Uric acid, height, weight were measured. Zygosity in all the same-sex twin pairs was determined by 16 polymorphic markers. Heritability was assessed by structural equation models, with age, gender and body mass index (BMI) included as covariates. RESULTS: In total, 687 twin pairs were available for data analyses, including 420 pairs of monozygotic and 267 pairs of dizygotic twins. After logarithm transformed, uric acid in males (17.47 +/- 1.91) was significantly higher than in females (15.22 +/- 1.70, P < 0.0001). After adjustment on age, sex and BMI, intraclass correlations for uric acid were 0.70 for monozygotic twins and 0.40 for dizygotic twins. The sex-limitation AE model, combining additive genetic and unique environmental factors, could produce the best fit for the data. Heritability estimate for uric acid was 70.5% (95%CI: 65.9 - 74.6), with the proportion of unique environmental effects as 29.5% (95%CI: 25.4 - 34.2). CONCLUSION: Additive genetic effects appeared to be the major contributor to the variation of uric acid in this twins sample being studied.