9 research outputs found

    Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence

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    Klebsiella pneumoniae is an opportunistic pathogen that mainly causes nosocomial infections and hospital-associated pneumonia in elderly and immunocompromised people. However, multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKp) has emerged recently as a serious threat to global health that can infect both immunocompromised and healthy individuals. It is scientifically established that plasmid-mediated regulator of mucoid phenotype genes (rmpA and rmpA2) and other virulence factors (aerobactin and salmochelin) are mainly responsible for this phenotype. In this study, we collected 23 MDR-hvKp isolates and performed molecular typing, whole genome sequencing, comparative genomic analysis, and phenotypic experiments, including the Galleria mellonella infection model, to reveal its genetic and phenotypic features. Meanwhile, we discovered two MDR-hvKp isolates (22122315 and 22091569) that showed a wide range of hypervirulence and hypermucoviscosity without rmpA and rmpA2 and any virulence factors. In phenotypic experiments, isolate 22122315 showed the highest hypervirulence (infection model) with significant mucoviscosity, and conversely, isolate 22091569 exhibited the highest mucoviscosity (string test) with higher virulence compared to control. These two isolates carried carbapenemase (blaKPC − 2), β-lactamase (blaOXA − 1, blaTEM − 1B), extended-spectrum β-lactamase (ESBL) genes (blaCTX − M − 15, blaSHV − 106), outer membrane protein-coding genes (ompA), fimbriae encoding genes (ecpABCDER), and enterobactin coding genes (entAB, fepC). In addition, single nucleotide polymorphism analysis indicated that both isolates, 22122315 and 22091569, were found to have novel mutations in loci FEBNDAKP_03184 (c. 2084A > C, p. Asn695Thr), and EOFMAFIB_02276 (c. 1930C > A, p. Pro644Thr), respectively. Finally, NCBI blast analysis suggested these mutations are located in the wzc of the capsule polysaccharide (cps) region and are responsible for putative tyrosine kinase. This study would be a strong reference for enhancing the current understanding of identifying the MDR-hvKp isolates that lacked both mucoid regulators and virulence factors

    Molecular Detection and Biological Control of Human Hair Dandruff Causing Microorganism Staphylococcus aureus

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    Human hair dandruff (HHD) is a common unwanted scalp disorder that is prevalent to most human populations all over the world. This study was designed to isolate and characterize pathogens that are responsible for HHD as well as the evaluation of their biological control technique. Isolated bacteria were characterized by different biochemical tests and molecular identification methods. Here, disc diffusion methods were used to determine antibiotic and antibacterial activity against isolated bacteria. The isolated bacterial colonies were found to be Gram-positive, small, round-shaped, and purple. PCR amplification was done using 27F and 1492R primer pairs. A BlastN search of a sequenced 1465 bp region of 16S rRNA in NCBI GenBank revealed approximately 99% genome similarity with Staphylococcus aureus. The sequence was deposited in GenBank (Accession No. MH603394). In the antibiotic sensitivity test, Kanamycin showed the highest 31.0±0.5 mm diameter zone of inhibition (DZI) against the isolated bacteria. Moreover, as a plant-derived compound, the Methanol extract of Allium sativum revealed the highest, 15.0±0.5 mm DZI. The present study would give a promising direction of identification and control of this pathogen biologically

    Harmful Effects of COVID-19 on Major Human Body Organs: A Review

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    The world experienced the outbreak of a new pandemic disease in 2019, known as coronavirus (CoV) disease 2019 (COVID-19), which is caused by the novel severe acute respiratory syndrome-CoV-2 (SARS-CoV-2). The respiratory system is the organ system most commonly affected by COVID-19; however, several other organ systems have been reported to be affected. The SARS-CoV-2 RNA found in infected stub samples can cause lung contagion by binding to the angiotensin-converting enzyme-2 (ACE-2) receptor of the alveolar epithelial cells. The gut microbiota (GM) promote immunity, indicating that the alignment of the microbiota and corresponding metabolic processes in COVID-19 can help to identify novel biomarkers and new therapeutic targets for this disease. The cause of kidney damage in COVID-19 patients is possibly multifactorial, involving a complex mechanism that involves complement dysregulation and thrombotic microangiopathy, as well as the occurrence of a “cytokine storm” syndrome, which are immune responses that are abandoned and dysfunctional with unfavorable prognosis in severe COVID-19 cases. Furthermore, COVID-19 involves a continuous proliferation and activation of macrophages and lymphocytes. SARS-CoV-2 can also bind to the ACE-2 receptor expressed in the cerebral capillary endothelial cells that can invade the blood-brain wall, to penetrate the brain parenchyma. However, in the ongoing pandemic, there has been a surge in studies on a wide range of topics, including causes of respiratory failure, asymptomatic patients, intensive care patients, and survivors. This review briefly describes the damaging effects of COVID-19 on vital human organs and the inhibitory function of the ACE-2 receptor on the GM, which causes gut dysbiosis, and thus, this review discusses topics that have an opportunity for further investigation

    Data_Sheet_1_Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence.docx

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    Klebsiella pneumoniae is an opportunistic pathogen that mainly causes nosocomial infections and hospital-associated pneumonia in elderly and immunocompromised people. However, multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKp) has emerged recently as a serious threat to global health that can infect both immunocompromised and healthy individuals. It is scientifically established that plasmid-mediated regulator of mucoid phenotype genes (rmpA and rmpA2) and other virulence factors (aerobactin and salmochelin) are mainly responsible for this phenotype. In this study, we collected 23 MDR-hvKp isolates and performed molecular typing, whole genome sequencing, comparative genomic analysis, and phenotypic experiments, including the Galleria mellonella infection model, to reveal its genetic and phenotypic features. Meanwhile, we discovered two MDR-hvKp isolates (22122315 and 22091569) that showed a wide range of hypervirulence and hypermucoviscosity without rmpA and rmpA2 and any virulence factors. In phenotypic experiments, isolate 22122315 showed the highest hypervirulence (infection model) with significant mucoviscosity, and conversely, isolate 22091569 exhibited the highest mucoviscosity (string test) with higher virulence compared to control. These two isolates carried carbapenemase (blaKPC − 2), β-lactamase (blaOXA − 1, blaTEM − 1B), extended-spectrum β-lactamase (ESBL) genes (blaCTX − M − 15, blaSHV − 106), outer membrane protein-coding genes (ompA), fimbriae encoding genes (ecpABCDER), and enterobactin coding genes (entAB, fepC). In addition, single nucleotide polymorphism analysis indicated that both isolates, 22122315 and 22091569, were found to have novel mutations in loci FEBNDAKP_03184 (c. 2084A > C, p. Asn695Thr), and EOFMAFIB_02276 (c. 1930C > A, p. Pro644Thr), respectively. Finally, NCBI blast analysis suggested these mutations are located in the wzc of the capsule polysaccharide (cps) region and are responsible for putative tyrosine kinase. This study would be a strong reference for enhancing the current understanding of identifying the MDR-hvKp isolates that lacked both mucoid regulators and virulence factors.</p

    Data_Sheet_2_Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence.zip

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    Klebsiella pneumoniae is an opportunistic pathogen that mainly causes nosocomial infections and hospital-associated pneumonia in elderly and immunocompromised people. However, multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKp) has emerged recently as a serious threat to global health that can infect both immunocompromised and healthy individuals. It is scientifically established that plasmid-mediated regulator of mucoid phenotype genes (rmpA and rmpA2) and other virulence factors (aerobactin and salmochelin) are mainly responsible for this phenotype. In this study, we collected 23 MDR-hvKp isolates and performed molecular typing, whole genome sequencing, comparative genomic analysis, and phenotypic experiments, including the Galleria mellonella infection model, to reveal its genetic and phenotypic features. Meanwhile, we discovered two MDR-hvKp isolates (22122315 and 22091569) that showed a wide range of hypervirulence and hypermucoviscosity without rmpA and rmpA2 and any virulence factors. In phenotypic experiments, isolate 22122315 showed the highest hypervirulence (infection model) with significant mucoviscosity, and conversely, isolate 22091569 exhibited the highest mucoviscosity (string test) with higher virulence compared to control. These two isolates carried carbapenemase (blaKPC − 2), β-lactamase (blaOXA − 1, blaTEM − 1B), extended-spectrum β-lactamase (ESBL) genes (blaCTX − M − 15, blaSHV − 106), outer membrane protein-coding genes (ompA), fimbriae encoding genes (ecpABCDER), and enterobactin coding genes (entAB, fepC). In addition, single nucleotide polymorphism analysis indicated that both isolates, 22122315 and 22091569, were found to have novel mutations in loci FEBNDAKP_03184 (c. 2084A > C, p. Asn695Thr), and EOFMAFIB_02276 (c. 1930C > A, p. Pro644Thr), respectively. Finally, NCBI blast analysis suggested these mutations are located in the wzc of the capsule polysaccharide (cps) region and are responsible for putative tyrosine kinase. This study would be a strong reference for enhancing the current understanding of identifying the MDR-hvKp isolates that lacked both mucoid regulators and virulence factors.</p

    Table_1_Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence.docx

    No full text
    Klebsiella pneumoniae is an opportunistic pathogen that mainly causes nosocomial infections and hospital-associated pneumonia in elderly and immunocompromised people. However, multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKp) has emerged recently as a serious threat to global health that can infect both immunocompromised and healthy individuals. It is scientifically established that plasmid-mediated regulator of mucoid phenotype genes (rmpA and rmpA2) and other virulence factors (aerobactin and salmochelin) are mainly responsible for this phenotype. In this study, we collected 23 MDR-hvKp isolates and performed molecular typing, whole genome sequencing, comparative genomic analysis, and phenotypic experiments, including the Galleria mellonella infection model, to reveal its genetic and phenotypic features. Meanwhile, we discovered two MDR-hvKp isolates (22122315 and 22091569) that showed a wide range of hypervirulence and hypermucoviscosity without rmpA and rmpA2 and any virulence factors. In phenotypic experiments, isolate 22122315 showed the highest hypervirulence (infection model) with significant mucoviscosity, and conversely, isolate 22091569 exhibited the highest mucoviscosity (string test) with higher virulence compared to control. These two isolates carried carbapenemase (blaKPC − 2), β-lactamase (blaOXA − 1, blaTEM − 1B), extended-spectrum β-lactamase (ESBL) genes (blaCTX − M − 15, blaSHV − 106), outer membrane protein-coding genes (ompA), fimbriae encoding genes (ecpABCDER), and enterobactin coding genes (entAB, fepC). In addition, single nucleotide polymorphism analysis indicated that both isolates, 22122315 and 22091569, were found to have novel mutations in loci FEBNDAKP_03184 (c. 2084A > C, p. Asn695Thr), and EOFMAFIB_02276 (c. 1930C > A, p. Pro644Thr), respectively. Finally, NCBI blast analysis suggested these mutations are located in the wzc of the capsule polysaccharide (cps) region and are responsible for putative tyrosine kinase. This study would be a strong reference for enhancing the current understanding of identifying the MDR-hvKp isolates that lacked both mucoid regulators and virulence factors.</p

    Table_2_Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence.xlsx

    No full text
    Klebsiella pneumoniae is an opportunistic pathogen that mainly causes nosocomial infections and hospital-associated pneumonia in elderly and immunocompromised people. However, multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKp) has emerged recently as a serious threat to global health that can infect both immunocompromised and healthy individuals. It is scientifically established that plasmid-mediated regulator of mucoid phenotype genes (rmpA and rmpA2) and other virulence factors (aerobactin and salmochelin) are mainly responsible for this phenotype. In this study, we collected 23 MDR-hvKp isolates and performed molecular typing, whole genome sequencing, comparative genomic analysis, and phenotypic experiments, including the Galleria mellonella infection model, to reveal its genetic and phenotypic features. Meanwhile, we discovered two MDR-hvKp isolates (22122315 and 22091569) that showed a wide range of hypervirulence and hypermucoviscosity without rmpA and rmpA2 and any virulence factors. In phenotypic experiments, isolate 22122315 showed the highest hypervirulence (infection model) with significant mucoviscosity, and conversely, isolate 22091569 exhibited the highest mucoviscosity (string test) with higher virulence compared to control. These two isolates carried carbapenemase (blaKPC − 2), β-lactamase (blaOXA − 1, blaTEM − 1B), extended-spectrum β-lactamase (ESBL) genes (blaCTX − M − 15, blaSHV − 106), outer membrane protein-coding genes (ompA), fimbriae encoding genes (ecpABCDER), and enterobactin coding genes (entAB, fepC). In addition, single nucleotide polymorphism analysis indicated that both isolates, 22122315 and 22091569, were found to have novel mutations in loci FEBNDAKP_03184 (c. 2084A > C, p. Asn695Thr), and EOFMAFIB_02276 (c. 1930C > A, p. Pro644Thr), respectively. Finally, NCBI blast analysis suggested these mutations are located in the wzc of the capsule polysaccharide (cps) region and are responsible for putative tyrosine kinase. This study would be a strong reference for enhancing the current understanding of identifying the MDR-hvKp isolates that lacked both mucoid regulators and virulence factors.</p

    p-type Bi₂ Se₃ for Topological Insulator and Low-Temperature Thermoelectric Applications

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    The growth and elementary properties of p-type Bi2Se3 single crystals are reported. Based on a hypothesis about the defect chemistry of Bi2Se3, the p-type behavior has been induced through low-level substitutions (1% or less) of Ca for Bi. Scanning tunneling microscopy is employed to image the defects and establish their charge. Tunneling and angle-resolved photoemission spectra show that the Fermi level has been lowered into the valence band by about 400 meV in Bi1.98Ca0.02Se3 relative to the n-type material. p-type single crystals with ab-plane Seebeck coefficients of +180 μV/K at room temperature are reported. These crystals show an anomalous peak in the Seebeck coefficient at low temperatures, reaching +120 μV K-1 at 7 K, giving them a high thermoelectric power factor at low temperatures. In addition to its interesting thermoelectric properties, p-type Bi2Se3 is of substantial interest for studies of technologies and phenomena proposed for topological insulators

    Development of Ferromagnetism in the Doped Topological Insulator Bi₂₋ₓ MnₓTe₃

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    The development of ferromagnetism in Mn-doped Bi2Te3 is characterized through measurements on a series of single crystals with different Mn content. Scanning tunneling microscopy analysis shows that the Mn substitutes on the Bi sites, forming compounds of the type Bi2-xMnxTe3, and that the Mn substitutions are randomly distributed, not clustered. Mn doping first gives rise to local magnetic moments with Curie-like behavior, but by the compositions Bi1.96 Mn0.04 Te3 and Bi1.91 Mn0.09 Te3, a second-order ferromagnetic transition is observed, with TC ~9-12 K. The easy axis of magnetization in the ferromagnetic phase is perpendicular to the Bi2 Te3 basal plane. Thermoelectric power and Hall effect measurements show that the Mn-doped Bi2Te3 crystals are p -type. Angle-resolved photoemission spectroscopy measurements show that the topological surface states that are present in pristine Bi2 Te3 are also present at 15 K in ferromagnetic Mn-doped Bi2-x MnxTe3 and that the dispersion relations of the surface states are changed in a subtle fashion
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