scholarly journals Transcriptional Response of Multidrug-Resistant Klebsiella pneumoniae Clinical Isolates to Ciprofloxacin Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Roman Farooq Alvi ◽  
Bilal Aslam ◽  
Muhammad Hidayat Rasool ◽  
Saima Muzammil ◽  
Abu Baker Siddique ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Stress Responses ◽  
Genetic Resistance ◽  
Transcriptional Response ◽  
Multidrug Resistant ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Isolation And Identification ◽  
Concentration Dependent Manner ◽  
High Level

Background. The term “persisters” refers to a small bacterial population that persists during treatment with high antibiotic concentration or dose in the absence of genetic resistance. The present study was designed to investigate the transcriptional response in indigenous Klebsiella pneumoniae under the ciprofloxacin stress. Methods. Isolation and identification of K. pneumoniae were carried out through standard microbiological protocols. The characterization of quinolone resistance was performed by estimating the quinolone susceptibility testing, MIC estimation, and detecting the QRDR and PMQR. Transcriptional response of the isolates to ciprofloxacin was determined using qPCR. Results. Among 34 isolates, 23 (67%) were resistant to ciprofloxacin. Both QRDR (gyrA and gyrB) and PMQR (qnrA, qnrB, and qnrS) were detected in the isolates, and all were found resistant to ciprofloxacin. The mRNA levels of both mutS and euTu under the influence of ciprofloxacin were significantly increased. On ciprofloxacin exposure, the mRNA levels of the DNA damage response element (mutS) were raised in a time-dependent fashion. K. pneumoniae showed high-level resistance to ciprofloxacin in the presence of mutations in QRDR and PMQR genes. Conclusion. The transcriptional response revealed the upregulation of DNA repair and protein folding elements (mutS and euTu) in ciprofloxacin stress and delayed cell division. The ciprofloxacin was found to trigger various stress responses in a time- and concentration-dependent manner.

scholarly journals Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Multidrug Resistant ◽  
Moderate Activity ◽  
Dependent Manner ◽  
Bacterial Strains ◽  
Acinetobacter Baumanii ◽  
Concentration Dependent Manner ◽  
Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

scholarly journals In the Model Host Caenorhabditis elegans, Sphingosine-1-Phosphate-Mediated Signaling Increases Immunity toward Human Opportunistic Bacteria

2020 ◽  
Vol 21 (21) ◽  
pp. 7813
Author(s):  
Kiho Lee ◽  
Iliana Escobar ◽  
Yeeun Jang ◽  
Wooseong Kim ◽  
Frederick M. Ausubel ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Stress Responses ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Cellular Functions ◽  
Kinase Gene ◽  
Concentration Dependent Manner ◽  
C Elegans ◽  
Opportunistic Bacteria ◽  
Free Living Nematode

Sphingosine-1-phophate (S1P) is a sphingolipid-derived signaling molecule that controls diverse cellular functions including cell growth, homeostasis, and stress responses. In a variety of metazoans, cytosolic S1P is transported into the extracellular space where it activates S1P receptors in a concentration-dependent manner. In the free-living nematode Caenorhabditis elegans, the spin-2 gene, which encodes a S1P transporter, is activated during Gram-positive or Gram-negative bacterial infection of the intestine. However, the role during infection of spin-2 and three additional genes in the C. elegans genome encoding other putative S1P transporters has not been elucidated. Here, we report an evolutionally conserved function for S1P and a non-canonical role for S1P transporters in the C. elegans immune response to bacterial pathogens. We found that mutations in the sphingosine kinase gene (sphk-1) or in the S1P transporter genes spin-2 or spin-3 decreased nematode survival after infection with Pseudomonas aeruginosa or Enterococcus faecalis. In contrast to spin-2 and spin-3, mutating spin-1 leads to an increase in resistance to P. aeruginosa. Consistent with these results, when wild-type C. elegans were supplemented with extracellular S1P, we found an increase in their lifespan when challenged with P. aeruginosa and E. faecalis. In comparison, spin-2 and spin-3 mutations suppressed the ability of S1P to rescue the worms from pathogen-mediated killing, whereas the spin-1 mutation had no effect on the immune-enhancing activity of S1P. S1P demonstrated no antimicrobial activity toward P. aeruginosa and Escherichia coli and only minimal activity against E. faecalis MMH594 (40 µM). These data suggest that spin-2 and spin-3, on the one hand, and spin-1, on the other hand, transport S1P across cellular membranes in opposite directions. Finally, the immune modulatory effect of S1P was diminished in C. eleganssek-1 and pmk-1 mutants, suggesting that the immunomodulatory effects of S1P are mediated by the p38 MAPK signaling pathway.

scholarly journals Estrogen Regulation of the Glucuronidation Enzyme UGT2B15 in Estrogen Receptor-Positive Breast Cancer Cells

Endocrinology ◽  
2006 ◽  
Vol 147 (8) ◽  
pp. 3843-3850 ◽  
Author(s):  
William R. Harrington ◽  
Surojeet Sengupta ◽  
Benita S. Katzenellenbogen
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Steroid Hormone ◽  
Transcriptional Response ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Estrogen Regulation ◽  
Estradiol Stimulation

Estrogens and androgens influence many properties of breast cancer cells; hence, regulation of local estrogen and androgen levels by enzymes involved in steroid hormone biosynthesis and metabolism would impact signaling by these hormones in breast cancer cells. In this study, we show that the UDP-glucuronosyltransferase (UGT) enzyme UGT2B15, a member of the UGT family of phase II enzymes involved in the glucuronidation of steroids and xenobiotics, is a novel, estrogen-regulated gene in estrogen receptor (ER)-positive human breast cancer cells (MCF-7, BT474, T47D, and ZR-75). UGT2B15 is the only UGT2B enzyme up-regulated by estrogen, and marked estradiol stimulation of UGT2B15 mRNA levels is observed, in a time- and dose-dependent manner. UGT2B15 stimulation by estradiol is blocked by the antiestrogen ICI182,780, but not by the translational inhibitor cycloheximide, indicating that UGT2B15 is likely a primary transcriptional response mediated through the ER. UGT2B15 up-regulation is also evoked by other estrogens (propylpyrazoletriol, genistein) and by the androgen 5α-dihydrotestosterone working through the ER, but not by other steroid hormone receptor ligands. Western blot and immunocytochemical analyses with several UGT2B-specific antibodies we have designed and steroid glucuronidation assays indicate a large increase in both cellular UGT2B15 protein and enzyme activity after estrogen treatment. Due to the important role of UGT enzymes in forming conjugates between steroids and glucuronic acid, thereby inactivating them and targeting them for removal, the estrogen-induced up-regulation of UGT2B15 might have a significant moderating effect on estrogen and androgen concentrations, thereby reducing their signaling in breast cancer cells.

Differential inhibition of inflammatory cytokine release from cultured alveolar macrophages from smokers and non smokers by No2

1997 ◽  
Vol 16 (10) ◽  
pp. 577-588 ◽  
Author(s):  
Tiziana Dandrea ◽  
Ba Tu ◽  
Anders Blomberg ◽  
Thomas Sandström ◽  
Magnus Sköld ◽  
...  
Keyword(s):  
Steady State ◽  
Alveolar Macrophages ◽  
Exposure Model ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α ◽  
Dependent Inhibition ◽  
Steady State Levels ◽  
Dose Dependent

Human alveolar macrophages (AMs) obtained from smokers and non-smokers by bronchoalveolar lavage (BAL) were subjected to various concentrations of NO2 in an inverted monolayer exposure model. Culture super natants were collected 4 h after the exposure and assayed for secreted TNF-α, IL-1β, IL-8 and MIP-1α. The steady state levels of the mRNAs for these cytokines were also analysed in the cells. The adherence of BAL cells to plastic prior to exposure to the gas elevated the steady state mRNA levels of all four cytokines tested in smoker's cells and that of TNF-α and IL-1β, but not IL-8 (MIP-1α not tested), in non-smoker's cells. Interestingly, adherent cells from non-smokers released circa 15-, 3-,1.5- and 3-fold the amounts of IL-1β, IL-8, TNF-α and MIP-1α, respectively, than smoker's cells during control incubation or exposure to air. A 20 min exposure to NO2 (5 or 20 p.p.m.) did not increase the secretion of any of the cytokines from either cell type. In contrast, NO2 caused a concentration- dependent inhibition of the secretion of all cytokines except IL-1β from smoker's cells. Additionally, NO2 greatly diminished the release of all cytokines in response to further treatment with lipopolysaccharide (LPS). In contrast, only the secretion of TNF-α from non-smoker's cells was inhibited by the gas in a concentration- dependent manner, whilst LPS-induced secretion of the cytokines was not affected by the gas. The steady state levels of the respective mRNAs for each of the cytokines were not significantly affected in smoker's cells by exposure to NO2, except for a negative, dose-dependent trend in the case of TNF-α. Nitrogen dioxide also failed to elevate the levels of the mRNAs in non-smoker's cells but, again, tended to diminish the levels, particularly of IL-1β mRNA. However, exposure to the gas inhibited LPS- induced accumulation of cytokine mRNAs in smoker's cells only. The data suggest that macrophage-derived cytokine mediators of the sepsis response may not play a role in the generation of NO2-induced inflammation in the human lung. Conversely, the gas seems to non-specifically inhibit the release and/or production of cytokines, particularly from smoker's cells, at the post-transcrip tional level, and impairs the ability of the cells to increase the transcription and release of the cytokines in response to bacterial LPS. The fact that NO2 seriously impaired the already diminished capacity of smoker's cells to release several important pro-inflammatory cytokines, both under control conditions and in response to LPS, strongly suggest that the inhalation of NO2 in cigarette smoke may contribute to impairing host defence against infection in the lung.

scholarly journals Bullatacin Triggered ABCB1-Overexpressing Cell Apoptosis via the Mitochondrial-Dependent Pathway

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Yong-Ju Liang ◽  
Xu Zhang ◽  
Chun-Ling Dai ◽  
Jian-Ye Zhang ◽  
Yan-Yan Yan ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Multidrug Resistant ◽  
Resistant Cell ◽  
Ros Generation ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Concentration Dependent Manner ◽  
Induced Apoptosis ◽  
Dependent Pathway

This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation ofΔΨmin a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.

scholarly journals Effects of Various Antibiotics Alone or in Combination with Doripenem againstKlebsiella pneumoniaeStrains Isolated in an Intensive Care Unit

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Berna Ozbek Celik ◽  
Emel Mataraci-Kara ◽  
Mesut Yilmaz
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Klebsiella Pneumoniae ◽  
Logarithmic Phase ◽  
Dependent Manner ◽  
Beta Lactam ◽  
Concentration Dependent Manner ◽  
Test Cultures

Colistin, tigecycline, levofloxacin, tobramycin, and rifampin alone and in combination with doripenem were investigated for their in vitro activities and postantibiotic effects (PAEs) onKlebsiella pneumoniae. The in vitro activities of tested antibiotics in combination with doripenem were determined using a microbroth checkerboard technique. To determine the PAEs,K. pneumoniaestrains in the logarithmic phase of growth were exposed for 1 h to antibiotics, alone and in combination. Recovery periods of test cultures were evaluated using viable counting after centrifugation. Colistin, tobramycin, and levofloxacin produced strong PAEs ranging from 2.71 to 4.23 h, from 1.31 to 3.82 h, and from 1.35 to 4.72, respectively, in a concentration-dependent manner. Tigecycline and rifampin displayed modest PAEs ranging from 1.18 h to 1.55 h and 0.92 to 1.19, respectively. Because it is a beta-lactam, PAEs were not exactly induced by doripenem (ranging from 0.10 to 0.18 h). In combination, doripenem scarcely changed the duration of PAE of each tested antibiotic alone. The findings of this study may have important implications for the timing of doses duringK. pneumoniaetherapy with tested antibiotics.

scholarly journals A Molecular Interaction Map of Klebsiella pneumoniae and Its Human Host Reveals Potential Mechanisms of Host Cell Subversion

2021 ◽  
Vol 12 ◽  
Author(s):  
Deeya Saha ◽  
Sudip Kundu
Keyword(s):  
Klebsiella Pneumoniae ◽  
Host Cell ◽  
Protein Complexes ◽  
Immune Surveillance ◽  
Transcriptional Response ◽  
Multidrug Resistant ◽  
Host Protein ◽  
Central Position ◽  
Human Interactome ◽  
Multifunctional Protein

Klebsiella pneumoniae is a leading cause of pneumonia and septicemia across the world. The rapid emergence of multidrug-resistant K. pneumoniae strains necessitates the discovery of effective drugs against this notorious pathogen. However, there is a dearth of knowledge on the mechanisms by which this deadly pathogen subverts host cellular machinery. To fill this knowledge gap, our study attempts to identify the potential mechanisms of host cell subversion by building a K. pneumoniae–human interactome based on rigorous computational methodology. The putative host targets inferred from the predicted interactome were found to be functionally enriched in the host’s immune surveillance system and allied functions like apoptosis, hypoxia, etc. A multifunctionality-based scoring system revealed P53 as the most multifunctional protein among host targets accompanied by HIF1A and STAT1. Moreover, mining of host protein–protein interaction (PPI) network revealed that host targets interact among themselves to form a network (TTPPI), where P53 and CDC5L occupy a central position. The TTPPI is composed of several inter complex interactions which indicate that K. pneumoniae might disrupt functional coordination between these protein complexes through targeting of P53 and CDC5L. Furthermore, we identified four pivotal K. pneumoniae-targeted transcription factors (TTFs) that are part of TTPPI and are involved in generating host’s transcriptional response to K. pneumoniae-mediated sepsis. In a nutshell, our study identifies some of the pivotal molecular targets of K. pneumoniae which primarily correlate to the physiological response of host during K. pneumoniae-mediated sepsis.

scholarly journals Antiproliferative effects of porins extracted from Klebsiella pneumoniae on HL-60, NIH/3T3 and Human foreskin fibroblast cell (HFFC) lines measured by ELISA method

2010 ◽  
Vol 4 (1) ◽  
pp. 28-35
Author(s):  
Amir H. Al–Shammary ◽  
Essam F. Al-Jumaily ◽  
Nidhal Abdulmohymen
Keyword(s):  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Primary Source ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Gram Negative ◽  
Isolation And Purification ◽  
Antiproliferative Effects

Approximately, 50% of the dry mass of the outer membrane of gram-negative bacteria consists of proteins, and more than 20 immunochemically distinct proteins (termed outer membrane proteins [OMPs]) have been identified. An identified local strain of Klebsiella pneumoniae was used as a primary source for the isolation and purification of porins. Multiple concentrations of purified porins (5, 10, 15, 20, 25) g/ml were incubated with three different cell lines for (24, 72 , 120) hrs, after the end of the incubation periods, the cells were treated with Cell proliferation ELISA, BrdU (colorimetric) kit to evaluate the antiproliferative effects of porins. The results revealed that porins are potent antiproliferative agent in a time and concentration dependent manner and thus could greatly affect prokaryote-eukaryote interaction as well as the whole inflammatory process resulted after infection with gram negative bacteria.

scholarly journals Involvement of BMP-15 in Glucocorticoid Actions on Ovarian Steroidogenesis by Rat Granulosa Cells

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A767-A768
Author(s):  
Chiaki Kashino ◽  
Toru Hasegawa ◽  
Yasuhiro Nakano ◽  
Nahoko Iwata ◽  
Koichiro Yamamoto ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Granulosa Cells ◽  
Type I ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ovarian Steroidogenesis ◽  
Cell Functions ◽  
Camp Synthesis ◽  
Bmp Receptors

Abstract Glucocorticoid receptor (GR) are known to be expressed in the ovary and glucocorticoids are shown to exert direct effects on granulosa cell functions. In the clinical setting, menstrual abnormality, amenorrhea and hypermenorrhea can be shown in patients with glucocorticoid excess. On the other hand, glucocorticoids can also be used for the treatment of PCOS with hyperandrogenism. However, the effects of glucocorticoids on the reproductive system have not been fully elucidated. In the present study, we investigated the influence of glucocorticoids on follicular steroidogenesis using primary culture of rat granulosa cells, by focusing on the ovarian bone morphogenetic proteins (BMPs) acting as a luteinizing inhibitor. Granulosa cells isolated from female immature rats were treated with follicle-stimulating hormone (FSH) in the presence of dexamethasone (Dex) in serum-free conditions. After treatment with Dex for 48 h, the changes of estradiol (E2) and progesterone (P4) production and cAMP synthesis induced by FSH treatments were measured by ELISA. Total RNAs of granulosa cells treated with FSH, Dex and BMPs were extracted and mRNA levels of steroidogenetic factors and enzymes, BMP receptors and Id-1 were quantified by real-time RT-PCR. Phosphorylation of Smad1/5/9 induced by BMPs was evaluated by Western blotting using cell lysates in the presence or absence of Dex. As a result, it was revealed that Dex treatment decreased FSH-induced E2 production by granulosa cells. In accordance with the steroid results, Dex suppressed FSH-induced P450arom mRNA expression as well as FSH-induced cAMP synthesis by granulosa cells. By contrast, Dex treatment augmented FSH-induced P4 production by granulosa cells in a concentration-dependent manner. Dex treatment was found to enhance basal and FSH-induced mRNA levels of P4-synthetic enzymes including P450scc and 3βHSD. Of note, Dex treatment activated the BMP target gene Id-1 transcription and Smad1/5/9 phosphorylation, in particular, induced by BMP-15 among various BMP ligands including BMP-2, -4, -6, -7, -9 and -15. It was also revealed that Dex treatment increased mRNA levels of ALK-6, a type-I receptor for BMP-15, and that BMP-15 treatment in turn upregulated GR mRNA levels expressed by granulosa cells. Given that BMP-15 acts as an inhibitor for P4 production by suppressing FSH-receptor actions, it was suggested that glucocorticoid is functionally linked to the enhancement of endogenous BMP-15, leading to the negative feedback toward the P4 overproduction induced by FSH and Dex in granulosa cells. Collectively, it was revealed that glucocorticoids elicit differential effects on the ovarian steroidogenesis of E2 and P4, in which GR and BMP-15 actions are mutually enhanced in granulosa cells.

scholarly journals Biomedical Potentialities of Silver Nanoparticles for Clinical Multiple Drug-Resistant Acinetobacter baumannii

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Minghui Chen ◽  
Xiaoxu Yu ◽  
Qianyu Huo ◽  
Qin Yuan ◽  
Xue Li ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Clinical Problem ◽  
Multidrug Resistant ◽  
Multiple Drug ◽  
High Morbidity ◽  
Dependent Manner ◽  
Drug Resistant ◽  
Concentration Dependent Manner ◽  
Multiple Drug Resistant ◽  
New Strategy

Multidrug-resistant A. baumannii is increasingly recognized as a significant problem in hospitals and causes high morbidity and mortality. Here, we studied the antibacterial effects of AgNPs on clinically isolated multiple drug-resistant A. baumannii, and search for the potential antibacterial mechanism. Based on the results from the colony-forming unit (CFU) method, flow cytometry (FC), and a BrdU ELISA, we conclude that AgNPs can simultaneously induce apoptosis and inhibit new DNA synthesis in bacteria in a concentration-dependent manner. This study presents the first discussion of an antibacterial effect by AgNPs in clinically isolated, multidrug-resistant A. Baumannii and provides a new strategy for the use of silver nanoparticles in the multidrug-resistant A. Baumannii clinical problem.

Sign in / Sign up

Export Citation Format

Share Document