7 results on '"Reuben Ramphal"'
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2. High pyocyanin production and non-motility of Pseudomonas aeruginosa isolates are correlated with septic shock or death in bacteremic patients.
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Asmita Gupte, Jeevan Jyot, Malleswari Ravi, and Reuben Ramphal
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Medicine ,Science - Abstract
Studies of the outcome of Pseudomonas aeruginosa bacteremia (Pab) have focused mainly on antibiotic appropriateness. However, P. aeruginosa possesses many virulence factors whose roles in outcomes have not been examined in humans, except for the type III secretion system (T3SS) toxins. The purpose of this study was to examine the role of virulence factors other than the T3SS toxins. Bacterial isolates were collected from 75 patients who suffered from Pa blood stream infections. Host factors such as neutropenia, immunosuppression, comorbidities, time to effective antibiotics, source of bacteremia, and presence of multidrug resistant (MDR) isolate were studied. The isolates were analyzed for the presence of toxin genes, proteolytic activity, swimming and twitching motility, and pyocyanin production. The data were analyzed to ascertain which virulence factors correlated with poor outcomes defined as septic shock or death (SS) within 7 days. Septic shock or death occurred in 25/75 patients. Univariate analysis identified age as a host factor that exerted a significant effect on these outcomes. Ineffective antibiotics administered during the first 24 hours of treatment or MDR P. aeruginosa did not influence the frequency of SS, nor did the presence of lasB, exoA, exoS exoU, plcH genes and proteolytic activity. However, 6/8 patients infected with non-motile isolates, developed SS, p = 0.014 and 5/6 isolates that produced large amounts of pyocyanin (>18ug/ml), were associated with SS, p = 0.014. Multivariate analysis indicated that the odds ratio (OR) for development of SS with a non-motile isolate was 6.8, with a 95% confidence interval (CI) (1.37, 51.5), p = 0.030 and with high pyocyanin producing isolates, an OR of 16.9, 95% CI = (2.27, 360), p = .017. This study evaluating the role of microbial factors that significantly effect outcomes following Pa bloodstream infection suggests that P. aeruginosa strains showing high pyocyanin production and the lack of motility independently increase the risk of SS.
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- 2021
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3. Pseudomonas aeruginosa Lipoxygenase LoxA Contributes to Lung Infection by Altering the Host Immune Lipid Signaling
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Eric Morello, Teresa Pérez-Berezo, Chloé Boisseau, Thomas Baranek, Antoine Guillon, Déborah Bréa, Philippe Lanotte, Xavier Carpena, Nicolas Pietrancosta, Virginie Hervé, Reuben Ramphal, Nicolas Cenac, and Mustapha Si-Tahar
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Pseudomonas aeruginosa ,lipoxygenase ,lungs ,infection ,lipid mediators ,inflammation ,Microbiology ,QR1-502 - Abstract
Pseudomonas aeruginosa is an opportunistic bacteria and a major cause of nosocomial pneumonia. P. aeruginosa has many virulence factors contributing to its ability to colonize the host. LoxA is a lipoxygenase enzyme secreted by P. aeruginosa that oxidizes polyunsaturated fatty acids. Based on previous in vitro biochemical studies, several biological roles of LoxA have been hypothesized, including interference of the host lipid signaling, and modulation of bacterial invasion properties. However, the contribution of LoxA to P. aeruginosa lung pathogenesis per se remained unclear. In this study, we used complementary in vitro and in vivo approaches, clinical strains of P. aeruginosa as well as lipidomics technology to investigate the role of LoxA in lung infection. We found that several P. aeruginosa clinical isolates express LoxA. When secreted in the lungs, LoxA processes a wide range of host polyunsaturated fatty acids, which further results in the production of bioactive lipid mediators (including lipoxin A4). LoxA also inhibits the expression of major chemokines (e.g., MIPs and KC) and the recruitment of key leukocytes. Remarkably, LoxA promotes P. aeruginosa persistence in lungs tissues. Hence, our study suggests that LoxA-dependent interference of the host lipid pathways may contribute to P. aeruginosa lung pathogenesis.
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- 2019
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4. Re-evaluation of cefepime or piperacillin/tazobactam to decrease use of carbapenems in ESBL-producing Enterobacterales urinary tract infections (REDUCE-UTI)
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Alexander C Branton, Catherine H Vu, Veena Venugopalan, Barbara A Santevecchi, Kartikeya Cherabuddi, Reuben Ramphal, Tanvi Manohar, and Kathryn E Desear
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Microbiology (medical) ,Infectious Diseases ,Immunology ,Immunology and Allergy ,Microbiology - Abstract
ObjectivesTo re-examine the use of non-carbapenems (NCBPs), specifically piperacillin/tazobactam and cefepime, for ESBL-producing Enterobacterales (ESBL-E) urinary tract infections (UTIs).PatientsRetrospective cohort study of adults hospitalized between January 2016 and June 2020 with pyuria on urinalysis, a urine culture positive for ESBL-E treated with a study antibiotic (meropenem, ertapenem, cefepime or piperacillin/tazobactam) and did not meet criteria for study exclusion.MethodsTo compare carbapenems (CBPs) with cefepime or piperacillin/tazobactam for the treatment of ESBL-E UTI. The primary outcome was clinical cure, defined as complete resolution of signs and symptoms of infection. Secondary outcomes included in-hospital mortality, recurrence within 30 days and resistance emergence within 30 days.ResultsOne-hundred and thirty-three patients were included, based on definitive therapy received; 69 (51.9%) received CBP and 64 (48.1%) received NCBP therapy. Of the total patient population, 17 (12.8%) were admitted to the ICU, 84 (63.1%) had a complicated UTI and 64 (48.1%) had pyelonephritis. There was no difference in clinical cure between the CBP and NCBP groups (95.7% versus 96.9%, P = 0.999). Additionally, no differences in secondary outcomes were observed.ConclusionsWhen compared with CBPs, cefepime and piperacillin/tazobactam resulted in similar clinical cure, in-hospital mortality, recurrence and resistance emergence in the treatment of ESBL-E UTI.
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- 2023
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5. No human exists in isolation or as an island: The outcomes of a multidisciplinary, global, and context-specific COVID-19 consortium
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Diana Hornby, Janice Limson, Chun-Yu Lin, Andrew Abbott, Daniel Urbine, Venkat Narayan Chekuri, Sharli Anne Paphitis, Hala Mohamed Moussa, Jonathan J. Cho, Reuben Ramphal, Anthony Byrne, Daisy Lekharu, Sunitha C. Srinivas, Lennox K Archibald, Shivanjali Shankaran, Frederick S. Southwick, Gautam Kalyatanda, Anna Shifrin, Roman Tandlich, Pretesh Rohan Kiran, Shraddha Patnala, Maneesh Paul-Satyaseela, and Matthew K Edwards
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0301 basic medicine ,Coronavirus disease 2019 (COVID-19) ,Isolation (health care) ,SARS-CoV-2 ,Distancing ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,COVID-19 ,General Medicine ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Multidisciplinary approach ,030220 oncology & carcinogenesis ,Preparedness ,Development economics ,Pandemic ,Context specific ,Humans ,Business ,Pandemics - Abstract
A pandemic, by definition, involves the whole world being impacted by a common threat and calls for a united response. A highly virulent pathogen, the novel coronavirus (SARS-CoV-2) has affected every facet of modern life. The virus has revealed the world’s underlying inherent inequities, such as economic and food insecurity and availability of and access to a functional healthcare system, not to mention preparedness of nations to manage a coordinated pandemic response. For these reasons, Coronavirus disease (COVID-19) represents an unprecedented challenge to economies, healthcare systems, and nations alike. The closing of international and internal borders, physical distancing, and the resulting decrease in travel and trade have led countries to become insular geographically, socially, and economically. Somewhat ironically, this necessitates an increased need for greater collaboration between countries and other stakeholders to control the transmission of SARS-CoV-2 and better manage the global crisis upon us, so as to mitigate the long-term sequelae of this pandemic.
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- 2020
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6. 1257. Re-Evaluation of Cefepime or Piperacillin-Tazobactam to Decrease Use of Carbapenems in ESBL-Producing Enterobacterales Urinary Tract Infections (REDUCE-UTI)
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Alexander C Branton, Catherine H Vu, Venugopalan Veena, Barbara A Santevecchi, Reuben Ramphal, Kartikeya Cherabuddi, Tanvi Manohar, David Rodriguez, Andrea Tello, and Kathryn DeSear
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AcademicSubjects/MED00290 ,Infectious Diseases ,Oncology ,Poster Abstracts - Abstract
Background Carbapenems (CBP) are considered first-line for infections caused by extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E). However, recent literature suggests that cefepime (FEP) and piperacillin-tazobactam (TZP) may produce similar outcomes vs. CBPs for the treatment of ESBL-E urinary tract infections (UTIs). The goal of this study was to determine if non-carbapenem (NCBP) therapy with FEP or TZP is as effective as CBPs for the treatment of ESBL-E UTIs. Methods This was a retrospective observational study of patients admitted to the hospital from January 1st, 2016 to June 30th, 2020 with a urine culture positive for ESBL-E. Patients were included if they received a study antibiotic (meropenem, ertapenem, TZP, or FEP). Patients were excluded if they had any of the following: absence of pyuria, prior receipt of study antibiotic, CBP-resistant organism isolated in urine culture, polymicrobial urine culture, end-stage renal disease, or concomitant gram-negative infection. The primary outcome was clinical cure defined as complete resolution of signs and symptoms of infection. Secondary outcomes included in-hospital mortality, recurrence within 30 days, and resistance within 30 days. Results A total of 133 patients were included based on definitive therapy received; 69 (52%) received CBP and 64 (48%) received NCBP therapy. Of the total patient population, 17 (13%) were admitted to the intensive care unit, 84 (63%) had a complicated UTI, and 64 (48%) had pyelonephritis. Baseline characteristics were similar between the two groups. There was no difference in clinical cure between the CBP and NCBP therapy groups (96% vs. 97%, p = 1.0). Additionally, no differences in secondary outcomes were observed. Subgroup analyses were performed in patients with specific pathogens, uncontrolled genitourinary source, complicated UTI, and pyelonephritis. These analyses did not reveal any differences in primary or secondary outcomes between the two groups. Conclusion FEP and TZP may be reasonable CBP-sparing alternatives for the treatment of ESBL-E UTIs as clinical and microbiological outcomes were similar with these NCBP agents vs. CBPs in this study population. Disclosures Venugopalan Veena, PharmD, Melinta (Other Financial or Material Support, Received a stipend for participation in a drug registry)Merck (Other Financial or Material Support, Received a stipend for participation in a drug registry)
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- 2021
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7. Evidence of early increased sialylation of airway mucins and defective mucociliary clearance in CFTR-deficient piglets
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Catherine Robbe-Masselot, Mustapha Si-Tahar, Ignacio S. Caballero, Renaud Léonard, Nicolas Pons, Andrea Bähr, Pascal Barbry, Antoine Guillon, Agnès Paquet, Claire Chevaleyre, Nikolai Klymiuk, Isabelle Fleurot, Mustapha Berri, Bélinda Ringot-Destrez, Kevin Lebrigand, Carole Baron, Céline Barc, Reuben Ramphal, Isabelle Lantier, Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Institut de pharmacologie moléculaire et cellulaire (IPMC), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA), Infectiologie et Santé Publique (UMR ISP), Université de Tours (UT)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre d’Etude des Pathologies Respiratoires (CEPR), UMR 1100 (CEPR), Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Service de Médecine Intensive et Réanimation [Tours], Plateforme d'Infectiologie Expérimentale (PFIE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ludwig Maximilian University [Munich] (LMU), Association Vaincre la Mucoviscidose (Grant No. RF20150 501357), Association Grégory Lemarchal (Grant No. RIF20160501690), Fondation pour la Recherche Médicale (DEQ20180339158), ANR-11-LABX-0028,SIGNALIFE,Réseau d'Innovation sur les Voies de Signalisation en Sciences de la Vie(2011), ANR-10-INBS-0009,France-Génomique,Organisation et montée en puissance d'une Infrastructure Nationale de Génomique(2010), Chanteloup, Nathalie Katy, Centres d'excellences - Réseau d'Innovation sur les Voies de Signalisation en Sciences de la Vie - - SIGNALIFE2011 - ANR-11-LABX-0028 - LABX - VALID, Organisation et montée en puissance d'une Infrastructure Nationale de Génomique - - France-Génomique2010 - ANR-10-INBS-0009 - INBS - VALID, Université de Tours (UT), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Centre Hospitalier Régional Universitaire de Tours (CHRU Tours), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Tours (UT), Unité de Glycobiologie Structurale et Fonctionnelle (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Gene Center and Center for Innovation Medical Models (CiMM), Ludwig Maximilians University of Munich, Université de Tours-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM), and Centre Hospitalier Régional Universitaire de Tours (CHRU TOURS)
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0301 basic medicine ,Pulmonary and Respiratory Medicine ,Male ,Glycosylation ,Mucociliary clearance ,Swine ,[SDV]Life Sciences [q-bio] ,Sus scrofa ,Cystic Fibrosis Transmembrane Conductance Regulator ,Context (language use) ,Inflammation ,Respiratory Mucosa ,Mucociliary transport ,medicine.disease_cause ,Cystic fibrosis ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Animals ,CFTR ,ComputingMilieux_MISCELLANEOUS ,Lung ,medicine.diagnostic_test ,business.industry ,Pseudomonas aeruginosa ,Mucin ,Mucins ,respiratory system ,medicine.disease ,3. Good health ,respiratory tract diseases ,Trachea ,[SDV] Life Sciences [q-bio] ,Mucin glycosylation ,030104 developmental biology ,medicine.anatomical_structure ,Bronchoalveolar lavage ,030228 respiratory system ,Animals, Newborn ,Mucociliary Clearance ,Pediatrics, Perinatology and Child Health ,Female ,medicine.symptom ,MESH: CFTR ,business - Abstract
International audience; Background: Bacterial colonization in cystic fibrosis (CF) lungs has been directly associated to the loss of CFTR function, and/or secondarily linked to repetitive cycles of chronic inflammation/infection. We hypothesized that altered molecular properties of mucins could contribute to this process.Methods: Newborn CFTR+/+ and CFTR-/- were sacrificed before and 6 h after inoculation with luminescent Pseudomonas aeruginosa into the tracheal carina. Tracheal mucosa and the bronchoalveolar lavage (BAL) fluid were collected to determine the level of mucin O-glycosylation, bacteria binding to mucins and the airways transcriptome. Disturbances in mucociliary transport were determined by ex-vivo imaging of luminescent Pseudomonas aeruginosa.Results: We provide evidence of an increased sialylation of CF airway mucins and impaired mucociliary transport that occur before the onset of inflammation. Hypersialylation of mucins was reproduced on tracheal explants from non CF animals treated with GlyH101, an inhibitor of CFTR channel activity, indicating a causal relationship between the absence of CFTR expression and the sialylation of mucins. This increased sialylation was correlated to an increased adherence of P. aeruginosa to mucins. In vivo infection of newborn CF piglets by live luminescent P. aeruginosa demonstrated an impairment of mucociliary transport of this bacterium, with no evidence of pre-existing inflammation.Conclusions: Our results document for the first time in a well-defined CF animal model modifications that affect the O-glycan chains of mucins. These alterations precede infection and inflammation of airway tissues, and provide a favorable context for microbial development in CF lung that hallmarks this disease.
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- 2020
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