Search results for "Bacteria"
showing 10 items of 4919 documents
The Efflux Pump MexXY/OprM Contributes to the Tolerance and Acquired Resistance of Pseudomonas aeruginosa to Colistin
2020
The intrinsic resistance of Pseudomonas aeruginosa to polymyxins in part relies on the addition of 4-amino-4-deoxy-l-arabinose (Ara4N) molecules to the lipid A of lipopolysaccharide (LPS), through induction of operon arnBCADTEF-ugd (arn) expression. As demonstrated previously, at least three two-component regulatory systems (PmrAB, ParRS, and CprRS) are able to upregulate this operon when bacteria are exposed to colistin. In the present study, gene deletion experiments with the bioluminescent strain PAO1::lux showed that ParRS is a key element in the tolerance of P. aeruginosa to this last-resort antibiotic (i.e., resistance to early drug killing). Other loci of the ParR regulon, such as th…
Gut Microbiota Cannot Compensate the Impact of (quasi) Aposymbiosis in Blattella germanica
2021
Simple Summary The German cockroach Blattella germanica is a good model to study complex symbiotic relationships because the following two symbiotic systems coexist in a single individual: the endosymbiont Blattabacterium (living inside specialized cells called bacteriocytes) and the gut microbiota. Although the role of the endosymbiont has been fully elucidated, the function of the gut microbiota remains unclear. The study of the gut microbiota will benefit from the availability of insects deprived of Blattabacterium. Our goal is to determine the effect of the removal (or, at least, the reduction) of the endosymbiont population on the cockroach’s fitness, in a normal gut microbiota communi…
Prediction of quinolone activity against Mycobacterium avium by molecular topology and virtual computational screening.
2000
ABSTRACT We conducted a quantitative structure-activity relationship study using a database of 158 quinolones previously tested against Mycobacterium avium-M. intracellulare complex in order to develop a model capable of predicting the activity of new quinolones against the M. avium-M. intracellulare complex in vitro. Topological indices were used as structural descriptors and were related to anti- M. avium-M. intracellulare complex activity by using the linear discriminant analysis (LDA) statistical technique. The discriminant equation thus obtained correctly classified 137 of the 158 quinolones, including 37 of a test group of 44 randomly chosen compounds. This model was then applied to 2…
Anti- Toxoplasma Activities of 24 Quinolones and Fluoroquinolones In Vitro: Prediction of Activity by Molecular Topology and Virtual Computational Te…
2000
ABSTRACT The apicoplast, a plastid-like organelle of Toxoplasma gondii , is thought to be a unique drug target for quinolones. In this study, we assessed the in vitro activity of quinolones against T. gondii and developed new quantitative structure-activity relationship models able to predict this activity. The anti- Toxoplasma activities of 24 quinolones were examined by means of linear discriminant analysis (LDA) using topological indices as structural descriptors. In parallel, in vitro 50% inhibitory concentrations (IC 50 s) were determined in tissue culture. A multilinear regression (MLR) analysis was then performed to establish a model capable of classifying quinolones by in vitro acti…
Botanicals and phytochemicals from the bark of Hypericum roeperianum (Hypericaceae) had strong antibacterial activity and showed synergistic effects …
2021
Abstract Ethnopharmacological relevance Infections due to multidrug-resistant (MDR) bacteria constitute a real problem in the public health worldwide. Hypericum roeperianum Schimp. ex A. Rich (Hypericaceae) is used traditionally for treatment of various ailments such as abdominal pains, constipation, diarrhea, indigestion, nausea, and bacterial diseases. Aim of the study This study was aimed at investigating the antibacterial and antibiotic-modifying activity of the crude methanol extracts (HRB), ethyl-acetate soluble fraction (HRBa), residual material (HRBb), and 11 compounds from the bark of Hypericum roeperianum against multi-drug resistant (MDR) bacteria expressing active efflux pumps. …
Cardiac safety and potential efficacy: two reasons for considering minocycline in place of azithromycin in COVID-19 management
2020
Currently, there is no effective therapy for COVID-19, and several approaches are under investigation. Nevertheless, some drugs are used off-label despite the absence of clear data on their effectiveness. Among these, hydroxychloroquine suppresses SARS-CoV-2 replication in vitro,1 and clinical trials are ongoing to evaluate its use as an anti-COVID-19 agent. To date, the FDA and EMA allow its use only in hospitalized patients with severe COVID-19 or in those at high risk, in cases where other trials are not feasible. According to a small non-randomized study, hydroxychloroquine’s efficacy might be enhanced by azithromycin, as the combination of these two drugs appeared to accelerate viral c…
Lemierre syndrome: Current evidence and rationale of the Bacteria-Associated Thrombosis, Thrombophlebitis and LEmierre syndrome (BATTLE) registry.
2020
Abstract Lemierre syndrome is a rare but potentially fatal condition characterized by septic thrombophlebitis of the head and neck district, preferentially affecting adolescents and young adults and manifesting as a complication of a local bacterial infection – typically, a pharyngotonsillitis or an abscess. It is historically associated with the Gram-negative anaerobic rod Fusobacterium necrophorum and with thrombophlebitis of the internal jugular vein. However, its definition has never been firmly established, and its spectrum within the continuum of bacteria-associated thrombophlebitis may be larger than what presumed so far. Recent evidence suggests that its prognosis remains serious ev…
Helicobacter pylori first-line and rescue treatments in patients allergic to penicillin: Experience from the European Registry on H pylori management…
2020
Background Experience in Helicobacter pylori eradication treatment of patients allergic to penicillin is very scarce. A triple combination with a PPI, clarithromycin (C), and metronidazole (M) is often prescribed as the first option, although more recently the use of a quadruple therapy with PPI, bismuth (B), tetracycline (T), and M has been recommended. Aim To evaluate the efficacy and safety of first-line and rescue treatments in patients allergic to penicillin in the "European Registry of H pylori management" (Hp-EuReg). Methods A systematic prospective registry of the clinical practice of European gastroenterologists (27 countries, 300 investigators) on the management of H pylori infect…
Current Concepts in Therapy of Chronic Rhinosinusitis and Nasal Polyposis
2004
The exact pathophysiological mechanisms leading to chronic rhinosinusitis (CRS) still to a large extent remain obscure. However, recently there has been some progress in elucidating the etiology of nasal polyposis, especially regarding tissue eosinophilia as well as the role of aspirin intolerance and eicosanoid mediators. Endonasal sinus surgery has evolved to be the treatment of choice in CRS and nasal polyposis in all cases where conservative treatment has failed or resulted in only a partial or temporary relief. Today, state of the art in surgical technique includes the ability to combine microscopic and endoscopic procedures. Regardless of technical advances like powered instrumentatio…
Economic evaluation of caspofungin vs liposomal amphotericin B for empirical therapy of suspected systemic fungal infection in the German hospital se…
2007
As antifungal agents are frequently used in hematology and oncology, economic data on the empirical therapy of suspected systemic fungal infection are pivotal. Data were analyzed according to: (1) the rate of nephrotoxicity related to treatment with caspofungin in comparison to liposomal amphotericin B (L-AmB) from a randomized clinical trial, (2) the effect of nephrotoxicity on length of hospital stay from a European observational study, and (3) an example of total bottom-up cost in a department of hematology in Germany. All estimates include 95% confidence intervals (CI) using two-stage Monte Carlo simulation on binominal and Gaussian random variables from separate studies with comparable…