Search results for "Pseudomonas aeruginosa"
showing 8 items of 158 documents
Cinnamaldehyde Induces Expression of Efflux Pumps and Multidrug Resistance in Pseudomonas aeruginosa
2019
Essential oils or their components are increasingly used to fight bacterial infections. Cinnamaldehyde (CNA), the main constituent of cinnamon bark oil, has demonstrated interesting properties in vitro against various pathogens, including Pseudomonas aeruginosa. In the present study, we investigated the mechanisms and possible therapeutic consequences of P. aeruginosa adaptation to CNA. Exposure of P. aeruginosa PA14 to subinhibitory concentrations of CNA caused a strong albeit transient increase in the expression of operons that encode the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY/OprM. This multipump activation enhanced from 2- to 8-fold the resistance (MIC) of PA14 to …
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…
Spanish Consensus on the Prevention and Treatment of Pseudomonas aeruginosa Bronchial Infections in Cystic Fibrosis Patients
2014
Pseudomonas aeruginosa is the main pathogen in bronchopulmonary infections in cystic fibrosis (CF) patients. It can only be eradicated at early infection stages while reduction of its bacterial load is the therapeutic goal during chronic infection or exacerbations. Neonatal screening and pharmacokinetic/pharmacodynamic knowledge has modified the management of CF-patients. A culture based microbiological follow-up should be performed in patients with no infection with P. aeruginosa. At initial infection, inhaled colistin (0,5-2 MU/tid), tobramycin (300 mg/bid) or aztreonam (75 mg/tid) with or without oral ciprofloxacin (15-20 mg/kg/bid, 2-3 weeks) are recommended. In chronic infections, trea…
A case report of double etiology of ecthyma gangrenosum
2019
Rationale Ecthyma gangrenosum is a cutaneous infection, most commonly occurring during sepsis evolution with Pseudomonas aeruginosa on an immunocompromised background. There have been rare case reports in previously healthy children and rarer are the cases with double etiology. Patient concerns We present the case of a female Caucasian patient, aged 1 year and 8 months, who developed severe sepsis during flu evolution with predominant respiratory and cerebral manifestations. On admission, at skin level, there was noticed a necrotic coccygeal ulceration (with rapid increasing dimensions 0.5/0.5 cm in 24 hours), and with the transformation from a dry necrosis in a sphacelus at the periphery a…
Community-onset Pseudomonas aeruginosa urinary sepsis in elderly people: Predictive factors, adequacy of empirical therapy and outcomes.
2019
Purpose To know the predictive factors for Pseudomonas aeruginosa (PA) urinary sepsis in hospitalised elderly patients coming from community, the adequacy of empirical antibiotic therapy and its outcomes. Methods Retrospective case-control study conducted between 2007 and 2017. Patients aged 65 years or older with PA urinary sepsis were included as cases. Three age-matched controls, with urinary sepsis caused by other microorganisms, were selected for each case. Predictors for PA urinary sepsis were determined by logistic regression analysis. Adequacy of empirical antibiotic therapy and outcomes were compared between both groups. Results A total of 332 patients, from which 83 were cases, we…
Analysis of the therapeutical properties of a phage against Staphylococcus aureus pig isolates, and phage isolation against Pseudomonas aeruginosa fr…
2017
Antibioottiresistenttiys on kasvava ongelma, jonka selättämiseksi tarvitaan uusia keinoja. Prekliinisten tutkimustulosten perusteella bakteereja infektoivien virusten eli faagien on havaittu olevan hyvä vaihtoehto antibiooteille. Sairaalanäytteestä löydettyä metisilliinille resistenttiä Staphylococcus aureus (MRSA) -kantaa vastaan eristetty bakteriofagi karakterisoitiin sekvensoimalla ja läpäisyelektronimikroskoopilla, jotta sen mahdollista terapeuttista käyttöä voitaisiin selvittää. Faagilla havaittiin olevan keskikokoinen 43,098 bp:n pituinen genomi ja faagin morfologian perusteella se lukeutuu Siphoviridae-heimoon kuuluviin hännällisiin faageihin. Faagi puhdistettiin anioninvaihtokromato…
Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation
2020
Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 a…