132 research outputs found
Management of carbapenem resistant Enterobacteriaceae infections
No full textCarbapenem resistance is defined as in vitro nonsusceptibility to any carbapenem and/or documented production of a carbapenemase. This feature has rapidly spread worldwide among clinical isolates of Enterobacteriaceae, mostly Klebsiella spp, and is associated with diverse molecular mechanisms. Carbapenem resistance is often associated with resistance to all traditional beta-lactams and other classes of antibiotics, denoting a typical example of extensively drug-resistant phenotype
Prevention and control of intensive care unit-acquired carbapenem-resistant Klebsiella pneumoniae: need for a multimodal approach
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Shynthesis, purification and conformational studies on Enkephalin derivatives containing gamma-amino-n-butyric-acid.
No full textConformation of GABA-5-enkephalinamide in water solution: carbon-13 and proton NMR study.
No full text13C and 1H magnetic resonances of g-aminobutyric acid-5 enkephalinamide [84244-52-0] were assigned in water by selective decoupling, spectral analyses, pD titrns., and literature data. The anal. of chem. shifts, coupling consts., and rotamer populations around c1 suggested a high pH-induced conformational transition at the N-terminus of the peptide corresponding to some rearrangement of tyrosine-1, glycine-2, and glycine-3 residues. Phenylalanine-4 and GABA-5 were not affected by this conformational transition. The conformational nature of both cationic and neutral forms seemed to exclude the presence of intramol. bends and favored an extended form. This conclusion was supported by the temp. coeffs. of the amino acid a-carbons and by theor. conformational calcns
Emergence of colistin resistance without loss of fitness and virulence after prolonged colistin administration in a patient with extensively drug-resistant Acinetobacter baumannii
No full textThe spread of extensively drug-resistant (XDR) gram-negative bacteria has boosted colistin use, with a resultant selection of colistin-resistant, often pandrug-resistant strains. Whether acquisition of further resistance mechanisms translates into a reduced virulence is the subject of active research. In this report, we describe clinical features of an immunocompromised patient who developed infection due to colistin-resistant Acinetobacter baumannii while on long-term colistin therapy. We analyzed phenotypic and genotypic characteristics, molecular mechanisms of colistin resistance, and in vitro and in vivo fitness of sequential colistin-sensitive and colistin-resistant strains isolated from the patient. Both colistin-sensitive and colistin-resistant strains were XDR and showed identical ST78 genotype. At variance with prior reports on colistin-resistant strains of A. baumannii, resistance to colistin due to P233S mutation in PmrB sensor kinase did not associate with any measurable reduction in strain fitness, growth characteristics, and virulence
Clinical efficacy and safety of cefiderocol for resistant gram-negative infections: a real-life, single center experience
No full textUnlabelled: : Cefiderocol is a 'siderophore' cephalosporin active against Gram-negative bacteria, including carbapenem-resistant strains. Data on the use of cefiderocol in real life are limited. We evaluated the efficacy and safety of cefiderocol in the context of our hospital clinical practice. Methods: This was a single center, observational, retrospective clinical study. We collected data of all patients who received cefiderocol therapy in our Hospital, with a focus on clinical outcomes and adverse events. Results: The study cohort included 28 patients, with a median age of 73 years [25-83] and a high burden of comorbidities. Up to 45 gram-negative isolates were grown from the study patients, the most common pathogen being Acinetobacter baumannii (31.1%). Cefiderocol was mostly prescribed for pneumonia (37.8% of cases), bloodstream (24.4%), urinary tract (22.2%), and intra-abdominal infections (20%), and largely as salvage therapy (92.8%). 14 (77.8%) of the 18 patients for whom follow up cultures were available achieved eradication of the causative microorganism. Therapeutic success (improvement/resolution of the infection) occurred in 64.28% at 7 days and 50% at 14 days from treatment start. Treatment failed in 9 cases (32.1%). No effects on kidney, liver or bone marrow function were observed. Conclusions: Cefiderocol showed a fair efficacy and excellent tolerability in highly comorbid patients with a range of multi-resistant infections. It may be an option for infections due to colistin-resistant pathogens, when other regimens fail or in cases at risk of kidney dysfunction
Nuclear magnetic resonance of protamines. A carbon-13 relaxation study of the three main fractions of clupeine.
No full textThe 3 main fractions of clupeine, the protamine extd. from herring sperm, were investigated by 13C NMR techniques. The dynamic behavior, examd. through the evaluation of the spin-lattice relaxation times (T1) of individual C resonances assigned to both backbone and side chains, reveals interesting features. The relaxation times of backbone a-C, interpreted on the basis of an axially sym. ellipsoid, point to the clupeine fractions as being essentially extended in aq. soln. These times remain const. along the polypeptide chain and are of the order of 0.16 s. Conversely, the side chains show different flexibilities in the presence of monophosphate counterions, thus demonstrating a diverging behavior which may be biol. relevant. In particular, the side-chain flexibilities of fraction YI decrease, whereas those of fractions Z and YII are either const. or increase. Comparison of these data with the viscosity measurements helps in explaining the viscosity obsd. in the presence of phosphate
Dalbavancin for infective endocarditis: a single centre experience
No full textInfective endocarditis (IE) is a life-threatening disease, mostly caused by gram-positive cocci, needing a 4-6 weeks antibiotic course. Dalbavancin is a lipoglycopeptide active on gram-positive microorganisms, with a unique pharmacokinetic profile. We describe our experience with dalbavancin to complete the intravenous antibiotic regimen for difficult-to-treat IE cases due to gram-positive bacteria. We treated 10 severely ill patients, each presenting several comorbidities. Seven patients were microbiologically cured from IE, but two patients experienced IE relapse due to the same microrganism. Short-term mortality after dalbavancin was nil, but late mortality (within 1 year of hospital discharge) was 60%. No death was related to dalbavancin therapy. Treatment was generally well tolerated. Dalbavancin may be an option to complete IE treatment in selected cases, once blood culture clearance and improvement of clinical conditions under standard therapy is reached, allowing shortening of hospitalization
Direct antiviral treatment of chronic hepatitis C in heart transplant recipients
No full textDirect-acting antiviral agents (DAAs) are a safe and effective treatment for chronic hepatitis C (CHC). This may be particularly valuable for patients with severe comorbidities or baseline conditions, including non-liver solid organ transplant. We report cases of two heart transplant recipients with CHC treated with DAAs (sofosbuvir and daclatasvir) achieving sustained virological response. Treatment was well tolerated and no relevant side effects were observed. The drug-drug interactions and graft function were carefully monitored
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