126 research outputs found
Tsukamurella tyrosinosolvens - An unusual case report of bacteremic pneumonia after lung transplantation
<p>Abstract</p> <p>Background</p> <p>Lung transplant recipients have an increased risk for actinomycetales infection secondary to immunosuppressive regimen.</p> <p>Case presentation</p> <p>A case of pulmonary infection with bacteremia due to <it>Tsukamurella tyrosinosolvens </it>in a 54-year old man who underwent a double lung transplantation four years previously is presented.</p> <p>Conclusion</p> <p>The identification by conventional biochemical assays was unsuccessful and <it>hsp </it>gene sequencing was used to identify <it>Tsukamurella tyrosinosolvens</it>.</p
Variable-number tandem-repeat markers for typing Mycobacterium intracellulare strains isolated in humans
<p>Abstract</p> <p>Background</p> <p><it>Mycobacterium intracellulare</it>, a species of the <it>Mycobacterium avium complex</it>, may be the cause of severe lung, lymphatic node, skin and bone/joint infections, as well as bacteriemia. The goal of this work was to identify Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) markers and to study their variability in a collection of isolates of <it>M. intracellulare </it>collected in humans. We studied 61 isolates collected in humans between 2001 and 2008, as well as the reference strain, <it>M. intracellulare </it>ATCC 13950.</p> <p>Results</p> <p>We identified 45 MIRU-VNTR candidates, of which 17 corresponded to the MIRU-VNTR identified in the genome of <it>M. intracellulare </it>ATCC 13950. Among the 45 potential MIRU-VNTR, seven were selected for use in a MIRU-VNTR assay applied to our collection of isolates. Forty-four patterns were found by MIRU-VNTR typing and the discriminatory power of the assay was high with a Hunter-Gaston diversity index of 0.98. We do not have evidence of a particular distribution of MIRU-VNTR polymorphism according to clinical situation.</p> <p>Conclusions</p> <p>Our results suggest that MIRU-VNTR typing could be used for molecular epidemiological studies applied to <it>M. intracellulare</it>.</p
Comparative in vitro activity of meropenem, imipenem and piperacillin/tazobactam against 1071 clinical isolates using 2 different methods: a French multicentre study
Occurrence and Clinical Relevance of Mycobacterium chimaera sp. nov., Germany
Retrospective molecular genetic analysis of 166 Mycobacterium intracellulare isolates showed that 143 (86%) strains could be assigned to Mycobacterium chimaera sp. nov. Of 97 patients from whom M. chimaera sp. nov. was isolated, only 3.3% exhibited mycobacterial lung disease, whereas all M. intracellulare isolates caused severe pulmonary infections
Polyether-based ionic liquids from simple mixing of terminal diamines with organic acids to dicationic diammonium carboxylates
A new family of dicationic ionic liquids (DIL) have been synthesised by the mixing of either 4,7,10-trioxa-1,13-tridecanediamine or a low molecular weight JeffamineTM with organic acids such as formic acid, acetic acid, propionic acid, butyric acid, maleic acid, valeric, hexanoic acid, heptanoic acid, benzoic acid and octanoic acid. The structure of the DILs was determined by 1H and 13C NMR and LC-MS. All ILs were soluble in protic polar solvents, especially DMSO, and mostly insoluble in aprotic or non-polar solvents. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to assess the thermal properties of the DILs. Temperature-dependant viscosity and ionic conductivity values were measured at temperatures ranging from 25 to 45 °C. The electrochemical stability of the library of ILs was determined using cyclic voltammetry (CV) with a working electrochemical window of 1.2 V (−0.6 V to 0.6 V)
Epidemiology of Nontuberculous Mycobacteria in Patients without HIV Infection, New York City
The incidence appears to be increasing
Nontuberculous Mycobacteria–associated Lung Disease in Hospitalized Persons, United States, 1998–2005
This bacterium is an underappreciated cause of lung disease and infection rates appear to be increasing
Time to positivity in blood cultures of adults with Streptococcus pneumoniae bacteremia
BACKGROUND: previous studies have established that bacterial blood concentration is related with clinical outcome. Time to positivity of blood cultures (TTP) has relationship with bacterial blood concentration and could be related with prognosis. As there is scarce information about the usefulness of TTP, we study the relationship of TTP with clinical parameters in patients with Streptococcus pneumoniae bacteremia. METHODS: TTP of all cases of Streptococcus pneumoniae bacteremia, detected between January 1995 and December 2004 using the BacT/Alert automated blood culture system in a teaching community hospital was analyzed. When multiple cultures were positive only the shortest TTP was selected for the analysis. RESULTS: in the study period 105 patients with Streptococcus pneumoniae bacteremia were detected. Median TTP was 14.1 hours (range 1.2 h to 127 h). Immunosuppressed patients (n = 5), patients with confusion (n = 19), severe sepsis or shock at the time of blood culture extraction (n = 12), those with a diagnosis of meningitis (n = 7) and those admitted to the ICU (n = 14) had lower TTP. Patients with TTP in the first quartile were more frequently hospitalized, admitted to the ICU, had meningitis, a non-pneumonic origin of the bacteremia, and a higher number of positive blood cultures than patients with TTP in the fourth quartile. None of the patients with TTP in the 90(th )decile had any of these factors associated with shorter TTP, and eight out of ten patients with TTP in the 10(th )decile had at least one of these factors. The number of positive blood cultures had an inverse correlation with TTP, suggesting a relationship of TTP with bacterial blood concentration. CONCLUSION: Our data support the relationship of TTP with several clinical parameters in patients with Streptococcus pneumoniae bacteremia, and its potential usefulness as a surrogate marker of outcome
Comparative in vitro activity of Meropenem, Imipenem and Piperacillin/tazobactam against 1071 clinical isolates using 2 different methods: a French multicentre study
<p>Abstract</p> <p>Background</p> <p>Meropenem is a carbapenem that has an excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The major objective of the present study was to assess the <it>in vitro </it>activity of meropenem compared to imipenem and piperacillin/tazobactam, against 1071 non-repetitive isolates collected from patients with bacteremia (55%), pneumonia (29%), peritonitis (12%) and wound infections (3%), in 15 French hospitals in 2006. The secondary aim of the study was to compare the results of routinely testings and those obtained by a referent laboratory.</p> <p>Method</p> <p>Susceptibility testing and Minimum Inhibitory Concentrations (MICs) of meropenem, imipenem and piperacillin/tazobactam were determined locally by Etest method. Susceptibility to meropenem was confirmed at a central laboratory by disc diffusion method and MICs determined by agar dilution method for meropenem, imipenem and piperacillin/tazobactam.</p> <p>Results</p> <p>Cumulative susceptibility rates against <it>Escherichia coli </it>were, meropenem and imipenem: 100% and piperacillin/tazobactam: 90%. Against other <it>Enterobacteriaceae</it>, the rates were meropenem: 99%, imipenem: 98% and piperacillin/tazobactam: 90%. All <it>Staphylococci</it>, <it>Streptococci </it>and anaerobes were susceptible to the three antibiotics. Against non fermeters, meropenem was active on 84-94% of the strains, imipenem on 84-98% of the strains and piperacillin/tazobactam on 90-100% of the strains.</p> <p>Conclusions</p> <p>Compared to imipenem, meropenem displays lower MICs against <it>Enterobacteriaceae</it>, <it>Escherichia coli </it>and <it>Pseudomonas aeruginosa</it>. Except for non fermenters, MICs90 of carbapenems were <4 mg/L. Piperacillin/tazobactam was less active against <it>Enterobacteriaceae </it>and <it>Acinetobacter </it>but not <it>P. aeruginosa</it>. Some discrepancies were noted between MICs determined by Etest accross centres and MICs determined by agar dilution method at the central laboratory. Discrepancies were more common for imipenem testing and more frequently related to a few centres. Overall MICs determined by Etest were in general higher (0.5 log to 1 log fold) than MICs by agar dilution.</p
Metal-catalyzed 1,3-dipolar cycloaddition reactions of nitrile oxides
In the present review advances in the metal-catalyzed 1,3-dipolar cycloaddition reactions of nitrile oxides, mainly in the last decade, will be presented and discussed. An overview on the structure, preparation, dimerization and related reactions as well as the relevant aspects in the cycloaddition chemistry of nitrile oxides (including mechanistic aspects) have also been considered
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