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Ronald J Quinn - One of the best experts on this subject based on the ideXlab platform.
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production of induced secondary metabolites by a co culture of sponge associated actinomycetes actinokineospora sp eg49 and Nocardiopsis sp rv163
Marine Drugs, 2014Co-Authors: Yousef Dashti, Tanja Grkovic, Usama Ramadan Abdelmohsen, Ute Hentschel, Ronald J QuinnAbstract:Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by 1H NMR. Ten known compounds, including angucycline, diketopiperazine and β-carboline derivatives 1–10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a,6,11a,12-tetrahydro-5a,11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes.
Reiner M. Kroppenstedt - One of the best experts on this subject based on the ideXlab platform.
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isolation of toxigenic Nocardiopsis strains from indoor environments and description of two new Nocardiopsis species n exhalans sp nov and n umidischolae sp nov
Applied and Environmental Microbiology, 2001Co-Authors: J Peltola, Reiner M. Kroppenstedt, Maria A Andersson, Peter Kampfer, Georg Auling, Hansjurgen Busse, Mirja Salkinojasalonen, Frederick A RaineyAbstract:Nocardiopsis strains were isolated from water-damaged indoor environments. Two strains (N. alba subsp. alba 704a and a strain representing a novel species, ES10.1) as well as strains of N. prasina, N. lucentensis, and N. tropica produced methanol-soluble toxins that paralyzed the motility of boar spermatozoa at <30 microg of crude extract (dry weight) x ml(-1). N. prasina, N. lucentensis, N. tropica, and strain ES10.1 caused cessation of motility by dissipating the mitochondrial membrane potential, Deltapsi, of the boar spermatozoa. Indoor strain 704a produced a substance that destroyed cell membrane barrier function and depleted the sperm cells of ATP. Indoor strain 64/93 was antagonistic towards Corynebacterium renale. Two indoor Nocardiopsis strains were xerotolerant, and all five utilized a wide range of substrates. This combined with the production of toxic substances suggests good survival and potential hazard to human health in water-damaged indoor environments. Two new species, Nocardiopsis exhalans sp. nov. (ES10.1T) and Nocardiopsis umidischolae sp. nov. (66/93T), are proposed based on morphology, chemotaxonomic and physiological characters, phylogenetic analysis, and DNA-DNA reassociations.
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the genus Nocardiopsis represents a phylogenetically coherent taxon and a distinct actinomycete lineage proposal of nocardiopsaceae fam nov
International Journal of Systematic and Evolutionary Microbiology, 1996Co-Authors: Fred A. Rainey, Reiner M. Kroppenstedt, Naomi Wardrainey, Erko StackebrandtAbstract:The genus Nocardiopsis was shown to be phylogenetically coherent and to represent a distinct lineage within the radiation of the order Actinomycetales. The closest relatives of the genus Nocardiopsis are members of the genera Actinomadura, Thermomonospora, Streptosporangium, and Microtetraspora. The intrageneric structure of the genus Nocardiopsis is shown to consist of a highly related species group containing Nocardiopsis dassonvillei, Nocardiopsis alborubida, and Nocardiopsis antarctica and a second group of less highly related species comprising Nocardiopsis alba subsp. alba, Nocardiopsis alba subsp. prasina, and Nocardiopsis listeri. Nocardiopsis lucentensis occupies a position intermediate between the two species groups. The results of a 16S ribosomal DNA sequence analysis are generally consistent with the available chemotaxonomic, phenotypic, and DNA-DNA hybridization data. The phylogenetic position and the morpho- and chemotaxonomic properties of Nocardiopsis species support the creation of a family for the genus Nocardiopsis, Nocardiopsaceae fam. nov.
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The genus Nocardiopsis represents a phylogenetically coherent taxon and a distinct actinomycete lineage: proposal of Nocardiopsaceae fam. nov
1996Co-Authors: Fred A. Rainey, Naomi Ward-rainey, Reiner M. KroppenstedtAbstract:The genus Nocardiopsis was shown to be phylogenetically coherent and to represent a distinct lineage within the radiation of the order Actinomycetales. The closest relatives of the genus Nocardiopsis are members of the genera Actinomadura, Thermomonospora, Streptosporangium, and Microtetraspora. The intrageneric structure of the genus Nucardiupsis is shown to consist of a highly related species group containing Nucardiupsis dassonvillei, Nocardiopsis alborubida, and Nocardiopsis antarctica and a second group of less highly related species comprising Nocardiopsis alba subs p. alba, Nocardiopsis alba subs p. prasina, and Nocardiopsis listeri. Nocardiopsis lucentensis occupies a position intermediate between the two species groups. The results of a 16s ribosomal DNA sequence analysis are generally consistent with the available chemotaxonomic, phenotypic, and DNA-DNA hybridization data. The phylogenetic position and the morpho- and chemotaxonomic properties of Nocardiopsis species support the creation of a family for the genus Nocardiopsis, Nocardiopsaceae fam. nov. Meyer described the genus Nocardiopsis for the species Actinomadura dassonvillei in 1976 on the basis of the morphological characteristics and cell wall type of this organism (21). The genus Nocardiopsis currently comprises seven validly described species, Nocardiopsis alborubidus, Nocardiopsis albus, Nocardiopsis antarcticus, Nocardiopsis dassonvillei, Nocardiopsis halophila
Erko Stackebrandt - One of the best experts on this subject based on the ideXlab platform.
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the genus Nocardiopsis represents a phylogenetically coherent taxon and a distinct actinomycete lineage proposal of nocardiopsaceae fam nov
International Journal of Systematic and Evolutionary Microbiology, 1996Co-Authors: Fred A. Rainey, Reiner M. Kroppenstedt, Naomi Wardrainey, Erko StackebrandtAbstract:The genus Nocardiopsis was shown to be phylogenetically coherent and to represent a distinct lineage within the radiation of the order Actinomycetales. The closest relatives of the genus Nocardiopsis are members of the genera Actinomadura, Thermomonospora, Streptosporangium, and Microtetraspora. The intrageneric structure of the genus Nocardiopsis is shown to consist of a highly related species group containing Nocardiopsis dassonvillei, Nocardiopsis alborubida, and Nocardiopsis antarctica and a second group of less highly related species comprising Nocardiopsis alba subsp. alba, Nocardiopsis alba subsp. prasina, and Nocardiopsis listeri. Nocardiopsis lucentensis occupies a position intermediate between the two species groups. The results of a 16S ribosomal DNA sequence analysis are generally consistent with the available chemotaxonomic, phenotypic, and DNA-DNA hybridization data. The phylogenetic position and the morpho- and chemotaxonomic properties of Nocardiopsis species support the creation of a family for the genus Nocardiopsis, Nocardiopsaceae fam. nov.
Claire Rouzaud - One of the best experts on this subject based on the ideXlab platform.
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clinical assessment of a nocardia pcr based assay for diagnosis of nocardiosis
Journal of Clinical Microbiology, 2018Co-Authors: Claire Rouzaud, Veronica Rodrigueznava, Emilie Catherinot, F Mechai, Emmanuelle Bergeron, Eric Farfour, Anne Scemla, S Poiree, C Delavaud, Daniel MathieuAbstract:The diagnosis of nocardiosis, a severe opportunistic infection, is challenging. We assessed the specificity and sensitivity of a 16S rRNA Nocardia PCR-based assay performed on clinical samples. In this multicenter study (January 2014 to April 2015), patients who were admitted to three hospitals and had an underlying condition favoring nocardiosis, clinical and radiological signs consistent with nocardiosis, and a Nocardia PCR assay result for a clinical sample were included. Patients were classified as negative control (NC) (negative Nocardia culture results and proven alternative diagnosis or improvement at 6 months without anti-Nocardia treatment), positive control (PC) (positive Nocardia culture results), or probable nocardiosis (positive Nocardia PCR results, negative Nocardia culture results, and no alternative diagnosis). Sixty-eight patients were included; 47 were classified as NC, 8 as PC, and 13 as probable nocardiosis. PCR results were negative for 35/47 NC patients (74%). For the 12 NC patients with positive PCR results, the PCR assay had been performed with respiratory samples. These NC patients had chronic bronchopulmonary disease more frequently than did the NC patients with negative PCR results (8/12 patients [67%] versus 11/35 patients [31%]; P = 0.044). PCR results were positive for 7/8 PC patients (88%). There were 13 cases of probable nocardiosis, diagnosed solely using the PCR results; 9 of those patients (69%) had lung involvement (consolidation or nodule). Nocardia PCR testing had a specificity of 74% and a sensitivity of 88% for the diagnosis of nocardiosis. Nocardia PCR testing may be helpful for the diagnosis of nocardiosis in immunocompromised patients but interpretation of PCR results from respiratory samples is difficult, because the PCR assay may also detect colonization.
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nocardia infections in solid organ and hematopoietic stem cell transplant recipients
Current Opinion in Infectious Diseases, 2017Co-Authors: Julien Coussement, David Lebeaux, Claire Rouzaud, Olivier LortholaryAbstract:Purpose of reviewNocardia spp. is a gram-positive bacteria that may cause infections in humans. Nocardiosis has been described since the early years of transplantation. This review aims to provide an overview of present knowledge regarding posttransplant nocardiosis, with a focus on recent findings.
David Lebeaux - One of the best experts on this subject based on the ideXlab platform.
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how do i manage nocardiosis
Clinical Microbiology and Infection, 2021Co-Authors: David Lebeaux, Ili Margalit, Ori Tishler, Elad Goldberg, Jihad Bishara, Dafna YahavAbstract:Abstract Background Nocardiosis is a rare infection that is often difficult to treat and may be life-threatening. There is no consensus on its management. Objectives Our aim was to provide the current evidence for the diagnosis and management of individuals with nocardiosis, and to propose a management approach for this uncommon infection. Sources We systematically searched the medical literature on nocardiosis for studies published between 2010 and 2020 and describing ten or more individuals. Content Nocardiosis, a primarily opportunistic infection which may occur in immunocompetent persons, most commonly involves the lungs and frequently disseminates to other sites including the central nervous system. The reference standard for Nocardia species identification is molecular biology, and the preferred method for antibiotic susceptibility testing (AST) is broth microdilution. Monotherapy seems appropriate for patients with primary skin nocardiosis or non-severe pulmonary disease; we reserve a multidrug regimen for more severe infections. Species identification and AST results are often missing at initiation of antibiotics. Trimethoprim-sulfamethoxazole is the preferred agent for initial therapy, because Nocardia is very often susceptible to this agent, and because it has been the keystone of nocardiosis treatment for years. Linezolid, to which Nocardia is almost always susceptible, may be an alternative. When combination therapy is required, the repertoire of companion drugs includes third-generation cephalosporins, amikacin and imipenem. Therapeutic modifications should take into account clinical response to initial therapy and AST results. Treatment duration of 6 months is appropriate for most situations, but longer durations are preferred for disseminated nocardiosis and shorter durations are reasonable in low-risk situations. Secondary prophylaxis may be considered in selected individuals with permanent immunosuppression. Implications We hereby provide the clinician with an easy-to-use algorithm for the management of individuals with nocardiosis. We also illuminate gaps in evidence and suggest future research directions.
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nocardia infections in solid organ and hematopoietic stem cell transplant recipients
Current Opinion in Infectious Diseases, 2017Co-Authors: Julien Coussement, David Lebeaux, Claire Rouzaud, Olivier LortholaryAbstract:Purpose of reviewNocardia spp. is a gram-positive bacteria that may cause infections in humans. Nocardiosis has been described since the early years of transplantation. This review aims to provide an overview of present knowledge regarding posttransplant nocardiosis, with a focus on recent findings.
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outcome and treatment of nocardiosis after solid organ transplantation new insights from a european study
Clinical Infectious Diseases, 2017Co-Authors: David Lebeaux, H Guillot, Romain Freund, S D Marbus, Benoit Douvry, Marie Matignon, Christian Van Delden, Eric Van Wijngaerden, Julien De GreefAbstract:Background Solid organ transplant (SOT) recipients are at risk of nocardiosis, a rare opportunistic bacterial infection, but prognosis and outcome of these patients are poorly defined. Our objectives were to identify factors associated with one-year mortality after nocardiosis and describe the outcome of patients receiving short-course antibiotics (≤120 days). Methods We analyzed data from a multicenter European case-control study that included 117 SOT recipients with nocardiosis diagnosed between 2000 and 2014. Factors associated with one-year all-cause mortality were identified using multivariable conditional logistic regression. Results One-year mortality was 10-fold higher in patients with nocardiosis (16.2%, 19/117) than in control transplant recipients (1.3%, 3/233, p<0.001). A history of tumor (odds ratio [OR] 1.4; 95% confidence interval [CI] 1.1-1.8), invasive fungal infection in the six months before nocardiosis (OR 1.3; 95%CI 1.1-1.5) and donor age (OR 1.0046; 95%CI 1.0007-1.0083) were independently associated with one-year mortality. Acute rejection in the year before nocardiosis was associated with improved survival (OR 0.85; 95%CI 0.73-0.98). Seventeen patients received short-course antibiotics (median duration 56 [24-120] days) with a one-year success rate (cured and surviving) of 88% and a 5.9% risk of relapse (median follow-up 49 [6-136] month). Conclusions One-year mortality was 10-fold higher in SOT patients with nocardiosis than in those without. Four factors, largely reflecting general medical condition rather than severity and/or management of nocardiosis, were independently associated with one-year mortality. Patients receiving short-course antibiotic treatment had good outcomes, suggesting this may be a strategy for further study.
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nocardia infection in solid organ transplant recipients a multicenter european case control study
Clinical Infectious Diseases, 2016Co-Authors: Julien Coussement, David Lebeaux, Christian Van Delden, H Guillot, Romain Freund, S D Marbus, Giovanna Melica, Eric Van Wijngaerden, Benoit Douvry, Steven Van LaeckeAbstract:Nocardiosis is a rare, life-threatening opportunistic infection, affecting 0.04% to 3.5% of patients after solid organ transplant (SOT). The aim of this study was to identify risk factors for Nocardia infection after SOT and to describe the presentation of nocardiosis in these patients.