Scope: The aim of these guidelines is to provide recommendations for decolonizing regimens targeting multidrug-resistant Gram-negative bacteria (MDR-GNB) carriers in all settings.Methods: These... Show moreScope: The aim of these guidelines is to provide recommendations for decolonizing regimens targeting multidrug-resistant Gram-negative bacteria (MDR-GNB) carriers in all settings.Methods: These evidence-based guidelines were produced after a systematic review of published studies on decolonization interventions targeting the following MDR-GNB: third-generation cephalosporin-resistant Enterobacteriaceae (3GCephRE), carbapenem-resistant Enterobacteriaceae (CRE), aminoglycoside-resistant Enterobacteriaceae (AGRE), fluoroquinolone-resistant Enterobacteriaceae (FQRE), extremely drug-resistant Pseudomonas aeruginosa (XDRPA), carbapenem-resistant Acinetobacter baumannn (CRAB), cotrimoxazole-resistant Stenotrophomonas maltophilia (CRSM), colistin-resistant Gram-negative organisms (CoRGNB), and pan-drug-resistant Gram-negative organisms (PDRGNB). The recommendations are grouped by MDR-GNB species. Faecal microbiota transplantation has been discussed separately. Four types of outcomes were evaluated for each target MDR-GNB:(a) microbiological outcomes (carriage and eradication rates) at treatment end and at specific post-treatment time-points; (b) clinical outcomes (attributable and all-cause mortality and infection incidence) at the same time-points and length of hospital stay; (c) epidemiological outcomes (acquisition incidence, transmission and outbreaks); and (d) adverse events of decolonization (including resistance development). The level of evidence for and strength of each recommendation were defined according to the GRADE approach. Consensus of a multidisciplinary expert panel was reached through a nominal-group technique for the final list of recommendations.Recommendations: The panel does not recommend routine decolonization of 3GCephRE and CRE carriers. Evidence is currently insufficient to provide recommendations for or against any intervention in patients colonized with AGRE, CoRGNB, CRAB, CRSM, FQRE, PDRGNB and XDRPA. On the basis of the limited evidence of increased risk of CRE infections in immunocompromised carriers, the panel suggests designing high-quality prospective clinical studies to assess the risk of CRE infections in immunocompromised patients. These trials should include monitoring of development of resistance to decolonizing agents during treatment using stool cultures and antimicrobial susceptibility results according to the EUCAST clinical breakpoints. (C) 2019 The Authors. Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. Show less
Since global food insecurity is one of the major problems faced by humanity, there is a necessity to increase plant productivity. For this, biofungicides and biofertilizers present an ecologically... Show moreSince global food insecurity is one of the major problems faced by humanity, there is a necessity to increase plant productivity. For this, biofungicides and biofertilizers present an ecologically friendly alternative to their chemical counterparts. Among these bioinoculants, endophytic bacteria with plant growth promotion and biocontrol abilities are the most promising candidates due to their ability to colonize the plant__s interior and establish a stable, long-lasting relationship with a plant. In this thesis, I succeeded in the isolation of many beneficial endophytic strains. Among them, Bacillus subtilis HC8 isolated from giant hogweed proved to be the most versatile promising bioinoculant since it expressed its beneficial effect on diverse plants under different growth conditions. It was also shown that this strain, so far, is the only endophytic Bacillus __ and one out of a few Bacillus strains __ which is capable of producing excessively high levels of a large variety of lipopeptide antibiotics. Attempts were also made to shed light on the endophytic lifestyle of several strains. This resulted in finding L-arabinose, a carbon source which might be important for endophytic pseudomonads in cucumber plants. This and other (yet-) unidentified traits could contribute to the complex interaction of endophytic bacteria and plants Show less
The research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through... Show moreThe research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through the mechanism competition for nutrients (and niches). The efficacy of biocontrol of one of these strains, P. putida PCL1760, was estimated under industrial conditions using both conventional and molecular techniques. Quantitative PCR was used also to distinguish between different forms of Fusarum oxysporum (Fox), which cannot be distinguished using otherwise so far. It was shown that nonpathogenic Fox strains in plant material cannot reach a concentration higher than 50 fg of fungal DNA per ng of total DNA. The obtained results are an illustration of an efficient strategy, which can be exploited for the isolation of biocontrol agents for greenhouses and of the application of fast molecular methods for the estimation of their efficacy in plant protection. Moreover, this molecular method a quantitative PCR can be used to monitor pathogenic strains in tomato. Show less
The biocontrol strain studied in this thesis is Pseudomonas chlororaphis strain PCL1391, which controls tomato foot and root rot caused by Fusarium oxysporum f. sp. radicis-licopersici (Chin-A... Show moreThe biocontrol strain studied in this thesis is Pseudomonas chlororaphis strain PCL1391, which controls tomato foot and root rot caused by Fusarium oxysporum f. sp. radicis-licopersici (Chin-A-Woeng et al., 1998). Production of the anti-fungal metabolite phenazine-1-carboxamide (PCN) and an efficient root colonizing ability (Chin-A-Woeng et al., 2000) are crucial for efficient biocontrol by P. chlororaphis strain PCL1391. This thesis aims at the identification and analysis of environmental conditions affecting the production of PCN and the identification of novel genes involved in the regulation of PCN production. Show less
A general overview of regulation of secondary metabolism in Pseudomonas species is given in Chapter 1. Several approaches were combined to identify novel genes involved in the regulation of PCN... Show moreA general overview of regulation of secondary metabolism in Pseudomonas species is given in Chapter 1. Several approaches were combined to identify novel genes involved in the regulation of PCN synthesis and to study their interactions with other regulators. Site-directed mutagenesis was used to test the hypothesis that rpoS is a regulatory gene of PCN synthesis (Chapter 2). To discover additional genes in the regulatory cascade, which already contains psrA and rpoS, a random DNA-fragment microarray of the PCL1391 genome was constructed and used for transcriptomics of the psrA and rpoS mutants (Chapter 3). A random mutagenesis approach resulted in the identification of pip, a novel gene that stimulates PCN production in PCL1391 (Chapter 4). Analyses on the role of Pip as a switch of PCN production depending on environmental conditions are described in Chapter 5. The results described in this thesis are summarized in Chapter 6, where in addition the regulatory network of PCN synthesis in P. chlororaphis PCL1391 is compared to regulatory networks of secondary metabolism in other Pseudomonas species. Show less
This thesis describes the tropic acid enzymes which in 4 steps catalyze the metabolic pathway of the alkaloid atropine. The enzymes have been discovered in a Pseudomonas bacterium from soil... Show moreThis thesis describes the tropic acid enzymes which in 4 steps catalyze the metabolic pathway of the alkaloid atropine. The enzymes have been discovered in a Pseudomonas bacterium from soil underneath the Atropa belladonna plant, the natural producer of atropine. These 4 enzymes are highly specific and show peculiar kinetics explained by the very asymmetrical equilibrium for step 2 and a keto-enol tautomerism for the product of step 2, the 2-phenylmalonic semialdehyde. The last part concerns the regulation of enzyme synthesis by product induction and its major advantage for cell economy. This thesis was written in the Dutch Language in 1969 and at that time deposited in the Repositorium of the Library of the Technical University, Delft, The Netherlands htpps://repository.tudelft.nl/view/tno; # 268336.Only in 2019 the thesis was translated by the author in English as precise copy nearly page by page of the 1969 version (no update). The English translation is only meant to disseminate the scientific data, described in the Dutch version. It does not intend to add any new data. In case of differences in the interpretation of the intellectual property only the Dutch version counts. Show less
