| 1. |
|
|
| 2. |
- Kanai, M, et al.
(author)
-
- 2023
-
swepub:Mat__t
|
|
| 3. |
- Niemi, MEK, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Abuzeid, Nadir, et al.
(author)
-
Antimycobacterial activity of selected medicinal plants traditionally used in Sudan to treat infectious diseases
- 2014
-
In: Journal of Ethnopharmacology. - : Elsevier. - 0378-8741 .- 1872-7573. ; 157, s. 134-139
-
Journal article (peer-reviewed)abstract
- Ethnopharmacological relevance: The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need for continuous development of new and efficient methods to determine the susceptibility of isolates of Mycobacterium tuberculosis in the search for novel antimycobacterial agents. Natural products constitute an important source of new drugs, and design and implementation of antimycobacterial susceptibility testing methods are necessary to evaluate the different extracts and compounds. In this study we have explored the antimycobacterial properties of 50 ethanolic extracts from different parts of 46 selected medicinal plants traditionally used in Sudan to treat infectious diseases. Materials and methods: Plants were harvested and ethanolic extracts were prepared. For selected extracts, fractionation with hydrophilic and hydrophobic solvents was undertaken. A luminometry-based assay was used for determination of mycobacterial growth in broth cultures and inside primary human macrophages in the presence or absence of plant extracts and fractions of extracts. Cytotoxicity was also assessed for active fractions of plant extracts. Results: Of the tested extracts, three exhibited a significant inhibitory effect on an avirulent strain of Mycobacterium tubercluosis (H37Ra) at the initial screening doses (125 and 6.25 mu g/ml). These were bark and leaf extracts of Khaya senegalensis and the leaf extract of Rosmarinus officinalis L. Further fractions of these plant extracts were prepared with n-hexane, chloroform, ethyl acetate, n-butanol, ethanol and water, and the activity of these extracts was retained in hydrophobic fractions. Cytotoxicity assays revealed that the chloroform fraction of Khaya senegalensis bark was non-toxic to human monocyte-derived macrophages and other cell types at the concentrations used and hence, further analysis, including assessment of IC50 and intracellular activity was done with this fraction. Conclusion: These results encourage further investigations to identify the active compound(s) within the chloroform fraction of Khaya senegalensis bark. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
|
|
| 8. |
- Eklund, Daniel, et al.
(author)
-
Validation of a Medium-Throughput Method for Evaluation of Intracellular Growth of Mycobacterium tuberculosis
- 2010
-
In: Clinical and Vaccine Immunology. - : American Society for Microbiology. - 1556-6811 .- 1556-679X. ; 17:4, s. 513-517
-
Journal article (peer-reviewed)abstract
- Intracellular pathogens such as Mycobacterium tuberculosis have adapted to a life inside host cells, in which they utilize host nutrients to replicate and spread. Ineffective methods for the evaluation of growth of intracellular pathogens in their true environment pose an obstacle for basic research and drug screening. Here we present the validation of a luminometry-based method for the analysis of intramacrophage growth of M. tuberculosis. The method, which is performed in a medium-throughput format, can easily be adapted for studies of other intracellular pathogens and cell types. The use of host cells in drug-screening assays dedicated to find antimicrobials effective against intracellular pathogens permits the discovery of not only novel antibiotics but also compounds with immunomodulatory and virulence-impairing activities, which may be future alternatives or complements to antibiotics.
|
|
| 9. |
- Hudson, Lawrence N, et al.
(author)
-
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
-
In: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
-
Journal article (peer-reviewed)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Schon, Thomas, et al.
(author)
-
A comparative study of three methods to evaluate an intervention to improve empirical antibiotic therapy for acute bacterial infections in hospitalized patients
- 2011
-
In: SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES. - : Informa Healthcare. - 0036-5548 .- 1651-1980. ; 43:4, s. 251-257
-
Journal article (peer-reviewed)abstract
- Background: In order to limit the use of broad-spectrum antibiotics, standardized empirical therapy against acute bacterial infections has been advocated. Methods: Guidelines for acute bacterial infections recommending increased usage of benzylpenicillin and restricted use of fluoroquinolones and cephalosporins have been implemented in Kalmar County, Sweden. We evaluated this strategy by recording therapy in patients with bacteraemia, antibiotic requisition, and point prevalence surveys prior to this intervention and at 6 and 12 months after. Results: Comparing the methods simultaneously, there was good agreement between them and an overall significant change in antibiotic usage. There was a significant shift from cefuroxime to cefotaxime and a borderline significant increase in the use of benzylpenicillin (p == 0.057). Based on the defined daily dose (DDD), a highly significant decrease in total cefotaxime and cefuroxime usage was observed that was not detected when applying the prescribed daily dose (PDD), which is adapted to local treatment practices. No change was found in mortality in Staphylococcus aureus bacteraemia or the incidence of Clostridium difficile infection. Conclusions: We conclude that the implementation of the new guidelines has resulted in a significant change in antibiotic usage, which could be conveniently monitored by antibiotic requisition if PDD is used in addition to DDD.
|
|
| 14. |
- Schon, Thomas, et al.
(author)
-
Evaluation of wild-type MIC distributions as a tool for determination of clinical breakpoints for Mycobacterium tuberculosis
- 2009
-
In: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 64:4, s. 786-793
-
Journal article (peer-reviewed)abstract
- Objectives: The aim of this study was to establish wild-type MIC distributions of first-line drugs for Mycobacterium tuberculosis, as well as to explore the usefulness of such distributions when setting clinical breakpoints. Methods: We determined the MICs of rifampicin, isonlazid and ethambutol for M. tuberculosis using a Middlebrook 7H10 dilution method for 90 consecutive clinical isolates, 8 resistant strains and 16 isolates from the WHO proficiency test panel. M. tuberculosis H37Rv was used for quality control and susceptibility results using 7H10 were compared with the results obtained with BACTEC460. Results: The agreement with BACTEC460 was very high for isonlazid (99.1%) and rifampicin (99.1%) but lower for ethambutol (94.7%). Intra- and inter-assay variation was below one MIC dilution. The MIC distributions for isoniazid and rifampicin provided a clear separation between susceptible and resistant strains. Regarding ethambutol, the current breakpoint for 7H10 (5 mg/L) is close to the wild-type and all strains (n=6) showing a disagreement between BACTEC460 and 7H10 were distributed very close to the breakpoint (MIC 4-8 mg/L). This problematic relation was confirmed by investigating isolates from the WHO panel with an agreement <95% (64%-88% among 26 laboratories, n=4) for which the MICs were 4-8 mg/L . Conclusions: Utilizing the wild-type MIC distribution was found to be as useful in M. tuberculosis as in other bacteria when setting clinical breakpoints. We suggest that the present clinical breakpoints should be re-evaluated, taking into account wild-type MIC distributions and available pharmacokinetic data.
|
|
| 15. |
- Schon, Thomas, et al.
(author)
-
Rifampicin-resistant and rifabutin-susceptible Mycobacterium tuberculosis strains: a breakpoint artefact?
- 2013
-
In: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP): Policy B - Oxford Open Option B. - 0305-7453 .- 1460-2091. ; 68:9, s. 2074-2077
-
Journal article (peer-reviewed)abstract
- It has long been assumed that some rifampicin-resistant Mycobacterium tuberculosis strains are susceptible to, and thus treatable with, rifabutin. However, clinical breakpoints for susceptibility testing of rifabutin as well as the evidence for a clinical effect of rifabutin in rifampicin-resistant strains remains poorly defined. The objective of this study was to re-evaluate the breakpoint for rifabutin in relation to its MIC wild-type distribution and the presence of mutations in rpoB. less thanbrgreater than less thanbrgreater thanThe MIC in 7H10 Middlebrook medium was determined for clinical isolates of M. tuberculosis (n95), where a majority were multidrug resistant. Additionally, all strains were screened for rpoB mutations by sequencing and the GenoType MTBDRplus assay. less thanbrgreater than less thanbrgreater thanRifampicin resistance was confirmed by genotypical and/or phenotypical tests in 73 isolates (76.8). Nineteen isolates, defined as rifampicin resistant and rifabutin susceptible according to the present breakpoint, exhibited significantly higher MICs of rifabutin (0.0640.5 mg/L) than rifabutin-susceptible isolates without any detectable mutations in rpoB (P0.001). These 19 isolates were clearly resistant to rifampicin (MIC 2256 mg/L) and all but one had mutations in rpoB, with 9 (47.4) specifically in Asp516Val. less thanbrgreater than less thanbrgreater thanOur results indicate that rifampicin-resistant but rifabutin-susceptible isolates according to the present breakpoints harbour rpoB mutations and have a rifabutin MIC significantly higher than strains without any detectable mutations in rpoB. So far there are no clinical, pharmacological or microbiological data to confirm that such isolates can be treated with rifabutin and we suggest a revision of the current breakpoints.
|
|
