LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 7 of total 7

Search options

  1. Article ; Online: Bioprospecting

    Oduor, Joseph M Ochieng' / Kadija, Ermir / Nyachieo, Atunga / Mureithi, Marianne W / Skurnik, Mikael

    Viruses

    2020  Volume 12, Issue 2

    Abstract: Emergence of antibiotic-resistant bacteria is a serious threat to the public health. This is also true ... ...

    Abstract Emergence of antibiotic-resistant bacteria is a serious threat to the public health. This is also true for
    MeSH term(s) Albania ; Biological Control Agents/isolation & purification ; Bioprospecting ; Chloroform/pharmacology ; Ethanol/pharmacology ; Genome, Viral ; Genomics ; Host Specificity ; Hydrogen-Ion Concentration ; Phage Therapy ; Sequence Analysis, DNA ; Staphylococcal Infections/therapy ; Staphylococcus Phages/classification ; Staphylococcus Phages/physiology ; Staphylococcus aureus/virology ; Temperature
    Chemical Substances Biological Control Agents ; Ethanol (3K9958V90M) ; Chloroform (7V31YC746X)
    Language English
    Publishing date 2020-01-23
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v12020133
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article: Bioprospecting Staphylococcus Phages with Therapeutic and Bio-Control Potential

    Oduor, Joseph M. Ochieng’ / Kadija, Ermir / Nyachieo, Atunga / Mureithi, Marianne W / Skurnik, Mikael

    Viruses. 2020 Jan. 23, v. 12, no. 2

    2020  

    Abstract: Emergence of antibiotic-resistant bacteria is a serious threat to the public health. This is also true for Staphylococcus aureus and other staphylococci. Staphylococcus phages Stab20, Stab21, Stab22, and Stab23, were isolated in Albania. Based on genomic ...

    Abstract Emergence of antibiotic-resistant bacteria is a serious threat to the public health. This is also true for Staphylococcus aureus and other staphylococci. Staphylococcus phages Stab20, Stab21, Stab22, and Stab23, were isolated in Albania. Based on genomic and phylogenetic analysis, they were classified to genus Kayvirus of the subfamily Twortvirinae. In this work, we describe the in-depth characterization of the phages that electron microscopy confirmed to be myoviruses. These phages showed tolerance to pH range of 5.4 to 9.4, to maximum UV radiation energy of 25 µJ/cm², to temperatures up to 45 °C, and to ethanol concentrations up to 25%, and complete resistance to chloroform. The adsorption rate constants of the phages ranged between 1.0 × 10⁻⁹ mL/min and 4.7 × 10⁻⁹ mL/min, and the burst size was from 42 to 130 plaque-forming units. The phages Stab20, 21, 22, and 23, originally isolated using Staphylococcus xylosus as a host, demonstrated varied host ranges among different Staphylococcus strains suggesting that they could be included in cocktail formulations for therapeutic or bio-control purpose. Phage particle proteomes, consisting on average of ca 60–70 gene products, revealed, in addition to straight-forward structural proteins, also the presence of enzymes such DNA polymerase, helicases, recombinases, exonucleases, and RNA ligase polymer. They are likely to be injected into the bacteria along with the genomic DNA to take over the host metabolism as soon as possible after infection.
    Keywords DNA ; DNA-directed DNA polymerase ; Myoviridae ; RNA ligase (ATP) ; Staphylococcus aureus ; Staphylococcus xylosus ; adsorption ; antibiotic resistance ; bacteria ; bacteriophages ; biological control ; chloroform ; electron microscopy ; energy ; ethanol ; genes ; genomics ; host range ; metabolism ; pH ; phylogeny ; polymers ; proteome ; public health ; recombinases ; structural proteins ; temperature ; therapeutics ; ultraviolet radiation ; Albania
    Language English
    Dates of publication 2020-0123
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2516098-9
    ISSN 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v12020133
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article: Experimental phage therapy against haematogenous multi-drug resistant

    Oduor, Joseph M Ochieng' / Onkoba, Nyamongo / Maloba, Fredrick / Nyachieo, Atunga

    African journal of laboratory medicine

    2016  Volume 5, Issue 1, Page(s) 435

    Abstract: Background: Community-acquired haematogenous : Objective: We sought to determine the efficacy of environmentally-obtained : Methods: Phages and MDRSA were isolated from sewage samples collected within Nairobi County, Kenya. Isolated : Results: ... ...

    Abstract Background: Community-acquired haematogenous
    Objective: We sought to determine the efficacy of environmentally-obtained
    Methods: Phages and MDRSA were isolated from sewage samples collected within Nairobi County, Kenya. Isolated
    Results: The viable MDRSA count was 0.5 ± 0.2 log
    Conclusion: Phage therapy is effective against haematogenous MDRSA infection. Thus, it can be explored as an alternative treatment method.
    Language English
    Publishing date 2016-09-30
    Publishing country South Africa
    Document type Journal Article
    ZDB-ID 2708535-1
    ISSN 2225-2010 ; 2225-2002
    ISSN (online) 2225-2010
    ISSN 2225-2002
    DOI 10.4102/ajlm.v5i1.435
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: Experimental phage therapy against haematogenous multi-drug resistant Staphylococcus aureus pneumonia in mice

    Joseph M. Ochieng' Oduor / Nyamongo Onkoba / Fredrick Maloba / Atunga Nyachieo

    African Journal of Laboratory Medicine, Vol 5, Iss 1, Pp e1-e

    2016  Volume 7

    Abstract: Background: Community-acquired haematogenous Staphylococcus aureus pneumonia is a rare infection, though it can be acquired nosocomially. Currently, antibiotics used against S. aureus pneumonia have shown reduced efficacy. Thus, there is need for an ... ...

    Abstract Background: Community-acquired haematogenous Staphylococcus aureus pneumonia is a rare infection, though it can be acquired nosocomially. Currently, antibiotics used against S. aureus pneumonia have shown reduced efficacy. Thus, there is need for an alternative therapy against multidrug-resistant S. aureus (MDRSA) strains in the community. Objective: We sought to determine the efficacy of environmentally-obtained S. aureus lytic phage against haematogenous MDRSA pneumonia in mice. Methods: Phages and MDRSA were isolated from sewage samples collected within Nairobi County, Kenya. Isolated S. aureus bacteria were screened for resistance against ceftazidime, oxacillin, vancomycin, netilmicin, gentamicin, erythromycin, trimethroprim-sulfamethoxazole and cefuroxime. Thirty BALB/c mice aged six to eight weeks were randomly assigned into three groups: the MDRSA-infection group (n = 20), the phage-infection group (n = 5) and the non-infection group (n = 5). Mice were infected with either MDRSA or phage (108 CFU/mL) and treated after 72 hours with a single dose of clindamycin (8 mg/kg/bwt) or 108 PFU/mL of phage or a combination therapy (clindamycin and phage). The efficacy of phage, clindamycin or clindamycin with phage combination was determined using resolution of lung pathology and bacterial load in lung homogenates. Results: The viable MDRSA count was 0.5 ± 0.2 log10 CFU/gm in the phage-treated group, 4.4 ± 0.2 log10 CFU/gm in the clindamycin-treated group and 4.0 ± 0.2 log10 CFU/gm in the combination-treated group. The efficacy of phage therapy was significantly different from other therapeutic modes (p = 0 < 0.0001). Histology showed that the mice treated with phage did not develop pneumonia. Conclusion: Phage therapy is effective against haematogenous MDRSA infection. Thus, it can be explored as an alternative treatment method.
    Keywords hematogenous pneumonia ; phage therapy ; multi-drug resistant Staphylococcus aureus (MDRSA) ; antibiotics ; Public aspects of medicine ; RA1-1270 ; Medicine (General) ; R5-920
    Subject code 500
    Language English
    Publishing date 2016-09-01T00:00:00Z
    Publisher AOSIS
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: High Resolution, Annual Maps of Field Boundaries for Smallholder-Dominated Croplands at National Scales.

    Estes, Lyndon D / Ye, Su / Song, Lei / Luo, Boka / Eastman, J Ronald / Meng, Zhenhua / Zhang, Qi / McRitchie, Dennis / Debats, Stephanie R / Muhando, Justus / Amukoa, Angeline H / Kaloo, Brian W / Makuru, Jackson / Mbatia, Ben K / Muasa, Isaac M / Mucha, Julius / Mugami, Adelide M / Mugami, Judith M / Muinde, Francis W /
    Mwawaza, Fredrick M / Ochieng, Jeff / Oduol, Charles J / Oduor, Purent / Wanjiku, Thuo / Wanyoike, Joseph G / Avery, Ryan B / Caylor, Kelly K

    Frontiers in artificial intelligence

    2022  Volume 4, Page(s) 744863

    Abstract: ... with randomly selected labels. We used the resulting 3.7 m map of cropland probabilities within a segmentation ...

    Abstract Mapping the characteristics of Africa's smallholder-dominated croplands, including the sizes and numbers of fields, can provide critical insights into food security and a range of other socioeconomic and environmental concerns. However, accurately mapping these systems is difficult because there is 1) a spatial and temporal mismatch between satellite sensors and smallholder fields, and 2) a lack of high-quality labels needed to train and assess machine learning classifiers. We developed an approach designed to address these two problems, and used it to map Ghana's croplands. To overcome the spatio-temporal mismatch, we converted daily, high resolution imagery into two cloud-free composites (the primary growing season and subsequent dry season) covering the 2018 agricultural year, providing a seasonal contrast that helps to improve classification accuracy. To address the problem of label availability, we created a platform that rigorously assesses and minimizes label error, and used it to iteratively train a Random Forests classifier with active learning, which identifies the most informative training sample based on prediction uncertainty. Minimizing label errors improved model F1 scores by up to 25%. Active learning increased F1 scores by an average of 9.1% between first and last training iterations, and 2.3% more than models trained with randomly selected labels. We used the resulting 3.7 m map of cropland probabilities within a segmentation algorithm to delineate crop field boundaries. Using an independent map reference sample (
    Language English
    Publishing date 2022-02-25
    Publishing country Switzerland
    Document type Journal Article
    ISSN 2624-8212
    ISSN (online) 2624-8212
    DOI 10.3389/frai.2021.744863
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: High Resolution, Annual Maps of Field Boundaries for Smallholder-Dominated Croplands at National Scales

    Lyndon D. Estes / Su Ye / Lei Song / Boka Luo / J. Ronald Eastman / Zhenhua Meng / Qi Zhang / Dennis McRitchie / Stephanie R. Debats / Justus Muhando / Angeline H. Amukoa / Brian W. Kaloo / Jackson Makuru / Ben K. Mbatia / Isaac M. Muasa / Julius Mucha / Adelide M. Mugami / Judith M. Mugami / Francis W. Muinde /
    Fredrick M. Mwawaza / Jeff Ochieng / Charles J. Oduol / Purent Oduor / Thuo Wanjiku / Joseph G. Wanyoike / Ryan B. Avery / Kelly K. Caylor

    Frontiers in Artificial Intelligence, Vol

    2022  Volume 4

    Abstract: ... with randomly selected labels. We used the resulting 3.7 m map of cropland probabilities within a segmentation ...

    Abstract Mapping the characteristics of Africa’s smallholder-dominated croplands, including the sizes and numbers of fields, can provide critical insights into food security and a range of other socioeconomic and environmental concerns. However, accurately mapping these systems is difficult because there is 1) a spatial and temporal mismatch between satellite sensors and smallholder fields, and 2) a lack of high-quality labels needed to train and assess machine learning classifiers. We developed an approach designed to address these two problems, and used it to map Ghana’s croplands. To overcome the spatio-temporal mismatch, we converted daily, high resolution imagery into two cloud-free composites (the primary growing season and subsequent dry season) covering the 2018 agricultural year, providing a seasonal contrast that helps to improve classification accuracy. To address the problem of label availability, we created a platform that rigorously assesses and minimizes label error, and used it to iteratively train a Random Forests classifier with active learning, which identifies the most informative training sample based on prediction uncertainty. Minimizing label errors improved model F1 scores by up to 25%. Active learning increased F1 scores by an average of 9.1% between first and last training iterations, and 2.3% more than models trained with randomly selected labels. We used the resulting 3.7 m map of cropland probabilities within a segmentation algorithm to delineate crop field boundaries. Using an independent map reference sample (n = 1,207), we found that the cropland probability and field boundary maps had respective overall accuracies of 88 and 86.7%, user’s accuracies for the cropland class of 61.2 and 78.9%, and producer’s accuracies of 67.3 and 58.2%. An unbiased area estimate calculated from the map reference sample indicates that cropland covers 17.1% (15.4–18.9%) of Ghana. Using the most accurate validation labels to correct for biases in the segmented field boundaries map, we estimated that the average ...
    Keywords active learning ; machine learning ; PlanetScope ; smallholder cropland ; field size ; label error ; Electronic computers. Computer science ; QA75.5-76.95
    Subject code 333
    Language English
    Publishing date 2022-02-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Genomic characterization of four novel Staphylococcus myoviruses.

    Oduor, Joseph Michael Ochieng' / Kiljunen, Saija / Kadija, Ermir / Mureithi, Marianne W / Nyachieo, Atunga / Skurnik, Mikael

    Archives of virology

    2019  Volume 164, Issue 8, Page(s) 2171–2173

    Abstract: We report here the annotation of the complete genomes of four novel lytic Staphylococcus phages; Stab20, Stab21, Stab22 and Stab23. These phages have double-stranded DNA genomes ranging between 153,338 and 155,962 bp in size with terminal repeats of 10, ... ...

    Abstract We report here the annotation of the complete genomes of four novel lytic Staphylococcus phages; Stab20, Stab21, Stab22 and Stab23. These phages have double-stranded DNA genomes ranging between 153,338 and 155,962 bp in size with terminal repeats of 10,814-12,304 bp. The genome analysis suggests that they represent new phage species within the genus Kayvirus in the subfamily Twortvirinae of the family Herelleviridae.
    MeSH term(s) DNA, Viral/genetics ; Genome, Viral/genetics ; Genomics/methods ; Myoviridae/genetics ; Phylogeny ; Sequence Analysis, DNA/methods ; Staphylococcus/genetics ; Staphylococcus Phages/genetics
    Chemical Substances DNA, Viral
    Language English
    Publishing date 2019-05-15
    Publishing country Austria
    Document type Journal Article
    ZDB-ID 7491-3
    ISSN 1432-8798 ; 0304-8608
    ISSN (online) 1432-8798
    ISSN 0304-8608
    DOI 10.1007/s00705-019-04267-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Ud II Zs.110: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top