Justina Krawczyk

Publications of Justina Krawczyk

• Online tools for polyphasic analysis of Mycobacterium tuberculosis complex genotyping data: Now and next.

  Authors: Thomas Weniger, Justina Krawczyk, Philip Supply, Dag Harmsen, Stefan Niemann

  Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases. 02/2012;

  Molecular diagnostics and genotyping of pathogens have become indispensable tools in clinical microbiology and disease surveillance. For isolates of the Mycobacterium tuberculosis complex (MTBC,Molecular diagnostics and genotyping of pathogens have become indispensable tools in clinical microbiology and disease surveillance. For isolates of the Mycobacterium tuberculosis complex (MTBC, causative agents of tuberculosis), multilocus variable number tandem repeat analysis (MLVA) targeting mycobacterial interspersed repetitive units (MIRU) has been internationally adopted as the new standard, portable, reproducible, and discriminatory typing method. Here, we review new sets of specialized web based bioinformatics tools that have become available for analyzing MLVA data especially in combination with other, complementary genotyping markers (polyphasic analysis). Currently, there are only two databases available that are not restricted to store one kind of genotyping data only, namely SITVIT/SpolDB4 and MIRU-VNTRplus. SITVIT/SpolDB4 (http://www.pasteur-guadeloupe.fr:8081/SITVITDemo) contains spoligotyping data from a large number of strains of diverse origin. However, besides options to query the data, the actual version of SITVIT/SpolDB4 offers no functionality for more complex analysis e.g. tree-based analysis. In comparison, the MIRU-VNTRplus web application (http://www.miru-vntrplus.org), represents a freely accessible service that enables users to analyze genotyping data of their strains alone or in comparison with a currently limited but well characterized reference database of strains representing the major MTBC lineages. Data (MLVA-, spoligotype-, large sequence polymorphism, and single nucleotide polymorphism) can be visualized and analyzed using just one genotyping method or a weighted combination of several markers. A variety of analysis tools are available such as creation of phylogenetic and minimum spanning trees, semi-automated phylogenetic lineage identification based on comparison with the reference database and mapping of geographic information. To facilitate scientific communication, a universal, expanding genotype nomenclature (MLVA MtbC15-9 type) service that can be queried via a web- or a SOAP-interface has been implemented. An extensive documentation guides users through all application functions. Perspectives for future development, including generalization to other bacterial species, are presented.

• MIRU-VNTRplus: a web tool for polyphasic genotyping of Mycobacterium tuberculosis complex bacteria.

  Authors: Thomas Weniger, Justina Krawczyk, Philip Supply, Stefan Niemann, Dag Harmsen

  Nucleic acids research. 05/2010; 38(Web Server issue):W326-31.

  Harmonized typing of bacteria and easy identification of locally or internationally circulating clones are essential for epidemiological surveillance and disease control. For MycobacteriumHarmonized typing of bacteria and easy identification of locally or internationally circulating clones are essential for epidemiological surveillance and disease control. For Mycobacterium tuberculosis complex (MTBC) species, multi-locus variable number tandem repeat analysis (MLVA) targeting mycobacterial interspersed repetitive units (MIRU) has been internationally adopted as the new standard, portable, reproducible and discriminatory typing method. However, no specialized bioinformatics web tools are available for analysing MLVA data in combination with other, complementary typing data. Therefore, we have developed the web application MIRU-VNTRplus (http://www.miru-vntrplus.org). This freely accessible service allows users to analyse genotyping data of their strains alone or in comparison with a reference database of strains representing the major MTBC lineages. Analysis and comparisons of genotypes can be based on MLVA-, spoligotype-, large sequence polymorphism and single nucleotide polymorphism data, or on a weighted combination of these markers. Tools for data exploration include search for similar strains, creation of phylogenetic and minimum spanning trees and mapping of geographic information. To facilitate scientific communication, an expanding genotype nomenclature (MLVA MtbC15-9 type) that can be queried via a web- or a SOAP-interface has been implemented. An extensive documentation guides users through all application functions.

• MIRU-VNTR

  Authors: Thomas Weniger, Justina Krawczyk, Philip Supply, Stefan Niemann, Dag Harmsen

  Nucleic Acids Research. 01/2010; 38:326-331.

• From Corynebacterium glutamicum to Mycobacterium tuberculosis--towards transfers of gene regulatory networks and integrated data analyses with MycoRegNet.

  Authors: Justina Krawczyk, Thomas A Kohl, Alexander Goesmann, Jörn Kalinowski, Jan Baumbach

  Nucleic acids research. 07/2009;

  Year by year, approximately two million people die from tuberculosis, a disease caused by the bacterium Mycobacterium tuberculosis. There is a tremendous need for new anti-tuberculosis therapiesYear by year, approximately two million people die from tuberculosis, a disease caused by the bacterium Mycobacterium tuberculosis. There is a tremendous need for new anti-tuberculosis therapies (antituberculotica) and drugs to cope with the spread of tuberculosis. Despite many efforts to obtain a better understanding of M. tuberculosis' pathogenicity and its survival strategy in humans, many questions are still unresolved. Among other cellular processes in bacteria, pathogenicity is controlled by transcriptional regulation. Thus, various studies on M. tuberculosis concentrate on the analysis of transcriptional regulation in order to gain new insights on pathogenicity and other essential processes ensuring mycobacterial survival. We designed a bioinformatics pipeline for the reliable transfer of gene regulations between taxonomically closely related organisms that incorporates (i) a prediction of orthologous genes and (ii) the prediction of transcription factor binding sites. In total, 460 regulatory interactions were identified for M. tuberculosis using our comparative approach. Based on that, we designed a publicly available platform that aims to data integration, analysis, visualization and finally the reconstruction of mycobacterial transcriptional gene regulatory networks: MycoRegNet. It is a comprehensive database system and analysis platform that offers several methods for data exploration and the generation of novel hypotheses. MycoRegNet is publicly available at http://mycoregnet.cebitec.uni-bielefeld.de.

• Trace2PS and FSA2PS: two software toolkits for converting trace and fsa files to PostScript format.

  Authors: Justina Krawczyk, Alexander Goesmann, Ralf Nolte, Martin Werber, Bernd Weisshaar

  Source code for biology and medicine. 02/2009; 4:4.

  ABSTRACT: BACKGROUND: Due to the advanced techniques in sequencing and fragment analysis, DNA sequencers and analyzers produce vast amounts of data within short time. To administrate the large dataABSTRACT: BACKGROUND: Due to the advanced techniques in sequencing and fragment analysis, DNA sequencers and analyzers produce vast amounts of data within short time. To administrate the large data volume conveniently, efficient data management systems are used in order to process and to store sequencers' or analyzers' data outcome. The inclusion of graphical reports in such systems is necessary to achieve a comprehensive view of the integrated data. However, the resulting data of sequencing and fragment analysis runs are stored in a proprietary format, the so-called trace or fsa format, which is only readable by programs provided by the instrument's vendor operating on the machine itself or by commercial tools designed for editing the respective data. To allow for a quick conversion of the proprietary data format into a commonly used one, toolkits are required that reach this aim and can be easily integrated into workflow systems. RESULTS: We have developed the software toolkits Trace2PS and Fsa2PS which allow to convert sequence and fragment analysis raw data files to PostScript images, respectively. The toolkits are implemented as Perl modules that can be used as standalone command line applications in conjunction with a script-based analysis pipeline, or integrated in software applications for displaying the data content of trace and fsa files. The converter modules support the commonly used file formats for storage of sequencing (ABI and SCF) and fragment analysis data (FSA). CONCLUSION: The software toolkits provide useful applications to convert sequencing and fragment analysis files from a proprietary into a more common, human-readable format. Trace2PS and FSA2PS are useful and capable in data management workflow systems like SAMS, or laboratory information systems that are used for displaying trace and fragment analysis results via web-based tools over an intranet or internet connection to users that can view their results directly on the screen.