Research Area B - Novel Diagnostic Tools and Approaches
To date, differential diagnosis of systemic inflammation versus sepsis is based primarily on clinical criteria and laboratory tests, which lack the required sensitivity and specificity.
This dilemma holds true for medical as well as surgical patients and involves patient populations as heterogeneous as those after major surgery, those with autoimmune diseases, or chemotherapy. The current gold standard of diagnostics is the cultivation of causative pathogens from blood or other body fluids and tissue. However, the microorganism can be detected in only 20-40% of patients and at the earliest after 24 hours. Therefore, novel diagnostic tools and approaches with high sensitivity and specificity are needed to enable timely recognition of sepsis and allow well-founded and appropriate initial antibiotic therapy. To approach this ambitious goal from different aspects in experimental studies as well as with one observational study in the clinical setting, scientists and clinicians with a broad range of expertise came together within this research area of the CSCC. The research field spans from “-omics” technologies to biochemistry, molecular biology, and finally spectroscopic imaging and bioinformatics. A broad range of analytical techniques is utilized including classical biochemical assays as well as advanced optical spectroscopy, such as SELDI-TOFMS, fluorescence and Raman spectroscopy. Microbial and cell culture techniques, rodent models as well as human samples (full blood, plasma, urine, etc.) are employed as sepsis trial systems. Three different strategies are pursued to find faster, reliable, sensitive, and specific diagnostic tools:
- Detection of the pathogen or pathogen-associated molecular patterns,
- Characterization of the host response and establishment of biomarkers, and
- Characterization of host factors predisposing to complications and adverse outcome.
With the first approach state-of-the art optical, microfluidic, and molecular-genetic techniques are employed to investigate novel tools for more efficient pathogen detection (Action, CanSep, Spade). The second approach is set to improve the assessment of host responses to establish novel and discriminative diagnostic markers that can help the physicians to recognize sepsis in the early phase (Lab-Alerts, Transseptomics, Aras, Shilers). Regarding the third key aspect, a prospective multicenter study will evaluate the association of translocation of bacterial fragments with survival and aims to identify clinical and genetic risk factors for infectious complications in a prospective multicenter-study (Action).
Projects in Research Area B
Action (completed)
Prognostic and Diagnostic Relevance of Bacterial DNA Detection in Patients with Liver Cirrhosis and Ascites at Risk for Spontaneous Bacterial Peritonitis - a prospective multicenter study (clinical trial)
T. Bruns, P. Reuken
Aras
Androgen-Regulation of the Sepsis response: Beneficial role of androgen receptor antagonists?
Acronym: Aras
Principal Investigator: Daniela Röll
Scientific Advisor: Prof. Aria Baniahmad
Research Area: B Novel Diagnostic Tools and Approaches
Project Number: B3.3
Duration: 01.04.2011 - 28.02.2014
Module: PhD Fellowship
The Problem
Clinical and animal studies revealed that females tolerate trauma-hemorrhage and sepsis far better than males. It is discussed that male sexual hormones repress the immune and cardiovascular response. Here, treatment of male mice with various different androgen antagonists and estrogens will clarify the potential of a beneficial role.
Contact
Universitätsklinikum Jena
Institut für Humangenetik
AG Molekulargenetik
Kollegiengasse 10
07743 Jena
CanSep
Identification of protein antigens from Candida albicans for fungal sepsis diagnostics
Acronym: CanSep
Principal Investigator: Dipl.-Biochem. Ting Luo
Scientific Advisor: Dr. Olaf Kniemeyer
Research Area: B Novel Diagnostic Tools and Approaches
Project Number: B3.5
Duration: 01.10.2011 - 30.09.2014
Module: PhD Fellowship
The Problem
Candida albicans is the most important fungal pathogen of nosocomial bloodstream infections (candidemia), which may lead to severe sepsis. The diagnosis of Candida infections remains difficult. By applying an immunoproteomic approach, we aim at identifying immunodominant antigens of C. albicans which could be used as serologic markers for an improved diagnosis of Candida sepsis.
Results so far
We are searching for C. albicans protein antigens of immunodiagnostic potential by using a combination of 2D-gel electrophoresis and Western-blotting. We have already been characterizing the antibody response against secreted C. albicans proteins in a murine model of candidemia. In preliminary experiments we determined the optimal medium and growth conditions. As a result of it, we use yeast nitrogen base (YNB) medium with sucrose as carbon source. We could show that the yeast secretome comprises particularly glycolytic enzymes, cell surface proteins, chaperones, antioxidative enzymes, proteases and so far uncharacterised proteins. In parallel, we monitored the kinetic of anti-C. albicans IgG antibody production in mice infected with C. albicans wild-type and virulence-attenuated mutant strains. First Candida-specific IgG-antibodies are detectable after 5-8 days, but the diversity of the antibody response increases at later time points (after 14 days).
Contact
Tel. +49 (0)3641 - 532 1071
Fax +49 (0)3641 - 532 0803
Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie e. V.
Hans-Knöll-Institut (HKI)
Molekulare und Angewandte Mikrobiologie
Beutenbergstr. 11a
07745 Jena
Drift
Characterization of a phenotypic drift in chronic infection
N. Jbeily
Inprot
Identification of Candida albicans and Aspergillus fumigatus protein antigens for fungal diagnostics and investigation of the A. fumigatus stress response
O. Kniemeyer
Lab-Alerts
Laboratory nested co-study of the: ”Effectiveness of a Hospital-wide Educational Programme for Infection Control to Reduce the Rate of Health-Care Associated Sepsis" (clinical trial)
M. Kiehntopf, F. Brunkhorst
Premospec
Prediction models for antibiotic susceptibility based on Raman spectroscopy
J. Hey, P. Schlattmann
Shilers (completed)
Spectral Hemogram for the Investigation of LEukocytes and their Role in Septicemia
A. Ramoji, U. Neugebauer
Spade
Novel Diagnostic Tools for Culture-Independent Sepsis Pathogen Detection
U. Neugebauer
TransSeptomics (completed)
Integrative analysis of omics data from experimental and clinical sepsis in a translational approach towards individualized prevention, diagnosis and therapy
Acronym: TransSeptomics (Translational Septomics)
Principal Investigator: Sandro Lambeck, PhD
Research Area: B Novel Diagnostic Tools and Approaches
Project Number: B3.4
Duration: 01.07.2011 bis 01.07.2013
Module: Start-up Scientist
The Problem
Understanding the molecular mechanisms involved in the pathophysiology of sepsis facilitates the optimization of clinical practice. The project aims to find diagnostic and therapeutic markers by analyzing high-throughput data comprising transcriptomic and metabolomic measurements obtained from animals and patients in a systems biology approach.
Results so far
Robust methods for the unbiased analysis of multidimensional data were developed and applied to the host response in experimental and clinical sepsis (ICU). Pneumonia-specific features, comprising an orchestrated hepatic response of transcripts and effectors along cholesterol metabolism, were identified and experimentally confirmed by interventional attenuation of severity in murine models. In addition, signatures for fibrosis and cholestasis, relevant sequelae of sepsis, could be determined in rodent peritonitis (PCI) and validated subsequently. Common expression patterns of conserved features from the innate and adaptive immune response, comprising upregulated toll-like receptor signaling and downregulated major histocompatibility (MHC) class II genes, were detected in an inter-species comparison of microarray data in blood. Obtained candidates from these translational methods harbour diagnostic and treatment options for septic shock patients, including the individualized prediction of outcome from hydrocortisone administration or other immunomodulators.
Publications
Weber M, Lambeck S, Ding N, Henken S, Kohl M, Deigner HP, Enot DP, Igwe EI, Frappart L, Kiehntopf M, Claus RA, Kamradt T, Weih D, Vodovotz Y, Briles DE, Ogunniyi AD, Paton JC, Maus UA, Bauer M: Hepatic induction of cholesterol biosynthesis reflects a remote adaptive response to pneumococcal pneumonia. FASEB J 2012 Jun, 26(6):2424-36.
Gonnert FA, Kunisch E, Gajda M, Lambeck S, Weber M, Claus RA, Bauer M, Kinne RW: Hepatic Fibrosis in a Long-Term Murine Model of Sepsis. Shock 2012 Apr, 37(4):399-407.
Lambeck S, Weber M, Gonnert FA, Mrowka R, Bauer M. Comparison of sepsis‐induced transcriptomic changes in a murine model to clinical blood samples identifies common response patterns. Frontiers: Systems Biology of Microbial Infection. [Epub ahead of print].
Contact
Tel.: +49 (0)3641 - 9 32 33 45
Center for Sepsis Control and Care
Universitätsklinikum Jena
Erlanger Allee 101
07747 Jena