Beyond our routine diagnostic services, we provide expertise in diagnostic microbiology to clinical partners in collaborative research projects based on the infrastructure of the laboratory for diagnostic microbiology. Furthermore, we regularly perform validation studies of newly marketed diagnostic tests based on our large sample collections provided by the routine laboratory. Some examples of our ongoing research activities are given below.
Validation of the QIAGEN Mycobacterium tuberculosis RG PCR kit in a low incidence setting
In a recent study we evaluated the performance of the commercially available artus MTBC real-time PCR assay to identify Mycobacterium tuberculosis in clinical samples in a low prevalence setting (Kohlmorgen et al. 2017). By analyzing over 1600 clinical samples with the artus MTBC PCR assay in parallel with mycobacterial culture and microscopy we could show that retesting of specimens in duplicate and applying a cycle-threshold cut-off value greater than 34 significantly increased accuracy, specificity, and negative predictive value without affecting sensitivity of the assay. We could further demonstrate that combining the modified artus MTB test with the GenoType MTBDRplus assays allows for rapid and accurate detection of MTBC along with rifampin and isoniazid resistance.
Molecular detection and phylogeny of tropical parasites
In a joint project with PD Dr. D. Tappe from the National Reference Centre (NRC) for Tropical Pathogens at the Bernhard-Nocht-Institute for Tropical Medicine we currently collaborate on the molecular diagnostics and phylogeny of tropical parasites with a special focus on Armillifer (e.g. Tappe et al. 2016). These snakeborne parasites are emerging human pathogens and comprise a unique group of crustacean-related worm-like parasites. They accidentally cause visceral pentastomiasis in humans that is often asymptomatic and an incidental finding during surgery or autopsy. However, fatal cases caused by heavy infections have been described in West and Central Africa.
Left: Photographic image of the parasite Armillifer armillatus (Image kindly provided by Dennis Tappe).
Right: Chromatogram of a Sanger sequencing run used for the molecular detection and identification of bacterial pathogens in parapneumonic effusions and empyema in children.
Molecular detection of bacterial pathogens in parapneumonic effusions and empyema in children
In another still ongoing nationwide surveillance study of parapneumonic effusion and empyema in children (http://www.esped.uni-duesseldorf.de/esped/erkrankungen) coordinated by Prof. Dr. J. Liese from the Department of Pediatrics at the University of Würzburg we provide the molecular detection of bacterial pathogens via 16S rRNA gene sequencing (Segerer et al. 2017). So far, almost half of the over 300 samples tested were positive for eubacterial 16S rDNA, and the spectrum of pathogens is currently subject to further analysis.
For more examples please see the selected references given below and in the publication list.
Selected recent publications
Kohlmorgen B., J. Elias and C. Schoen (2017). Improved performance of the artus Mycobacterium tuberculosis RG PCR kit in a low incidence setting: a retrospective monocentric study. Sci Rep7:14127
Segerer F. J., K. Seeger, A. Maier, C. Hagemann, C. Schoen, M. van der Linden, A. Streng, M. A. Rose and J. G. Liese (2017) Therapy of 645 children with parapneumonic effusion and empyema-A German nationwide surveillance study. Pediatr Pulmonol52:540-7
Tappe D., M. Sulyok, T. Riu, L. Rózsa, I. Bodó, C. Schoen, B. Muntau, G. Babocsay and R. Hardi (2016) Co-infections in Visceral Pentastomiasis, Democratic Republic of the Congo. Emerg Infect Dis22:1333-9