Navigation and service

Unit 13: Nosocomial Pathogens and Antibiotic Resistances

Guido Werner
Ingo Klare

We are primarily concerned with surveying and studying the emergence and spread of those bacterial nosocomial pathogens that can act as indicators of hospital hygiene efficacy and rational antibacterial chemotherapy. Although our work primarily focusses on aspects of MRSA and VRE, further analyses and studies of gram-negative bacteria (E.coli, Klebsiella spp., and others) with production of extended spectrum beta-lactamases (ESBL) and carbapenemases are also addressed in our group.

Of particular interest is the spread and evolution of newly emerging resistance characteristics, of multiresistant strains and of epidemic strain variants. Our studies are based on population-wide analysis of successful clonal lineages and on the identification of genetic determinants for antibiotic resistance and pathogenicity. In addition, we have targeted projects aimed at evaluating advanced diagnostic and typing methodologies. Since decades we serve the "One-health" approach by participating or coordinating various interdisciplinary research projects to identify and quantify agricultural and environmental reservoirs of antibiotic resistance.

Scientists of our unit are active members in various national and international societies and their corresponding working and study groups (German Society for Hygiene and Microbiology (DGHM), the Paul-Ehrlich Society (PEG), the European Society for Clinical Microbiology and Infectious Diseases (ESCMID)) and represent the institute at distinct national and international commissions and institutions, such as at the European Centre for Disease Prevention and Control (ECDC).

Scientists of our unit give lectures and are actively involved in students’ education at universities in neighbouring cities (Braunschweig, Magdeburg, Göttingen, Hanover). Regularly, bachelor, master and PhD students perform their experimental work as part of their studies in our laboratories and under supervision of our scientists.

The unit hosts the German National Reference Centre for Staphylococci and Enterococci.


  • Tracing the emergence and spread of bacterial pathogens (Staphylococcus spp., Enterococcus spp., Enterobacteriaceae) and their characteristic determinants (antibiotic resistance, pathogenicity)
  • Deducing important markers for successful and prevalent bacterial strain types
  • Analysing nosocomial staphylococcal, enterococcal and enterobacterial isolates based on various typing methods
  • evaluating diagnostic and typing assays based on a representative set of staphylococcal, enterococcal and enterobacterial reference and type strains
  • Supporting regulatory bodies and commissions in establishing recommendations for infection prevention and control regarding nosocomial pathogens (KRINKO)

Date: 01.02.2016

National Reference Centre for Staphylococci and Enterococci

Guido Werner
Ingo Klare

Our main focus is the epidemiological surveillance of staphylococcal infections in hospitals and the community as well as of emerging and disseminating staphylococcal strains with special resistance and virulence traits (Hospital associated HA-MRSA, community-associated CA-MRSA, livestock-associated LA-MRSA).

The reference centre provides a typing service to support the analysis of nosocomial infections in a network of bacteriological laboratories at university hospitals, general hospitals, public health institutions and private diagnostic laboratories. Furthermore prospective clinical studies are supported and performed in collaboration with clinical partners. The reference centre is further involved in the evaluation of new methods of staphylococcal and enterococcal diagnostics and typing. We analyse, characterize and type approximately 4000 staphylococci (mainly MRSA) and 1000 enterococci (mainly VRE) per year. The reference centre collaborates closely with other reference laboratories mainly in Europe.

Date: 15.02.2016


  • Pietsch M, Eller C, Wendt C, Holfelder M, Falgenhauer L, Fruth A, Grössl T, Leistner R, Valenza G, Werner G, Pfeifer Y; RESET Study Group (2017): Molecular characterisation of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from hospital and ambulatory patients in Germany.
    Vet. Microbiol. 200: 130-137. Epub 2015 Nov 24. doi: 10.1016/j.vetmic.2015.11.028. more

  • Cuny C, Witte W (2017): MRSA in equine hospitals and its significance for infections in humans.
    Vet. Microbiol. 200 (2): 59-64. Epub 2016 Jan 21. doi: 10.1016/j.vetmic.2016.01.013. more

  • Bender JK, Fleige C, Klare I, Fiedler S, Mischnik A, Mutters NT, Dingle KE, Werner G (2016): Detection of a cfr(B) variant in German Enterococcus faecium clinical isolates and the impact on linezolid resistance in Enterococcus spp..
    PLoS One 11 (11): e0167042. Epub Nov 28. doi: 10.1371/journal.pone.0167042. more

  • Pfeifer Y, Trifonova A, Pietsch M, Brunner M, Todorova I, Gergova I, Wilharm G, Werner G, Savov E (2016): Clonal transmission of gram-negative bacteria with carbapenemases NDM-1, VIM-1, and OXA-23/72 in a Bulgarian hospital.
    Microb. Drug Resist.: Epub Jul 26. doi: 10.1089/mdr.2016.0059. more

  • Bender JK, Kalmbach A, Fleige C, Klare I, Fuchs S, Werner G (2016): Population structure and acquisition of the vanB resistance determinant in German clinical isolates of Enterococcus faecium ST192.
    Sci. Rep. 6: 21847. Epub Feb 23. doi: 10.1038/srep21847. more

  • Pfeifer Y, Hunfeld KP, Borgmann S, Maneg D, Blobner W, Werner G, Higgins PG (2016): Carbapenem-resistant Acinetobacter baumannii ST78 with OXA-72 carbapenemase and ESBL gene blaCTX-M-115.
    J. Antimicrob. Chemother. 71 (5): 1426-1428. Epub Jan 17. doi: 10.1093/jac/dkv462. more

  • Strommenger B, Layer F, Klare I, Werner G (2015): Pre-use susceptibility to ceftaroline in clinical Staphylococcus aureus isolates from Germany: is there a non-susceptible pool to be selected?.
    PLoS One 10 (5): e0125864. Epub May 8. doi: 10.1371/journal.pone.0125864. more

  • Cuny C, Layer F, Werner G, Harmsen D, Daniels-Haardt I, Jurke A, Mellmann A, Witte W, Köck R (2015): State-wide surveillance of antibiotic resistance patterns and spa types of Methicillin-resistant Staphylococcus aureus from blood cultures in North-Rhine-Westphalia, 2011–2013.
    Clin. Microbiol. Infect. 21 (8): 750–757. Epub Feb 19. doi: 10.1016/j.cmi.2015.02.013. more

  • Bender JK, Strommenger B, Steglich M, Zimmermann O, Fenner I, Lensing C, Dagwadordsch U, Kekulé AS, Werner G, Layer F (2015): Linezolid resistance in clinical isolates of Staphylococcus epidermidis from German hospitals and characterization of two cfr-carrying plasmids.
    J. Antimicrob. Chemother. 70 (6): 1630-1638. Epub Mar 3. doi: 10.1093/jac/dkv025. more

  • Fiedler S, Bender JK, Klare I, Halbedel S, Grohmann E, Szewzyk U, Werner G (2015): Tigecycline resistance in clinical isolates of Enterococcus faecium is mediated by an upregulation of plasmid-encoded tetracycline determinants tet(L) and tet(M).
    J. Antimicrob. Chemother.: Epub Dec 18. doi: 10.1093/jac/dkv420. more

Participation in current research activities

  • EU-funded project COMPARE:
  • BMBF-funded project IRMRESS/InfectControl2020:
  • BMBF-funded project MedVetStaph:
  • BMBF-funded project RESET:
  • BMG-funded project on genome-based phylogeny and contact-network analysis of Klebsiella pneumoniae (IIA5-2513NIK006//321-4471-02/129)
    The project aims at quantifying the benefit of a combined epidemiological, modelling and whole-genome based approach in real-time analyses of outbreaks caused by carbapenemase-producing Klebsiella penumoniae isolates. We collaborate with Units FG37 and P4 of the RKI and the National Reference Centre for multiresistant Gram-negative bacteria, Bochum, Germany.
  • BMG-funded project on Transmission dynamics of nosocomial pathogens (IIA5-2512-FSB-726)
    The project aims at identifying factors other than antibiotic usage influencing emergence and transmission dynamics of multiresistant pathogens at German Intensive Care Units. We collaborate with the University Hospital Charité, Berlin and the National Reference Centre for multiresistant Gram-negative bacteria, Bochum, Germany.
  • BMG-funded project on the Introduction of multiresistant pathogens into hospitals
    The project aims at quantifying the introduction of multiresistant pathogens into German hospitals and Intensive Care Units. We collaborate with the University Hospital Charité, Berlin, and the National Reference Centre for multiresistant Gram-negative bacteria, Bochum, Germany.
  • BMG-funded Network project of National Reference Laboratories (with focus on antibiotic resistance)
    The project aims at analysing the benefit of whole-genome analysis in a network of clinical, public health and reference laboratories in real-time surveillance and outbreak situations. We collaborate with the University Hospital Homburg, the National Reference Centre for multiresistant Gram-negative bacteria, Bochum, Unit FG37, RKI, and the Federal Public Health Laboratory Saarland, Germany.