Nadja Haarmann
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Nadja Haarmann has a total of 9 co-authors. Here are the top co-authors by number of shared publications:
- Alexander Mellmann
Institute for Hygiene, University Hospital Münster, Münster, Germany
1 shared publication - Gerald. B. Koudelka
Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260, USA
1 shared publication - Herbert Schmidt
Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
1 shared publication - Lang Peng
Institute of Hygiene, University of Münster, 48149 Münster, Germany
1 shared publication - Marco Chittò
AO Research Institute Davos, 7270 Davos, Switzerland
1 shared publication - Michael Berger
Institute of Hygiene, University of Münster, Münster, Germany
1 shared publication
Latest Publications
- Open Access
- 23 August 2022
- Published by MDPI AG in Microorganisms
- Vol. 10 (9) , 1689
A Robust One-Step Recombineering System for Enterohemorrhagic Escherichia coli
Enterohemorrhagic Escherichia coli (EHEC) can cause severe diarrheic in humans. To improve therapy options, a better understanding of EHEC pathogenicity is essential. The genetic manipulation of EHEC with classical one-step methods, such as the transient overexpression of the phage lambda (λ) Red functions, is not very efficient. Here, we provide a robust and reliable method for increasing recombineering efficiency in EHEC based on the transient coexpression of recX together with gam, beta, and exo. We demonstrate that the genetic manipulation is 3–4 times more efficient in EHEC O157:H7 EDL933 Δstx1/2 with our method when compared to the overexpression of the λ Red functions alone. Both recombineering systems demonstrated similar efficiencies in Escherichia coli K-12 MG1655. Coexpression of recX did not enhance the Gam-mediated inhibition of sparfloxacin-mediated SOS response. Therefore, the additional inhibition of the RecFOR pathway rather than a stronger inhibition of the RecBCD pathway of SOS response induction might have resulted in the increased recombineering efficiency by indirectly blocking phage induction. Even though additional experiments are required to unravel the precise mechanistic details of the improved recombineering efficiency, we recommend the use of our method for the robust genetic manipulation of EHEC and other prophage-carrying E. coli isolates.
- 23 August 2022
- Published by MDPI AG in Microorganisms
- Vol. 10 (9) , 1689
Open AccessA Robust One-Step Recombineering System for Enterohemorrhagic Escherichia coli
Enterohemorrhagic Escherichia coli (EHEC) can cause severe diarrheic in humans. To improve therapy options, a better understanding of EHEC pathogenicity is essential. The genetic manipulation of EHEC with classical one-step methods, such as the transient overexpression of the phage lambda (λ) Red functions, is not very efficient. Here, we provide a robust and reliable method for increasing recombineering efficiency in EHEC based on the transient coexpression of recX together with gam, beta, and exo. We demonstrate that the genetic manipulation is 3–4 times more efficient in EHEC O157:H7 EDL933 Δstx1/2 with our method when compared to the overexpression of the λ Red functions alone. Both recombineering systems demonstrated similar efficiencies in Escherichia coli K-12 MG1655. Coexpression of recX did not enhance the Gam-mediated inhibition of sparfloxacin-mediated SOS response. Therefore, the additional inhibition of the RecFOR pathway rather than a stronger inhibition of the RecBCD pathway of SOS response induction might have resulted in the increased recombineering efficiency by indirectly blocking phage induction. Even though additional experiments are required to unravel the precise mechanistic details of the improved recombineering efficiency, we recommend the use of our method for the robust genetic manipulation of EHEC and other prophage-carrying E. coli isolates.