A Novel Genome-Editing Platform for Drug-Resistant Acinetobacter baumannii Reveals an AdeR-Unrelated Tigecycline Resistance Mechanism
| Autor: | Birgit Schellhorn, Marcus Tötzl, Pablo Manfredi, Dirk Bumann, Vincent Trebosc, Marcel Tigges, Christian Kemmer, Michel Pieren, Sergio Lociuro, Peter C. Sennhenn, Kevin Royet, Sarah Gartenmann, Marc Gitzinger |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Acinetobacter baumannii 030106 microbiology Virulence Minocycline Drug resistance Tigecycline Microbial Sensitivity Tests Biology Genome Bacterial genetics Microbiology 03 medical and health sciences Gene Knockout Techniques Genome editing Mechanisms of Resistance Drug Resistance Multiple Bacterial medicine Pharmacology (medical) Gene Knock-In Techniques Pharmacology Gene Editing Base Sequence Sequence Analysis DNA biology.organism_classification Anti-Bacterial Agents Infectious Diseases ATP-Binding Cassette Transporters Efflux Genome Bacterial medicine.drug Acinetobacter Infections |
| Zdroj: | Antimicrobial agents and chemotherapy. 60(12) |
| ISSN: | 1098-6596 |
| Popis: | Infections with the Gram-negative coccobacillus Acinetobacter baumannii are a major threat in hospital settings. The progressing emergence of multidrug-resistant clinical strains significantly reduces the treatment options for clinicians to fight A. baumannii infections. The current lack of robust methods to genetically manipulate drug-resistant A. baumannii isolates impedes research on resistance and virulence mechanisms in clinically relevant strains. In this study, we developed a highly efficient and versatile genome-editing platform enabling the markerless modification of the genome of A. baumannii clinical and laboratory strains, regardless of their resistance profiles. We applied this method for the deletion of AdeR, a transcription factor that regulates the expression of the AdeABC efflux pump in tigecycline-resistant A. baumannii , to evaluate its function as a putative drug target. Loss of adeR reduced the MIC 90 of tigecycline from 25 μg/ml in the parental strains to 3.1 μg/ml in the Δ adeR mutants, indicating its importance in the drug resistance phenotype. However, 60% of the clinical isolates remained nonsusceptible to tigecycline after adeR deletion. Evolution of artificial tigecycline resistance in two strains followed by whole-genome sequencing revealed loss-of-function mutations in trm , suggesting its role in an alternative AdeABC-independent tigecycline resistance mechanism. This finding was strengthened by the confirmation of trm disruption in the majority of the tigecycline-resistant clinical isolates. This study highlights the development and application of a powerful genome-editing platform for A. baumannii enabling future research on drug resistance and virulence pathways in clinically relevant strains. |
| Databáze: | OpenAIRE |
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