Universität zu Köln

Meyer, Christina ORCID: 0000-0001-6157-6132 (2025). Contribution of RND-type efflux pumps in reduced susceptibility to biocides in Acinetobacter baumannii. PhD thesis, Universität zu Köln.

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Abstract

Bacterial efflux pumps are among the key mechanisms of resistance against antibiotics and biocides. We investigated whether differential expression levels of the RND-type efflux pumps AdeABC and AdeIJK impacted the susceptibility to commonly used biocides in multidrug-resistant Acinetobacter baumannii. Susceptibility testing and time–kill assays of defined laboratory and clinical A. baumannii strains with different levels of efflux pump expression were performed after exposure to the biocides benzalkonium chloride, chlorhexidine digluconate, ethanol, glucoprotamin, octenidine dihydrochloride, and triclosan. While the impact of efflux pump expression on susceptibility to the biocides was limited, noticeable differences were found in kill curves, where AdeABC expression correlated with greater survival after exposure to benzalkonium chloride, chlorhexidine digluconate, glucoprotamin, and octenidine dihydrochloride. AdeABC expression levels did not impact kill kinetics with ethanol nor triclosan. In conclusion, these data indicate that the overexpression of the RND-type efflux pumps AdeABC and AdeIJK contributes to the survival of A. baumannii when exposed to residual concentrations of biocides.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Meyer, Christina christinameyer@posteo.de orcid.org/0000-0001-6157-6132 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-784929
Date:	2025
Language:	English
Faculty:	Faculty of Medicine
Divisions:	Faculty of Medicine > Medizinische Mikrobiologie, Immunologie und Hygiene > Institut für Medizinische Mikrobiologie, Immunologie und Hygiene
Subjects:	Life sciences Medical sciences Medicine
Uncontrolled Keywords:	Keywords Language efflux English biocides English Acinetobacter baumannii English
Date of oral exam:	24 August 2024
Referee:	Name Academic Title Seifert, Harald Universitätsprofessor Dr. med. Gründemann, Dirk Professor Dr. phil. nat.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/78492