Publikationsdatenbank

Molecular investigation of heteroresistance in a multi-resistant clinical Enterobacter cloacae complex strain (2021)

Art

Poster

Autoren

Kupke, Johannes (WE 7)

Brombach, Julian (WE 7)

Semmler, Torsten

Hanke, Dennis (WE 7)

Ghazisaeedi, Fereshteh (WE 7)

Lübke-Becker, Antina (WE 7)

Fulde, Marcus (WE 7)

Kongress

Zoonoses 2021

online, 13. – 15.10.2021

Quelle

Zoonoses 2021 - International Symposium on Zoonoses Research : joint meeting of the German Research Platform for Zoonoses and the Research Network Zoonotic Diseases : program and abstracts — Forschungsnetz zoonotische Infektionskrankheiten, German Research Platform for Zoonoses (Hrsg.)

— S. 26

Sprache

Englisch

Verweise

URL (Volltext): https://evis.events/event/170/attachments/90/194/Zoonoses%202021%20-%20BoA_13.10.2021-2.pdf

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Introduction:
Heteroresistance (HR) describes a growing subpopulation in presence of bactericidal antibiotic concentrations that kill most of the bacterial population. We investigated HR in a clinical Enterobacter cloacae complex (ECC) strain (IMT49658).

Materials & Methods:
Population analysis profiles (PAPs) were conducted on Mueller-Hinton II agar with 0, 0.125, 0.25, 0.5, 1, 2, 4, 8 and 16 x breakpoint-concentration (16 µg/ml) of ceftazidime (CAZ) in accordance with CLSI standard to confirm a resistant subpopulation. The latter we investigated by continuous subcultivation on non-selective media without CAZ.

Results:
Subcultivation-steps revealed the increased CAZ resistant phenotype as unstable as cells reverted to a less resistant population. PAPs underlined the observation of HR with growth at up to 16-fold breakpointconcentration. WGS showed identical genomes of resistant and susceptible colonies. Nonetheless qRTPCR shed light on an increased expression of blaDHA-1 and its corresponding regulator ampR in resistant bacterial entities. Furthermore, proteomic analysis confirmed an upregulated arginin-deiminase-system (ADS) in the resistant subpopulation.

Conclusion:
Research on HR constitutes an urgent contribution to treatment-pitfall against bacterial zoonotic infections. Our results identified DHA-1/AmpR as a potential mediator of HR in the studied clinical ECCstrain. Association of the ADS with β-lactamase may provide a fitness-advantage.