Effect of Gold Nanostars Plus Amikacin against Carbapenem-Resistant Klebsiella pneumoniae Biofilms
Departamento de Química en Ciencias Farmacéuticas, Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain
Networking Research Centre on Infectious Diseases (CIBERINFEC), 28029 Madrid, Spain
Bone and Joint Unit, IIS-Fundación Jiménez Diaz, UAM, Avenida Reyes Católicos, 2, 28037 Madrid, Spain
Clinical Microbiology Department, IIS-Fundación Jiménez Diaz, UAM, Avenida Reyes Católicos, 2, 28037 Madrid, Spain
Networking Research Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Academic Editors: Thomas Caspari and Annalisa Pinsino
Received: 6 November 2021
Revised: 11 January 2022
Accepted: 18 January 2022
Published: 20 January 2022
Carbapenem-resistant Klebsiella pneumoniae (CR-KP) infection rates represent a challenging treatment since the pipeline for effective antibiotics against this pathogen, such as beta-lactams among others, is practically nil. This study aims to evaluate the antibacterial effect of gold nanostars (GNS) alone or associated with some of the most widely used antibiotics for the treatment of CR-KP strains, i.e., meropenem or amikacin, on both planktonic or free-living and sessile forms. GNS were able to inhibit the planktonic growth of CR-KP at 80 µM, to eradicate the bacterial viability at 160 µM, and were unable to inhibit or eradicate the biofilm growth of this bacterium. GNS gave rise to filamentous bacteria through mechanisms mediated by the inhibition of energy-dependent cytoplasmic proteases. The combination of GNS and amikacin was able to inhibit or even eradicate the CR-KP biofilm. This combination was administered to greater wax moth larvae (Galleria mellonella), and this treatment was found to be tolerated well and to prevent the CR-KP infection. Thus, GNS in combination with amikacin represent a promising anti-CR-KP nanomaterial.