Amongst the many synthetic aminoglycoside analogues that were developed to regain the efficacy of this class of antibiotics against resistant bacterial strains, the 1-N-acylated analogues are the most clinically used. In this study we demonstrate that 6'-N-acylation of the clinically used compound tobramycin and 6'''-N-acylation of paromomycin result in derivatives resistant to deactivation by 6'-aminoglycoside acetyltransferase (AAC(6')) which is widely found in aminoglycoside resistant bacteria. When tested against AAC(6')- or AAC(3)-expressing bacteria as well as pathogenic bacterial strains, some of the analogues demonstrated improved antibacterial activity compared to their parent antibiotics. Improvement of the biological performance of the N-acylated analogues was found to be highly dependent on the specific aminoglycoside and acyl group. Our study indicates that as for 1-N-acylation, 6'- and 6'''-N-acylation of aminoglycosides offer an additional promising direction in the search for aminoglycosides capable of overcoming infections by resistant bacteria.
A nondestructive
one-step approach was applied for grafting biocide-free
monodispersed silica nanoparticles (SNPs) with a diameter of 30 ±
10 nm on polystyrene, polyethylene, and polyvinyl chloride surfaces.
The prepared surfaces were comprehensively characterized using spectroscopic
(Fourier transform infrared attenuated total reflection, ultraviolet–visible,
and X-ray photoelectron spectroscopy) and microscopic (high-resolution
scanning electron microscopy and atomic force microscopy) methods.
The modified polymers were found to maintain their original mechanical
and physical properties, while their nanoroughness on the other hand
had risen by 1.6–2.7 times because of SNP grafting. The SNP-grafted
surfaces displayed anti-biofouling properties, resulting in a significant
reduction in the attached Gram-positive
Bacillus licheniformis
or Gram-negative
Pseudomonas aeruginosa
bacteria compared to their nongrafted counterparts. Confocal laser
scanning microscopy and scanning electron microscopy studies have
confirmed that bacterial cells could not successfully adhere onto
the SNP-grafted polymer films regardless of the polymer type, and
their biofilm formation was therefore damaged. The presented facile
and straightforward protocol allows eliminating the need for biocidal
agents and resorts to grafted nanosilica instead. This strategy may
serve as a feasible and safe platform for the development of sustainable
anti-biofouling surfaces in biomedical devices; food, water, and air
treatment systems; and industrial equipment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.