ABSTRACT
Antimicrobial peptide amphiphiles (PAs) are a promising class of molecules that can disrupt the bacterial membrane or act as drug nanocarriers. In this study, we prepared 33â PAs to establish supramolecular structure-activity relationships. We studied the morphology and activity of the nanostructures against different Gram-positive and Gram-negative bacterial strains (such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii). Next, we used principal component analysis (PCA) to determine the key contributors to activity. We found that for S. aureus, the zeta potential was the major contributor to the activity while Gram-negative bacteria were more influenced by the partition coefficient (LogP) with the following order P. aeruginosa>E. coli>A. baumannii. We also performed a study of the mechanism of action of selected PAs on the bacterial membrane assessing the membrane permeability and depolarization, changes in zeta potential and overall integrity. We studied the toxicity of the nanostructures against mammalian cells. Finally, we performed an inâ vivo study using the wax moth larvae to determine the therapeutic efficacy of the active PAs. This study shows cationic PA nanostructures can be an intriguing platform for the development of nanoantibacterials.
Subject(s)
Anti-Infective Agents , Staphylococcus aureus , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Escherichia coli , Anti-Infective Agents/pharmacology , Peptides , Structure-Activity Relationship , Microbial Sensitivity Tests , Pseudomonas aeruginosa , MammalsABSTRACT
The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05 % showed susceptibility to all antimicrobials tested, 20.58 % were resistant to cefepime, and 24 % showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.
Subject(s)
Abattoirs , Drug Resistance, Microbial , Pseudomonas/drug effects , Sus scrofa/microbiology , Animals , Anti-Bacterial Agents/pharmacology , Brazil , Disk Diffusion Antimicrobial Tests , Industrial Waste , Medical Waste Disposal/methods , Pseudomonas/classification , Pseudomonas/isolation & purification , Retrospective Studies , Species Specificity , Swine , Waste Disposal, Fluid/methods , Wastewater/microbiology , Water MicrobiologyABSTRACT
The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05
showed susceptibility to all antimicrobials tested, 20.58
were resistant to cefepime, and 24
showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.
Subject(s)
Abattoirs , Pseudomonas/drug effects , Drug Resistance, Microbial , Sus scrofa/microbiology , Animals , Anti-Bacterial Agents/pharmacology , Brazil , Waste Disposal, Fluid/methods , Medical Waste Disposal/methods , Species Specificity , Retrospective Studies , Water Microbiology , Pseudomonas/classification , Pseudomonas/isolation & purification , Industrial Waste , Swine , Disk Diffusion Antimicrobial Tests , Wastewater/microbiologyABSTRACT
The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05
showed susceptibility to all antimicrobials tested, 20.58
were resistant to cefepime, and 24
showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.
