The adhered cells have been removed from the catheter sections by vortexing and brief sonication, and serial tenfold dilutions ranging from 10−4 to 10−12 of the obtained inocula have been spotted on Muller-Hinton agar, CP-690550 ic50 incubated for 24 h at 37°C, and assessed for VCCs [23, 42]. All tests were performed in triplicate. Characterization of biofilm development on the surface of nano-modified prosthetic device After 24, 48, and 72 h of incubation, the samples prepared
as described above were removed from the plastic wells, washed three times with PBS, fixed with cold methanol, and dried before microscopic examination. The biofilm development on the surface of coated and uncoated prosthetic devices was visualized using a Hitachi S2600N scanning electron microscope (SEM; Tokyo, Japan) at 25 keV, in primary electron fascicles, on samples covered with a thin silver layer. Results and discussion The increasing occurrence of multiresistant pathogenic bacterial strains has gradually rendered traditional antimicrobial treatment ineffective. The prognosis is worsened by the formation of bacterial
biofilms on the biomaterials used in medicine, even if the planktonic cells are susceptible to some antibiotics. Public reports stated that 60% to 85% of all microbial infections involve biofilms developed on natural intact or damaged tissues or artificial devices [43]. GW-572016 cell line selleck inhibitor These infections are characterized by slow onset, middle-intensity symptoms, chronic evolution, and high tolerance to antibiotics and other antimicrobials [44]. The efficiency of essential oils, polyphenolic extracts obtained from foregoing plants, and their synergic effects as alternative strategies
for the treatment of severe infections caused by highly resistant bacteria was tested on the following species: methicillin-resistant S. aureus, extended-spectrum beta-lactamases producing Escherichia coli, and multiresistant Pseudomonas aeruginosa[8]. Previous studies have demonstrated that the mint essential oil (Mentha sp.) exhibited synergistic inhibitory effects with low pH and sodium chloride against Listeria and inhibited some organisms such as S. aureus, E. coli, Candida albicans, Acinetobacter baumanii, Enterococcus faecalis, Klebsiella pneumoniae, Salmonella enterica subsp. enterica serotype Typhimurium, and Serratia marcescens[45]. The analyzed M. piperita EO proved to be rich in β-pinene, limonene, menthone, isomenthol, and menthol. These results are in concordance with reported literature [46, 47]. We have suggested before the efficiency of nanosystem-vectored essential oil strategy [23]. The Fe3O4/C12 nanoparticles seem not to be cytotoxic on the HEp2 cell line, which is a great advantage for the in vivo use of these nanostructure systems for biomedical applications with minor risks of the occurrence of side effects [48].