Subclonal typing of ST131 E. coli by Fourier-transform infrared spectroscopy reveals variable metabolic profiles within the predominant H30 subclone

Author(s):  
Angela Novais
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Simona-Liliana Iconaru ◽  
Mikael Motelica-Heino ◽  
Daniela Predoi

Fourier transform infrared spectroscopy (FT-IR) analysis was conducted on europium-doped hydroxyapatite,Ca10-xEux(PO4)6(OH)2nanocrystalline powders (Eu:HAp) with0≤xEu≤0.2. Antimicrobial studies were also performed for the first time on Eu:HAp. The antimicrobial properties of Eu:HAp nanoparticles with0≤xEu≤0.2on Gram-negative (E. coli ATCC 25922,Pseudomonas aeruginosa 1397) and Gram-positive (Staphylococcus aureus 0364,Enterococcus faecalis ATCC 29212) bacteria systems and a species of fungus (Candida albicans ATCC 10231) were reported. Our study demonstrates that the antimicrobial activity of Eu:HAp nanoparticles is dependent on the europium concentration.


Author(s):  
B Aksakal ◽  
M Demirel

Selenium (Se)- and Silver (Ag)-doped Bioglass®-based biografts were synthesized using the sol–gel method. Fourier-transform infrared spectroscopy, inductively coupled plasma mass spectrometry, scanning electron microscopy and energy-dispersive X-ray analyses were carried out in order to examine mechanostructure of synthesized bioglass-based bioceramics. The effects of Se and Ag additions on cell viability were investigated via cytotoxicity and antibacterial activity analysis, respectively. The bacteria of Escherichia coli ( E. coli, JM103) and Gram-positive Staphylococcus aureus ( S. aureus, ATCC29293) were used to perform the antibacterial tests. Moreover, cell viability studies were conducted using the Saos-2 osteoblast cells by performing dimethylthiazol diphenyltetrazolium bromide assay. It was observed that while (PO4)3− and (CO3)2− peaks were observed in Fourier-transform infrared spectroscopy analyses, crystallinity also increased with increasing amount of AgNO3 addition into the Bioglass®. In addition, it was determined from scanning electron microscopy images that small irregular thin lamellar grain distribution was formed in synthesized B45Ag5Se20 and B30Ag10Se15 biografts. From antibacterial activity tests, it was determined that while some grafts was affected by E. coli, which is a Gram-negative, however, some did not affect the Gram-positive S. aureus and had antimicrobial activity on E. coli and S. aureus. According to the cell viability tests, it was found that the synthesized grafts did not have toxic effect on living cells. While the cell growth was greater for some grafts, however, some others had lower growth.


Author(s):  
Tiago Mateus ◽  
Idália Almeida ◽  
Adriana Costa ◽  
Diana Viegas ◽  
Sandra Magalhães ◽  
...  

Myotonic dystrophy type 1 (DM1) is a hereditary disease characterized by progressive distal muscle weakness and myotonia. Patients with DM1 have abnormal lipid metabolism and a high propensity to develop a metabolic syndrome in comparison to the general population. It follows that metabolome evaluation in these patients is crucial and may contribute to a better characterization and discrimination between DM1 disease phenotypes and severities. Several experimental approaches are possible to carry out such an analysis; among them is Fourier-transform infrared spectroscopy (FTIR) which evaluates metabolic profiles by categorizing samples through their biochemical composition. In this study, FTIR spectra were acquired and analyzed using multivariate analysis (Principal Component Analysis) using skin DM1 patient-derived fibroblasts and controls. The results obtained showed a clear discrimination between both DM1-derived fibroblasts with different CTG repeat length and with the age of disease onset; this was evident given the distinct metabolic profiles obtained for the two groups. Discrimination could be attributed mainly to the altered lipid metabolism and proteins in the 1800–1500 cm−1 region. These results suggest that FTIR spectroscopy is a valuable tool to discriminate both DM1-derived fibroblasts with different CTG length and age of onset and to study the metabolomic profile of patients with DM1.


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