Valentina Y

Abstract

Aim: To compare the different phenotypic methods for detection of bacteriological profile on Vancomycin Resistant Enterococci (VRE) among clinical isolates Design: Prospective study Material and Methods: 480 Clinical samples sent for bacteriological examination and culture sensitivity were taken up in this study. Preliminary findings and identification of Enterococci species was carried out using Grams staining, Catalase test, Bile esculin test and growth in NaCl, followed by Antibiotic sensitivity testing in Muller Hilton Agar. The resistant strains were subjected to agar dilution method, Vancomycin estrip method and Vitek-2 automated system for phenotypic detection of Vancomycin resistance. The results were observed and analysed. Results: Among 480 clinical specimens analysed, 120 Enterococci species (25.0%) were isolated. Out of 120 isolates, 40 (33.33%) were resistant to Vancomycin and 80 (66.7%) were sensitive to Vancomycin by disc diffusion method. On further analysis, Vancomycin E-Strip and Vitek-2 showed almost similar results making them more reliable compared to agar dilution method. Keywords: VRE, Enterococci, Phenotypic methods, Vitek2, Estrip, Resistance.

View Article

Abstract

Introduction: The all-around attraction towards Silver Nanoparticles (AgNPs) is fairly due to its biocompatibility, so that it can be used in therapeutics and diagnostics. In order, to harvest them with such unique properties, there is this pressing urge to develop a cheaper and an eco-friendly process without the use of toxic chemicals. In lieu of this, this study was taken up to optimise the reactant parameters required to obtain a maximum yield of AgNPs using cell-free culture extract of bacteria obtained from clinical sources. Materials and Methods: Bacterial strains were procured from routine clinical samples. Bacterial biomass production was done in liquid media which was further harvested and lysed. The supernatent(E) in varying concentrations was then mixed with varying concentrations of 1mM AgNO3(M) (E:M ratio). Visual examination for colour change and confirmation by UV-Spectrophotometry (UV-S) was done and AgNPs were separated by Ultra-centrifugation. The synthesised NanoParticles(NPs) were characterized by Scanning Electron Microscopy(SEM) and X-Ray Diffraction(XRD) studies for confirmation. Results: The UV-S showed an absorption value at 450nm as 1.3 in 1E:1M for Escherichia coli followed by Abs: 1.0 for Staphylococcus aureus in 1E:1M ratio. The Dynamic Light Scattering study showed that the particles obtained in the study were predominantly in the acceptable range of 127.35nm & 90.96nm for Staphylococcus aureus & Escherichia coli respectively. When observed under SEM, the synthesised particles were found to be agglomerated, but polydispersed and crystalline in nature. In XRD study a maximum peak was obtained at 38.22 which confirmed the crystalline structure synthesized from bacterial extract as AgNPs when compared with JCPD standards. Keywords: Nanotechnology, Nanoparticles, Silver, Bacteria.

View Article