silicon and Escherichia-coli-Infections

Bacteria detection plays an important role in the guarantee of food and water safety. This work proposed a new sensing strategy for the rapid detection of bacteria based on its blockage effect on nanopore array, which was prepared from electrochemically etched silicon. With the assistance of microfluidic technology, the nanopore array attached with Escherichia coli antibody can selectively and rapidly capture E. coli bacteria, resulting in the decrease of pore accessibility. The signal of pore blockage can be measured by in-direct Fourier Transformed Reflectometric Interference Spectroscopy (FT-RIS). The pore blockage signal has a linear relationship with the logarithm of bacterial density in aqueous sample within the range from 10(3) to 10(7)cfuml(-1). Due to the specific interaction between the antibody and target bacteria, only the E. coli sample displayed significant pore blockage effect, whereas the non-target bacteria, Nox and P17, almost did not show any pore blockage effect. The strategy established in this work might be pervasively applied in the rapid detection of target bacteria and cell in a label-free manner.

Topics: Antibodies, Immobilized; Biosensing Techniques; Equipment Design; Escherichia coli; Escherichia coli Infections; Humans; Lab-On-A-Chip Devices; Nanopores; Silicon; Spectrum Analysis

Methodology for the functionalization of silicon-based materials employed for the development of photonic label-free nanobiosensors is reported. The studied functionalization based on organosilane chemistry allowed the direct attachment of biomolecules in a single step, maintaining their bioavailability. Using this immobilization approach in probe microarrays, successful specific detection of bacterial DNA is achieved, reaching hybridization sensitivities of 10 pM. The utility of the immobilization approach for the functionalization of label-free nanobiosensors based on photonic crystals and ring resonators was demonstrated using bovine serum albumin (BSA)/anti-BSA as a model system.

Topics: Animals; Antibodies; Biosensing Techniques; Cattle; DNA, Bacterial; Equipment Design; Escherichia coli; Escherichia coli Infections; Humans; Immobilized Proteins; Interferometry; Limit of Detection; Nanostructures; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Optics and Photonics; Serum Albumin, Bovine; Silicon; Surface Properties

The aim of this study was evaluation of adhesion of E. coli rods to urological catheters made of different synthetic materials. This study included 74 of E. coli strains isolated from urine and blood samples. All of these strains were isolated in the Clinical Microbiology Department of dr A. Jurasz University Hospital in 2003-2006. Analized strains significantly more often adhered to latex catheters than latex catheters covered by silicon and significantly more often adhered to PCV catheters than latex catheters covered by silicon. Four strains were characterized by a strong adhesion to all kinds used urological catheters, used in this study. Among E. coli strains isolated from the blood a higher percentage of strains demonstated adhesion to latex and PCV catheters than in the group of E. coli strains isolated from urine samples (79.3% vs. 68.9% and 69.0% vs. 55.6%, respectively). Out of strains demonstrating the adhesion to urological catheters, the most came from the patients from Clinic of the Nephrology, of Arterial Hypertension and Internal Diseases with the Station of Dialyses. All of lactose-negative E. coli strains adhered weakly to urological catheters.

Topics: Bacterial Adhesion; Biocompatible Materials; Catheters, Indwelling; Equipment Contamination; Escherichia coli; Escherichia coli Infections; Humans; Latex; Materials Testing; Silicon; Urinary Catheterization