Abstract
This study aimed at evaluating real-time, low-cost detection and quantification of bacteria, exemplified by E. coli O157 and Salmonella enterica serovar Typhimurium in aqueous systems. The approach takes advantage of the well-established latex-based immunoassay (LBI) and combines it with bacteria trapping and measuring using ultrasound. The results obtained demonstrate the utility of combining ultrasound standing waves of mean energy density 10 W cm-2, acoustic amplitude 100 kPa, and a laminar flow rate of the medium of 60 μl min-1 to trap selectively E. coli O157 or Salmonella enterica serovar Typhimurium (S. typhimurium) bacteria attached to 300-400 nm-antibody-coated latex particles. The ultrasound velocity measurements enabled a sensitivity down to 1.6 × 104 colony-forming units (CFU) ml-1 for E. coli O157 and 4.0 × 104 CFU ml-1 for S. typhimurium, compared to a sensitivity of 8.36 × 105 CFU ml-1 for E. coli O157 and 6.4 × 10 6 CFU ml-1 for S. typhimurium obtained by the standard LBI. The assay sensitivity can be further improved by use of various fluorescence methodologies.
Original language | English |
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Pages (from-to) | 395-403 |
Number of pages | 9 |
Journal | Analytical Methods |
Volume | 6 |
Issue number | 2 |
DOIs | |
State | Published - 21 Jan 2014 |