On-chip acoustophoretic isolation of microflora including S. typhimurium from raw chicken, beef and blood samples
| Autor: | Pradip Patel, Maria Jose Lopez-Martinez, Bongkot Ngamsom, Jean-Claude Raymond, Nicole Pamme, Patrick Broyer |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Microbiology (medical)
Salmonella typhimurium Salmonella Meat Food Contamination 02 engineering and technology Biology medicine.disease_cause 01 natural sciences Microbiology Polymerase Chain Reaction law.invention food law medicine Animals Humans Sample preparation Centrifugation Food science Molecular Biology Filtration business.industry 010401 analytical chemistry Contamination Microfluidic Analytical Techniques 021001 nanoscience & nanotechnology Isolation (microbiology) Minced beef food.food 0104 chemical sciences Biotechnology Blood Cattle 0210 nano-technology business Chickens Food contaminant |
| Zdroj: | Journal of microbiological methods. 123 |
| ISSN: | 1872-8359 |
| Popis: | Pathogen analysis in food samples routinely involves lengthy growth-based pre-enrichment and selective enrichment of food matrices to increase the ratio of pathogen to background flora. Similarly, for blood culture analysis, pathogens must be isolated and enriched from a large excess of blood cells to allow further analysis. Conventional techniques of centrifugation and filtration are cumbersome, suffer from low sample throughput, are not readily amenable to automation and carry a risk of damaging biological samples. We report on-chip acoustophoresis as a pre-analytical technique for the resolution of total microbial flora from food and blood samples. The resulting 'clarified' sample is expected to increase the performance of downstream systems for the specific detection of the pathogens. A microfluidic chip with three inlets, a central separation channel and three outlets was utilized. Samples were introduced through the side inlets, and buffer solution through the central inlet. Upon ultrasound actuation, large debris particles (10-100 μm) from meat samples were continuously partitioned into the central buffer channel, leaving the 'clarified' outer sample streams containing both, the pathogenic cells and the background flora (ca. 1 μm) to be collected over a 30 min operation cycle before further analysis. The system was successfully tested with Salmonella typhimurium-spiked (ca. 10(3)CFU mL(-1)) samples of chicken and minced beef, demonstrating a high level of the pathogen recovery (60-90%). When applied to S. typhimurium contaminated blood samples (10(7)CFU mL(-1)), acoustophoresis resulted in a high depletion (99.8%) of the red blood cells (RBC) which partitioned in the buffer stream, whilst sufficient numbers of the viable S. typhimurium remained in the outer channels for further analysis. These results indicate that the technology may provide a generic approach for pre-analytical sample preparation prior to integrated and automated downstream detection of bacterial pathogens. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect