An Examination of the Validity of MRPS Method for the Detection of Label-free E. Coli and Enterococci in Ships Ballast Water

Abstract

To test for compliance with the D-2 standard for ballast water management convention of the International Maritime Organization, the bacteriological quality of ship's ballast water is determined to evaluate the risk of invasion of non-indigenous species both onboard ship and in Port. In this article, hydrodynamic flow focusing particles viewed through a microfluidic resistive pulse sensor (MRPS) was used to detect the pathogenic bacteria from ship's ballast water. Escherichia coli and Enterococci were addressed as bacterial indicators to determine of their characteristic and concentration. The system provided the individual particle-by-particle readout in rather large 20 μm x 10 μm x 8 μm (length x width x height) horizontal rectangular microchannel duct. The average volume flow rate was 4.5 μl/min. However, it returned online and real time results for a complete of 30 μl sample volume during 15 min. The system was low maintenance, high in sensitivity, good accuracy and reliable. Targeted bacteria needed neither labelling nor extracting DNA.