Rapid detection of ESKAPE and enteric bacteria using tapered dielectrophoresis and their presence in urban water cycle

ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and enteric bacteria Shigella dysenteriae, Salmonella typhimurium and Escherichia Coli have been causing increasing nosocomial infections worldwide, contributing to high mortality and morbidity in surgical wards. This study attempts to investigate the feasibility of dieletrophoresis (DEP) electrode in detecting both ESKAPE and enteric bacteria in water samples. The detection is based on the bacteria's response to the non-uniform electric field in micro tapered DEP electrode and microfluidic chamber. Responses of each bacterium were recorded by varying the frequency of sinusoidal 6 voltage (peak to peak) from 10 to 13,000 kHz. Utilising the unique electrokinetic responses of each bacterium, the performance of DEP application is assessed in detecting the ESKAPE and enteric bacteria from samples within the urban water cycle, i. e., wastewater, river, runoff, and treated water from an urbanised developed area. The positive (PDEP), negative (NDEP) and transitional, (denote as the crossover frequency fx0) responses for each bacterium were consistently determined, spanning between 52.3 and 12,000 kHz. DEP technique was successfully able to detect ESKAPE and enteric bacteria from water samples, where water from the river proved to be the most microbially contaminated in urban water cycle.

Automated summary

This study investigates the feasibility of using dielectrophoresis (DEP) electrode to detect ESKAPE and enteric bacteria in water samples. By recording the response of bacteria to the non-uniform electric field in micro tapered DEP electrode and microfluidic chamber at varying frequencies, the positive, negative, and transitional electrokinetic responses of each bacterium can be determined. DEP technique successfully detects ESKAPE and enteric bacteria in water samples, with the highest microbial contamination found in river water in the urban water cycle.