Screening of antibiotic susceptibility to β-lactam-induced elongation of gram-negative bacteria based on dielectrophoresis

Cheng Che Chung, I. Fang Cheng, Hung Mo Chen, Heng Chuan Kan, Wen Horng Yang, Hsien Chang Chang

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


We demonstrate a rapid antibiotic susceptibility test (AST) based on the changes in dielectrophoretic (DEP) behaviors related to the β-lactam- induced elongation of Gram-negative bacteria (GNB) on a quadruple electrode array (QEA). The minimum inhibitory concentration (MIC) can be determined within 2 h by observing the changes in the positive-DEP frequency (pdf) and cell length of GNB under the cefazolin (CEZ) treatment. Escherichia coli and Klebsiella pneumoniae and the CEZ are used as the sample bacteria and antibiotic respectively. The bacteria became filamentous due to the inhibition of cell wall synthesis and cell division and cell lysis occurred for the higher antibiotic dose. According to the results, the pdfs of wild type bacteria decrease to hundreds of kHz and the cell length is more than 10 μm when the bacterial growth is inhibited by the CEZ treatment. In addition, the growth of wild type bacteria and drug resistant bacteria differ significantly. There is an obvious decrease in the number of wild type bacteria but not in the number of drug resistant bacteria. Thus, the drug resistance of GNB to β-lactam antibiotics can be rapidly assessed. Furthermore, the MIC determined using dielectrophoresis-based AST (d-AST) was consistent with the results of the broth dilution method. Utilizing this approach could reduce the time needed for bacteria growth from days to hours, help physicians to administer appropriate antibiotic dosages, and reduce the possibility of the occurrence of multidrug resistant (MDR) bacteria.

Original languageEnglish
Pages (from-to)3347-3354
Number of pages8
JournalAnalytical Chemistry
Issue number7
Publication statusPublished - 2012 Apr 3

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry


Dive into the research topics of 'Screening of antibiotic susceptibility to β-lactam-induced elongation of gram-negative bacteria based on dielectrophoresis'. Together they form a unique fingerprint.

Cite this