Quantitative biofilm assay using a microtiter plate to screen for enteroaggregative Escherichia coli

Naoko Wakimoto, Junichiro Nishi, Jalaluddin Sheikh, James P. Nataro, Jav Sarantuya, Mayumi Iwashita, Kunihiro Manago, Koichi Tokuda, Masao Yoshinaga, Yoshifumi Kawano

Research output: Contribution to journalArticlepeer-review

117 Citations (Scopus)


The gold standard for identification of Enteroaggregative Escherichia coli (EAEC) remains the HEp-2 cell adherence test, which is time-consuming and requires specialized facilities. We evaluated the usefulness of a quantitative biofilm assay to screen for EAEC from a total of 1,042 E. coli strains from children with diarrhea. Bacteria were incubated overnight in high-glucose Dulbecco's modified Eagle's medium using a polystyrene microtiter plate. The plate was stained with crystal violet after washing, and the biofilm was quantified using an enzyme-linked immunosorbent assay plate reader. The aggR gene was evaluated by a polymerase chain reaction. Forty-eight (77.4%) of 62 strains with an optical density at 570 nm (OD570) > 0.2 were identified as EAEC by the HEp-2 adherence test, while no EAEC was found in strains with an OD570 ≤ 0.2. Twenty-one aggR+ and 27 aggR- EAEC strains could be screened by an OD570 > 0.2 using this assay. Although confirmation by a HEp-2 cell adherence test is needed, this biofilm assay is convenient and useful in screening for EAEC.

Original languageEnglish
Pages (from-to)687-690
Number of pages4
JournalAmerican Journal of Tropical Medicine and Hygiene
Issue number5
Publication statusPublished - 2004 Nov
Externally publishedYes

ASJC Scopus subject areas

  • Parasitology
  • Virology
  • Infectious Diseases


Dive into the research topics of 'Quantitative biofilm assay using a microtiter plate to screen for enteroaggregative Escherichia coli'. Together they form a unique fingerprint.

Cite this