Anti-microbial action against verotoxigenic Escherichia coli O157:H7 of nitric oxide derived from sodium nitrite

Hidetoshi Morita, Hiroshi Yoshikawa, Takehito Suzuki, Shin Hisamatsu, Yukio Kato, Ryoichi Sakata, Yukiharu Nagata, Tetsuhiko Yoshimura

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


The levels of verotoxin-1 and verotoxin-2 released by verotoxigenic Escherichia coli O157:H7 treated in vitro with sodium nitrite, sodium chloride and several antibiotics were evaluated. Of the three strains of E. coli O157:H7 used in this study, two strains produced both verotoxin-1 and verotoxin-2, and one strain produced only verotoxin-2. Treatment of E. coli O157:H7 with sodium nitrite (6,000 mg/l, minimum inhibitory concentration) did not increase the levels of verotoxin-1 and verotoxin-2 compared with a treatment by sodium chloride or antibiotics. When the electron paramagnetic resonance spectrum of sodium nitrite-treated bacterial cells was examined at 77 K to clarify the mechanism for the anti-bacterial activity of nitric oxide derived from sodium nitrite, electron paramagnetic resonance signals with g-values of 2.035 and 2.010 were observed. These were identified as being derived from iron-nitric oxide complexes. It appears that the dinitrosyl iron complexes in the E. coli O157:H7 cells were generated from the reaction of iron-sulfur proteins (enzymes) with nitric oxide formed by the reduction of sodium nitrite. The amount of ATP was decreased by the presence of sodium nitrite in the cell suspension. These findings indicate that nitric oxide derived from sodium nitrite penetrated the cells and inactivated enzymes related to the respiratory chain.

Original languageEnglish
Pages (from-to)1027-1034
Number of pages8
JournalBioscience, Biotechnology and Biochemistry
Issue number5
Publication statusPublished - May 2004
Externally publishedYes


  • Dinitrosyl iron complex
  • Nitric oxide
  • Verotoxigenic Escherichia coli O157:H7

ASJC Scopus subject areas

  • Biotechnology
  • Analytical Chemistry
  • Biochemistry
  • Applied Microbiology and Biotechnology
  • Molecular Biology
  • Organic Chemistry


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