title: Nitrite inhibits hydrogen production and kills the cattle parasite Tritrichomonas foetus.
abstract: OBJECTIVE
  To investigate the effects of NaNO2 on the microaerophilic flagellated protozoan, Tritrichomonas foetus KV1, an economically important cattle parasite that inhabits the vagina and can spread rapidly through herds of animals by sexual transmission and leads to abortion of foetal calves.
  
  
  RESULTS
  Growth of the parasite was inhibited by 50% in the presence of 4 mm NaNO2; immediate killing occurred at 10 mm. Mass spectrometric monitoring of gases showed that H2 and CO2 evolution were inhibited by NaNO2, and electron paramagnetic resonance spectrometry revealed a signal similar to that of a thiolate-iron-NO complex. Growth with sublethal concentrations of NaNO2 yielded organisms that produced ethanol rather than H2.
  
  
  CONCLUSIONS
  NaNO2 probably inactivates FeS protein(s) of hydrogenosomes so as to inhibit the conversion of pyruvate (derived from maltose in the growth medium) to H2 and acetate.
  
  
  CONCLUSIONS
  The use of NaNO2 as a topical antitrichomonal agent in veterinary practice is a possibility. At present, slaughter of infected animals is the favoured method of control.
authors.affiliation: Microbiology (BIOSI 1), Cardiff University, Cardiff, Wales, UK. lloydd@cardiff.ac.uk
authors.forename: D
authors.initials: D
authors.lastname: Lloyd
authors.forename: A S
authors.initials: AS
authors.lastname: Williams
authors.forename: C J
authors.initials: CJ
authors.lastname: James
mesh_terms: D000818:Animals; D000994:Antitrichomonal Agents / Q000494:pharmacology*; D002245:Carbon Dioxide / Q000378:metabolism; D002417:Cattle; D003470:Culture Media; D004578:Electron Spin Resonance Spectroscopy; D006859:Hydrogen / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D010100:Oxygen / Q000378:metabolism; D012977:Sodium Nitrite / Q000494:pharmacology*; D016835:Tritrichomonas foetus / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D000994:Antitrichomonal Agents; D003470:Culture Media; D002245:Carbon Dioxide; D006859:Hydrogen; D012977:Sodium Nitrite; D010100:Oxygen