title: Chlorhexidine digluconate induces mitotic recombination in diploid cells of Aspergillus nidulans.
abstract: Chlorhexidine digluconate (1,1'-hexamethylene-bis[(5-p-clorophenyl)-biguanide]) is a bisbiguanidine antiseptic, used to decrease plaque formation and to control periodontal diseases. The determination of the frequency of mitotic crossing-over constitutes a very important method for detecting carcinogenic agents.
  
  
  OBJECTIVE
  The recombinogenic potential of chlorhexidine digluconate was evaluated on Aspergillus nidulans by the production of cells homozygous for the following nutritional markers: riboA1, pabaA124, biA1, methA17 and pyroA4.
  
  
  METHODS
  A. nidulans was exposed to three concentrations of chlorhexidine digluconate (1, 5, and 10 microM).
  
  
  RESULTS
  Inhibition of colony development, conidiophore morphological alteration (cytotoxic effect), and the recombinogenic effect, indicated by homozygotization index (HI) values higher than 2.0, were observed for all concentrations of chlorhexidine digluconate. A homozygous pyro+//pyro+ diploid strain and a diploid homozygous for the recessive w gene were isolated from UT448//A757 diploid treated with chlorhexidine digluconate, emphasazing its recombinogenic potential.
  
  
  CONCLUSIONS
  Although, beneficial effects of chlorhexidine, as an antiseptic agent, are reported in the literature, our results revealed that chlorhexidine digluconate, at less levels lowered those used clinically, caused toxic and recombinogenic effects on diploid A. nidulans strain.
authors.affiliation: Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, Brazil.
authors.forename: S A
authors.initials: SA
authors.lastname: Souza-Júnior
authors.forename: M A A
authors.initials: MA
authors.lastname: Castro-Prado
mesh_terms: D000890:Anti-Infective Agents / Q000009:adverse effects*; D001233:Aspergillus nidulans / Q000187:drug effects* / Q000235:genetics; D002710:Chlorhexidine / Q000009:adverse effects / Q000031:analogs & derivatives*; D003434:Crossing Over, Genetic / Q000187:drug effects* / Q000235:genetics; D004171:Diploidy; D006720:Homozygote; D009152:Mutagenicity Tests
chemical_list: D000890:Anti-Infective Agents; C010882:chlorhexidine gluconate; D002710:Chlorhexidine