title: Introducing nitazoxanide as a promising alternative treatment for symptomatic to metronidazole-resistant giardiasis in clinical isolates.
abstract: OBJECTIVE
  To identify the frequencies (F) of ferredoxin and nitroreductase mutations on Iranian clinical isolates of Giardia lamblia in order to predict whether the nitazoxanide can be prescribed as suitable drug for symptomatic to metronidazole-resistant giardiasis.
  
  
  METHODS
  Forty Giardia lamblia isolates as of 38 symptomatic and two metronidazole-resistant patients were collected from Iran. DNAs were extracted and amplified by targeting ferredoxin and GlNR genes. The amplicons were directly sequenced to determine gene mutations.
  
  
  RESULTS
  The various amino acid substitutions (F: 20%, Haplotype diversity: 0.891, Tajima's D: -0.44013) were identified by analyzing ferredoxin gene in four symptomatic and two resistant isolates. Only two haplotypes (F: 5%, HD: 0.345; Tajima's D: 0.77815) characterized in metronidazole-resistant isolates of GlNR, however, no point mutations was found in symptomatic isolates.
  
  
  CONCLUSIONS
  Non-synonymous mutations of ferredoxin oxidoreductase gene reduce translational regulatory protein's binding affinity which concludes reduction of ferredoxin expression and its activity. This leads to decrease in metronidazole drug delivery into the cells. Mutations in these isolates may lead to their resistance to metronidazole. No to low synonymous mutations of GlNR demonstrates that nitazoxanide can be prescribed as promising alternative treatment for symptomatic to metronidazole-resistant giardiasis in Iranian clinical isolates.
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Tahereh Mikaeili
authors.initials: TM
authors.lastname: Galeh
authors.affiliation: Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Abdolhassan
authors.initials: A
authors.lastname: Kazemi
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Mahami-Oskouei
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Baradaran
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: adelespotin@gmail.com.
authors.forename: Adel
authors.initials: A
authors.lastname: Spotin
authors.affiliation: East Azerbaijan Province Health Center, Tabriz Health Center, Tabriz, Iran.
authors.forename: Seddigheh
authors.initials: S
authors.lastname: Sarafraz
authors.affiliation: Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Karamat
keywords: Ferredoxin oxidoreductase; Giardia lamblia; Metronidazole; Nitazoxanide; Nitroreductase