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.
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: −0.440 13) were identified by analyzing ferredoxin gene in four symptomatic and two resistant isolates. Only two haplotypes (F: 5%, HD: 0.345; Tajima's D: 0.778 15) 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.
ABSTRACT
Adherence of Candida species, mainly C. albicans to denture surfaces, forms a biofilm which causes denture stomatitis in denture users. Removal of Candida plaque on dentures is essential to control the colonization of this yeast and to prevent infections related to C. albicans. The aim of this study was to compare the effectiveness of sodium hypochlorite with white vinegar for the disinfection of C. albicans from acrylic resin. 82, 10x10x1 mm acrylic resin plates were inoculated with 1x103 C. albicans suspension for 24 hours to prepare experimental Candida biofilm. The total number of Candida cells which adhered to 10 acryl resin plates was determined and the remaining 72 plates were randomly divided into four groups. The test plates were immersed in a solution of 1% sodium hypochlorite, 5% or 10%white vinegar for a period of 8 hours and distilled water was used as the negative control group. The Candida removing ability of the 3 disinfectants and the negative control group was assessed by comparing the number of colony forming units per 1 mL of the plates washing solution before and after the removing protocol. Data was analyzed using Kruskal-Wallis and Mann-Whitney tests. Sodium hypochlorite [1%] and white vinegar [10%] removed 100% of the C. albicans cells, followed by white vinegar [5%], which removed 99% of the adhered C. albicans from the acrylic resin plates. There wasn't any significant statistical difference found between the 5% and 10% white vinegar in removing Candida from the acryl resin plates [P = 0.161]. Overnight immersion of complete removable dentures in 10% or even a 5% white vinegar solution effectively removed C. albicans cells that had adhered to the denture surface and their removal properties the same as 1% sodium hypochlorite.