الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 274 |  |  |
| | | from | 274 | | |
Abstract
Background: Trichomonas vaginalis is a protozoan parasite that infects the urogenital tract of men and women, causing trichomoniasis which is considered the most common nonviral, STD in the world. A number of methods have been used in previous attempts to characterize the genetic diversity of T. vaginalis with variable levels of reproducibility and precision. Currently, there is no gold standard method for genotyping isolates of T. vaginalis.
Aim of the work: Genotyping using multilocus sequence typing (MLST) targeting 3 housekeeping genes to identify genotypes among Egyptian isolates of T. vaginalis, to correlate genotypes with the clinical presentation and to determine the phylogenetic relationship in comparison with reference strains.
Material and Method: Three hundred vaginal washouts collected from Egyptian women patients aged 20-45 years suspected for trichomoniasis. Positive samples for T. vaginalis were cultured on modified TYM medium. Growth kinetics for each isolate, in vitro sensitivity to metronidazole were done; followed by DNA extraction from the samples and PCR amplification using multilocus sequence typing targeting three house-keeping genes (P1, P8, P13). Sequencing of the amplification products and sequence analysis was done with phylogenetic analysis and correlation between clinical data of positive cases and T. vaginalis genotypes.
Results: Twelve samples were found positive for T. vaginalis trophozoite. Among them, 26 polymorphic nucleotide sites were detected. Nucleotide diversity for the 3 loci ranged from 0.00473 to 0.00706 differences /site. The number of different alleles for each locus ranged from 3 to 5. Sequencing of the amplification products was successful in 10 out of 12 isolates (83.3%). In total a two type population structure was evident from the genetic analysis and cladograms with genotype I, constituting 70 % of the isolates and genotype II, 20 %. Mixed infection was detected in 10 % of cases.
Conclusion: MLST was successful in determining the genetic diversity of the Egyptian isolates at the level of single and combined loci. Genotyping of the isolates has shown that the Egyptian population of T. vaginalis parasite conforms to the two-type population structure found in other regions of the world. No significant correlation was found between T. vaginalis genotypes or age of the patients, character of discharge or findings on clinical examination.