Molecular typing of Trichomonas vaginalis isolates by actin gene sequence analysis and carriage of T. vaginalis viruses

Abstract

BackgroundThe protozoan parasite Trichomonas vaginalis is the most common non-viral, sexually transmitted pathogen. Although T. vaginalis is highly prevalent among women in Kenya, there is lack of data regarding genetic diversity of isolates currently in circulation in Kenya.MethodsTyping was performed on 22 clinical isolates of T. vaginalis collected from women attending the antenatal care clinic at Kilifi County Hospital, Kenya, in 2015. Genotyping followed a previously proposed restriction fragment length polymorphism (RFLP) scheme, which involved in silico cleavage of the amplified actin gene by HindII, MseI and RsaI restriction enzymes. Phylogenetic analysis of all the sequences was performed to confirm the results obtained by RFLP-analysis and to assess the diversity within the RFLP genotypes. Additionally, we determined carriage of the four different types of Trichomonas vaginalis viruses (TVVs) by polymerase chain reaction.ResultsIn silico RFLP-analysis revealed five actin genotypes; 50.0% of the isolates were of actin genotype E, 27.3% of actin genotype N, 13.6% of actin genotype G and 4.5% of actin genotypes I and P. Phylogenetic analysis was in agreement with the RFLP-analysis, with the different actin genotypes clustering together. Prevalence of TVVs was 43.5% (95% confidence interval, CI: 23.2–65.5). TVV1 was the most prevalent, present in 39.1% of the strains and 90% of the T. vaginalis isolates which harbored TVVs had more than one type of TVV. None of the isolates of actin genotype E harbored any TVV.ConclusionThe presence of five actin genotypes in our study suggests notable diversity among T. vaginalis isolates occurring among pregnant women in Kilifi, Kenya. Isolates of the most prevalent actin genotype E lacked TVVs. We found no association between T. vaginalis genotype, carriage of TVVs and symptoms. Further studies with higher number of strains should be conducted in order to corroborate these results.Electronic supplementary materialThe online version of this article (10.1186/s13071-017-2496-7) contains supplementary material, which is available to authorized users.

Trichomonas vaginalis Virus Among Women With Trichomoniasis and Associations With Demographics, Clinical Outcomes, and Metronidazole Resistance

“…These results are similar to a study of TV-infected women in India, in which TVV+ isolates were not associated with genital symptoms [30]. A Kenyan study of TV-infected women also found no association between genital symptoms and TVV+ isolates [31]. In contrast, a Cuban study of 37 TV isolates found an association between the presence of genital symptoms and signs and TVV positivity among 21 isolates that were TVV+ (P < .01) [32].…”

“…El-Gayar et al [27] also found a significant association between TVV positivity and clinical manifestations of trichomoniasis among 40 TV-infected women in Egypt. However, the sample sizes of these studies were small and the associations between genital symptoms and TVV+ isolates have not been seen in larger studies, including our present study [28,30,31].…”

Prevalence and genetic diversity of Trichomonas vaginalis clinical isolates in a targeted population in Xinxiang City, Henan Province, China

“…Although actin genotypes A and P of T. vaginalis have been found in previous studies, neither were identified in the targeted population [ 14 ]. In Kenya, five actin genotypes were revealed by RFLP analysis in 2015, and 50.0% of the isolates were of actin genotype E, 27.3% of actin genotype N, 13.6% of actin genotype G and 4.5% of actin genotypes I and P [ 21 ]. Based on 18S rRNA gene sequences, genetic variants among T. vaginalis were found in the cities of Anyang, Zhengzhou, Shangqiu, Luoyang, Pingdingshan, Zhumadian and Xinyang, Henan Province, China, and the results indicated that the T. vaginalis isolates identified could be regarded as a single population [ 22 ].…”

Molecular typing of Trichomonas vaginalis circulating in Ukraine based on actin gene polymorphism

“…Можно отметить, что в большинстве исследований наиболее распространенными генотипами являются генотипы E и G. Исключением является только исследование Matini et al (2017) [5] с 56% генотипа А. В украинской популяции отмечается доминирование генотипа Е, выраженное больше, чем в других исследованиях (68,96%). Сходное, хотя и менее выраженное доминирование ДЕРМАТОЛОГіЯ та вЕнЕРОЛОГіЯ генотипа Е было выявлено Crucitti et al [9] в Конго (55,7%) и Masha S. C. et al [10] в Кении (50%). В целом, в наибольшей степени показатели украинской популяции сходны с данными, полученными Crucitti et al в Конго [9].…”

“…Необходимо отметить, что, по результатам исследования Masha S. C. et al [10], трихомонады, относящиеся к генотипу Е, обладают рядом биологических особенностей, среди которых -клональная стабильность и низкий уровень инфицирования вирусами. Возможно, эти особенности генотипа Е могут быть связаны с его высокой распространенностью в украинской популяции.…”