International Journal of Multidisciplinary Research and Publications ISSN (Online): 2581-6187 1 Nguyen Thi Ha Trinh, Ton Nu Phuong Anh, and Paola Rappelli, “Evaluation of the Susceptibility of Trichomonas vaginalis Isolates to Melaleuca cajuputi ,” International Journal of Multidisciplinary Research and Publications (IJMRAP), Volume 3, Issue 8, pp. 1-4, 2021. Evaluation of the Susceptibility of Trichomonas vaginalis Isolates to Melaleuca cajuputi Nguyen Thi Ha Trinh 1 , Ton Nu Phuong Anh 2 , Paola Rappelli 3 1 Faculty of Medicine, Buon Ma Thuot University, Daklak, Vietnam – 630000 2 Department of Parasitology, Hue University of Medicine and Pharmacy, Vietnam – 47000 3 Department of Biomedical Sciences, University of Sassari, Italia – 07100 Email address: nthtrinh @ bmtuvietnam.com, tonnuphuonganh @ gmail.com, rappelli @ uniss.it Abstract— Introduction: Trichomonosis is the most common non- viral sexually transmitted disease (STD) in the world. Due to the development of metronidazole-resistant isolates, therapeutic alternatives to 5-nitroimidazole are being investigated. T. vaginalis can be naturally infected with Mycoplasma hominis, Mycoplasma girerdii and Trichomonas vaginalis virus (TVV). Objective: In this research, the essential oil from plant Melaleuca cajuputi used to test the anti-trichomonas activity. Meanwhile, symbiosis was checked to determine whether any correlation between sensitive and non- sensitive T. vaginalis isolates with essential oil. Materials and methods: A total of 32 T. vaginalis isolates from Hue province and Sassari University subjected to susceptibility testing against essential oils by broth microdilution method. Polymerase chain reaction (PCR) was used to detect the presense of M. hominis and M. girerdii. TVV haboring protozoan was identified by total RNA extraction. Result: The M. cajuputi essential oil showed antitrichomonal activity at the mean of MIC at 0.08±0.05% after 24 hours and 0.06±0.05% after 48 hours . There was no significant differences in MIC of EO to T. vaginalis-microorganism-infected and T. vaginalis-free. Conclusion: M. cajuputi essential oil can be used as potential therapeutic natural resource for development of antitrichomonal drugs, to not only T. vaginalis-free isolates but also T. vaginalis- infected isolates. Keywords— Melaleuca cajuputi, Mycoplasma girerdii, Mycoplasma hominis, TVV, Trichomonas vaginalis. I. INTRODUCTION Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral transmitted disease with 156 million new cases each year (according to WHO, 2016). The clinical manifestations of trichomoniasis in women can range from asymptomatic to severe vaginitis, while in men this infection typically has no symptoms. This disease is associated with unfavorable outcomes of pregnancy[1] and increased risk of HIV infection[2] as well as invasive cervical cancer[3] and prostate cancer[4]. The treatment options for trichomoniasis are limited to nitroimidazole compounds (metronidazole and tinidazole), it has been unchanged since 1959. However, the T.vaginalis strains which are resistant to metronidazole has been noted for years and may be increasing in prevalence. T.vaginalis drug resistance is relative and can lead to increased doses of metronidazole[5]. In addition, many side effects of these drugs such as headache, dry mouth, metallic taste, glossitis, and urticaria caused by lengthy treatment or high doses[6]–[8] or reinfection[9]. Occasionally, patients who are allergic to nitroimidazoles may manifest an immediate-type hypersensitivity reaction[5]. So it is necessary to improve new chemotherapy against T.vaginalis infection, and natural products with high effectiveness and low toxicity have shown promising therapeutic sources. Essential oils (EOs) are very important natural plant products with various biological properties. It is estimated that out of 15 anti-parasitic medications accepted by health authorities from 1981 to 2010, 50% are natural products or derivatives[10]. The anti-trichomonas activity of natural plant products has been investigated and increased in the past decade[10]. Melaleuca cajuputi which is cultivated and extracted in Hue - Vietnam with strong antimicrobial activity was used in this research to test whether having the antitrichomonas activity or not. T.vaginalis is an extracellular pathogen; in order to establish an infection, it must mediate adherence to host epithelial cells, evade the host immune system and compete with the vaginal microbiota[11]. In addition, surface and secreted proteins and exosome, especially the T.vaginalis- microbes interactions include T.vaginalis virus, a double- stranded RNA totivirus, and two different mycoplasma species, likely contribute to T.vaginalis pathogenesis[11], [12]. TVV infection can lead the host immune towards an antiviral inflammatory response that is incapable of antiparasitic activities[13]. Mycoplasma hominis, another common symbiont, has been shown not only increasing T.vaginalis growth rate but also contributing to T.vaginalis inflammation[11]. And the correlation between metronidazole resistance with the presence of M.hominis inside T.vaginalis is still debated. Therefore, this study will also detect the presence of symbiotic agents including M.hominis, M.girerdii and dsRNA inside T.vaginalis and use a statistical test to determine whether any connection between essential oil susceptibility and symbiosis. The main Objectives of this study: 1. To determine the susceptibility of T.vaginalis isolates to Melaleuca cajuputi essential oil. 2. To identify the presence of Mycoplasma hominis, Mycoplasma girerdii and dsRNA virus inside T. vaginalis strains and illustrate the correlation between symbiosis to essential oil susceptibility. II. MATERIALS AND METHODS A. Study Design This was a cross-sectional study and in vitro study.