Research Brief Double-stranded RNA viral infection of Trichomonas vaginalis and correlation with genetic polymorphism of isolates Jorge Fraga ⇑ , Lazara Rojas, Idalia Sariego, Ayme Fernández-Calienes Departamento de Parasitologia, Instituto de Medicina Tropical ‘‘Pedro Kourí”, Autopista Novia del Mediodía km 61/2, Apartado Postal 601, Marianao 13, Ciudad de La Habana, Cuba article info Article history: Received 4 October 2009 Received in revised form 3 September 2010 Accepted 18 September 2010 Available online 25 September 2010 Keywords: Trichomonas vaginalis virus RAPD Polymorphism TVV abstract Trichomonas vaginalis can be infected with double-stranded RNA (dsRNA) viruses known as T. vaginalis virus (TVV). This viral infection may have important implications for trichomonal virulence and disease pathogenesis. The objective of this study was to determine the possible correlation between the T. vaginalis genetic polymorphism and the isolate infection with TVV. The Random Amplified Polymorphic DNA (RAPD) technique was used to determine genetic differences among 37 isolates of T. vaginalis using a panel of 30 random primers and these genetic data were correlated with the infection of isolates with TVV. The trees drawn based on RAPD data showed significantly association with the presence of TVV (P = 0.028) demonstrating the existence of concordance between the genetic relatedness and the pres- ence of TVV in T. vaginalis isolates. This result could point to a predisposition of T. vaginalis for the viral enters and/or survival. Ó 2010 Elsevier Inc. All rights reserved. 1. Introduction Trichomoniasis, caused by the flagellated protozoan parasite Trichomonas vaginalis, is the most prevalent non-viral sexually transmitted disease worldwide (WHO, 1997). Both sexes can be affected by the disease, and can demonstrate a wide clinical forms variation in symptoms, from an asymptomatic presentation to severe sequelae. For women, whom are primarily affected in the vulva, vagina, and uterine cervix, and secondarily, in the urinary tract, trichomoniasis can have major health consequences. In addition, infection with T. vaginalis in pregnant women has been associated with premature rupture of membranes and premature delivery (Cotch et al., 1997). Trichomoniasis has also been associ- ated with an increased risk of human immunodeficiency virus (HIV) acquisition and transmission and cervical cancer (Wang and Wang, 1991; Laga et al., 1993; Viikki et al., 2000). The host–parasite relationship is very complex, and the broad range of clinical symptoms are unlikely be attributable to a single pathogenic mechanism. The exact mechanisms of pathogenesis resulting in the wide variation in clinical presentation (from asymptomatic to severe symptomatic) has not been clearly elucidated to date (Petrin et al., 1998). Many T. vaginalis isolates are infected by a small double-stranded RNA virus (dsRNA) designated T. vaginalis virus (TVV) (Wang and Wang, 1986). The genomic organization and genetic diversity identified TVV as a legitimate member of the Totiviridae family (Wang et al., 1993). Although the TVV are currently grouped as ten- tative members of the Giardiavirus genus as a sub-species (Catalogue of Life, 2007). Similar dsRNA viruses of virus-like particles (VLPs) have been found in several other protozoa including Giardia lamblia, Cryptosporidium parvum, Entamoeba hystolitica, Babesia bovis, sev- eral Eimeria spp. and Leishmania spp. (Wang and Wang, 1991; Kniel et al., 2004). TVV have been found in the cytoplasm closely associ- ated with the Golgi complex or adjacent to the plasma membrane. The population may include viruses of different sizes (33–200 nm) and shape (filamentous, cylindrical and spherical particles) (Benchi- mol et al., 2002). The genomic size of dsRNA viruses varying from 4.3 to 5.0 kbp and have been found, together with another of only 0.5 kbp dsRNA (Khoshnan and Alderete, 1995; Tai and Ip, 1995). This genomic complexity of TVV was confirmed by the results that the capsid proteins among the TVV isolates varied in size (75–85 kDa), as did their immunoreactions against capsid protein antibody (Alderete et al., 2003). It is possible that one isolate could be infected by different viruses simultaneously (Benchimol et al., 2002). Those T. vaginalis isolates not infected by such viruses are described as Type I or TVV uninfected isolates, whilst those infected by TVV are described as Type II or TVV infected isolates. The infection rate described in the literature is between less than 50% and over 80%. Vanácová et al. (1997) and Hampl et al. (2001b), found an infection rate of 44% when they analyzed 20 isolates from different geographic origin. Snipes et al. (2000) found a 50% infection rate when they analyzed 109 US isolates. Other studies reported a higher rate, 81.9% and 75%, in the analyses of 72 South African and 28 American T. vaginalis isolates (Wendel et al., 2002; Weber et al., 2003). In Cuba, the estimate infection rate 0014-4894/$ - see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.exppara.2010.09.005 ⇑ Corresponding author. Address: Laboratorio de Biología Molecular, Departa- mento de Parasitología, Instituto de Medicina Tropical Pedro Kourí, Apartado Postal 601, Marianao 13, Ciudad de La Habana, Cuba. Fax: +53 7 204 6051. E-mail address: fraga@ipk.sld.cu (J. Fraga). Experimental Parasitology 127 (2011) 593–599 Contents lists available at ScienceDirect Experimental Parasitology journal homepage: www.elsevier.com/locate/yexpr