Examination for double-stranded RNA viruses in Trichomonas gallinae and identification of a novel sequence of a Trichomonas vaginalis virus.

To determine if double-stranded RNA (dsRNA) viruses exist and are potential virulence factors in Trichomonas gallinae, virus purification via ultracentrifugation was attempted for 12 T. gallinae isolates recovered from wild birds. Following purification, virus-like particles were not observed by transmission electron microscopy, nor were dsRNA segments visualized in agarose gels after electrophoresis of extracted RNA from any of the 12 T. gallinae isolates. However, virus particles and dsRNA segments were detected from a previously determined virus-infected T. vaginalis isolate as a control using identical purification procedures. Subsequent reverse transcription-polymerase chain reaction analysis of the dsRNA of the virus in this isolate revealed a novel sequence of the RNA-dependent RNA polymerase gene of T. vaginalis viruses.