Survey and molecular characterization of trichomonads in pigs in Anhui Province, East China

 Background: In pigs, several different trichomonad species such as Tritrichomonas foetus, Tetratrichomonas buttreyi and Pentatrichomonas hominis have been described as inhabiting the digestive tract. However, little information is available on the epidemiology of these neglected parasites in the Chinese pig population. The prevalence of T. suis, T. buttreyi and P. hominis among 500 fecal specimens from pigs at seven pigs farms inAnhuiProvince inChina was determined by PCR and DNA sequence analysis of the small subunit ribosomal RNA (SSU rRNA) genes. The prevalence rates for T. suis, T. buttreyi and P. hominis were 2.8 % (14/500), 42.0 % (210/500) and 7.8 % (39/500), respectively. Mixed infections of two or three trichomonads were detected in 24 samples. The prevalence of the three trichomonads differed significantly between some age groups, with higher infection rates of T. suis and T. buttreyi in nursery pigs and P. hominis in preweaned pigs. The SSU rRNA sequences from T. suis and P. hominis showed 100 % homology with their respective homologous database sequences. However, we observed minor allelic variations in the SSU rRNA sequences from T. buttreyi, and the five representative sequence identified were named firstly as types 1, 2, 3, 4 and 5.Moreover, type 1 was found to be dominant in the present study. These findings highlight the potential risk posed by pigs in the transmission of trichomonad infections to humans and other animals.