Comparative RNA-seq analysis of the Tritrichomonas foetus PIG30/1 isolate from pigs reveals close association with Tritrichomonas foetus BP-4 isolate 'bovine genotype'.

Tritrichomonas foetus was described as a commensal of the stomach, caecum and nasal cavity of pigs before it was recognised as the cause of reproductive tract disease of cattle. T. foetus also causes chronic large bowel diarrhoea in domestic cats. Multi-locus genotyping and comparative transcriptome analysis has previously revealed that T. foetus isolated from cat and cattle hosts are genetically distinct, referred to as the 'feline genotype' and 'bovine genotype', respectively. Conversely, multi-locus genotyping has grouped porcine T. foetus with the 'bovine genotype'. To compare the extent of the similarity between porcine T. foetus and cattle 'bovine genotype' isolates, RNA-sequencing (RNA-seq) was used to produce the first cell-wide transcriptome library of porcine T. foetus PIG30/1. Comparative transcriptome analysis of the PIG30/1 with the published bovine (BP-4) and feline (G10/1) transcriptomes revealed that the porcine T. foetus shares a 4.7 fold greater number of orthologous genes with the bovine T. foetus than with the feline T. foetus. Comparing transcription of the virulence factors, cysteine proteases (CP) between the three isolates, the porcine T. foetus was found to preferentially transcribe CP8 like the 'bovine genotype' T. foetus, compared to thehigh transcription of CP7 seen for 'feline genotype' T. foetus. At the cell-wide transcriptome level, the porcine T. foetus isolate (PIG30/1) groups closer with the 'bovine genotype' T. foetus rather than the 'feline genotype' T. foetus.