Integrative omics reveals candidate drug-repurposing targets in Tritrichomonas foetus

Abstract

Background Feline tritrichomonosis is a globally distributed chronic large-bowel diarrhoea of cats caused by the flagellated protozoan Tritrichomonas foetus. The only drug with demonstrated clinical efficacy is the off-label 5-nitroimidazole ronidazole, which has a narrow therapeutic window and against which clinical resistance has now been documented across three continents. The last comprehensive in silico drug-target prioritisation for T. foetus was published a decade ago and proposed 113 candidates based on homology to ChEMBL alone; the genomic and pharmacological landscape has since changed substantially, but no integrative reanalysis has been undertaken. Results Starting from the predicted proteome of strain K (25030 proteins), an integrative subtractive pipeline combining filtering against the feline host proteome, three pharmacological reference data- bases, essential-gene resources from three model eukaryotes, and the PHI-base virulence reference re- turned 433 priority candidates. Application of the same pipeline to the chromosome-scale strain KV-1 assembly yielded 436 candidates, with 66% cross-strain recovery as reciprocal best hits. Gene-level expression analysis showed that 82.7% of priority candidates were actively transcribed in the feline isolate G10/1, and a proof-of-concept docking screen against three top-ranked candidates recovered internally consistent, structure-based affinity rankings that await experimental validation. Nine of the ten most highly expressed candidates correspond to a protein family with clinically advanced small- molecule inhibitors; the tenth, a Rab4B GTPase, belongs to the broader, pharmacologically tractable Ras/GTPase superfamily but has no Rab4B-specific inhibitor characterised to date. Conclusions This work provides a substantially expanded and cross-validated drug-target landscape for T. foetus. Nine of the ten most highly expressed priority candidates fall into protein families for which clinically advanced small-molecule inhibitors are already available, namely Hsp70 and Hsp90 chaperones, the CDC48/p97 AAA+ ATPase, the ubiquitin-proteasome pathway, and serine/threonine kinases; the tenth, a Rab4B GTPase, belongs to the broader Ras/GTPase superfamily but has no Rab4B-specific inhibitor characterised to date. Together they offer an immediate opportunity for drug-repurposing studies in feline tritrichomonosis, a disease that lacks any approved therapy and against which off-label ronidazole resistance is increasingly documented.