SUSCEPTIBILITY ASSAY TO TRICHOSTATIN A IN Tritrichomonas foetus ISOLATES

RIVERO MB; LUQUE ME; ABDALA ME; DI LULLO D; LUNA BE; VOLTA BJ; SCRIMINI S; ASSIS MA; LÓPEZ L; RIVERO FD; CARRANZA PG

Congreso; IV JOINT MEETING OF BIOLOGY SOCIETIES OF THE ARGENTINE REPUBLIC; 2020

Tritrichomonas foetus (T. foetus) is a flagellated protozoan parasite and the etiologic agent of the Bovine Trichomonosis (TB), a venereal disease of cattle. In countries like Argentina where the natural service is used as a reproductive method, the pathology is endemic and causes great economic losses due to the decrease in the pregnancy rate in herds, as a consequence of transitory infertility and occasional abortions caused by the parasite. Infected animals are frequently slaughtered because there is still no effective drug therapy. The most widely used drug is Metronidazole (Mz) and its derivatives, with a range of IC50 (half -50%- of the minimum inhibitory concentration) around μM. Currently, strains resistant to this drug have been reported, which has led to a decrease in its use. For these reasons, the search for new effective drugs at low concentration, with few side effects is highly relevant. Recently, it has been used several drugs with effects on epigenetic mechanisms that regulates cellular adaptation process of microorganisms. Trichostatin A (TSA) is a deacetylase enzymes inhibitor that modifies gene expression and affects cell proliferation and growth of related protozoan parasites. In this regard, the objective of this work was to evaluate the susceptibility to Trichostatin A (TSA) in T. foetus isolates from different regions of the country, through the calculation of IC50 and MLC (minimum lethal concentration). For this purpose, 6 isolates of T. foetus were incubated with different concentrations of TSA under anaerobic conditions for 24 and 48 hours. Live parasites were stained with FDA (fluorescein di acetate), then they were counted by flow cytometry to estimate IC50 and LMC was determined by recovering live parasites in a drug-free medium. The IC50 values were in the range of nM (2.2 to 13.2 nM at 24 hours and from 2.6 to 7.1 nM at 48 hours) and the LMC were higher than 50 nM and 100 nM. The parasites exhibited a biological variability in the response between isolates and a high susceptibility to low concentrations of TSA. Based on these results, very low doses on TSA or analogues drugs could be used as new treatment strategies for this infection that produce economics losses in our country.