Development of highly sensitive one step-PCR for improved detection of B. bigemina and B. bovis

PAOLETTA, MARTINA; DE LA FOURNIERE, SOFÍA; GUILLEMI, ELIANA; SARMIENTO, NESTOR; DONATI PABLO; WILKOWSKY, SILVINA E.; FARBER MARISA D

Conferencia; PARASITRAVAGANZA 2021; 2021

THE AUSTRALIAN SOCIETY FOR PARASITOLOGY

Bovine babesiosis caused by Babesia bigemina and B. bovis is an economically relevant tick-borne disease distributedworldwide. Animals that recover from clinical disease are epidemiologically important since they remain persistently infectedbeing a source of infection to others. Their minimum levels of parasitemias are a challenge for detection. The recommended47molecular diagnosis test for both species is a nested (nPCR) based on the amplification of the rap-1 gene. To minimize costsand risks that nPCRs imply, we developed a single-step PCR for each species based on the multi-copy ves-1α gene (VESAPCRs). We achieved detection limits of 1x10-12% parasitemia for B. bigemina and 1x10-6% for B. bovis using reference strains,resulting in an improvement in sensitivity. When applying VESA PCRs in field samples we detected a significantly higherproportion of positive animals compared to the reference nPCRs. Concordance between both diagnostic schemes (Cohen´skappa coefficient) showed minimal to non-agreement since VESA PCRs have a significantly higher detection capacity. Inconclusion, the high sensitivity of the assay, and the lower demand of time and reagents make the VESA PCR methods avaluable diagnostic tool for the molecular detection and epidemiological survey of both Babesia pathogens.