Selection of new diagnostic markers for Dirofilaria repens infections with the use of phage display technology

Mateusz Pękacz,Alicja Kalinowska,Diana Stopka,Marcin Wiśniewski,Anna Zawistowska-Deniziak,Daniel Młocicki,Maciej Klockiewicz,Katarzyna Basałaj,Piotr Bąska,Justyna Karabowicz,Ewa Długosz

doi:10.1038/s41598-022-06116-8

Abstract

Dirofilaria repens is a parasitic nematode causing vector-borne disease (dirofilariasis), considered an emerging problem in veterinary and human medicine. Although main hosts are carnivores, particularly dogs, D. repens shows high zoonotic potential. The disease spreads uncontrollably, affecting new areas. Since there is no vaccine against dirofilariasis, the only way to limit disease transmission is an early diagnosis. Currently, diagnosis depends on the detection of microfilariae in the host bloodstream using modified Knott's test or multiplex PCR. However, the efficacy of tests relying on microfilariae detection is limited by microfilariae periodic occurrence. Therefore, a new reliable diagnostic test is required. Our study aimed to select new diagnostic markers for dirofilariasis with potential application in diagnostics. We focused on single epitopes to ensure high specificity of diagnosis and avoid cross-reactivity with the other parasite infections common in dogs. Using phage display technology and 12-mer peptides library, we selected epitopes highly reactive with IgG from sera of infected dogs. Additionally, our study presents the possibility of detecting D. repens specific cell-free DNA in dogs with no microfilaria but high IgG and IgM antibody levels against parasite somatic antigen.

Highlights

Dirofilaria repens is a parasitic nematode causing vector-borne disease, considered an emerging problem in veterinary and human medicine
Diagnosis of closely related Dirofilaria immitis is much easier since several diagnostic tests are available on the m arket[16] and based on serological techniques detecting molecules secreted by parasites
Our study presents the possibility of detecting D. repens specific cell-free DNA in dogs with no microfilaria but high IgG and IgM antibody levels against parasite somatic antigen

Summary

Introduction

Dirofilaria repens is a parasitic nematode causing vector-borne disease (dirofilariasis), considered an emerging problem in veterinary and human medicine. In the twenty-first century, over 70% of described human dirofilariasis cases were caused by D. repens, and 42.95% of recovered worms were mature, mainly females, and 26.42% contained microfilariae in the uterus[3]. These reports suggest that humans should be considered as a potential reservoir of subcutaneous dirofilariasis. Diagnosis of closely related Dirofilaria immitis is much easier since several diagnostic tests are available on the m arket[16] and based on serological techniques detecting molecules secreted by parasites Our study presents the possibility of detecting D. repens specific cell-free DNA in dogs with no microfilaria but high IgG and IgM antibody levels against parasite somatic antigen

Methods

Results

Conclusion