A sensitive polymerase chain reaction based assay for the detection of Setaria digitata: the causative organism of cerebrospinal nematodiasis in goats, sheep and horses.

This study presents a new and sensitive method to detect Setaria digitata, a parasite causing cerebrospinal nematodiasis in goats, sheep and horses, through an enhanced polymerase chain reaction (PCR) assay.

Introduction & Objective

• The primary objective of this study was to design a more sensitive Polymerase Chain Reaction (PCR) assay to detect Setaria digitata, a parasitic nematode that causes cerebrospinal nematodiasis in livestock animals like goats, sheep, and horses. This disease often results in severe neurological disorders and sometimes in the death of these animals.

Methodology

• The researchers employed two oligonucleotide primers of 17 nucleotides that were designed from a previously studied and described repetitive sequence of Setaria digitata.
• These primers made it possible for the researchers to amplify tiny amounts (100 femtograms) of S. digitata genomic DNA – the genetic material of the organism.
• A straightforward procedure was followed to process the host blood samples and mosquitoes harboring L3 larvae, the infective stage of the nematode’s life cycle. This procedure involved the use of proteinase K, an enzyme that breaks down proteins, and non-ionic detergent NP 40, a cleaning agent that helps to release the DNA of the nematode.

Results & Conclusion

• The sensitivity of this newly developed PCR assay surpassed previous microscopic methods and chemiluminescent detection techniques. These conventional detection techniques were less capable of identifying the presence of microfilariae, the early stage of nematodes, in infected host blood samples and L3 larvae in vector mosquitoes.
• The improved sensitivity, due to the ability to detect minuscule quantities of S. digitata genomic DNA, makes this assay highly effective in the early detection and diagnosis of cerebrospinal nematodiasis in livestock animals, potentially preventing disease progression and reducing animal death rates.