Equine Herpesvirus Type 1: Filling Gaps Toward Improved Outbreak Management

Equine herpesvirus type 1 (EHV-1) is a common pathogen of horses that typically causes upper respiratory disease, however is also associated with late-term abortion, neonatal foal death and neurologic disease. Once a horse is infected, the virus concentrates to local lymphoid tissue, where it becomes latent. The virus can recrudesce during times of stress, which can lead to the initiation of devastating outbreaks. Some variants of EHV-1 have been associated with more severe disease outcomes. Appropriate outbreak management focuses on minimizing the movement of potentially exposed horses. This approach lacks a strategy for prevention at the level of latency largely due to a knowledge paucity in regards to carriage rate of latent EHV-1. Biosecurity decisions are also dependent on awaiting currently-available diagnostic testing that often take several days for results. Thus, our work has been focused on understanding the carriage rate of the latent virus in different geographic regions as well as improving diagnostic efficiency, both of which are essential for improving the management of EHV-1 disease. Loop mediated isothermal amplification (LAMP) is a method that amplifies nucleic acid rapidly at a constant temperature and is minimally affected by inhibitors that are often found in clinical samples. This procedure can be followed by multiple detection methods. A new, efficient sequencing method, called nanopore sequencing, has been developed in a handheld device, called MinION, that provides thorough output in a timely manner. When combined with LAMP, it has been referred to as LAMPore. The first objective of our work was to estimate the prevalence of latent EHV-1 and compare the frequency of each variant in the submandibular lymph nodes from horses in Virginia. Our second objective was to perform direct DNA sequencing of EHV-1 using the mobile MinION sequencer in combination with LAMP viral enrichment. Our findings demonstrated a low apparent prevalence of latent EHV-1 DNA in submandibular lymph nodes in this population of horses in Virginia as well as successful detection and identification of EHV-1 in equine nasal swab samples using LAMPore sequencing.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Biomedical and Veterinary Sciences

Department dc:contributor.department

Biomedical and Veterinary Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Saklou, Nadia Talal

Chair dc:contributor.committeechair

• Lahmers, Kevin K.

Committee members dc:contributor.committeemember

• Buechner-Maxwell, Virginia A.
• LeRoith, Tanya
• Burgess, Brandy Ann
• Duggal, Nisha K.

• horse
• herpesvirus
• submandibular lymph nodes
• PCR
• latency
• nanopore sequencing
• DNA
• equine herpesvirus-1

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:38145

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/116234