Abstract
Equine infectious anaemia virus (EIAV) is the causative agent of equine infectious
anaemia (EIA), a disease of equids which causes a persistent infection that cannot be
treated and therefore disease detection and monitoring is critical for its control.
Serological screening is the most reliable form of diagnosis due to a persistent antibody
response and as clinical signs vary. The capsid p26 protein is the target for most of the
serological diagnostic tests. Concerningly, serologically non-detectable equids have
been proposed which threaten control programmes. This problem may be due to EIAV
strain(s) with mutations within the p26. This study aimed to identify the effect p26
mutations have on EIAV serological diagnosis and infectivity. Mutated p26
recombinant proteins were produced and used to generate equine antisera for analysis.
It was identified that antibodies generated against a highly mutated p26 led to a
reduction in serological detection. However, some ELISAs and immunoblots could
detect such antisera thus setting up a 3-tiered diagnostic system should reduce the risk
of missing divergent strains. To strengthen disease surveillance capability I set up an
immunoblot capable of detecting three of the immunogenic recombinant proteins (p26,
gp45 and gp90). The immunoblot showed excellent sensitivity, an ability to detect
divergent strains, higher throughput capabilities and could detect multiple proteins
simultaneously thus will be useful for future EIAV diagnosis. It is unknown what effect
p26 mutations may have on infectivity. I therefore created a full-length EIAV clone
incorporating the mutated p26 sequence, using golden gate assembly for cloning the
full EIAV genome. Once rescued a recEIAVmut-p26 can be used to assess its infectivity
in equine cells.