Dr. Lia Rotherham or
Dr. Antoinette van Schalkwyk
The development of novel molecular diagnostic tests and reagents for viral diseases. This group also focuses on the improvement of current diagnostic tests for diseases within the South African environment.
African horse sickness is a non-contagious infection of equids caused by an
orbivirus of the same name. It is endemic to southern
Africa where all nine of virus serotypes have been described. The outer
capsid protein VP2, encoded by the most variable genome segment 2
(Seg-2), is the primary target for AHSV specific neutralising antibodies
and subsequently determines the virus serotype. Full length segment-2
sequences from more than 100 AHSV isolated over the last 80 years were
compared and Single Nucleotide Polymorphisms (SNPs) identified between
the reference and recent field viruses (see
full genome sequencing).
Unique regions to each individual serotype were identified and primers
were designed to differentially amplify each of the nine serotypes. The
resulting amplicon contained a significant amount of SNPs to
discriminate between field and reference viruses. The PCR assay was
subsequently evaluated and is implemented to determine the prevalence of
different AHSV serotypes associated with outbreaks of the disease
during each season (see
Dr. van Schalkwyk].
Transboundary Animal diseases
animal diseases (TADs) are deﬁned by the FAO as those diseases that are
of economic, trade and/or food security importance for a substantial
number of countries. These diseases can easily spread to other countries
and reach epidemic proportions; and their control requires cooperation
between several countries. Research include novel diagnostic strategies
for Classical swine fever (CSF), Aujeszky's disease (AD), Porcine
Reproductive and Respiratory Syndrome (PRRS) as well as Peste des petits
ruminants (PPR). [Contact:
Dr. van Heerden].
Infectious bronchitis disease
The development of a one-step RT-PCR for the differentiation of field viruses and vaccines. [Contact:
Dr. Lia Rotherham]
Foot and Mouth Disease
development of novel diagnostic reagents for the testing of Foot and
Mouth Disease as well as the validation of current diagnostic methods in
the South African setting. [Contact:
swine fever (ASF) is the most important disease affecting domestic pigs
listed by the World Animal Health organization (OIE) caused by ASF
virus. A virus originally confined within the sylvatic cycle of its
natural hosts (Ornithodoros soft tick and wild suids). There is
no treatment or vaccine. Its control is based on rapid diagnosis and
implementation of strict sanitary measures. Its genome size ranges from
170 to 193 kilobase pairs depending on the virus strain. The virus
presents high genetic and antigenic variability, with 23 genotypes
identified based on P72 gene sequences (see
epidemiology). We are sequencing full genomes (see
full genome sequencing) on available ASFV isolates from outbreaks occurring in the Southern African Development Community (SADC).
Soft ticks of the
Ornithodoros moubata species complex are haematophagous ectoparasites of terrestrial vertebrates that are of veterinary and medical importance.
Ornithodoros porcinus, one of four species within the
O. moubata species complex, is the vector for African
swine fever (ASF) virus. These vectors occur throughout southern,
eastern and central Africa, and on the Indian Ocean island of
Madagascar. Mitochondrial 16S rRNA gene characterisation has previously
identified the presence of three regionally distinct lineages in
sub-Saharan Africa. In this study, we expand both the sampling and
genetic characterisation of ticks from the southern African region to
include tick salivary protein genes and mitochondrial gene targets.
Dr. van Heerden].
The improvement of pathotyping H5 and H7 viruses via real-time PCR in the South African setting. [Contact:
Dr. Lia Rotherham]