Notes on maternal behaviour in soft ticks: Specifically observed in Argas (Argas) striatus Bedford, 1932 and Argas (Secretargas) transgariepinus White, 1846.

Maternal behaviour (carrying of larvae on the opisthosoma) in ticks has thus far only been observed in Antricola (Parantricola) marginatus and was considered a unique derived adaptation of this genus. The authors extend this observation to two additional argasid species, namely Argas (Argas) striatus and Argas (Secretargas) transgariepinus. In addition, brooding behaviour over eggs were observed with A. (S.) transgariepinus. Maternal behaviour may be an evolutionary adaptation to ecological challenges in habitats unsuited for larval survival and may be related to the presence of pulvilli in larvae. This adaptation might have been present in the ancestral tick lineage since pulvilli occur in all tick families, and may have been derived from a more ancient adaptation in chelicerates where maternal behaviour was common. Female A. (S.) transgariepinus also possess a unique area on their ventral abdomen that is absent in males and may be a unique adaptation for maternal behaviour in this species. Phylogenetic analysis of the 16S rRNA genes for both species indicate that they are unique lineages that group basal to other members of the Argas genus, supporting the possibility that they harbour ancestral traits for this group.

Synthesis of empty african horse sickness virus particles.

As a means to develop African horse sickness (AHS) vaccines that are safe and DIVA compliant, we investigated the synthesis of empty African horse sickness virus (AHSV) particles. The emphasis of this study was on the assembly of the major viral core (VP3 and VP7) and outer capsid proteins (VP2 and VP5) into architecturally complex, heteromultimeric nanosized particles. The production of fully assembled core-like particles (CLPs) was accomplished in vivo by baculovirus-mediated co-synthesis of VP3 and VP7. The two different outer capsid proteins were capable of associating independently of each other with preformed cores to yield partial virus-like particles (VLPs). Complete VLPs were synthesized, albeit with a low yield. Crystalline formation of AHSV VP7 trimers is thought to impede high-level CLP production. Consequently, we engineered and co-synthesized VP3 with a more hydrophilic mutant VP7, resulting in an increase in the turnover of CLPs.

Lumpy skin disease of cattle: an emerging problem in the Sultanate of Oman.

Lumpy skin disease (LSD) is a highly infectious disease of cattle caused by a virus belonging to the Capripoxvirus genus of the family Poxviridae. The purpose of this study is to place on record the first confirmation of LSD in the Sultanate. The disease was diagnosed and confirmed using polymerase chain reaction, histopathology, transmission electron microscopy and serum neutralization testing. The epizootic occurred in 2009 involving a large number of animals and covering a wide area including Nezwa, Alqabel, Sohar, Saham and Burimi. Morbidity and mortality rates of 29.7 and 26.3 %, and 13.6 and 15.4 % were observed at Nezwa and Sohar, respectively. The clinical signs were much more severe in Holstein-Friesian cattle compared to indigenous breeds and were characterized by multiple skin nodules covering the neck, back, perineum, tail, limbs and genital organs. Affected animals also exhibited lameness, emaciation and cessation of milk production. Oedema of limbs and brisket, and superficial lymph node enlargement were highly prominent. It is not known from where the virus originated, or how it spread to the Sultanate. The disease has become endemic in the country and is liable to extend to other Gulf Cooperation Council Countries and cause a pandemic. It is of major concern to the Omani dairy industry. Due to the widespread presence of screw worm, serious economic losses can follow outbreaks.

Redescription of Setaria graberi Shoho in Troncy, Graber & Thal, 1976 (Nematoda: Filarioidea) based on specimens from Redunca arundinum (Bovidae) in South Africa.

The filarial onchocercid Setaria graberi Shoho in Troncy, Graber & Thal, 1976 is redescribed from the abdominal cavity of Southern reedbuck, Redunca arundinum (Boddaert), in South Africa, including illustrations and scanning electron micrographs of important morphological features. Morphometric data for this species are provided for the first time. Setaria graberi is characterised by the possession of bifid deirids, and females having a distinctly bulbous tail. The slightly raised peribuccal crown forms a dumbbell-shaped unit with the cephalic elevations in apical view; the dorsal and ventral elevations, spaced 73-115 µm apart in females and 71-93 µm in males, carry two well-separated tips each. In dorsoventral view, the cephalic elevations appear more or less rectangular with a slightly notched apex and are narrow in comparison to the width of the anterior end. They are triangular in lateral view. Four cephalic and four external labial papillae are arranged in a laterally elongated rectangle each. The species is distinguished from other Setaria Viborg, 1795 species that possess bifid deirids or occur in members of the same host genus. The presence of S. graberi in R. arundinum in South Africa constitutes a new host and geographic record.

Nuttalliella namaqua (Ixodoidea: Nuttalliellidae): first description of the male, immature stages and re-description of the female.

Nuttalliella namaqua is the only species of the enigmatic third tick family. Females possess features of hard and soft ticks and have been designated as the "missing link" between the main tick families. Its position at the base of the tick tree suggests that some of the features unique to hard and soft ticks were present in the ancestral tick lineage. Larvae, nymphae and males have not been described to date and questions regarding their biological affinities to the main tick families remain unclear. The current study addressed these questions via the description of larvae, nymphae and males and resolved issues pertaining to female morphology. Field collected as well as laboratory-engorged females laid eggs and viable larvae subsequently hatched. The larvae possess morphological structures not present in subsequent stages: namely, a sclerotized scutum, pores on the dorsal surface of legs and a dentate anal plate. The last two characters are not present in ixodids and argasids. N. namaqua larvae and nymphae show a similar morphology to females: a unique hypostomal structure i.e., bluntly rounded apically in nymphae and females and ball-like in the larvae. A re-description of some structures in female N. namaqua has resolved differences in the original descriptions, namely that N. namaqua have 4 palpal segments as found in ixodids and argasids and posthypostomal setae. The male was discovered for the first time and described. Characteristic male features include: a pseudoscutum over most of the dorsum, an outgrowth on the chelicerae forming a unique rod-like structure similar to a spematodactyl in mites and medial extension of palpal segment 2 forming a large ventral crib for segment 4. All life stages possess some features found in hard and soft ticks and its status as the "missing link" between the tick families remains.

Preparation and in vitro characterisation of Ehrlichia ruminantium plasmid DNA and proteins encapsulated into and DNA adsorbed onto biodegradable microparticles.

Four E. ruminantium 1H12 open reading frames and their proteins known to protect sheep against heartwater needle challenge were encapsulated into, or adsorbed onto poly(d,l-lactide-co-glycolide) microparticles. Microspheres with smooth surface and smaller than 5 µm diameters were produced, with high adsorption and encapsulation efficiencies. Gel electrophoresis showed that neither encapsulation nor adsorption affected the stability of the DNA or proteins. Cationic microparticles released ∼40% of plasmid DNA on day 1 while PLGA 50:50-COOH microparticles co-encapsulating plasmid DNA and polyvinyl alcohol only started to release from days 12-28. Recombinant proteins were released from PLGA 85:15 and homopolymer R 203 S microparticles in a biphasic manner with a high initial burst release (∼45-80%). In contrast, PLGA 50:50 microparticles had low (15-65%) initial burst release followed by (25-80%) release by days (days 28-42). A cocktail of these microparticles could therefore be used as single-dose auto-booster vaccine.

Theileria-infected cell line from an African buffalo (Syncerus caffer).

Mononuclear cells were isolated from the peripheral blood of a buffalo infected with a Theileria sp. using density gradient centrifugation, and the cells were put into culture flasks covered by a monolayer of bovine endothelial cells. Twenty days after culture initiation, cells containing macroschizonts were detected in Giemsa-stained smears. The first subculture was carried out on day 45 of culture propagation. Subsequently, infected cells were subcultured twice a week, and each time 1 to 2 x 10(6) per milliliter cells were harvested. DNA was extracted from culture material and a partial polymerase chain reaction amplification of the 18S ribosomal RNA (rRNA) gene was carried out using Theileria genus-specific primers. Sequence data and phylogenetic analysis using the 18S rRNA gene indicated a close relationship to Theileria sp. buffalo, previously described in literature. Here, the first successful attempt to establish a macroschizont-infected lymphoblastoid cell line of Theileria sp. (buffalo) from an African buffalo is described.