| detection of lumpy skin disease virus in saliva of ticks fed on lumpy skin disease virus-infected cattle. | lumpy skin disease is an economically important disease of cattle that is caused by the lumpy skin disease virus (lsdv), which belongs to the genus capripoxvirus. it is endemic in africa and outbreaks have also been reported in the middle-east. transmission has mostly been associated with blood-feeding insects but recently, the authors have demonstrated mechanical transmission by rhipicephalus appendiculatus as well as mechanical/intrastadial and transstadial transmission by amblyomma hebraeum. ... | 2013 | 23456606 |
| protozoan and bacterial pathogens in tick salivary glands in wild and domestic animal environments in south africa. | a total of 7364 ticks belonging to 13 species was collected from 64 game animals (belonging to 11 species) and from 64 livestock animals (cattle and sheep) living in close vicinity at 6 localities in 3 south african provinces (free state, mpumalanga, and limpopo). the geographic distribution of all tick species was congruent with the literature except for haemaphysalis silacea. from each infested host, a maximum of 10 males and 10 females of each tick species were dissected to isolate the saliva ... | 2014 | 24378080 |
| parasites of domestic and wild animals in south africa. li. ticks infesting leopard tortoises <i>stigmochelys pardalis</i>, hingeback tortoises <i>kinixys zombensis</i> and angulate tortoises <i>chersina angulata</i>. | the objective of the study was to record the tick species collected from three species of tortoise, each in a different province of south africa. ticks were collected from leopard tortoises, stigmochyles pardalis, in the southern region of the kruger national park, mpumalanga province; from hingeback tortoises, kinixys zombensis, in the enseleni nature reserve, kwazulu-natal province and from angulate tortoises, chersina angulata, in the west coast national park, western cape province. of the 63 ... | 2017 | 28281776 |
| parasites of domestic and wild animals in south africa. xlix. ticks (acari: ixodidae) infesting white and black rhinoceroses in southern africa. | the objectives of the study were to determine the species composition of ticks infesting white and black rhinoceroses in southern africa as well as the conservation status of those tick species that prefer rhinos as hosts. ticks were collected opportunistically from rhinos that had been immobilised for management purposes, and 447 white rhinoceroses (ceratotherium simum) and 164 black rhinoceroses (diceros bicornis) were sampled in south africa, 61 black rhinos in namibia, 18 white and 12 black ... | 2017 | 28155285 |
| shifts in the distribution of ixodid ticks parasitizing cattle in zimbabwe. | in an attempt to update information on the ecological distribution of ixodid ticks (ixodida: ixodidae) in zimbabwe, a cross-sectional survey was carried out between september 2013 and may 2015 at 322 dip tanks. a total of 15 tick species were collected, namely: amblyomma hebraeum koch (65.2%, n = 210/322), amblyomma variegatum fabricius (14.9%, n = 48/322), hyalomma rufipes koch (62.4%, n = 201/322), hyalomma truncatum koch (37.9%, n = 122/322), rhipicephalus appendiculatus neumann (60.6%, n = 1 ... | 2017 | 27935088 |
| cloning and molecular analysis of voraxin-α gene of rhipicephalus (boophilus) microplus. | to identify suitable targets for development of cross-protective tick vaccine, in silico analysis was attempted and male tick derived molecule, voraxin-α was targeted. the voraxin-α homologue of rhipicephalus (boophilus) microplus was cloned, sequenced and analyzed employing standard methods. the deduced amino acids sequence analysis of the 419 bp cloned voraxin-α gene of r. (b.) microplus indicated very high (94.6 %) similarity with voraxin-α of the r. appendiculatus and moderate to low identit ... | 2016 | 27065622 |
| diversity of ticks (acari: ixodidae) infesting cheetahs (acinoyx jubatus) at three breeding centres in south africa and activity patterns of questing ticks. | ticks were collected from 191 cheetahs at three breeding centres in north west and limpopo provinces, south africa. haemaphysalis elliptica, a common tick of large felids, was the most abundant species collected, while amblyomma hebraeum and rhipicephalus simus occurred in lower numbers. in addition to these three species, drag-sampling of the vegetation revealed the presence of amblyomma marmoreum, rhipicephalus (b.) decoloratus and rhipicephalus zambeziensis. the presence of free-ranging antel ... | 2016 | 27020735 |
| genome-wide association study of tick resistance in south african nguni cattle. | ticks and tick-borne diseases are among the main causes of economic loss in the south african cattle industry through high morbidity and mortality rates. concerns of the general public regarding chemical residues may tarnish their perceptions of food safety and environmental health when the husbandry of cattle includes frequent use of acaricides to manage ticks. the primary objective of this study was to identify single nucleotide polymorphism (snp) markers associated with host resistance to tic ... | 2016 | 26897394 |
| cuticle expansion during feeding in the tick amblyomma hebraeum (acari: ixodidae): the role of hydrostatic pressure. | female amblyomma hebraeum ticks (acari: ixodidae) increase their weight ∼10-fold during a 'slow phase of engorgement' (7-9 days), and a further 10-fold during the 'rapid phase' (12-24h). during the rapid phase, the cuticle thins by half, with a plastic (permanent) deformation of greater than 40% in two orthogonal directions. a stress of 2.5 mpa or higher is required to achieve this degree of deformation (flynn and kaufman, 2015). using a dimensional analysis of the tick body and applying the lap ... | 2016 | 26872533 |
| questing ixodid ticks on the vegetation of sable antelope and multi-herbivore enclosures in thabazimbi. | this survey of ixodid ticks was the first to compare the species composition and population dynamics of free-living ticks in intensive, sable antelope breeding enclosures, now commonplace in commercial wildlife ranching in south africa, with those of multi-herbivore enclosures. the species composition, abundance and seasonal abundance of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelope (hippotragus niger), on which strategic tick control is practised, w ... | 2015 | 26244584 |
| distribution of endemic and introduced tick species in free state province, south africa. | the distributions of endemic tick vector species as well as the presence of species not endemic to free state province, south africa, were determined during surveys or opportunistic collections from livestock, wildlife and vegetation. amongst endemic ticks, the presence of rhipicephalus appendiculatus was confirmed in the north of the province, whilst rhipicephalus decoloratus was collected at 31 localities mostly in the centre and east, and ixodes rubicundus at 11 localities in the south, south ... | 2015 | 26244582 |
| mechanical properties of the cuticle of the tick amblyomma hebraeum (acari: ixodidae). | female ticks of the family ixodidae increase their mass up to 100-fold during the 7-10 day feeding period. we determined the material properties of the alloscutal cuticle of female amblyomma hebraeum from the time of moulting through to full engorgement. the material properties of the cuticle were evaluated by a kelvin-voigt analysis of compliance determined from the stretch of loops of cuticle under stress. there was a 3-fold increase in cuticle dry mass during the first 3 weeks post-moult, dur ... | 2015 | 26163583 |
| an update on the ecological distribution of the ixodidae ticks in zimbabwe. | in total 7657 ticks were collected from 121 dip tanks in 12 districts representative of zimbabwe's five ecological regions between september 2013 and may 2014. based on morphological traits four genera and 13 species of ticks were identified. amblyomma hebraeum (60.3 %), rhipicephalus microplus (58.7 %), rhipicephalus decoloratus (47.1 %), rhipicephalus appendiculatus (56.2 %), rhipicephalus evertsi evertsi (67.8 %), rhipicephalus (near) punctatus (13.2 %), hyalomma truncatum (38 %) and hyalomma ... | 2015 | 25721256 |
| risk factors associated with clinical dermatophilosis in smallholder sector cattle herds of zimbabwe at the amblyomma variegatum and amblyomma hebraeum interface. | a cross-sectional study was conducted to investigate factors for clinical dermatophilosis herd-level positivity in smallholder dip tanks from gokwe (chemawororo, gwanyika), kwekwe (koronika) and chegutu (chivero), zimbabwe, between september 2013 and april 2014. a total of 185 herds were clinically examined for disease and tick infestation. data on herd and potential herd level risk factors were collected using a structured questionnaire. a herd was classified as clinically positive if an animal ... | 2015 | 25465222 |
| molecular characterization of two vitellogenin genes from the tick, amblyomma hebraeum (acari: ixodidae). | we have identified full-length cdnas encoding two vitellogenins (vg) from the african bont tick amblyomma hebraeum koch (1844). vg is a large storage protein that is the precursor to vitellin (vn), the major yolk protein found in eggs. the first vg cdna is 5866 bp long, with a 5715 bp reading frame encoding a 1904 amino acid protein. the second vg cdna is 5963 bp long, with a 5781 open reading frame encoding a 1926 amino acid protein. both proteins possess a short n-terminal signal peptide of 21 ... | 2014 | 25108782 |
| salivary gland degeneration and ovarian development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). i. post-engorgement events. | it is well known that female ixodid ticks undergo salivary gland degeneration and the greater part of ovarian development following engorgement. the process has been particularly well studied in amblyomma hebraeum, including the hormonal control of these processes. the purpose of this study, and the second one in this series, is to compare the processes in dermacentor andersoni with those of a. hebraeum. a major difference between the two species is that virgin female d. andersoni feed to a much ... | 2014 | 24973274 |
| salivary gland degeneration and ovary development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). ii. determination of the 'critical weight'. | the feeding cycle of female ixodid ticks is divided into preparatory, slow, and rapid feeding phases. when a female amblyomma hebraeum is removed from the host after achieving a minimum size of about 10-13× the unfed weight, various physiological and behavioural changes occur: (a) haemolymph ecdysteroid concentration rises dramatically, (b) the tick does not reattach to the host when given the opportunity, (c) its salivary glands degenerate within about 4 days (if mated) or 8 days (if virgin), a ... | 2014 | 24865927 |
| molecular characterization of the vitellogenin receptor from the tick, amblyomma hebraeum (acari: ixodidae). | we have identified the full-length cdna encoding a vitellogenin receptor (vgr) from the african bont tick amblyomma hebraeum koch (1844). vgrs are members of the low-density lipoprotein receptor superfamily that promote the uptake of the yolk protein vitellogenin (vg), from the haemolymph. the ahvgr (genbank accession no. jx846592) is 5703 bp, and encodes an 1801 aa protein with a 196.5 kda molecular mass following cleavage of a 22 aa signal peptide. phylogenetic analysis indicates that ahvgr is ... | 2013 | 24128609 |
| a comparison between tick species collected in a controlled and control free area on a game ranch in south africa. | despite the large number of collection records, there are no recent collections of ixodid ticks of this magnitude in the waterberg area, limpopo province, south africa. free-living ticks on a commercial game farm were obtained by a total of 432 drag-samples in eight sample sites from september 2003 to august 2008. the ticks were collected to establish the difference between tick species and densities associated with acaricide-controlled (semi-intensive) and control-free areas on a game farm in t ... | 2013 | 23718159 |
| antimicrobial activity in the egg wax of the tick amblyomma hebraeum (acari: ixodidae) is associated with free fatty acids c16:1 and c18:2. | untreated eggs of the tick amblyomma hebraeum koch (acari: ixodidae) exhibited antimicrobial activity (ama) against gram-negative but not gram-positive bacteria; eggs denuded of wax by solvent extraction showed no ama. the unfractionated egg wax extract, however, showed ama against gram-positive but not gram-negative bacteria, as also shown by arrieta et al. (exp appl acarol 39: 297-313, 2006). in this study we partitioned the egg wax into various fractions, using a variety of techniques, analyz ... | 2012 | 22692850 |
| the dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the kruger national park (1988-2002). part i. total ticks, amblyomma hebraeum and rhipicephalus decoloratus. | despite a large number of studies on tick biology, there is limited information on long- term changes in tick populations. this study thus aimed to assess the long-term population dynamics of questing ixodid ticks in two landscape zones of the kruger national park (knp). questing ixodid ticks were collected in the knp from august 1988 to march 2002 by monthly dragging of the vegetation in three habitats (grassland, woodland and gully) at two sites (nhlowa road and skukuza). findings pertaining t ... | 2011 | 23327204 |
| avathrin: a novel thrombin inhibitor derived from a multi-copy precursor in the salivary glands of the ixodid tick, amblyomma variegatum. | tick saliva is a rich source of antihemostatic compounds. we amplified a cdna from the salivary glands of the tropical bont tick (amblyomma variegatum) using primers based on the variegin sequence, which we previously identified as a novel thrombin inhibitor from the same tick species. the transcript encodes a precursor protein comprising a signal peptide and 5 repeats of variegin-like sequences that could be processed into multiple short peptides. these peptides share 31 to 34% identity with va ... | 2017 | 28363953 |
| dermal gland secretions of tropical bont tick,amblyomma variegatum (acarina: ixodidae): biological activity on predators and pathogens. | when they are mechanically disturbed, all instars of the tropical bont tickamblyomma variegatum exude droplets of a liquid on the dorsal, lateral, and ventral cuticle. these spread out and quickly evaporate. in this study, the possible role of these secretions was investigated in relation to predators and pathogens. in laboratory bioassays, it was demonstrated that the secretions from engorged larvae, nymphs, and females have an antibiotic activity against the bacteria speciesbacillus thuringien ... | 1994 | 24242646 |
| anteroposterior gradient during nymphal-adult moulting cycle of the tropical bont tick, amblyomma variegatum (acarina: ixodidae) : correlation between ecdysteroid titers and integument structure. | the structure of the extensible (alloscutum) and inextensible (scutum) integument of the nymph, amblyomma variegatum was examined during the whole bloodmeal and the nymphal-adult moulting cycle. integumental events were tentatively correlated with the ecdysteroid levels measured by radioimmunoassay. we observed that all the integumental events were realised along an anteroposterior gradient. during the 5 days corresponding to the bloodmeal, although the hormone concentration was low, a new endoc ... | 1990 | 28305410 |
| occurrence of <i>coxiella burnetii</i>, <i>ehrlichia canis</i>, <i>rickettsia</i> species and <i>anaplasma phagocytophilum</i>-like bacterium in ticks collected from dogs and cats in south africa. | ticks are major vectors of arthropod-borne infections and transmit a wide variety of zoonotic pathogens. this study was conducted mainly to determine the occurrence of canine tick-borne bacterial and rickettsial pathogens especially those with zoonotic potential. we examined 276 rhipicephalus sanguineus, 38 haemaphysalis elliptica and 4 amblyomma hebraeum ticks from 90 dogs and 4 cats from the free state, kwazulu-natal, north west and mpumalanga provinces. dna of coxiella burnetii (41%), ehrlich ... | 2017 | 28582983 |
| immunomodulatory effects of amblyomma variegatum saliva on bovine cells: characterization of cellular responses and identification of molecular determinants. | the tropical bont tick, amblyomma variegatum, is a tick species of veterinary importance and is considered as one of major pest of ruminants in africa and in the caribbean. it causes direct skin lesions, transmits heartwater, and reactivates bovine dermatophilosis. tick saliva is reported to affect overall host responses through immunomodulatory and anti-inflammatory molecules, among other bioactive molecules. the general objective of this study was to better understand the role of saliva in int ... | 2017 | 29354598 |
| structural and functional studies of differentially o-glycosylated analogs of a thrombin inhibitory peptide - variegin. | variegin is a 32-amino acid long thrombin inhibitory peptide isolated from the salivary gland extract of tropical bont tick amblyomma variegatum. it was identified to be o-glycosylated on its thr-14 side chain, and this glycosylated form was 14-fold more potent than that of its non-glycosylated form. however, as the identity of this glycosylation remained elusive, the mechanistic details underlying its functional impact are not yet known. in this report, we synthesized four different o-glycosyla ... | 2017 | 29110415 |
| preliminary study of ectoparasites of horses in the western highlands of cameroon. | to evaluate the prevalence of infestation of ectoparasites of horses, a total of 894 horses (367 males and 527 females), aged 1-7 years old were examined. horses were groomed for collection of ectoparasites. out of the horses examined, 164 came from fundong, 80 from acha, 30 from fongo-tongo, 30 from fokoue and 17 from dschang, all of which were infested with ectoparasites. five hundred and seventy-three (573) horses came from banso and 99.48% were infested by ectoparasites. from the results obt ... | 2017 | 28713574 |
| genetic parameters for tick counts across months for different tick species and anatomical locations in south african nguni cattle. | the objective of the study was to characterise genetic parameters across months for different tick species and anatomical locations in south african nguni cattle. tick counts were conducted monthly, over a 2-year period, on 586 nguni cattle under natural infestation, from four herds located in different provinces of south africa. the counts were recorded for six species of ticks (amblyomma hebraeum, rhipicephalus evertsi evertsi, rhipicephalus decoleratus and microplus (boofilids), rhipicephalus ... | 2017 | 28687941 |