Publications

vector potential and population dynamics for amblyomma inornatum.	we studied the natural life cycle of amblyomma inornatum and its vector potential in south texas. this tick is distributed throughout south texas and most of central america. a. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the tamaulipan biotic province in south texas. the life cycle of a. inornatum in south texas showed a clear seasonal pattern consistent with one generation per year. nymphs emerged in the spring with a peak i ...	2015	25881916
tick-borne infections in human and animal population worldwide.	the abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. they are obligatory hematop ...	2015	27047089
rna-seq analyses of the midgut from blood- and serum-fed ixodes ricinus ticks.	adult females of the genus ixodes imbibe blood meals exceeding about 100 times their own weight within 7‒9 days. during this period, ticks internalise components of host blood by endocytic digest cells that line the tick midgut epithelium. using rna-seq, we aimed to characterise the midgut transcriptome composition in adult ixodes ricinus females during early and late phase of engorgement. to address specific adaptations to the haemoglobin-rich diet, we compared the midgut transcriptomes of gene ...	2016	27824139
multiple pathogens including potential new species in tick vectors in côte d'ivoire.	our study aimed to assess the presence of different pathogens in ticks collected in two regions in côte d'ivoire.	2016	26771308
matrix-assisted laser desorption/ionization time of flight mass spectrometry for comprehensive indexing of east african ixodid tick species.	the tick population of africa includes several important genera belonging to the family ixodidae. many of these ticks are vectors of protozoan and rickettsial pathogens including theileria parva that causes east coast fever, a debilitating cattle disease endemic to eastern, central and southern africa. effective surveillance of tick-borne pathogens depends on accurate identification and mapping of their tick vectors. a simple and reproducible technique for rapid and reliable differentiation of l ...	2016	26979606
rickettsia in mosquitoes, yangzhou, china.		2016	27729642
paralog analyses reveal gene duplication events and genes under positive selection in ixodes scapularis and other ixodid ticks.	hard ticks (family ixodidae) are obligatory hematophagous ectoparasites of worldwide medical and veterinary importance. the haploid genomes of multiple species of ixodid ticks exceed 1 gbp, prompting questions regarding gene, segmental and whole genome duplication in this phyletic group. the availability of the genome assembly for the black legged tick, ixodes scapularis, and transcriptome datasets for multiple species of ticks offers an opportunity to assess the contribution of gene duplication ...	2016	26984180
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
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
the eco-epidemiology of pacific coast tick fever in california.	rickettsia philipii (type strain "rickettsia 364d"), the etiologic agent of pacific coast tick fever (pctf), is transmitted to people by the pacific coast tick, dermacentor occidentalis. following the first confirmed human case of pctf in 2008, 13 additional human cases have been reported in california, more than half of which were pediatric cases. the most common features of pctf are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four ca ...	2016	27706171
ph dependent antimicrobial peptides and proteins, their mechanisms of action and potential as therapeutic agents.	antimicrobial peptides (amps) are potent antibiotics of the innate immune system that have been extensively investigated as a potential solution to the global problem of infectious diseases caused by pathogenic microbes. a group of amps that are increasingly being reported are those that utilise ph dependent antimicrobial mechanisms, and here we review research into this area. this review shows that these antimicrobial molecules are produced by a diverse spectrum of creatures, including vertebra ...	2016	27809281
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
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
investigation of rickettsia, coxiella burnetii and bartonella in ticks from animals in south africa.	ticks are involved in the epidemiology of several human pathogens including spotted fever group (sfg) rickettsia spp., coxiella burnetii and bartonella spp. human diseases caused by these microorganisms have been reported from south africa. the presence of sfg rickettsia spp., c. burnetii and bartonella spp. was investigated in 205 ticks collected from domestic and wild animals from western cape and limpopo provinces (south africa). rickettsia massiliae was detected in 10 amblyomma sylvaticum an ...	2016	26718068
molecular diagnosis of african tick bite fever using eschar swabs in a traveller returning from tanzania.	african tick bite fever is an emerging infectious disease among travellers caused by the pathogen rickettsia africae. most travel-associated cases have been reported from countries in southern africa. so far it has rarely been reported among travellers to eastern africa and our patient is one of the first described cases imported from tanzania. a woman presented with fever, chills, headache, myalgia and a rickettsial eschar on her ankle after returning from tanzania. the diagnosis of african tic ...	2016	27488618
analyses of mitochondrial genes reveal two sympatric but genetically divergent lineages of rhipicephalus appendiculatus in kenya.	the ixodid tick rhipicephalus appendiculatus transmits the apicomplexan protozoan parasite theileria parva, which causes east coast fever (ecf), the most economically important cattle disease in eastern and southern africa. recent analysis of micro- and minisatellite markers showed an absence of geographical and host-associated genetic sub-structuring amongst field populations of r. appendiculatus in kenya. to assess further the phylogenetic relationships between field and laboratory r. appendic ...	2016	27334334
ehrlichia ruminantium infects rhipicephalus microplus in west africa.	the invasion of west africa by rhipicephalus microplus during the past decade has changed the ecological situation of the agent of heartwater ehrlichia ruminantium in this area. before, its local vector, amblyomma variegatum, was the most abundant tick species found on livestock. today, the abundance of the r. microplus is one magnitude higher than that of a. variegatum in many west-african localities. we investigated the potential of this new ecological situation to impact the circulation of e. ...	2016	27334439
ectoparasites of stray dogs in mazandaran, gilan and qazvin provinces, north and center of iran.	the aim of the present study was to determine the prevalence of ectoparasite infestations in stray dogs in mazandaran, gilan and qazvin provinces in fall and winter in 2013(december to march).	2016	27308294
recombination is a major driving force of genetic diversity in the anaplasmataceae ehrlichia ruminantium.	the disease, heartwater, caused by the anaplasmataceae e. ruminantium, represents a major problem for tropical livestock and wild ruminants. up to now, no effective vaccine has been available due to a limited cross protection of vaccinal strains on field strains and a high genetic diversity of ehrlichia ruminantium within geographical locations. to address this issue, we inferred the genetic diversity and population structure of 194 e. ruminantium isolates circulating worldwide using multilocus ...	2016	27747194
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
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
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
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
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
parasites of domestic and wild animals in south africa. l. ixodid ticks infesting horses and donkeys.	the aim of the study was to determine the species spectrum of ixodid ticks that infest horses and donkeys in south africa and to identify those species that act as vectors of disease to domestic livestock. ticks were collected opportunistically from 391 horses countrywide by their owners or grooms, or by veterinary students and staff at the faculty of veterinary science, university of pretoria. ticks were also collected from 76 donkeys in limpopo province, 2 in gauteng province and 1 in north we ...	2017	28281774