Infection dynamics of Theileria annulata over a disease season following cell line vaccination

Tropical theileriosis is a tick-borne haemoparasitic disease of cattle caused by the protozoan parasite Theileria annulata. Globally, the economic impact of the disease is immense and enhanced control measures would improve livestock production in endemic regions. Immunisation with a live attenuated vaccine is an effective and widely used control method, however, the repeated use of live vaccines may have an impact on the field parasite population at a genetic level. Additionally, there has been an increasing number of reports of vaccine breakthrough cases in recent years. Thus, the present study was designed to evaluate the genetic composition of a parasite population over a disease season in a locality where live cell line vaccination is practised. A diverse range of parasite genotypes was identified and every T. annulata positive cattle blood sample harboured multiple parasite genotypes. An alteration in the major genotype and an increasing multiplicity of infection in individual animals was observed over the course of the disease season. Vaccination status was found not to effect within-host multiplicity of infection, while a significantly higher number of genotypes was detected in grazed cattle compared to non-grazed ones. A degree of genetic isolation was evident between parasite populations on a micro-geographic scale, which has not been reported previously for T. annulata. Analysis of parasite genotypes in vaccinated animals suggested only a transient effect of the vaccine genotype on the genetic diversity of the T. annulata population. The vaccine genotype was not detected among clones of two vaccine ‘breakthrough’ isolates and there is no suggestion that it was responsible for disease. The obtained data indicated that in the system studied there is no apparent risk of introducing the vaccine genotype into the population with only a transient effect on the genetic diversity of the parasite population during the disease season

In vitro feeding of all life stages of two-host Hyalomma excavatum and Hyalomma scupense and three-host Hyalomma dromedarii ticks

Ticks are blood-sucking ectoparasites and can transmit various pathogens of medical and veterinary relevance. The life cycle of ticks can be completed under laboratory conditions on experimental animals, but the artificial feeding of ticks has attracted increased interest as an alternative method. This study represents the first report on the successful in vitro feeding of all life stages of two-host tick species, Hyalomma scupense and Hyalomma excavatum, and the three-host tick Hyalomma dromedarii. The attachment and engorgement rates of adults were 84% (21/25) and 76% (19/25) for H. scupense females. For adult H. excavatum and H. dromedarii, 70% (21/30) and 34.4% (11/32) of the females attached and all attached females successfully fed to repletion. The oviposition rates of the artificially fed females were 36.4%, 57.1% and 63.1% for H. dromedarii, H. excavatum and H. scupense, respectively, with a reproductive efficiency index varying between 44.3 and 60.7%. For the larvae, the attachment and engorgement rates were 44.2% (313/708) and 42.8% (303/708) for H. dromedarii, 70.5% (129/183) and 56.8% (104/183) for H. excavatum and 92.6% (113/122) and 55.7% (68/122) for H. scupense. The attachment and engorgement rates for the nymphs were 90.2% (129/143) and 47.6% (68/143) for H. dromedarii, 66.7% (34/51) and 41.2% (21/51) for H. excavatum, and 44.1% (30/68) and 36.8% (25/68) for H. scupense. Molting rates of the immature stages varied between 71.3% (216/303) and 100% (68/68) for the larvae and between 61.9% (13/21) and 96% (24/25) for the nymphs. The successful in vitro feeding of all stages of the three Hyalomma species makes this method a valuable tool for tick research, with potential applications in studies on the pathogens transmitted by these tick species such as Theileria annulata

Selection of genotypes harbouring mutations in the cytochrome b gene of Theileria annulata is associated with resistance to buparvaquone

Buparvaquone remains the only effective therapeutic agent for the treatment of tropical theileriosis caused by Theileria annulata. However, an increase in the rate of buparvaquone treatment failures has been observed in recent years, raising the possibility that resistance to this drug is associated with the selection of T. annulata genotypes bearing mutation(s) in the cytochrome b gene (Cyto b). The aim of the present study was: (1) to demonstrate whether there is an association between mutations in the T. annulata Cyto b gene and selection of parasite-infected cells resistant to buparvaquone and (2) to determine the frequency of these mutations in parasites derived from infected cattle in the Aydın region of Türkiye. Susceptibility to buparvaquone was assessed by comparing the proliferative index of schizont-infected cells obtained from cattle with theileriosis before and/or after treatment with various doses of buparvaquone, using the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colourimetric assay. The DNA sequence of the parasite Cyto b gene from cell lines identified as resistant or susceptible was determined. A total of six nonsynonymous and six synonymous mutations were identified. Two of the nonsynonymous mutations resulted in the substitutions V135A and P253S which are located at the putative buparvaquone binding regions of cytochrome b. Allele-specific PCR (AS-PCR) analyses detected the V135A and P253S mutations at a frequency of 3.90% and 3.57% respectively in a regional study population and revealed an increase in the frequency of both mutations over the years. The A53P mutation of TaPIN1 of T. annulata, previously suggested as being involved in buparvaquone resistance, was not detected in any of the clonal cell lines examined in the present study. The observed data strongly suggested that the genetic mutations resulting in V135A and P253S detected at the putative binding sites of buparvaquone in cytochrome b play a significant role in conferring, and promoting selection of, T. annulata genotypes resistant to buparvaquone, whereas the role of mutations in TaPIN1 is more equivocal

Multifunctional 3D printing of heterogeneous hydrogel structures

Multimaterial additive manufacturing or three-dimensional (3D) printing of hydrogel structures provides the opportunity to engineer geometrically dependent functionalities. However, current fabrication methods are mostly limited to one type of material or only provide one type of functionality. In this paper, we report a novel method of multimaterial deposition of hydrogel structures based on an aspiration-on-demand protocol, in which the constitutive multimaterial segments of extruded filaments were first assembled in liquid state by sequential aspiration of inks into a glass capillary, followed by in situ gel formation. We printed different patterned objects with varying chemical, electrical, mechanical, and biological properties by tuning process and material related parameters, to demonstrate the abilities of this method in producing heterogeneous and multi-functional hydrogel structures. Our results show the potential of proposed method in producing heterogeneous objects with spatially controlled functionalities while preserving structural integrity at the switching interface between different segments. We anticipate that this method would introduce new opportunities in multimaterial additive manufacturing of hydrogels for diverse applications such as biosensors, flexible electronics, tissue engineering and organ printing

Studies on the application of the sterile-male technique on the tick Hyalomma excavatum

TrdizinScopu

Geographical distribution of ticks in Turkey

Bu proje, Avrupa Birliği tarafından desteklenmiştir. Integrated Consortium Ticks Tick Borne Dis 3 (ICTTD-3, IC18-CT95-0009)Turkey's tick fauna is composed of about 32 species in two families and ten genera in mammals, reptiles, and birds. The ticks of veterinary significance in the family Ixodidae comprise seven genera with 28 different species. Ixodes spp. are mostly seen in northern Turkey. It is likely that the high rainfall and the intensive forest in this area may contribute to this observation. To date, the following species have been found to be sporadically present: Amblyomma variegatum in Hatay province (border to Syria), Boophilus kohlsi in southeastern Turkey (border of Syria), Ornithodorus in Central and East Anatolia, and Otobius megnini in East Anatolia (Malatya Province). Ticks of the genera Haemaphysalis, Hyalomma, Boophilus, Dermacentor, Rhipicephalus, and Argas are widespread throughout Anatolia. Thus, their role in the epidemiology of important human and livestock diseases such as Crimean-Congo hemorrhagic fever, Lyme disease, and diseases caused by hemoparasites needs to be examined in greater detail.Avrupa Birliğ

Diversity of ticks biting humans in Aydın province of Turkey

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Laboratuvar şartlarında Hyalomma excavatum'un üretilmesi ve kolonizasyonu

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Distribution of tick species on cattle in the Western Anatolia

Bu çalışma Batı Anadolu Bölgesi sığırlarında bulunan kene türlerini, mevsimsel aktivitelerini ve yaygınlıklarını belirlemek amacıyla planlanmış ve Haziran 2006-Mayıs 2008 tarihleri arasında Manisa, İzmir ve Aydın illerine bağlı dokuz köyde yürütülmüştür. Belirlenen çalışma merkezlerine yirmi dört ay boyunca ayda bir düzenli olarak gidilmiş, bu merkezlerdeki 75 hayvan barınağı ve bu barınaklardaki sığırlar çalışma boyunca 8018 kez kene varlığı açısından incelenmiştir.Araştırma süresince sığırların %23,01'inin kene ile enfeste olduğu saptanmış ve sığırlardan toplam 19679 erişkin kene toplanmıştır. Toplanan bu kenelerden 3318 (%16,86)'i Manisa'da, 8980 (%45,63)'i İzmir'de ve 7381 (%37,51)'i Aydın ilinde bulunmuştur. Çalışma merkezlerindeki sığırlarda erişkin olarak 12 kene türü (Ixodes ricinus %2,88, Rhipicephalus (Boophilus) annulatus %0,14, Dermacentor marginatus %4,49, Hyalomma anatolicum %0,86, Hyalomma excavatum %18,89, Hyalomma detritum %13,68, Hyalomma marginatum %37,39, Hyalomma rufipes %0,07, Haemaphysalis parva %0,04, Rhipicephalus bursa %4,22, Rhipicephalus sanguineus %0,04, Rhipicephalus turanicus %17,24) saptanmıştır. Tür tayini yapılamayan kene oranı ise %0,06 olarak belirlenmiştir. Teşhis edilen kene türlerinin mevsimsel aktivitelerine bakıldığında, Ixodes ricinus'un erişkinlerinin, Kasım ayının başlarında başlayıp, Mayıs ayı başlarına kadar görüldüğü, Rhipicephalus (Boophilus) annulatus'un, Temmuz, Ağustos ile Ekim, Kasım aylarında gözlendiği, Dermacentor marginatus'un Eylül ? Haziran (Mayıs ayı hariç) ayları arasında görüldüğü tespit edilmiştir. Çalışma yürütülen bölgede Hyalomma türlerinin erişkinlerinin tüm yıl boyunca görüldüğü, ancak kış aylarında sınırlı sayılarda kaldığı belirlenmiştir. Haemaphysalis parva türünün sığırlar üzerinde sadece Ekim, Kasım aylarında az sayıda olduğu saptanmıştır. Rhipicephalus türleri ise daha çok ilkbahar ve yaz aylarında tespit edilmiştir.Hyalomma marginatum (%37,39) ve Hyalomma excavatum (%18,89) bölgede en yaygın kene türleri olarak tespit edilmiş olup, Ege Bölgesinde daha önceleri bildirilmeyen Ixodes ricinus (%2,88) , Dermacentor marginatus (%4,49) ve Haemaphysalis parva (%0,04) sığırlarda saptanmıştır. Bunun dışında daha önce Türkiye'de bildirilmeyen Hyalomma rufipes (%0,07) türü de Ege Bölgesindeki sığırlarda bulunmuş olup, bu kene türünün varlığı Türkiye'de ilk kez belirlenmiştir.The aims of the present study were to determine the identity, seasonal activity and distribution of tick species of cattle in the Western Anatolia of Turkey between June2006- May 2008. Nine villages within three cities, viz. Manisa, Izmir and Aydin, were included in the study and a total of 75 animal cernals were visited monthly for a period of 24 months and cattle were examined 8018 times for the presence of ticks.In this study, 23,01 % of cattle were determined to be infested with ticks. A total of 19679 adult ticks were collected. 3318 (16,86%), 8980 (45,63%), 7381 (37,51%) out of 19679 adult ticks were collected from Manisa, Izmir and Aydin, respectively. Twelve tick species (Ixodes ricinus 2,88%, Rhipicephalus (Boophilus) annulatus 0,14%, Dermacentor marginatus 4,49%, Hyalomma anatolicum 0,86%, Hyalomma excavatum 18,89%, Hyalomma detritum 13,68%, Hyalomma marginatum 37,39%, Hyalomma rufipes 0,07%, Haemaphysalis parva 0,04%, Rhipicephalus bursa 4,22%, Rhipicephalus sanguineus 0,04%, Rhipicephalus turanicus 17,24%) were identified. The percantage of unidentified ticks was 0,06%. Among the identified tick species, adult Ixodes ricinus occurred between 1st of November and begining of May. Occurrence of Rhipicephalus (Boophilus) annulatus, between July and August and October and November, on cattle. Dermacentor marginatus was observed between September and June (excluding May). Adults of Hyalomma species were observed during the whole year, although they were more abundant in summer time than that observed in winter. Rhiphicephalus species were found to be more abundant in the spring and summer.Hyalomma marginatum (37,39%) and Hyalomma excavatum (18,89%) were determined to be the most abundant tickspecies. Species that have not been reported previously, namely, Ixodes ricinus (2,88%), Dermacentor marginatus (4,49%) and Haemaphysalis parva (0,04%), were detected on cattle in the Aegean Region of Turkey. In addition, the present study demonstrates that Hyalomma rufipes (0,07%), a species that is not known to exist in Turkey, is present in cattle in the Aegean Region of Turkey.ADÜ Araştırma Fon