Tick species from cattle in the Adama Region of Ethiopia and pathogens detected

Ticks will diminish productivity among farm animals and transmit zoonotic diseases. We conducted a study to identify tick species infesting slaughter bulls from Adama City and to screen them for tick-borne pathogens. In 2016, 291 ticks were collected from 37 bulls in Adama, which were ready for slaughter. Ticks were identified morphologically. Total genomic DNA was extracted from ticks and used to test for Rickettsia spp. with real-time PCR. Species identification was done by phylogenetic analysis using sequencing that targeted the 23S-5S intergenic spacer region and ompA genes. Four tick species from two genera, Amblyomma and Rhipicephalus, were identified. Amblyomma cohaerens was the dominant species (n = 241, 82.8%), followed by Amblyomma variegatum (n = 22, 7.5%), Rhipicephalus pulchellus (n = 19, 6.5%), and Rhipicephalus decoloratus (n = 9, 3.0%). Among all ticks, 32 (11%) were positive for Rickettsia spp. and 15 (5.2%) of these were identified as R. africae comprising at least two genetic clades, occurring in A. variegatum (n = 10) and A. cohaerens (n = 5). The remainder of Rickettsia-positive samples could not be amplified due to low DNA yield. Furthermore, another 15 (5.2%) samples carried other pathogenic bacteria: Ehrlichia ruminantium (n = 9; 3.1%) in A. cohaerens, Ehrlichia sp. (n = 3; 1%) in Rh. pulchellus and A. cohaerens, Anaplasma sp. (n = 1; 0.5%) in A. cohaerens, and Neoehrlichia mikurensis (n = 2; 0.7%) in A. cohaerens. All ticks were negative for Bartonella spp., Babesia spp., Theileria spp., and Hepatozoon spp. We reported for the first time E. ruminatium, N. mikurensis, Ehrlichia sp., and Anaplasma sp. in A. cohaerens. Medically and veterinarily important pathogens were mostly detected from A. variegatum and A. cohaerens. These data are relevant for a One-health approach for monitoring and prevention of tick-borne disease transmission.

The Prevalence of Ticks Infestation of Dogs in Runjin Sambo Area of Sokoto, Sokoto State, Nigeria

Ticks are still considered a major cause of zoonotic diseases most especially to dogs and other related animals. This study was conducted to assess the ticks infestation of dogs in Runjin Sambo area Sokoto. The sample was collected using hand picking and hair brushing method with the assistance of dog owners. A total of sixty dogs were randomly selected in four different sub areas in Runjin Sambo. The locality, sex and age of the dogs were noted. The ticks species were identified in the entomology laboratory using key devices. Four species of ticks namely, Amlyomma variegatum, Rhipicephalus pulchellus, Boophilus decolaratus and Hyalomma excavatum were identified. The 45 (75%) of dogs were found infected with prevalence of 11.67%, 21.67%, 25.00% and 16.67% in the four sub-areas respectively. The prevalence rate of infection was 31.67% in male dogs and 43.33% in female dogs. Similarly 55.00% and 20.00% in adult and puppy dogs respectively. Tick infestation of dogs seems to be due to poor and unhygienic condition of the dogs and can be reduced by proper sanitation, improve hygiene and health education.

In Vitro Acaricidal Activity of Selected Medicinal Plants Traditionally Used against Ticks in Eastern Ethiopia

A study was carried out to evaluate the acaricidal activities of crude methanolic extract of leaves of six medicinal plants, namely, Vernonia amygdalina, Calpurnia aurea, Schinus molle, Ricinus communis, Croton macrostachyus, and Nicotiana tabacum, against Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus using an in vitro adult immersion test. Five graded concentrations of the crude extracts, 6.25, 12.5, 25, 50, and 100 mg/ml, were tested at different time intervals, and temporal changes in tick viability were recorded for 24 hours. Diazinon (0.1%) and distilled water were used as positive and negative controls, respectively. Standard procedures were applied to screen the phytochemical constituents of the tested plant parts. Phytochemical screening showed the presence of a condensed amount of tannins in all extracts. Starting from 30 min post exposure, the 100 mg/ml concentration of C. aurea and R. communis extracts has caused significantly higher mortality (P<0.05) compared to the diazinon. A significant increase in tick mortality started 2 hr post exposure with diazinon and 50 and 100 mg/ml concentrations of S. molle. Vernonia amygdalina extract and diazinon showed a significant increase in tick mortality 3 hr post exposure with 100 mg/ml concentration. Similarly, a significant increase in tick mortality started 2 hr post exposure with diazinon and 100 mg/ml concentrations of C. macrostachyus and N. tabacum. At 24 hr post exposure, diazinon and 50 and 100 mg/ml concentrations of all the extracts have caused significantly higher tick mortality than the rest of the concentrations (P<0.05). Higher concentrations of all the extracts had showed a comparable and strong acaricidal effect on Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus having no significant difference with that of the positive control (P>0.05) at 24 hr post exposure period. Tick killing activity of all evaluated plant extracts increases with increasing exposure time and concentration as well. Thus, all the tested plants could be used against Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus as a potential alternative to substitute commercially available drugs. We recommend further study on fractionating each component separately and validating the materials.

An inhibitor of complement C5 provides structural insights into activation

The complement system is a crucial part of innate immune defenses against invading pathogens. The blood-meal of the tickRhipicephalus pulchelluslasts for days, and the tick must therefore rely on inhibitors to counter complement activation. We have identified a class of inhibitors from tick saliva, the CirpT family, and generated detailed structural data revealing their mechanism of action. We show direct binding of a CirpT to complement C5 and have determined the structure of the C5–CirpT complex by cryoelectron microscopy. This reveals an interaction with the peripheral macro globulin domain 4 (C5_MG4) of C5. To achieve higher resolution detail, the structure of the C5_MG4–CirpT complex was solved by X-ray crystallography (at 2.7 Å). We thus present the fold of the CirpT protein family, and provide detailed mechanistic insights into its inhibitory function. Analysis of the binding interface reveals a mechanism of C5 inhibition, and provides information to expand our biological understanding of the activation of C5, and thus the terminal complement pathway.

PREVALENCE OF TICK AND MANGE MITES’ INFESTATION IN GOATS IN BENATSEMAY DISTRICT OF SOUTH OMO ZONE, ETHIOPIA

Across sectional, study of tick was conducted to identify types of tick species and determine the Prevalence of tick and mange mites infestation in small ruminants in Benatsemayworeda, South Omozone, Southern Nation Nationality of Ethiopia. Collection and identification of the ticks and mange mites were undertaken from June 6----- /15/ 2019. The overall prevalence of tick and mange mites infestation in the study area was 172 (40.66%) All visible individual adult ticks were collected from the body of 172 goats. The prevalence of tickand mange mites infestation in goats was found to be (40.66%). In this study, one/ species of ticks, which grouped under one genus, was identified. The most abundant species found in this study were Rhipicephalus/pulchellus, eversi, simus, B(decoloratus) and psoroptics mites.

A novel inhibitor of complement C5 provides structural insights into activation

The complement system is a crucial part of innate immune defences against invading pathogens. The blood-meal of the tick Rhipicephalus pulchellus lasts for days, and the tick must therefore rely on inhibitors to counter complement activation. We have identified a novel class of inhibitors from tick saliva, the CirpT family, and generated detailed structural data revealing their mechanism of action. We show direct binding of a CirpT to complement C5 and have determined the structure of the C5-CirpT complex by cryo-electron microscopy. This reveals an interaction with the peripheral macro globulin domain 4 (C5_MG4) of C5. To achieve higher resolution detail, the structure of the C5_MG4-CirpT complex was solved by X-ray crystallography (at 2.7 Å). We thus present the novel fold of the CirpT protein family, and provide detailed mechanistic insights into its inhibitory function. Analysis of the binding interface reveals a novel mechanism of C5 inhibition, and provides information to expand our biological understanding of the activation of C5, and thus the terminal complement pathway.

Cattle and rainfall affect tick abundance in central Kenya

SUMMARYEast Africa is a global hot spot for the diversity of ixodid ticks. As ectoparasites and as vectors of pathogens, ticks negatively affect the well-being of humans, livestock and wildlife. To prevent tick infestations, livestock owners and managers typically treat livestock with acaricides that kill ticks when they attempt to feed on livestock hosts. Because of the costs of preventing and mitigating tick parasitism, predicting where and when ticks will be abundant is an important challenge in this region. We used a 7-year monthly record of tick abundance on large experimental plots to assess the effects of rainfall, wildlife and cattle on larvae, nymphs and adults of two common tick species, Rhipicephalus pulchellus and Rhipicephalus praetextatus. Nymphal and adult ticks were more abundant when there had been high cumulative rainfall in the prior months. They were less abundant when cattle were present than when only large wild mammals were. Larval abundance was not affected by the presence of cattle, and larvae did not appear to be sensitive to rainfall in prior months, though they were less abundant in our surveys when rainfall was high in the sampling month. The challenges of managing ticks in this region are being exacerbated rapidly by changes in rainfall patterns wrought by climate change, and by overall increases in livestock, making efforts to predict the impacts of these drivers all the more pressing.

PREVALENCE OF TICK INFESTATION ON SMALL RUMINANTS IN AND AROUND DIRE DAWA, EASTERN ETHIOPIA

Across section, study of tick was conducted to identify types of tick species and determine the Prevalence of tick infestation in small ruminants in and around Dire Dawa Administrative council, Eastern Ethiopia. Collection and identification of the ticks were undertaken from November 2014 to May 2015. The overall prevalence of tick infestation in the study area was 278 (72.39% /384). All visible individual adult ticks were collected from the body of 196 goats and 188 sheep. The prevalence of tick infestation in goats and sheep was found to be 73.9% and 70.7%, respectively. In this study, eight species of ticks, which grouped under four genera, were identified. The most abundant species found in this study were Rhipicephalus pulchellus (34.1%), Amblyomma variegatum (24.5%), Rhipicephalus evertsievertsi (22.1%), Hyalomma truncatum (15.6%), Hyalomma marginatum rufipes (12.2%) and Amblyomma gemma (10.9 according to predominance. Hyalomma dromedari (4.2%) and Boophilus decoloratus was the minor species observed on both goats and sheep in the study area. The difference in prevalence of tick infestation was found statistically significant variation (P < 0.05) between the sex, age exception of Boophilus decoloratus and Hyalomma dromedari in all cases male ticks dominated females.