scholarly journals High infection rates of the tick Hyalomma anatolicum anatolicum with Trypanosoma theileri

2004 ◽  
Vol 71 (4) ◽  
Author(s):  
A.A. Latif ◽  
M.A. Bakheit ◽  
Amna E. E. Mohamed ◽  
E. Zweygarth
Keyword(s):  
Developmental Stages ◽  
Blood Parasites ◽  
Hyalomma Anatolicum ◽  
Hyalomma Anatolicum Anatolicum ◽  
Regular Control ◽  
High Infection ◽  
Centrifugation Technique ◽  
Very High ◽  
Peak Parasitaemia ◽  
Trypanosoma Theileri

A crossbred calf (3 months old) obtained from a farm where regular control of ticks was practised and found to be free of blood parasites was inoculated with 20 ml pooled blood collected from four field cattle which had very low Trypanosoma theileri parasitaemias (one parasite per 70 µl blood as determined by the haematocrit centrifugation technique). Trypanosoma theileri was present in the blood 6 days after injection and a peak parasitaemia of 42 parasites per 70 µl blood was recorded by day 12. Hyalomma anatolicum anatolicum nymphs were applied on the ears of the calf on day 8 and they dropped engorged by days 13 and 14. The resulting adult ticks were examined for the presence of T. theileri by severing a leg and making a smear of the clear haemolymph which exuded from the wound. The smear was fixed in methanol and stained with Giemsa stain. The infection rate with T. theileri in the ticks was 43.3 % (26 out of 60). The intensity of infection was very high and various developmental stages of the flagellates were observed (epimastigotes, sphaeromastigotes, trypomastigotes and other intermediate stages). The haemolymph from 12 ticks was also collected in tissue culture medium and the trypanosomes survived for 25 weeks before eventually dying. The results demonstrated unequivocally the high vectorial capacity of the tick H. a. anatolicum for T. theileri.

scholarly journals MicroRNA-1 Expression and Function in Hyalomma Anatolicum anatolicum (Acari: Ixodidae) Ticks

2021 ◽  
Vol 12 ◽  
Author(s):  
Jin Luo ◽  
Qiaoyun Ren ◽  
Wenge Liu ◽  
Xiaofei Qiu ◽  
Gaofeng Zhang ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Gene Selection ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Tissue Expression ◽  
Hyalomma Anatolicum ◽  
Internal Reference ◽  
Hyalomma Anatolicum Anatolicum ◽  
Significant Difference

MicroRNAs act as mRNA post-transcriptional regulators, playing important roles in cell differentiation, transcriptional regulation, growth, and development. In this study, microRNA expression profiles of Hyalomma anatolicum anatolicum ticks at different developmental stages were detected by high-throughput sequencing and functionally assessed. In total, 2,585,169, 1,252,678, 1,558,217, and 1,155,283 unique reads were obtained from eggs, larvae, nymphs, and adults, respectively, with 42, 46, 45, and 41 conserved microRNAs in these stages, respectively. Using eggs as a control, 48, 43, and 39 microRNAs were upregulated, and 3, 10, and 9 were downregulated in larvae, nymphs, and adults, respectively. MicroRNA-1 (miR-1) was expressed in high abundance throughout Ha. anatolicum development, with an average of nearly one million transcripts, and it is highly conserved among tick species. Quantitative real-time PCR (qPCR) showed that miR-1 expression gradually increased with tick development, reaching the highest level at engorgement. Differential tissue expression was detected, with significantly higher levels in the salivary glands and epidermis than in the midgut. Inhibition assays showed no significant change in body weight or spawning time or amount between experimental and control groups, but there was a significant difference (p < 0.01) in engorgement time. With miR-1 inhibition, ticks displayed obvious deformities during later development. To more fully explain the microRNA mechanism of action, the miR-1 cluster was analyzed according to the target gene; members that jointly act on Hsp60 include miR-5, miR-994, miR-969, and miR-1011. Therefore, microRNAs are critical for normal tick development, and the primary structure of the mature sequence of miR-1 is highly conserved. Nonetheless, different developmental stages and tissues show different expression patterns, with a certain role in prolonging feeding. miR-1, together with other cluster members, regulates mRNA function and may be used as a molecular marker for species origin, evolution analysis, and internal reference gene selection.

scholarly journals Plasmodium oocysts respond with dormancy to crowding and nutritional stress

2020 ◽  
Author(s):  
Tibebu Habtewold ◽  
Aayushi A. Sharma ◽  
Claudia A.S. Wyer ◽  
Ellen K.G. Masters ◽  
Nikolai Windbichler ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Rna Polymerase Iii ◽  
Nutritional Stress ◽  
Alternative Methods ◽  
Anopheles Coluzzii ◽  
Energy Reserves ◽  
Transmission Blocking ◽  
High Infection ◽  
Very High ◽  
Starvation Conditions

AbstractMalaria parasites develop and grow as oocysts in the mosquito for several days before being able to infect another human. During this time, mosquitoes take regular bloodmeals to replenish their nutrient and energy reserves needed for flight and reproduction. We hypothesized that supplemental bloodmeals are critical for oocyst growth and that experimental infection protocols, typically involving a single bloodmeal, cause nutritional stress to developing oocysts. Therefore, enumerating oocysts independently of their growth and differentiation state may lead to erroneous conclusions regarding the efficacy of malaria transmission blocking interventions. We tested this hypothesis in Anopheles coluzzii mosquitoes infected with human and rodent parasites Plasmodium falciparum and Plasmodium berghei, respectively. We find that oocyst growth rates decrease at late developmental stages as infection intensities increase; an effect exacerbated at very high infection intensities. Oocyst growth and differentiation can be restored by supplemental bloodmeals even at high infection intensities. We show that high infection intensities as well as starvation conditions reduce RNA Polymerase III activity in oocysts unless supplemental bloodmeals are provided. Our data suggest that oocysts respond to crowding and nutritional stress by employing a dormancy-like strategy and urge development of alternative methods to assess the efficacy of transmission blocking interventions.

scholarly journals MicroRNA-1 promotes the development of and prolongs engorgement time in Hyalomma anatolicum anatolicum (Acari: Ixodidae) ticks

2020 ◽  
Author(s):  
Jin Luo ◽  
Qiaoyun Ren ◽  
Wenge Liu ◽  
Xiaofei Qiu ◽  
Gaofeng Zhang ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Gene Selection ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Hyalomma Anatolicum ◽  
Internal Reference ◽  
Hyalomma Anatolicum Anatolicum ◽  
Origin And Evolution ◽  
Significant Difference

AbstractMicroRNAs act as mRNA posttranscriptional regulators, playing important roles in cell differentiation, transcriptional regulation, growth and development. In this study, microRNA expression profiles of Hyalomma anatolicum anatolicum ticks at different developmental stages were detected by high-throughput sequencing and functionally assessed. In total, 2,585,169, 1,252,678, 1,558,217 and 1,155,283 unique reads were obtained from eggs, larvae, nymphs and adults, respectively, with 42, 46, 45 and 41 conserved microRNAs in these stages, respectively. Using eggs as a control, 48, 43 and 39 microRNAs were upregulated and 3, 10 and 9 downregulated in larvae, nymphs and adults, respectively. microRNA-1 (miR-1) was expressed in high abundance throughout Ha. anatolicum development, with an average of nearly one million transcripts, and it is highly conserved among tick species. Quantitative real-time PCR (qPCR) showed that miR-1 expression gradually increased with tick development, reaching the highest level at engorgement. Differential tissue expression was detected, with significantly higher levels in the salivary glands and epidermis than in the midgut. Inhibition assays showed no significant change in body weight or spawning time or amount between experimental and control groups, but there was a significant difference (p<0.01) in engorgement time. With miR-1 inhibition, ticks displayed obvious deformities during later development. To more fully explain the microRNA mechanism of action, the miR-1 family was analyzed regarding target gene; members acting on Hsp60 include miR-5, miR-994, miR-969, and miR-1011, which jointly play a role. Therefore, microRNAs are critical for normal tick development, and the primary structure of the mature sequence of miR-1 is highly conserved. Nonetheless, different developmental stages and tissues show different expression patterns, with a certain role in prolonging feeding. miR-1, together with other family members, regulates mRNA function and may be used as a molecular marker for species origin and evolution analysis and internal reference gene selection.

scholarly journals Plasmodium Oocysts Respond With Dormancy to Crowding and Nutritional Stress

2020 ◽  
Author(s):  
Tibebu Habtewold ◽  
Aayushi Sharma ◽  
Claudia Wyer ◽  
Ellen Masters ◽  
Nikolai Windbichler ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Rna Polymerase Iii ◽  
Nutritional Stress ◽  
Alternative Methods ◽  
Anopheles Coluzzii ◽  
Energy Reserves ◽  
Transmission Blocking ◽  
High Infection ◽  
Time Of Infection ◽  
Very High

Abstract Malaria parasites develop as oocysts in the mosquito for several days before they are able to infect a human host. During this time, mosquitoes take regular bloodmeals to replenish their nutrient and energy reserves needed for flight and reproduction. We hypothesized that these bloodmeals are critical for oocyst growth and that experimental infection protocols, typically involving a single bloodmeal at the time of infection, cause nutritional stress to the developing oocysts. Therefore, enumerating oocysts disregarding their growth and differentiation state may lead to erroneous conclusions about the efficacy of transmission blocking interventions. Here, we examine this hypothesis in Anopheles coluzzii mosquitoes infected with the human and rodent parasites Plasmodium falciparum and Plasmodium berghei, respectively. We found that oocyst growth rates decrease at late developmental stages as infection intensities increase; an effect exacerbated at very high infection intensities. Oocyst growth and differentiation are restored with post infection bloodmeals even at high infection intensities. High infection intensities and starvation conditions reduce RNA Polymerase III activity in oocysts unless supplemental bloodmeals are provided. Our results suggest that oocysts respond to crowding and nutritional stress with a dormancy-like strategy, which urges the development of alternative methods to assess the efficacy of transmission blocking interventions.

scholarly journals Plasmodium oocysts respond with dormancy to crowding and nutritional stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tibebu Habtewold ◽  
Aayushi A. Sharma ◽  
Claudia A. S. Wyer ◽  
Ellen K. G. Masters ◽  
Nikolai Windbichler ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Rna Polymerase Iii ◽  
Nutritional Stress ◽  
Alternative Methods ◽  
Anopheles Coluzzii ◽  
Energy Reserves ◽  
Transmission Blocking ◽  
High Infection ◽  
Time Of Infection ◽  
Very High

AbstractMalaria parasites develop as oocysts in the mosquito for several days before they are able to infect a human host. During this time, mosquitoes take bloodmeals to replenish their nutrient and energy reserves needed for flight and reproduction. We hypothesized that these bloodmeals are critical for oocyst growth and that experimental infection protocols, typically involving a single bloodmeal at the time of infection, cause nutritional stress to the developing oocysts. Therefore, enumerating oocysts disregarding their growth and differentiation state may lead to erroneous conclusions about the efficacy of transmission blocking interventions. Here, we examine this hypothesis in Anopheles coluzzii mosquitoes infected with the human and rodent parasites Plasmodium falciparum and Plasmodium berghei, respectively. We show that oocyst growth and maturation rates decrease at late developmental stages as infection intensities increase; an effect exacerbated at very high infection intensities but fully restored with post infection bloodmeals. High infection intensities and starvation conditions reduce RNA Polymerase III activity in oocysts unless supplemental bloodmeals are provided. Our results suggest that oocysts respond to crowding and nutritional stress with a dormancy-like strategy, which urges the development of alternative methods to assess the efficacy of transmission blocking interventions.

scholarly journals Temporal Dynamics of ‘Ca. Phytoplasma mali’ Load in the Insect Vector Cacopsylla melanoneura

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 592
Author(s):  
Valentina Candian ◽  
Monia Monti ◽  
Rosemarie Tedeschi
Keyword(s):  
Host Plants ◽  
Developmental Stages ◽  
Temporal Dynamics ◽  
Control Strategies ◽  
Vector Competence ◽  
Insect Vector ◽  
Life Stages ◽  
Candidatus Phytoplasma Mali ◽  
High Infection ◽  
Cacopsylla Melanoneura

The transmission of phytoplasmas is the result of an intricate interplay involving pathogens, insect vectors and host plants. Knowledge of the vector’s competence during its lifespan allows us to define more sustainable well-timed control strategies targeted towards the most worrisome life stages. We investigated the temporal dynamics of ‘Candidatus Phytoplasma mali’ load in Cacopsylla melanoneura in the different developmental stages in Northwest Italy. The phytoplasma load in the vector was evaluated in overwintering adults, nymphs and newly emerged adults after different acquisition access periods. Moreover, we followed the multiplication of the phytoplasma during the aestivation and the overwintering period on conifers. Our results confirmed the ability of remigrants to retain the phytoplasma until the end of winter. We also highlighted the high acquisition efficiency and vector competence, based on phytoplasma load, of nymphs and newly emerged adults. Therefore, particular attention should be paid to the management of overwintered C. melanoneura as soon as they return to the orchards, but also to newly emerged adults, particularly in orchards with a high infection rate and when the migration to conifers is delayed.

A new ovine Babesia species transmitted by Hyalomma anatolicum anatolicum

2009 ◽  
Vol 122 (4) ◽  
pp. 261-267 ◽  
Author(s):  
Guiquan Guan ◽  
Miling Ma ◽  
Emmanuelle Moreau ◽  
Junlong Liu ◽  
Bingyi Lu ◽  
...  
Keyword(s):  
Hyalomma Anatolicum ◽  
Babesia Species ◽  
Hyalomma Anatolicum Anatolicum

Identification of the larvae of Hyalomma (Hyalomma) anatolicum subspecies (Ixodoidea: Ixodidae) with special reference to chaetotaxy

Parasitology ◽  
1971 ◽  
Vol 63 (1) ◽  
pp. 101-107
Author(s):  
Keith R. Snow
Keyword(s):  
Special Reference ◽  
Morphological Characteristics ◽  
Hyalomma Anatolicum ◽  
Hyalomma Anatolicum Anatolicum

An account is given of the morphological characteristics of the larvae of Hyalomma anatolicum anatolicum and H. a. excavatum. Emphasis is placed on the importance of chaetotaxy in the identification of the larvae.I am most grateful to Professor Don R. Arthur for reading the manuscript and for his most useful advice and encouragement. Also I wish to express my sincere thanks to Dr R. P. Chaudhuri, Dr C. M. Clifford, Dr V. Dhanda, Dr H. Hoogstraal and Profesor B. Feldman-Muhsam for supplying me with specimens.

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