scholarly journals Macrogeographic population structure of the tsetse fly, Glossina pallidipes (Diptera: Glossinidae)

2005 ◽  
Vol 95 (5) ◽  
pp. 437-447 ◽  
Author(s):  
J.O. Ouma ◽  
J.G. Marquez ◽  
E.S. Krafsur
Keyword(s):  
Gene Flow ◽  
Microsatellite Loci ◽  
Gene Diversity ◽  
Random Mating ◽  
Glossina Pallidipes ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Fixation Index ◽  
Tsetse Flies ◽  
Sub Saharan

AbstractTsetse flies are confined to sub-Saharan Africa where they occupy discontinuous habitats. In anticipation of area-wide control programmes, estimates of gene flow among tsetse populations are necessary. Genetic diversities were partitioned at eight microsatellite loci and five mitochondrial loci in 21 Glossina pallidipes Austin populations. At microsatellite loci, Nei's unbiased gene diversity averaged over loci was 0.659 and the total number of alleles was 214, only four of which were shared among all populations. The mean number of alleles per locus was 26.8. Random mating was observed within but not among populations(fixation index FST = 0.180) and 81% of the genetic variance was within populations. Thirty-nine mitochondrial variants were detected. Mitochondrial diversities in populations varied from 0 to 0.85 and averaged 0.42, and FST=0.51. High levels of genetic differentiation were characteristic, extending even to subpopulations separated by tens and hundreds of kilometres, and indicating low rates of gene flow.

scholarly journals Tsetse fly distribution and occurrence of Trypanosoma species among cattle and goats around Queen Elizabeth National park, Uganda

2020 ◽  
Author(s):  
Mallion Kangume ◽  
Denis Muhangi ◽  
Joseph Byaruhanga ◽  
Aggrey Agaba ◽  
Joachim Sserunkuma ◽  
...  
Keyword(s):  
National Park ◽  
Glossina Pallidipes ◽  
Dual Infection ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Baseline Information ◽  
Veterinary Importance ◽  
Sub Saharan ◽  
Animal Trypanosomiasis

Abstract Background: African Animal Trypanosomiasis (AAT) is an infectious disease of economic and veterinary importance in Sub-Saharan Africa. The current study aimed at providing baseline information on tsetse fly distribution and occurrence of Trypanosoma species in cattle and goats within and around Queen Elizabeth National Park (QENP), in western Uganda. A minimal entomological survey was conducted in April 2017 while blood samples collected from cattle (n = 576) and goats (n = 319) in June 2015 and May 2017 were subjected to Polymerase Chain Reaction (PCR) to determine the occurrence of Trypanosoma species.Results: Glossina pallidipes and G. fuscipes were the only tsetse fly species trapped in the study area with apparent density of 20.6. The overall prevalence of Trypanosoma spp. was 27% for goats and approximately 38% for cattle. The most prevalent Trypanosoma spp. in goats was T. brucei (n = 60, 18.8%) while the most prevalent in cattle was T. congolense (n = 102, 27.1%). In both cattle and goats, a dual infection of T. brucei + T. congolense was most encountered. In goats a triple infection of T. brucei + T. congolense + T. vivax was higher than that in cattle. Conclusions: Current findings show that there are two species of tsetse flies, and three species of Trypanosoma, important in transmission of AAT in both cattle and goats. Control efforts of AAT have mainly focused on cattle and this study proves that prevention and control efforts should also involve goat farmers.

scholarly journals Molecular screening for Anaplasmataceae in ticks and tsetse flies from Ethiopia

2016 ◽  
Vol 64 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Sándor Hornok ◽  
Getachew Abichu ◽  
Nóra Takács ◽  
Miklós Gyuranecz ◽  
Róbert Farkas ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Tsetse Fly ◽  
Ixodid Ticks ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Ehrlichia Ruminantium ◽  
Blood Sucking ◽  
Sub Saharan ◽  
Transmission Studies ◽  
First Time

Hard ticks and tsetse flies are regarded as the most important vectors of disease agents in Sub-Saharan Africa. With the aim of screening these blood-sucking arthropods for vector-borne pathogens belonging to the family Anaplasmataceae in South-Western Ethiopia, four species of tsetse flies (collected by traps) and seven species of ixodid ticks (removed from cattle) were molecularly analysed. DNA was extracted from 296 individual ticks and from 162 individuals or pools of tsetse flies. Besides known vector–pathogen associations, in Amblyomma cohaerens ticks sequences of Anaplasma marginale and A. phagocytophilum were detected, the latter for the first time in any ticks from cattle in Africa. In addition, part of the gltA gene of Ehrlichia ruminantium was successfully amplified from tsetse flies (Glossina pallidipes). First-time identification of sequences of the above pathogens in certain tick or tsetse fly species may serve as the basis of further epidemiological and transmission studies.

scholarly journals Tsetse fly distribution and occurrence of Trypanosoma species among cattle and goats around Queen Elizabeth National park, Uganda

2020 ◽  
Author(s):  
Mallion Kangume ◽  
Denis Muhangi ◽  
Joseph Byaruhanga ◽  
Aggrey Agaba ◽  
Joachim Sserunkuma ◽  
...  
Keyword(s):  
Mixed Infection ◽  
National Park ◽  
Glossina Pallidipes ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Public Health Importance ◽  
Baseline Information ◽  
Sub Saharan ◽  
Animal Trypanosomiasis ◽  
And Control

Abstract Background African Animal Trypanosomiasis (AAT) is an infectious disease of economic and public health importance hindering agricultural productivity in Sub-Saharan Africa. The current study aimed at providing baseline information on tsetse fly distribution and occurrence of Trypanosoma species in cattle and goats within and around Queen Elizabeth National Park (QENP), in western Uganda. A minimal entomological survey was conducted in April 2017 while blood samples collected from cattle (n = 576) and goats (n = 319) in June 2015 and May 2017 were subjected to microscopy and Polymerase Chain Reaction (PCR) to determine the occurrence of trypanosome species. Results Glossina pallidipes and G. fuscipes were the only tsetse fly species trapped in the study area with apparent density of 20.6. The overall prevalence of Trypanosoma spp. in cattle and goats was 38.9% and 37% respectively for samples collected in 2015 while the prevalence of Trypanosome spp in cattle samples collected in 2017 was 38%. In 2015, T. brucei was the highest prevalent trypanosome in both cattle (23%) and goats (18.8%). In both cattle and goats, a mixed infection of T. brucei + T. congolense was most encountered with prevalence of 4.8% and 4.1% in cattle and goats, respectively. In goats a mixed infection of T. brucei + T. congolense + T. vivax was higher (2.8%) than in cattle (2.4%). In 2017, in cattle (n = 250), the prevalence for T. congolense was 32.4%, T. vivax was 6.8% and T. brucei was 6.4%. A co-infection of T. brucei and T. congolense was most prevalent (7.4%). Only 3.2% of the cattle were co-infected with all the three Trypanosome species. Conclusions Current findings show that there are two types of Tsetse fly specie, s important in transmission of AAT. Presence of these parasites in goats shows that they also play a key role in epidemiology of the disease and control efforts should aim also involve goat farmers.

scholarly journals Positional Dynamics and Glycosomal Recruitment of Developmental Regulators during Trypanosome Differentiation

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Balázs Szöőr ◽  
Dorina V. Simon ◽  
Federico Rojas ◽  
Julie Young ◽  
Derrick R. Robinson ◽  
...  
Keyword(s):  
Life Cycle ◽  
Trypanosoma Brucei ◽  
Tyrosine Phosphatase ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Metabolic Adaptation ◽  
Tsetse Flies ◽  
Content Type ◽  
African Trypanosomes ◽  
Sub Saharan

ABSTRACT Glycosomes are peroxisome-related organelles that compartmentalize the glycolytic enzymes in kinetoplastid parasites. These organelles are developmentally regulated in their number and composition, allowing metabolic adaptation to the parasite’s needs in the blood of mammalian hosts or within their arthropod vector. A protein phosphatase cascade regulates differentiation between parasite developmental forms, comprising a tyrosine phosphatase, Trypanosoma brucei PTP1 (TbPTP1), which dephosphorylates and inhibits a serine threonine phosphatase, TbPIP39, which promotes differentiation. When TbPTP1 is inactivated, TbPIP39 is activated and during differentiation becomes located in glycosomes. Here we have tracked TbPIP39 recruitment to glycosomes during differentiation from bloodstream “stumpy” forms to procyclic forms. Detailed microscopy and live-cell imaging during the synchronous transition between life cycle stages revealed that in stumpy forms, TbPIP39 is located at a periflagellar pocket site closely associated with TbVAP, which defines the flagellar pocket endoplasmic reticulum. TbPTP1 is also located at the same site in stumpy forms, as is REG9.1, a regulator of stumpy-enriched mRNAs. This site provides a molecular node for the interaction between TbPTP1 and TbPIP39. Within 30 min of the initiation of differentiation, TbPIP39 relocates to glycosomes, whereas TbPTP1 disperses to the cytosol. Overall, the study identifies a “stumpy regulatory nexus” (STuRN) that coordinates the molecular components of life cycle signaling and glycosomal development during transmission of Trypanosoma brucei. IMPORTANCE African trypanosomes are parasites of sub-Saharan Africa responsible for both human and animal disease. The parasites are transmitted by tsetse flies, and completion of their life cycle involves progression through several development steps. The initiation of differentiation between blood and tsetse fly forms is signaled by a phosphatase cascade, ultimately trafficked into peroxisome-related organelles called glycosomes that are unique to this group of organisms. Glycosomes undergo substantial remodeling of their composition and function during the differentiation step, but how this is regulated is not understood. Here we identify a cytological site where the signaling molecules controlling differentiation converge before the dispersal of one of them into glycosomes. In combination, the study provides the first insight into the spatial coordination of signaling pathway components in trypanosomes as they undergo cell-type differentiation.

scholarly journals Colonization of the tsetse fly midgut with commensal Enterobacter inhibits trypanosome infection establishment

2018 ◽  
Author(s):  
Brian L. Weiss ◽  
Michele A. Maltz ◽  
Aurélien Vigneron ◽  
Yineng Wu ◽  
Katharine Walter ◽  
...  
Keyword(s):  
Control Strategies ◽  
Vector Competence ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Wild Type ◽  
African Trypanosomes ◽  
Control Programs ◽  
Causative Agents ◽  
Sub Saharan

AbstractTsetse flies (Glossina spp.) vector pathogenic trypanosomes (Trypanosoma spp.) in sub-Saharan Africa. These parasites cause human and animal African trypanosomiases, which are debilitating diseases that inflict an enormous socio-economic burden on inhabitants of endemic regions. Current disease control strategies rely primarily on treating infected animals and reducing tsetse population densities. However, relevant programs are costly, labor intensive and difficult to sustain. As such, novel strategies aimed at reducing tsetse vector competence require development. Herein we investigated whether an Enterobacter bacterium (Esp_Z), which confers Anopheles gambiae with resistance to Plasmodium, is able to colonize tsetse and induce a trypanosome refractory phenotype in the fly. Esp_Z established stable infections in tsetse’s gut, and exhibited no adverse effect on the survival of individuals from either group. Flies with established Esp_Z infections in their gut were significantly more refractory to infection with two distinct trypanosome species (T. congolense, 6% infection; T. brucei, 32% infection) than were age-matched flies that did not house the exogenous bacterium (T. congolense, 36% infected; T. brucei, 70% infected). Additionally, 52% of Esp_Z colonized tsetse survived infection with entomopathogenic Serratia marcescens, compared with only 9% of their wild-type counterparts. These parasite and pathogen refractory phenotypes result from the fact that Esp_Z acidifies tsetse’s midgut environment, which inhibits trypanosome and Serratia growth and thus infection establishment. Finally, we determined that Esp_Z infection does not impact the fecundity of male or female tsetse, nor the ability of male flies to compete with their wild-type counterparts for mates. We propose that Esp_Z could be used as one component of an integrated strategy aimed at reducing the ability of tsetse to transmit pathogenic trypanosomes.Author SummaryTsetse flies transmit pathogenic African trypanosomes, which are the causative agents of socio-economically devastating human and animal African trypanosomiases. These diseases are currently controlled in large part by reducing the population size of tsetse vectors through the use of insecticides, traps and sterile insect technique. However, logistic and monetary hurdles often preclude the prolonged application of procedures necessary to maintain these control programs. Thus, novel strategies, including those aimed at sustainably reducing the ability of tsetse to transmit trypanosomes, are presently under development. Herein we stably colonize tsetse flies with a bacterium (Enterobacter sp. Z, Esp_Z) that acidifies their midgut, thus rendering the environment inhospitable to infection with two distinct, epidemiologically important trypanosome strains as well as an entomopathogenic bacteria. In addition to inducing a trypanosome refractory phenotype, colonization of tsetse with Esp_Z exerts only a modest fitness cost on the fly. Taken together, these findings suggest that Esp_Z could be applied to enhance the effectiveness of currently employed tsetse control programs.

Breeding structure of Glossina pallidipes (Diptera: Glossinidae) populations in East and southern Africa

1997 ◽  
Vol 87 (1) ◽  
pp. 67-73 ◽  
Author(s):  
E. S. Krafsur ◽  
N. Griffiths ◽  
C. L. Brockhouse ◽  
J. Brady
Keyword(s):  
Gene Flow ◽  
Genetic Variance ◽  
Gene Diversity ◽  
Glossina Pallidipes ◽  
Fixation Index ◽  
Allozyme Electrophoresis ◽  
Gene Frequencies ◽  
African Populations ◽  
Strong Measure ◽  
Hardy Weinberg Equilibrium

AbstractGene diversity and gene flow in Glossina pallidipes Austen were studied by using allozyme electrophoresis on samples from southern and East Africa. Recorded were 30 alleles segregating at eight loci. Gene diversity was 0.212±0.085 S.E. in four southern African populations and 0.163±0.076 in seven Kenyan populations. All loci were in Hardy-Weinberg equilibrium. Pgm and 6pgd were sex linked. Spatial components of gene diversity were measured by using F statistics. Mating was random within each population. The ‘fixation index’ FST was 0.133±0.062 among southern African populations. Among the Kenyan populations. FST was 0.159±0.069. FST was 0.238±0.051 among all populations. Analysis of variance of gene frequencies showed that 65.8% of the genetic variance lay within populations and 34.2% of the genetic variance lay between Kenyan and southern African populations. These data suggest a strong measure of genetic drift among tsetse populations even in a region where it is thought they are continuously distributed. The causes of this drift require investigation.

Distribution of tsetse flies and its Trypanosoma species infection in Old Oyo National Park, Nigeria

2021 ◽  
Vol 18 (1) ◽  
pp. 33-38
Author(s):  
A.O. Omonona ◽  
S.A. Abioye ◽  
P.O. Odeniran ◽  
I.O. Ademola
Keyword(s):  
National Parks ◽  
National Park ◽  
Ground Level ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Trypanosome Infection ◽  
Wet Season ◽  
Significant Difference ◽  
Sub Saharan

Tsetse fly infestation in national parks is a major health risk to both the wildlife and tourists coming to sub-Saharan Africa. However, information on distribution and diversity of tsetse flies and trypanosome infection rate in Protected Areas like Old Oyo National Park in south-west Nigeria is largely unknown. Thus, the study evaluates distribution and diversity of tsetse flies in Magurba Range of Old Oyo National Park. Twelve Nzi traps were set at 50 m equidistance to capture Glossina species for a period of six months between February and August, 2019, considering both the altitudinal and ecological significance. A total of 136 tsetse flies belonging to four species; G. palpalis, G. tachinoides, G. morsitans and G. fusca; were captured. More Glossina species were captured during dry season 77.9% (70.0-84.6) than the wet season 22.1% (15.4-30.0). There was significant difference (p = 0.0001; x2 = 84.9; OR = 12.5) between the proportion of Glossina species captured at the riverine areas (106; 77.9%) and the woodland/forest areas (30; 22.1%). Glossina captured at ground level and 30 cm above ground were 71 (52.2 %) and 65 (47.8%) respectively. The overall prevalence of trypanosome infection (2.94%) was observed for Glossina spp. The presence of infected Glossina spp. indicated an urgent need to establish a concise strategic vector control in National Parks, in order to reduce the risk of transmission to both wildlife and humans in the area. The park is frequently visited by tourists, rangers, researchers and students for educational purposes. Keywords: Glossina spp.; Trypanosoma spp.; vector distribution; Old Oyo National Park

scholarly journals Comparative performance of traps in catching tsetse flies (Diptera: Glossinidae) in Tanzania

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Imna I. Malele ◽  
Johnson O. Ouma ◽  
Hamisi S. Nyingilili ◽  
Winston A. Kitwika ◽  
Deusdedit J. Malulu ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Abundant Species ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Comparative Performance ◽  
Control Programmes ◽  
Fly Control ◽  
Tsetse Fly Control ◽  
Species Being ◽  
Biconical Traps

This study was conducted to determine the efficiency of different tsetse traps in 28 sites across Tanzania. The traps used were biconical, H, NGU, NZI, pyramidal, S3, mobile, and sticky panels. Stationary traps were deployed at a distance of 200 m apart and examined 72 h after deployment. The results showed that 117 (52.2%) out of the 224 traps deployed captured at least one Glossina species. A total of five Glossina species were captured, namely Glossina brevipalpis, Glossina pallidipes, Glossina swynnertoni, Glossina morsitans, and Glossina fuscipes martinii. Biconical traps caught tsetse flies in 27 sites, pyramidal in 26, sticky panel in 20, mobile in 19, S3 in 15, NGU in 7, H in 2 and NZI in 1. A total of 21 107 tsetse flies were trapped, with the most abundant species being G. swynnertoni (55.9%), followed by G. pallidipes (31.1%), G. fuscipes martinii (6.9%) and G. morsitans (6.0%). The least caught was G. brevipalpis (0.2%). The highest number of flies were caught by NGU traps (32.5%), followed by sticky panel (16%), mobile (15.4%), pyramidal (13.0%), biconical (11.3%) and S3 (10.2%). NZI traps managed to catch 0.9% of the total flies and H traps 0.7%. From this study, it can be concluded that the most efficient trap was NGU, followed by sticky panel and mobile, in that order. Therefore, for tsetse fly control programmes, NGU traps could be the better choice. Conversely, of the stationary traps, pyramidal and biconical traps captured tsetse flies in the majority of sites, covering all three ecosystems better than any other traps; therefore, they would be suitable for scouting for tsetse infestation in any given area, thus sparing the costs of making traps for each specific Glossina species.Keywords: tseste; traps; densties; Glossina; mobile; stationary; Tanzania

Antioxidants promote establishment of trypanosome infections in tsetse

Parasitology ◽  
2007 ◽  
Vol 134 (6) ◽  
pp. 827-831 ◽  
Author(s):  
E. T. MacLEOD ◽  
I. MAUDLIN ◽  
A. C. DARBY ◽  
S. C. WELBURN
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Trypanosoma Brucei ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Oxygen Species ◽  
Infection Rates ◽  
Trypanosoma Brucei Brucei ◽  
Sub Saharan ◽  
Cyclical Transmission

SUMMARYEfficient, cyclical transmission of trypanosomes through tsetse flies is central to maintenance of human sleeping sickness and nagana across sub-Saharan Africa. Infection rates in tsetse are normally very low as most parasites ingested with the fly bloodmeal die in the fly gut, displaying the characteristics of apoptotic cells. Here we show that a range of antioxidants (glutathione, cysteine, N-acetyl-cysteine, ascorbic acid and uric acid), when added to the insect bloodmeal, can dramatically inhibit cell death of Trypanosoma brucei brucei in tsetse. Both L- and D-cysteine invoked similar effects suggesting that inhibition of trypanosome death is not dependent on protein synthesis. The present work suggests that antioxidants reduce the midgut environment protecting trypanosomes from cell death induced by reactive oxygen species.

scholarly journals Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Purity K. Gitonga ◽  
Kariuki Ndung’u ◽  
Grace A. Murilla ◽  
Paul C. Thande ◽  
Florence N. Wamwiri ◽  
...  
Keyword(s):  
Survival Time ◽  
Trypanosoma Brucei ◽  
Acute Infection ◽  
Glossina Pallidipes ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Economic Losses ◽  
Entire Group ◽  
Tsetse Flies ◽  
African Countries

African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4–11) and 4.5 ± 0.2 (range, 4–6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

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