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effect of polyclonal anti-procyclic antibodies on development of trypanosoma brucei brucei in tsetse flies.results obtained in experiments testing the efficacy of anti-procyclic-form rabbit sera on the development of homologous and heterologous stocks of trypanosoma brucei brucei in glossina morsitans morsitans indicated that this development was affected little, or not at all, by such sera. the absence of effect of anti-procyclic stage antibodies can be explained by the failure to detect by either direct or indirect fluorescent antibody methods the presence of antibodies acquired in vivo by either t ...19911994370
the effect of trypanocidal drugs on the transmission of trypanosoma brucei brucei by glossina morsitans centralis.the effects of trypanocidal drugs on trypanosoma b. brucei infections in glossina m. centralis have been investigated. pentamidine and suramin exhibited no significant effects but both berenil and samorin reduced the number of salivary gland infections in comparison with controls. berenil at concentrations of 10, 1.0 and 0.1 microgram/ml significantly reduced the number of mature infections when fed to flies throughout the whole period of trypanosome development. a similar result was obtained wi ...19872884836
cultivation of the life cycle stages of trypanosoma brucei sspp.a culture system was devised for the production of the various stages in the developmental cycle of trypanosoma brucei brucei and t. b. rhodesiense. the bloodstream forms were grown at 37 degrees c on a feeder layer of fibroblasts from embryos of microtus montanus or cd-1 mice in hepes-buffered minimum essential medium with earle's salts, supplemented with 15% heat-inactivated rabbit serum. when they were transferred to hepes-buffered cunningham's medium and incubated at 27 degrees c, they trans ...19882896444
cyclical transmission of in vitro cultivated bloodstream forms and procyclic trypomastigotes of trypanosoma brucei brucei by glossina morsitans morsitans.in vitro cultivated bloodstream and procyclic forms of trypanosoma b. brucei stib 247 were cyclically transmitted by glossina m. morsitans. the tsetse flies were infected artificially on a silicon membrane. metacyclic trypanosomes from mature salivary gland infections were used to initiate bloodstream form cultures. they transformed into slender bloodstream forms and gave rise to established cultures that proved to be infective for the vector. the metacyclic forms retained the strain-specific ba ...19826182705
the acquisition of human serum resistance during cyclical passage of a trypanosoma brucei brucei clone through glossina morsitans morsitans maintained on human serum. 19846464124
ability of trypanosome-infected tsetse flies (diptera: glossinidae) to acquire an infection with a second trypanosome species.the epidemiology of human and animal trypanosomiasis is determined to a large extent by the number of infected tsetse flies in a specific area. in the field, a substantial proportion of infected flies carry mixed trypanosome infections. the way in which these tsetse flies acquire a mixed infection is not fully understood. in particular, the susceptibility of tsetse flies to sequential infection with trypanosomes is not well understood. accordingly, laboratory studies were made of the effects of ...200516465745
differential expression of fat body genes in glossina morsitans morsitans following infection with trypanosoma brucei brucei.to determine which fat body genes were differentially expressed following infection of glossina morsitans morsitans with trypanosoma brucei brucei we generated four suppression subtractive hybridisation (ssh) libraries. we obtained 52 unique gene fragments (ssh clones) of which 30 had a known orthologue at e-05 or less. overall the characteristics of the orthologues suggest: (i) that trypanosome infection has a considerable effect on metabolism in the tsetse fly; (ii) that self-cured flies are m ...200817697681
nutritional stress of adult female tsetse flies (diptera: glossinidae) affects the susceptibility of their offspring to trypanosomal infections.the epidemiology of tsetse-transmitted trypanosomiasis depends, among other factors, on the proportion of infected flies in a tsetse population. a wide range of intrinsic and extrinsic factors seem to determine the ability of a tsetse fly to become infected and to transmit the parasite. in this paper, we investigated the effect of nutritional stress of reproducing female glossina morsitans morsitans on the susceptibility of their offspring to trypanosomal infections. adult female flies that were ...200919445895
tsetse ep protein protects the fly midgut from trypanosome establishment.african trypanosomes undergo a complex developmental process in their tsetse fly vector before transmission back to a vertebrate host. typically, 90% of fly infections fail, most during initial establishment of the parasite in the fly midgut. the specific mechanism(s) underpinning this failure are unknown. we have previously shown that a glossina-specific, immunoresponsive molecule, tsetse ep protein, is up regulated by the fly in response to gram-negative microbial challenge. here we show by kn ...201020221444
the transmission of mixed trypanosoma brucei brucei/t. congolense infections by tsetse (glossina morsitans morsitans).laboratory experiments and field observations clearly show that tsetse flies can be carriers of mixed trypanosome infections. question remains how easy it is for the tsetse fly to acquire such a mixed infection during the first bloodmeal. this is of particular importance in the epidemiology of trypanosoma brucei s.l., often a cryptic infection and difficult to transmit to non-teneral tsetse flies. to determine the transmission rate of t. brucei as part of a mixed infection, teneral glossina mors ...200414746974
maturation of a trypanosoma brucei infection to the infectious metacyclic stage is enhanced in nutritionally stressed tsetse flies.we report on the effect of tsetse fly starvation on the maturation of an established trypanosoma brucei brucei midgut infection, i.e., the development of procyclic infection into the infectious metacyclic parasites in the tsetse fly salivary glands. glossina morsitans morsitans flies were nutritionally stressed 10 d after the uptake of a t. b. brucei-infected bloodmeal by depriving these flies from feeding for seven consecutive days, whereas the control fly group (nonstarved group) continued to ...200919960695
tsetse fly (glossina pallidipes) midgut responses to trypanosoma brucei challenge.tsetse flies (glossina spp.) are the prominent vector of african trypanosome parasites (trypanosoma spp.) in sub-saharan africa, and glossina pallidipes is the most widely distributed species in kenya. this species displays strong resistance to infection by parasites, which are typically eliminated in the midgut shortly after acquisition from the mammalian host. although extensive molecular information on immunity for the related species glossina morsitans morsitans exists, similar information i ...201729258576
a study on the maturation of procyclic trypanosoma brucei brucei in glossina morsitans centralis and g. brevipalpis.teneral glossina morsitans centralis and g. brevipalpis were fed in vitro upon medium containing procyclic trypanosoma brucei brucei derived from the midguts of g. m. centralis or g. brevipalpis which had immature trypanosome infections. the tsetse were then maintained on rabbits and, on day 31, were dissected to determine the infection rates. in g. m. centralis the midgut and salivary gland infection rates by t. b. brucei were 46.0% and 27.0% with procyclic trypanosomes from g. m. centralis, an ...19947841491
some observations on factors associated with the development of trypanosoma brucei brucei infections in glossina morsitans morsitans.the susceptibility of glossina morsitans morsitans to trypanosoma brucei brucei infection was shown to be age-dependent during the first 12 h: the youngest age group (1-8 h after emergence) being more susceptible than the older ones. the susceptibility was enhanced by cooling the young flies to a temperature of 0-5 degrees c for 30 min. male flies were found to be more susceptible than females. the number of trypanosomes ingested did not influence the subsequent salivary-gland infection rates ob ...19836136171
suppression of cyclical development of trypanosoma brucei brucei in glossina morsitans centralis by an anti-procyclics monoclonal antibody.five hundred and sixty teneral male glossina morsitans centralis were fed, at the height of parasitaemia, on a goat infected with trypanosoma brucei brucei. thereafter, the tsetse were divided into 4 equal groups. group i was fed in vitro once weekly for 4 weeks and group ii twice weekly for 4 weeks on fresh defibrinated ox blood containing 2 mg/ml purified monoclonal antibody against t. b. brucei procyclics, while group iii was fed twice a week for 4 weeks on blood containing 2 mg/ml anti-t. vi ...19882901200
the effect of trypanosoma brucei infection of the localization of salivary gland cholinesterase in glossina morsitans morsitans.when salivary glands of the tsetse fly, glossina morsitans morsitans, are stained for cholinesterase (che) activity, a net-like pattern of reaction product is observed surrounding each epithelial cell of the gland's secretory region. glands infected with trypanosoma brucei brucei show a progressive reduction in this che activity as the parasites develop. when the infection is mature, che is rarely detected in the epithelial layer but appears in the lumen of gland. the luminal che responds to sub ...19872892368
defence reactions of glossina morsitans morsitans against different species of bacteria and trypanosoma brucei brucei.tsetse flies, glossina morsitans morsitans, fed on rats infected with trypanosoma brucei brucei showed wide fluctuations in total and differential haemocyte counts. similar fluctuations occurred in controls fed on non-infected rats and also between the two groups without showing any difference which could be attributed to the infection. trypanosome infection of the tsetse haemocoel occurred in 16.25% of the flies, starting from the second day after feeding on the infected rats, but salivary glan ...19862872785
inhibitory effect of trypanosoma brucei brucei on glossina morsitans midgut trypsin in vitro.the ability of trypanosoma brucei brucei to inhibit trypsin or trypsin-like enzymes in crude midgut homogenates of glossina morsitans morsitans was studied in vitro. the isolated parasites caused a concentration-dependent decrease in midgut trypsin activity. furthermore, trypanosomes lysed by repeated freeze-thawing had a similar effect on trypsin activity. in both cases, the inhibition by either intact or lysed parasites was partial as revealed by dixon plots. similarly, trypanosome membrane pr ...19921409526
quantitative ultrastructural investigations of the life cycle of trypanosoma brucei: a morphometric analysis.the quantitative ultrastructure of the developmental stages of trypanosoma brucei brucei in its vector glossina morsitans was studied by morphometric analysis. values from ectoperitrophic midgut forms, proventricular forms, epimastigote and metacyclic forms in the salivary gland are compared with results from bloodstream forms, published previously. significant differences in the volume densities of the trypanosome's single mitochondrion, of microbody-like organelles and in the surface densities ...19751195156
post eclosion age predicts the prevalence of midgut trypanosome infections in glossina.the teneral phenomenon, as observed in glossina sp., refers to the increased susceptibility of the fly to trypanosome infection when the first bloodmeal taken is trypanosome-infected. in recent years, the term teneral has gradually become synonymous with unfed, and thus fails to consider the age of the newly emerged fly at the time the first bloodmeal is taken. furthermore, conflicting evidence exists of the effect of the age of the teneral fly post eclosion when it is given the infected first b ...201122087240
effect of isometamidium chloride treatment on susceptibility of tsetse flies (diptera: glossinidae) to trypanosome infections.experiments were conducted to determine the effect of a single isometamidium chloride treatment of teneral tsetse flies, glossina morsitans morsitans westwood (diptera: glossinidae), on the subsequent susceptibility to an infection with trypanosoma congolense or trypanosoma brucei brucei. flies were offered a first bloodmeal on sterile gamma-irradiated defibrinated bovine blood that contained either 10 or 100 microg ofisometamidium chloride/ml. treated flies were subsequently infected with t. co ...200616739416
anti-trypanosomal factor in the haemolymph of glossina.the motility of cultured procyclic forms of trypanosoma brucei brucei antat serodeme derived from eatro 1125 was greatly reduced when incubated in vitro with the haemolymph of glossina morsitans morsitans at dilutions as low as 1:512 after incubation periods of 1-2 h at 27 degrees c. this effect was demonstrated in the haemolymph of male and female, teneral and non-teneral g.m. morsitans but was abolished by heat inactivation. a significant reduction in the motility of cultured forms of trypanos ...19826187195
increased sensitivity to a natural pyrethrum extract of trypanosoma-infected glossina morsitans.topical application of a natural pyrethrum extract on male and pregnant female glossina morsitans morsitans resulted in higher mortality for flies infected with trypanosoma brucei brucei than for uninfected control flies. infected males showed a significantly higher mortality while infected pregnant females showed a marginally significant increase in mortality. results support the hypothesis that infected flies are less healthy than uninfected flies. results also parallel previous findings using ...19846143486
surface coat synthesis and turnover from epimastigote to bloodstream forms of trypanosoma brucei.monoclonal antibodies to metacyclic surface coat glycoproteins of trypanosoma brucei brucei stib 247lg were produced for a study of the synthesis of metacyclic variable surface glycoproteins (vsgs) within the salivary gland of glossina morsitans morsitans, and of the first exchange of the surface glycoproteins after infection in mice. immunofluorescence antibody tests and protein a-gold labelling revealed that the vsgs are continuously integrated into the whole surface of the trypanosome while i ...19911686146
immunopeptides in the defense reactions of glossina morsitans to bacterial and trypanosoma brucei brucei infections.several dipteran insects are vectors of parasites causing major human infectious diseases. among these, the tsetse fly, glossina spp., is responsible for the transmission of trypanosomes, the pathogens responsible for sleeping sickness in africa. a better understanding of insect-parasite interactions will help establish new strategies to fight this important often fatal disease. antimicrobial peptides (amps) are part of the humoral immune response in insects during bacterial, fungal and parasiti ...200211886771
control of trypanosoma brucei brucei infections in tsetse, glossina morsitans.numbers of immature trypanosoma brucei brucei within a tsetse midgut remain remarkably constant after establishment throughout the course of an infection, irrespective of whether the infection eventually matures. these results suggest a system of self regulation of the parasite population in the insect gut based on a form of programmed cell death which would carry advantages for both the parasite and the vector.19979330261
induction of resistance to melarsenoxide cysteamine (mel cy) in trypanosoma brucei brucei.a population of trypanosoma brucei brucei with reduced sensitivity to melarsenoxide cysteamine (mel cy) was produced in immunosuppresed mice using subcurative drug treatment. melarsenoxide cysteamine resistance was stable after cyclical transmission through glossina morsitans centralis. in vitro, the blood-stream forms showed 15-fold higher values for the minimal inhibitory concentration as compared with the parental clone. cross-resistance could be determined with another arsenical drug, melars ...19947709858
analysis of the variable antigen composition of trypanosoma brucei brucei metacyclic trypanosomes using monoclonal antibodies.the metacyclic trypanosomes of a trypanosoma brucei brucei clone (iltat 2.1) were analysed with regard to their variable antigen (vat) composition using monoclonal antibodies. the metacyclic population was antigenically heterogeneous. despite the heterogeneity, however, the overall vat composition of the metacyclic population appeared to be limited in number. a similar pattern of reactivity was observed when the monoclonal antibodies were tested on metacyclics of another clone (il tat 2.2) deriv ...19836190388
trypanosoma brucei: infectivity and immunogenicity of cultured parasites.trypanosoma brucei brucei, derived from the salivary glands of infected tsetse flies (glossina morsitans morsitans) and maintained in culture for over 4 years, were infective to both albino rats and tsetse flies. virulence was markedly enhanced during the first passage in albino rats or tsetse flies. irradiated cultured trypanosomes induced immunity to homologous challenge but not to tsetse fly or blood-induced challenge with the same stock.19854029345
the humoral defense system in tsetse: differences in response due to age, sex and antigen types.inoculation of live escherichia coli into tsetse flies, glossina morsitans morsitans, stimulated a higher antibacterial immune response in females than in males. it increased with age in females from emergence to approximately 2 weeks and thereafter declined. in males, there was also a significant decrease in immune response with aging. inoculation of killed bacteria failed to stimulate antibacterial activity but stimulated a lysozyme response which was weaker than that stimulated by live bacter ...19883384155
comparative study on the susceptibility of different glossina species to trypanosoma brucei brucei infection.teneral glossina morsitans centralis, g. austeni, g. palpalis palpalis, g. p. gambiensis, g. fuscipes fuscipes, g. tachinoides and g. brevipalpis from laboratory-bred colonies, were allowed to feed simultaneously for 34 days on the flanks of ten goats infected with trypanosoma brucei brucei isolated in tanzania or in nigeria, and then the tsetse were dissected. the seven tsetse species and subspecies showed salivary glands infections over the range of 0% to 40.4%. survival of the tanzanian and n ...19883194664
studies on tsetse midgut factors that induce differentiation of blood-stream trypanosoma brucei brucei in vitro.an in vitro system for studying the transformation of bloodstream forms of trypanosoma brucei brucei into procylic (midgut) forms is described. in this system, transformation of the parasites was stimulated by glossina morsitans morsitans midgut homogenates at 27 degrees c but not at 4 degrees c. the transformation-stimulating capacity was irreversibly destroyed by heating the midgut homogenates at 60 degrees c for 1 h. a correlation was established between the transformation activity of the mid ...19921584740
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