| antigenic analysis by agglutination of trypanosoma brucei brucei parasitemias initiated in mice with in vitro-produced metacyclics. | trypanosomes from 14 first-peak parasitemias initiated in mice by injection of in vitro-produced metacyclics were stabilated. strains derived from these stabilates were analyzed for their antigenic composition by cross-agglutination with immune sera produced in rabbits against 12 of the stabilates. the antigenic composition of the 14 stabilates was compared also with two first-peak parasitemias from mice inoculated with fly-derived metacyclics, the variant-specific antigen of the strain used to ... | 1979 | 86245 |
| trypanosoma brucei brucei: in vitro production of metacyclic forms. | an in vitro method has been established to obtain metacyclic form populations of trypanosoma brucei brucei. trypanosome populations containing more than 98% of metacyclic forms were obtained from cultures which were: 1) initiated with bloodstream forms in primary cultures in the presence of microtus montanus embryonic fibroblast-like cells (feeder cell layers); 2) maintained in glucose-free eagle's minimum essential medium supplemented with 10 mm l-proline, 2 mm l-glutamine and 20% (v/v) fetal b ... | 1992 | 1522545 |
| [infection of glossina palpalis palpalis (diptera, glossinidae) by trypanosomes in the forest zone of gagnoa in the ivory coast]. | 2,153 glossina palpalis palpalis caught in biconical traps from different biotopes in relation with human activities in the forest areas of côte d'ivoire were used to calculate the trypanosome infection rates. the results showed that there was no preferential biotope for glossina infected by trypanosomes. the most widespread species of trypanosomes infecting glossina p. palpalis is t. congolense (10.13%) followed by t. vivax (8.22%) and seldomly by t. brucei (0.70%). female glossina are infected ... | 1991 | 1665576 |
| anatomy of the parp gene promoter of trypanosoma brucei. | while growing in the tsetse fly, trypanosoma brucei expresses a major surface glycoprotein, the procyclic acidic repetitive protein (parp). the parp genes are transcribed by an alpha-amanitin-resistant rna polymerase. we have determined the sequence requirements for parp promoter activity. studies of rna produced from input dna in transiently transfected trypanosomes indicate that the rna is correctly processed by trans-splicing and polyadenylation. deletion analyses show that 330 bp are suffici ... | 1991 | 1840521 |
| [vectorial capacity of glossina palpalis gambiensis (bobo dioulasso) for trypanosoma brucei brucei eatro 1125]. | a total of 440 teneral glossina palpalis gambiensis received one single bloodmeal on a guinea pig infected chronically with trypanosoma brucei brucei eatro 1125. metacyclic infections were present in 11.29% of the flies, in 2.32% infections were limited to procyclical stages. no significant difference in vectorial capacity was observed between male and female flies, the level of metacyclic infections being 13.19% in the former and 9.55% in the latter. the parasitaemia level, the percentage of st ... | 1991 | 1843825 |
| identification of midgut trypanolysin and trypanoagglutinin in glossina palpalis sspp. (diptera: glossinidae). | a midgut trypanolysin and an agglutinin from glossina palpalis subspecies were isolated and partially characterized using anion-exchange chromatography and polyacrylamide gel electrophoresis. fplc fractions of midgut extracts of glossina palpalis palpalis caused agglutination and lysis of two trypanosome species (trypanosoma congolense and trypanosoma brucei brucei), although glossina palpalis gambiensis caused only agglutination. the trypanolysin and agglutinin were active only in the posterior ... | 1990 | 2092294 |
| [east african sleeping sickness (trypanosoma rhodesiense infection) in 2 swiss travelers to the tropics]. | we report on two swiss travellers who acquired african sleeping sickness (trypanosoma rhodesiense) the same day while visiting the akagera park in rwanda. the first patient developed clinical signs of sleeping sickness 8 days after being bitten by a tsetse fly. trypanosomes were demonstrated in the blood and csf. the other patient fell ill 13 days after the bite and trypanosomes were found only in blood samples. the first patient (cerebral trypanosomiasis), was treated with melarsoprol. he devel ... | 1990 | 2218457 |
| surface carbohydrate differences of glossina salivary glands and infectivity of trypanosoma brucei gambiense to glossina. | incubation of fluorescein- and biotin-lectin conjugates with the salivary glands of glossina spp has revealed inter- and intraspecific variation in the surface carbohydrates of the glands. the degree of con a binding to the basal laminae of the glands of the two glossina palpalis subspecies, g.p. palpalis and g.p. gambiensis was markedly different. the infectivity of t.b. gambiense sensu lato isolates to g.p. palpalis and g.p. gambiensis was compared. g.p. gambiensis from the field and from labo ... | 1990 | 2369168 |
| trypanosoma brucei: a membrane-associated protein in coated endocytotic vesicles. | membrane proteins were isolated from purified trypanosoma brucei coated endocytotic vesicles by phase separation with triton x-114. the largest abundant membrane protein was a doublet band with a molecular mass of about 77 kda. a specific antiserum was prepared against this protein by immunization with antigen bands excised from sodium dodecyl sulfate-polyacrylamide gels. immunoblot analyses with this antiserum showed that the 77-kda protein was present in other t. brucei, in t. congolense, and ... | 1990 | 2404779 |
| trypanosome sociology and antigenic variation. | survival of the trypanosome (trypanosoma brucei) population in the mammalian body depends upon paced stimulation of the host's humoral immune response by different antigenic variants and serial sacrifice of the dominant variant (homotype) so that minority variants (heterotypes) can continue the infection and each become a homotype in its turn. new variants are generated by a spontaneous switch in gene expression so that the trypanosome puts on a surface coat of a glycoprotein differing in antige ... | 1989 | 2682484 |
| vector susceptibility to african trypanosomes. | susceptibility of tsetse fly to trypanosome depends on two distinct barriers controlling respectively colonization of midgut and, migration to salivary glands. those barriers are modulated by barely known factors, pertaining to the physiological status of the fly as well as to cytoplasmic and nuclear inheritance. quantification of colonization (p) and migration (m) rates provides a way to calculate intrinsic vectorial capacity (ivc) as a product ivc = p x m, and to undergo comparative analysis o ... | 1989 | 2802818 |
| tsetse ecology in a liberian rain-forest focus of gambian sleeping sickness. | investigations on tsetse ecology were undertaken in bong county of liberia during the dry season, october 1981 to february 1982, around villages where the human infection rate with trypanosoma brucei gambiense dutton was about 2%. most tsetse captured in biconical traps were glossina palpalis robineau-desvoidy and g. pallicera bigot, with relatively few g. fusca walker and g. nigrofusca newstead. swamps and water-gathering places were predominant habitats of all four species, but tsetse were als ... | 1987 | 2979539 |
| effect of ivermectin and isometamidium chloride on glossina palpalis palpalis (diptera: glossinidae). | | 1988 | 3178326 |
| prevalence of trypanosomiasis in cattle in south-west zambia. | a trypanosomiasis survey was conducted in south-west zambia. from a total of 3,346 cattle sampled 342 cattle showed a positive trypanosomiasis parasitaemia. during the survey trypanosome species and pcv values were also recorded. with simple statistical analysis populations with higher and lower prevalence rates were differentiated. the results indicated that the kwando river basin tsetse fly belt and the kafue river basin tsetse fly belt infested a larger area than originally assumed and that a ... | 1988 | 3400114 |
| culture form and tsetse fly midgut form procyclic trypanosoma brucei express common proteins. | proteins expressed by culture form and tsetse fly midgut form procyclic trypanosomes were examined by polyacrylamide gel electrophoretic techniques. analysis of the proteins of the two forms of procyclic organisms was performed by comparison of autoradiographs of high resolution two-dimensional polyacrylamide gels prepared using [35s]methionine-labelled parasites. only eight spots were found to differ between autoradiographs of culture form and tsetse fly midgut form parasites. seven of these di ... | 1987 | 3696176 |
| expression of garp, a major surface glycoprotein of trypanosoma congolense, on the surface of trypanosoma brucei: characterization and use as a selectable marker. | procyclic and epimastigote forms of trypanosoma congolense express an immunodominant glutamic acid/alanine-rich protein (garp) that covers the parasite surface. although garp shows no sequence similarity to procyclins from t. brucei, the general characteristics of the two sets of surface glycoproteins suggest that they have analogous functions, in much the same way that variant surface glycoproteins with unrelated primary sequences fulfil the same function in bloodstream form trypanosomes. since ... | 1995 | 7637714 |
| mixed populations of trypanosoma brucei in wild glossina palpalis palpalis. | in many previous characterization studies of trypanozoon, isolates have been subpassaged numerous times in laboratory rodents until a quantity of trypanosomes sufficient for analysis has been obtained. in addition to the numerous biochemical effects of such a process on the parasite, it appears probable that adaptation to an unnatural host may also serve to filter out less virulent populations from mixed infections, leading to an underestimate of the true level of genetic diversity. by the early ... | 1994 | 7716394 |
| a successful backcross in trypanosoma brucei. | genetic exchange can take place between different strains of trypanosoma brucei ssp. when they are cotransmitted via the tsetse fly vector, but the mechanism and limits of compatibility between strains are ill-defined as yet. following the recovery of several hybrid genotypes with single drug resistance from a cross of drug resistant parental strains, we attempted a series of backcrosses and f1 crosses, selecting hybrids by double drug resistance. of 4 backcrosses, one produced hybrid progeny, t ... | 1995 | 7723777 |
| midgut lectin activity and sugar specificity in teneral and fed tsetse. | midgut infection rates of trypanosoma congolense in glossina palpalis palpalis and of trypanosoma brucei rhodesiense in glossina pallidipes are potentiated by the addition of d+ glucosamine to the infective feed, but not to the levels of super-infection reported for g.m.morsitans, g.p.palpalis and g.pallidipes are shown to possess two trypanocidal molecules: a glucosyl lectin which can be inhibited by d+ glucosamine and a galactosyl molecule inhibited by d+ galactose. addition of both d+ glucosa ... | 1994 | 8161852 |
| major surface glycoproteins of procyclic stage african trypanosomes. | the procyclic stage in the life cycle of african trypanosomes is adapted for life in the harsh environment of the midgut of the tsetse fly vector. procyclic forms derived by transformation from antigenically distinct bloodstream variants are antigenically similar and have lost the variant surface glycoprotein coat of the bloodstream forms. in contrast to bloodstream forms, where the variant surface glycoprotein coat is essentially the only molecule exposed, many different proteins can be labeled ... | 1994 | 8206145 |
| man-fly contact in the gambian trypanosomiasis focus of nola-bilolo (central african republic). | a study using bipyramid tetse fly traps in the nola-bilolo sleeping sickness focus (central african republic) reveals ecological and behavioural differences between two vectors, glossina palpalis palpalis and g. fuscipes fuscipes. the latter species inhabits mainly open water sites and surrounding forest, whereas g. p. palpalis occurs mainly in coffe plantations near villages. consequently, the man-fly contact differs considerably according to the species. the intensity of trypanosomiasis transm ... | 1993 | 8256100 |
| thyroid dysfunction in african trypanosomiasis: a possible role for inflammatory cytokines. | sleeping sickness (african trypanosomiasis) is an anthropozoonosis transmitted by the tsetse fly. the treatments of choice are the antiparasitic agents suramin and/or melarsoprol. experimental infection of animals with trypanosoma brucei results in inflammatory lesions in the pituitary and/or the thyroid gland. in biochemical terms, these animals have hypothyroidism. we evaluated the functional integrity of the hypothalamic-pituitary-thyroid axis in patients with african trypanosomiasis before, ... | 1993 | 8287572 |
| a promotor directing alpha-amanitin-sensitive transcription of garp, the major surface antigen of insect stage trypanosoma congolense. | the major surface antigen of procyclic and epimastigote forms of trypanosoma congolense in the tsetse fly is garp (glutamic acid/alanine-rich protein), which is thought to be the analogue of procyclin/parp in trypanosoma brucei. we have studied two t.congolense garp loci (the 4.3 and 4.4 loci) whose transcription is alpha-amanitin sensitive. whilst a transcriptional gap 5' of the first garp gene in the cloned region of the 4.4 locus could not be detected, such a gap was present in the 5' flank o ... | 1996 | 8628650 |
| trypanosome characterization by polymerase chain reaction in glossina palpalis gambiensis and g.tachinoides from burkina faso. | following the discovery of four cases of african human trypanosomiasis, an entomological survey was conducted along the mouhoun river in southwest burkina faso to collect glossina palpalis gambiensis and g.tachinoides. among 226 flies dissected, 4.87% (eleven individuals) were infected in midgut or proboscis, but never in the salivary glands. polymerase chain reaction analysis was undertaken, and was able to characterize all the proboscis infections, and half of the midgut infections. only trypa ... | 1996 | 8994137 |
| trypanosomiasis. | african (sleeping sickness) and american (chagas' disease) trypanosomiasis, caused by protozoa of the family trypanosomatidae, are diseases that are endemic in parts of africa and latin america, respectively. physicians in developed countries may occasionally see cases because of extensive travel and immigration from endemic countries. although neurological involvement is common in both, its incidence and clinical presentation differ considerably. african trypanosomiasis, caused by subspecies of ... | 1997 | 9034568 |
| trypanosome-binding proteins of the tsetse flies glossina palpalis gambiensis and g. morsitans morsitans. | in this paper we describe a new, selective approach to identify protein ligand-receptor interactions between an arthropod vector and the parasite it transmits. biotinylated vector proteins were incubated with living parasites in physiological conditions. after extensive washing, the parasites were subjected to sds-page electrophoresis and the polypeptides were electroblotted onto nitrocellulose membrane. staining with avidin-horseradish peroxidase revealed only biotin-labeled proteins from the v ... | 1996 | 9198586 |
| commitment to differentiation and cell cycle re-entry are coincident but separable events in the transformation of african trypanosomes from their bloodstream to their insect form. | african trypanosomes undergo extensive changes in cellular morphology, biochemistry and surface antigen expression as they differentiate from their bloodstream form to those forms that colonise the midgut of their tsetse fly vector. if initiated with stumpy-form cells, a non-dividing sub-type of the bloodstream parasite, differentiation and cell cycle re-entry occur synchronously in the population and provide a means to dissect the respective controls of proliferation and transformation. we have ... | 1997 | 9372450 |
| a trypanosome metacyclic vsg gene promoter with two functionally distinct, life cycle stage-specific activities. | in the mammalian bloodstream, african trypanosomes express the variant surface glycoprotein (vsg), continual switching of which allows evasion of the host immune response. bloodstream vsg genes are transcribed from polycistronic bloodstream expression sites with promoters which are located 45-60 kb upstream. these promoters are not exclusively stage-regulated, being active in the insect midgut stage where vsg is not expressed. however, the metacyclic vsg (m-vsg) genes, a small subset activated w ... | 1998 | 9518493 |
| detection and identification of trypanosomes by polymerase chain reaction in wild tsetse flies in cameroon. | the prevalence of various species and subgroups of trypanosomes in infected flies from three sleeping sickness foci in cameroon was determined by the use of polymerase chain reaction (pcr). the predominant tsetse species found were glossina palpalis palpalis. microscopical examination of 943 non-teneral tsetse flies revealed an average infection rate of 10.4%. a total of 90 flies were analyzed for trypanosome identification with primer sets specific for trypanosoma (trypanozoon) brucei s.l., t. ... | 1998 | 9707369 |
| transformation of monomorphic trypanosoma brucei bloodstream form trypomastigotes into procyclic forms at 37 degrees c by removing glucose from the culture medium. | african trypanosomes have been shown previously to undergo efficient transformation from bloodstream forms to procyclic (insect dwelling) forms in vitro by adding citrate and/or cis-aconitate to the culture medium and lowering incubation temperature to 27 degrees c. in this paper, it is shown that strain 427 monomorphic bloodstream forms of trypanosoma brucei grown in axenic culture at 37 degrees c can be transformed to procyclic forms by simply replacing the glucose carbon source in the culture ... | 1998 | 9719513 |
| glossina morsitans morsitans and glossina palpalis palpalis: dosage compensation raises questions about the milligan model for control of trypanosome development. | evidence that dosage compensation occurs in tsetse flies was obtained by comparing the activities of x chromosome-linked enzymes, arginine phosphokinase and glucose-6-phosphate dehydrogenase in glossina m. morsitans and hexokinase and phosphoglucomutase in glossina p. palpalis, with the activity of an autosome-linked enzyme, malate dehydrogenase, in each species. the shortcomings of the x chromosome model for the control of trypanozoon maturation in tsetse are discussed in light of these finding ... | 1998 | 9806869 |
| [vectorial competence of glossina tachinoides westwood and glossina palpalis gambiensis vanderplank infected by trypanosoma brucei brucei eatro 1125]. | the vectorial competence (vc) of teneral (less than 32 h) glossina tachinoides westwood and g. palpalis gambiensis vanderplank, fed simultaneously on a guinea-pig infected with trypanosoma brucei brucei eatro 1125, was assessed. statistical analysis of the experimental results revealed that female g. tachinoides had a significantly higher midgut infection rate than males. such a sex-related difference was not observed in g. p. gambiensis. male g. p. gambiensis had higher midgut infection rates t ... | 1998 | 9851007 |
| genetic exchange in the trypanosomatidae. | the only trypanosomatid so far proved to undergo genetic exchange is trypanosoma brucei, for which hybrid production after co-transmission of different parental strains through the tsetse fly vector has been demonstrated experimentally. analogous mating experiments have been attempted with other trypanosoma and leishmania species, so far without success. however, natural leishmania hybrids, with a combination of the molecular characters of two sympatric species, have been described amongst both ... | 1999 | 10214689 |
| resurgence of sleeping sickness in tambura county, sudan. | endemic foci of human african trypanosomiasis are present in southern sudan. in 1996 and 1997, trypanosomiasis increased sharply in tambura county. to define the magnitude and geographic distribution of the outbreak, we conducted a prevalence survey using population-based cluster sampling in 16 villages: 1,358 participants answered questions about routine activities and tsetse fly contact and received serologic testing. seroprevalence in the surveyed area was 19.4% (95% confidence interval = 16. ... | 1999 | 10463686 |
| n-linked glycans containing linear poly-n-acetyllactosamine as sorting signals in endocytosis in trypanosoma brucei. | african trypanosomes, such as trypanosoma brucei, are protozoan parasites that are transmitted by the tsetse fly and cause sleeping sickness in humans and nagana in cattle. trypanosomes evade the immune responses of their hosts by varying their surface coat protein (vsg) and restricting exocytosis and endocytosis to an invagination of the plasma membrane called the flagellar pocket (fp). the fp represents only 0.5% of the cellular surface but membrane turnover here occurs at high rates [1] [2] [ ... | 1999 | 10531030 |
| a structural and transcription pattern for variant surface glycoprotein gene expression sites used in metacyclic stage trypanosoma brucei. | african trypanosomes first express the variant surface glycoprotein (vsg) at the metacyclic stage in the tsetse fly vector, in preparation for transfer into the mammal. metacyclic (m)vsgs comprise a specific vsg repertoire subset and their expression is regulated differently from that of bloodstream vsgs, involving exclusively transcriptional regulation during the life cycle. to identify basic structural and functional features that may be common to mvsg telomeric transcription units, we have ch ... | 1999 | 10551359 |
| slender and stumpy bloodstream forms of trypanosoma brucei display a differential response to extracellular acidic and proteolytic stress. | natural infections of mammals with african trypanosomes, such as trypanosoma brucei, are generally pleomorphic, the population consisting of different forms, termed slender and stumpy forms, that vary in number as the parasitaemia develops. we show that the differentiation of slender into stumpy forms is characterized by the acquisition by the parasite of the ability to regulate its internal ph, even in the face of a large, inwardly directed gradient of h+, as well as a tolerance towards externa ... | 2000 | 10601846 |
| chalcone, acyl hydrazide, and related amides kill cultured trypanosoma brucei brucei. | protozoan parasites of the genus trypanosoma cause disease in a wide range of mammalian hosts. trypanosoma brucei brucei, transmitted by tsetse fly to cattle, causes a disease (nagana) of great economic importance in parts of africa. t. b. brucei also serves as a model for related trypanosoma species, which cause human sleeping sickness. | 2000 | 11055585 |
| glycosylphosphatidylinositol-anchored surface molecules of trypanosoma congolense insect forms are developmentally regulated in the tsetse fly. | procyclic culture forms of trypanosoma congolense have been shown to express a glutamic acid/alanine-rich protein (garp) on their surface. by labelling t. congolense procyclic culture forms with glycosylphosphatidylinositol (gpi) precursors, we show that garp is bound to the membrane by a gpi anchor and demonstrate the presence of two additional gpi-anchored surface molecules of 24-34 and 58 kda that are abundantly expressed. the 24-34 kda molecule, which is recognised by monoclonal antibodies t ... | 2002 | 11755181 |
| surface coat remodeling during differentiation of trypanosoma brucei. | african trypanosomes (trypanosoma brucei) are digenetic parasites whose lifecycle alternates between the mammalian bloodstream and the midgut of the tsetse fly vector. in mammals, proliferating long slender parasites transform into non-diving short stumpy forms, which differentiate into procyclic forms when ingested by the tsetse fly. a hallmark of differentiation is the replacement of the bloodstream stage surface coat composed of variant surface glycoprotein (vsg) with a new coat composed of p ... | 2003 | 12716904 |
| studies on the deposition, migration, and development to the blood forms of trypanosomes belonging to the trypanosoma brucei group. i. an account of the process of feeding adopted by the tsetse-fly when obtaining a blood-meal from the mammalian host, with special reference to the ejection of saliva and the relationship of the feeding process to the deposition of the metacyclic trypanosomes. | | 1956 | 13395333 |
| monitoring the developmental status of trypanosoma brucei gambiense in the tsetse fly by means of pcr analysis of anal and saliva drops. | teneral glossina palpalis gambiensis (diptera: glossinidae) were infected with a culture of procyclic forms of trypanosoma brucei gambiense using a single-bloodmeal membrane feeding technique. the infection was monitored by analysing the saliva (mature infection) and anal drop (midgut infection) of each fly at different post-infection times both by microscopic observation and polymerase chain reaction (pcr). amplification revealed many more positive anal drops than microscopy. the monitoring sho ... | 2003 | 14516928 |
| inhibition of the dna amplification of trypanosomes present in tsetse flies midguts: implications for the identification of trypanosome species in wild tsetse flies. | the present study was carried out in order to investigate if there was really a failure of pcr in identifying parasitologically positive tsetse flies in the field. tsetse flies (glossina palpalis gambiensis and glossina morsitans morsitans) were therefore experimentally infected with two different species of trypanosoma (trypanosoma brucei gambiense or trypanosoma congolense). a total of 152 tsetse flies were dissected, and organs of each fly (midgut, proboscis or salivary glands) were examined. ... | 2004 | 15071836 |
| african trypanosome interactions with an in vitro model of the human blood-brain barrier. | the neurological manifestations of sleeping sickness in man are attributed to the penetration of the blood-brain barrier (bbb) and invasion of the central nervous system by trypanosoma brucei gambiense and trypanosoma brucei rhodesiense. however, how african trypanosomes cross the bbb remains an unresolved issue. we have examined the traversal of african trypanosomes across the human bbb using an in vitro bbb model system constructed of human brain microvascular endothelial cells (bmecs) grown o ... | 2004 | 15562595 |
| mixed infections of trypanosomes in tsetse and pigs and their epidemiological significance in a sleeping sickness focus of côte d'ivoire. | in a sleeping sickness focus of côte d'ivoire, trypanosomes were characterized in humans, pigs and tsetse using various techniques. out of 74 patients, all the 43 stocks isolated by kivi (kit for in vitro isolation) appeared to belong to only one zymodeme of trypanosoma brucei gambiense group 1 (the major zymodeme z3). the only stock isolated on rodents belonged to a different, new, zymodeme (z50), of t. b. gambiense group 1. from 18 pigs sampled in the same locations as the patients, pcr showed ... | 2004 | 15648692 |
| [human african trypanosomiasis: urban transmission in the focus of bonon (côte d'ivoire)]. | human african trypanosomiasis (hat) is a vector-borne parasitic disease which has often been considered a rural disease. population increases in african countries have entailed the spread of urban centres, creating favourable conditions for the appearance of new epidemiological conditions. in cote d'ivoire, hat transmission has been described in the surroundings of towns such as daloa or sinfra. in the focus of bonon, located in central-western cote d'ivoire, a medical survey detected 96 patient ... | 2005 | 15807798 |
| a mitogen-activated protein kinase controls differentiation of bloodstream forms of trypanosoma brucei. | african trypanosomes undergo differentiation in order to adapt to the mammalian host and the tsetse fly vector. to characterize the role of a mitogen-activated protein (map) kinase homologue, tbmapk5, in the differentiation of trypanosoma brucei, we constructed a knockout in procyclic (insect) forms from a differentiation-competent (pleomorphic) stock. two independent knockout clones proliferated normally in culture and were not essential for other life cycle stages in the fly. they were also ab ... | 2006 | 16835456 |
| vector competence of glossina palpalis gambiensis for trypanosoma brucei s.l. and genetic diversity of the symbiont sodalis glossinidius. | tsetse flies transmit african trypanosomes, responsible for sleeping sickness in humans and nagana in animals. this disease affects many people with considerable impact on public health and economy in sub-saharan africa, whereas trypanosomes' resistance to drugs is rising. the symbiont sodalis glossinidius is considered to play a role in the ability of the fly to acquire trypanosomes. different species of glossina were shown to harbor genetically distinct populations of s. glossinidius. we there ... | 2007 | 17012373 |
| cyclical transmission of trypanosoma brucei gambiense in glossina palpalis gambiensis displays great differences among field isolates. | six sets of teneral glossina palpalis gambiensis (diptera: glossinidae) were fed on mice infected with six different isolates of trypanosoma brucei gambiense (each mouse was infected with one of the isolates), previously isolated from patients in the sleeping sickness focus of bonon, côte d'ivoire and in makoua, congo. all the tsetse flies were dissected 42 days post-infection and midgut and salivary glands were examined for trypanosomes by microscopical examination. no infection was observed wi ... | 2006 | 17069743 |
| trypanosoma brucei 29-13 strain is inducible in but not permissive for the tsetse fly vector. | using green fluorescent protein as a reporter, we have shown that the strain 29-13 of trypanosoma brucei, widely used for inducible down-regulation of mrna, is inducible in, but not permissive for the tsetse flies glossina palpalis gambiensis and glossina morsitans morsitans. within two weeks post-infection, 42% males and females of teneral and non-teneral tsetse flies harboured intestinal infections, yet not a single infection progressed into the salivary glands. | 2007 | 17603043 |
| tsetse fly host preference from sleeping sickness foci in cameroon: epidemiological implications. | to determine the tsetse fly host preferences in two sleeping sickness foci of southern cameroon, four entomological surveys (two in each focus) were carried out. for the whole study, 4929 tsetse flies were caught: 3933 (79.8%) glossina palpalis palpalis, 626 (12.7%) glossina pallicera pallicera, 276 (5.6%) glossina nigrofusca and 94 (1.9%) glossina caliginea. one hundred and thirty-eight blood meals were collected and the origin of 118 (85.5%) meals was successfully identified: 38.4% from man, 2 ... | 2008 | 17977803 |
| the direct route: a simplified pathway for protein import into the mitochondrion of trypanosomes. | trypanosoma brucei is a unicellular eukaryote that causes the deadly human african trypanosomiasis ('sleeping sickness') in humans. the parasite has a complicated lifestyle, it developmentally changes aspects of its mitochondrial function as it alternates from forms in the tsetse fly to forms adapted for life in the human bloodstream. the single mitochondrion found in each trypanosome has to be duplicated precisely in each round of the cell cycle in order for parasites to replicate, and this dep ... | 2008 | 18068984 |
| trypanosoma brucei brucei induces alteration in the head proteome of the tsetse fly vector glossina palpalis gambiensis. | parasitic manipulations of host behaviour are known from a wide range of host-parasite associations. however, the understanding of these phenomena is far from complete and detailed investigation of their proximate causes is needed. many studies report behavioural modifications, such as altered feeding rates in tsetse fly (glossina) infected with the mature transmissible stage (i.e. metacyclic) of the trypanosomes. here, bidimensional (2d) gel electrophoresis and mass spectrometry were employed t ... | 2007 | 18092995 |
| n-acetyl d-glucosamine stimulates growth in procyclic forms of trypanosoma brucei by inducing a metabolic shift. | summarythe lectin-inhibitory sugars d-glucosamine (glcn) and n-acetyl d-glucosamine (glcnac) are known to enhance susceptibility of the tsetse fly vector to infection with trypanosoma brucei. glcnac also stimulates trypanosome growth in vitro in the absence of any factor derived from the fly. here, we show that glcnac cannot be used as a direct energy source, nor is it internalized by trypanosomes. it does, however, inhibit glucose uptake by binding to the hexose transporter. deprivation of d-gl ... | 2008 | 18371239 |
| does isometamidium chloride treatment protect tsetse flies from trypanosome infections during sit campaigns? | african animal trypanosomosis is a major pathological constraint to cattle breeding across 10 million km2 of sub-saharan west african countries infested by tsetse flies, their cyclic vectors. the release of sterile males (sterile insect technique [sit]) is a potentially important control technique aimed at eliminating the vectors. prior to release, tsetse are generally treated with isometamidium chloride, a trypanocide, to prevent them from transmitting parasites. the present study investigated ... | 2008 | 18498613 |
| differential expression of a protease gene family in african trypanosomes. | during their life cycle african trypanosomes must quickly adapt to the different environments of the tsetse fly midgut and the mammalian bloodstream by modulating expression of many of their genes. one group of these differentially expressed genes encodes different forms of a major surface protease. using a luciferase reporter gene transiently or permanently transfected into trypanosomes, we show here that the 3'-utrs of these protease genes are responsible for their differential expression. del ... | 2009 | 18848586 |
| a surface transporter family conveys the trypanosome differentiation signal. | microbial pathogens use environmental cues to trigger the developmental events needed to infect mammalian hosts or transmit to disease vectors. the parasites causing african sleeping sickness respond to citrate or cis-aconitate (cca) to initiate life-cycle development when transmitted to their tsetse fly vector. this requires hypersensitization of the parasites to cca by exposure to low temperature, conditions encountered after tsetse fly feeding at dusk or dawn. here we identify a carboxylate-t ... | 2009 | 19444208 |
| monitoring the pleomorphism of trypanosoma brucei gambiense isolates in mouse: impact on its transmissibility to glossina palpalis gambiensis. | substantial differences have been observed between the cyclical transmission of three trypanosoma brucei gambiense field isolates in glossina palpalis gambiensis (ravel et al., 2006). differences in the pleomorphism of these isolates in rodent used to provide the infective feed to glossina, could explain such results, since stumpy forms are preadapted for differentiation to procyclic forms when taken up in a tsetse bloodmeal. to assess this possibility, mice were immunosuppressed and inoculated ... | 2009 | 19720159 |
| influence of habitat and seasonal variation on wild mammal diversity and distribution with special reference to the trypanosoma brucei gambiense host-reservoir in bipindi (cameroon). | to evaluate the role of wildlife in the resurgence and perenisation of human african trypanosomiasis (hat), we investigated the influence of habitat and seasonal variations on the diversity and spatial distribution of wild mammals, with special reference to those recognised as potential host-reservoirs of trypanosoma brucei gambiense in bipindi (southwestern cameroon). to achieve this, we carried out transect surveys in four habitat types over two years. a total of 31 mammal species were recorde ... | 2009 | 19732737 |
| the epidemiology of trypanosomiasis in rumphi district, malawi: a ten year retrospective study. | human african trypanosomiasis (hat) is caused by two species of the tsetse fly vectored protozoan hemoflagellates belonging to trypanosma brucei, namely t.b gambiense which predominates in western africa and follows a chronic disease course and t.b rhodensiense which is more prevalent in southern and eastern africa, malawi included, and follows a more acute and aggressive disease course. previous studies in the democratic republic of congo, angola, uganda and sudan have demonstrated that the pre ... | 2009 | 19780474 |
| diversity and spatial distribution of vectors and hosts of t. brucei gambiense in forest zones of, southern cameroon: epidemiological implications. | host and vector distribution of trypanosoma brucei gambiense was studied in relation to habitat types and seasons. six (19.35%) of the 31 mammal species recorded in bipindi were reservoir hosts. cercopithecus nictitans was confined to the undisturbed forest and the low intensive shifting cultivation zones, while cephalophus monticola, cephalophus dorsalis, cricetomys gambianus, atherurus africanus and nandinia binotata occurred in all the habitat types. as for vectors of human african trypanosom ... | 2010 | 20067756 |
| tsetse fly blood meal modification and trypanosome identification in two sleeping sickness foci in the forest of southern cameroon. | the blood meal origins of 222 tsetse flies (213 glossina palpalis palpalis, 7 glossina pallicera pallicera, one glossina nigrofusca and one glossina caliginea) caught in 2008 in two human african trypanosomiasis foci (bipindi and campo) of south cameroon were investigated. 88.7% of tsetse flies blood meals were identified using the heteroduplex method and the origin of the remaining blood meals (11.3%) was identified by sequencing the cytochrome b gene. most of the meals were from humans (45.9%) ... | 2010 | 20541513 |
| [glossina feeding habits and diversity of species of trypanosomes in an active focus of human african trypanosomiasis in gabon]. | feeding host is an important factor upon which depend the glossina infection rate and the proportion of different species of trypanosome. glossina feed both upon animals and humans. in order to identify species of trypanosomes present in the komo-mondah focus and to verify whether there is any relationship between the prevalence of sleeping sickness and the feeding habits of glossina, we have carried out an entomological survey in this focus of gabon. flies were dissected and organs were analyse ... | 2010 | 20821180 |
| the prevalence of african animal trypanosomoses and tsetse presence in western senegal. | in 2005, the government of senegal initiated a tsetse eradication campaign in the niayes and la petite côte aiming at the removal of african animal trypanosomosis (aat), which is one of the main constraints to the development of more effective cattle production systems. the target area has particular meteorological and ecological characteristics that provide great potential for animal production, but it is unfortunately still infested by the riverine tsetse species glossina palpalis gambiensis v ... | 2010 | 21073148 |
| a new transmission risk index for human african trypanosomiasis and its application in the identification of sites of high transmission of sleeping sickness in the fontem focus of southwest cameroon. | a new index for the risk for transmission of human african trypanosomiasis was developed from an earlier index by adding terms for the proportion of tsetse infected with trypanosoma brucei gambiense group 1 and the contribution of animals to tsetse diet. the validity of the new index was then assessed in the fontem focus of southwest cameroon. averages of 0.66 and 4.85 glossina palpalis palpalis (diptera: glossinidae) were caught per trap/day at the end of one rainy season (november) and the sta ... | 2010 | 21198712 |
| spatio-temporal distribution of tsetse and other biting flies in the mouhoun river basin, burkina faso. | in the mouhoun river basin, burkina faso, the main vectors of african animal trypanosomoses are glossina palpalis gambiensis vanderplank and glossina tachinoides westwood (diptera: glossinidae), both of which are riverine tsetse species. the aim of our study was to understand the impact of landscape anthropogenic changes on the seasonal dynamics of vectors and associated trypanosomosis risk. three sites were selected on the basis of the level of disturbance of tsetse habitats and predominant tse ... | 2010 | 21198714 |
| trypanosoma brucei s.l.: microsatellite markers revealed high level of multiple genotypes in the mid-guts of wild tsetse flies of the fontem sleeping sickness focus of cameroon. | to identify trypanosoma brucei genotypes which are potentially transmitted in a sleeping sickness focus, microsatellite markers were used to characterize t. brucei found in the mid-guts of wild tsetse flies of the fontem sleeping sickness focus in cameroon. for this study, two entomological surveys were performed during which 2685 tsetse flies were collected and 1596 (59.2%) were dissected. microscopic examination revealed 1.19% (19/1596) mid-gut infections with trypanosomes; the pcr method iden ... | 2011 | 21376044 |
| epidemiology of sleeping sickness in boffa (guinea): where are the trypanosomes? | human african trypanosomiasis (hat) in west africa is a lethal, neglected disease caused by trypanosoma brucei gambiense transmitted by the tsetse glossina palpalis gambiensis. although the littoral part of guinea with its typical mangrove habitat is the most prevalent area in west africa, very few data are available on the epidemiology of the disease in such biotopes. as part of a hat elimination project in guinea, we carried a cross-sectional study of the distribution and abundance of people, ... | 2012 | 23272259 |
| differential expression of midgut proteins in trypanosoma brucei gambiense-stimulated vs. non-stimulated glossina palpalis gambiensis flies. | the unicellular pathogenic protozoan trypanosoma brucei gambiense is responsible for the chronic form of sleeping sickness. this vector-borne disease is transmitted to humans by the tsetse fly of the group glossina palpalis, including the subspecies g. p. gambiensis, in which the parasite completes its developmental cycle. sleeping sickness control strategies can therefore target either the human host or the fly vector. indeed, suppression of one step in the parasite developmental cycle could ab ... | 2015 | 26029185 |
| rna-seq de novo assembly reveals differential gene expression in glossina palpalis gambiensis infected with trypanosoma brucei gambiense vs. non-infected and self-cured flies. | trypanosoma brucei gambiense (tbg), causing the sleeping sickness chronic form, completes its developmental cycle within the tsetse fly vector glossina palpalis gambiensis (gpg) before its transmission to humans. within the framework of an anti-vector disease control strategy, a global gene expression profiling of trypanosome infected (susceptible), non-infected, and self-cured (refractory) tsetse flies was performed, on their midguts, to determine differential genes expression resulting from in ... | 2015 | 26617594 |
| comparative gene expression of wigglesworthia inhabiting non-infected and trypanosoma brucei gambiense-infected glossina palpalis gambiensis flies. | tsetse flies (glossina sp.) that transmit trypanosomes causing human (and animal) african trypanosomiasis (hat and aat, respectively) harbor symbiotic microorganisms, including the obligate primary symbiont wigglesworthia glossinidia. a relationship between wigglesworthia and tsetse fly infection by trypanosomes has been suggested, as removal of the symbiont results in a higher susceptibility to midgut infection in adult flies. to investigate this relationship and to decipher the role of w. glos ... | 2014 | 25452752 |
| technical data of the transcriptomic analysis performed on tsetse fly symbionts, sodalis glossinidius and wigglesworthia glossinidia, harbored, respectively by non-infected, trypanosoma brucei gambiense infected and self-cured glossina palpalis gambiensis tsetse flies. | microarray is a powerful and cheap method to identify and quantify gene expression in particular in a mix of total rna extracted from biological samples such as the tsetse fly gut, including several organisms (here, the fly tissue and the intestinal microorganisms). besides, biostatistics and bioinformatics allow comparing the transcriptomes from samples collected from differently treated flies, and thus to identify and quantify differential expressed genes. here, we describe in details a whole ... | 2015 | 26484198 |
| the transcriptional signatures of sodalis glossinidius in the glossina palpalis gambiensis flies negative for trypanosoma brucei gambiense contrast with those of this symbiont in tsetse flies positive for the parasite: possible involvement of a sodalis-hosted prophage in fly trypanosoma refractoriness? | tsetse flies, such as glossina palpalis gambiensis, are blood-feeding insects that could be subverted as hosts of the parasite trypanosoma brucei gambiense: initiated in the tsetse fly mid gut, the developmental program of this parasite further proceeds in the salivary glands. the flies act as vectors of this human-invasive parasite when their salivary glands sustain the generation of metacyclic trypomastigotes, the exclusive morphotypes pre-programmed to further develop in the human individuals ... | 2014 | 24637266 |
| high frequency of (kinetoplastida: trypanosomatidae) type among (diptera: glossinidae) in a historic trypanosoma foci in north-eastern gabon: preliminary study. | human african trypanosomiasis became a neglected disease after the 1960s, when case numbers dropped dramatically. it again became a public health problem in sub-saharan africa at the end of the 1990s, when new cases were reported, notably in central africa, and specifically in gabon, where historic foci existed and new cases have been reported. therefore, the present study reports on an entomological survey conducted in may 2012 to determine the pathogenic trypanosome infection rate in tsetse fl ... | 2016 | 27113105 |
| xenomonitoring of sleeping sickness transmission in campo (cameroon). | the sleeping sickness focus of campo in south cameroon is still active, at a low endemic level, for more than a century, despite a regular medical surveillance. the present study focuses on the spatial distribution of xenomonitoring information obtained from an entomological survey performed in the dry season 2012. it appears that humans constitute a third of the blood meals and that the flies' densities were coherent with those classically observed in the different biotopes. paradoxically, the ... | 2016 | 27071554 |
| [ecology of glossina palpalis vanderplank, 1949 (diptera: glossinidae) in mangrove area of guinea: influence of tides on tsetse densities]. | the mangrove area on the guinea littoral constitutes a favourable habitat for transmission of trypanosoma brucei gambiens, the parasite causing sleeping sickness also called human african trypanosmosis (hat), due the simultaneous presence of the vector (tsetse flies) and the human hosts. in order to assess the influence of the sea tides on the densities of glossina palpalis gambiensis (gpg), major vector of hat in the mangrove, entomological surveys were performed using two transects, according ... | 2016 | 26875082 |
| detection and identification of pathogenic trypanosome species in tsetse flies along the comoé river in côte d'ivoire. | in order to identify pathogenic trypanosomes responsible for african trypanosomiasis, and to better understand tsetse-trypanosome relationships, surveys were undertaken in three sites located in different eco-climatic areas in côte d'ivoire during the dry and rainy seasons. tsetse flies were caught during five consecutive days using biconical traps, dissected and microscopically examined looking for trypanosome infection. samples from infected flies were tested by pcr using specific primers for ... | 2015 | 26035296 |
| midgut expression of immune-related genes in glossina palpalis gambiensis challenged with trypanosoma brucei gambiense. | tsetse flies from the subspecies glossina morsitans morsitans and glossina palpalis gambiensis, respectively, transmit trypanosoma brucei rhodesiense and trypanosoma brucei gambiense. the former causes the acute form of sleeping sickness, and the latter provokes the chronic form. although several articles have reported g. m. morsitans gene expression following trypanosome infection, no comparable investigation has been performed for g. p. gambiensis. this report presents results on the different ... | 2014 | 25426112 |
| challenges towards the elimination of human african trypanosomiasis in the sleeping sickness focus of campo in southern cameroon. | the sleeping sickness focus of campo lies along the atlantic coast and extends along the ntem river, which constitutes the cameroonian and equatorial guinean border. it is a hypo-endemic focus with the disease prevalence varying from 0.3 to 0.86% during the last few decades. investigations on animal reservoirs revealed a prevalence of trypanosoma brucei gambiense of 0.6% in wild animals and 4.83% in domestic animals of this focus. from 2001 to 2012, about 19 931 tsetse were collected in this foc ... | 2014 | 25129168 |
| population genetics of trypanosoma brucei circulating in glossina palpalis palpalis and domestic animals of the fontem sleeping sickness focus of cameroon. | human african trypanosomiasis is still a public health threat in cameroon. to assess trypanosoma brucei strains circulating in the fontem sleeping sickness focus, we conducted a genetic structure study using microsatellites to assess genotypes circulating in both tsetse flies and domestic animals. | 2014 | 24690359 |
| identification of glossina palpalis gambiensis specific salivary antigens: towards the development of a serologic biomarker of human exposure to tsetse flies in west africa. | the saliva of blood sucking arthropods contains a number of pharmacologically active compounds that induce an antibody response in exposed human individuals. the objectives of the present study were (i) to assess the human igg response directed against salivary antigens of glossina palpalis gambiensis, the main vector of trypanosoma brucei gambiense in west africa, as a biomarker of human-tsetse contacts; and (ii) to identify specific salivary antigens. immune reactivity of human plasma collecte ... | 2013 | 23500186 |
| identification of different trypanosome species in the mid-guts of tsetse flies of the malanga (kimpese) sleeping sickness focus of the democratic republic of congo. | the malanga sleeping sickness focus of the democratic republic of congo has shown an epidemic evolution of disease during the last century. however, following case detection and treatment, the prevalence of the disease decreased considerably. no active survey has been undertaken in this focus for a couple of years. to understand the current epidemiological status of sleeping sickness as well as the animal african trypanosomiasis in the malanga focus, we undertook the identification of tsetse blo ... | 2012 | 22992486 |
| transcriptional profiling of midguts prepared from trypanosoma/t. congolense-positive glossina palpalis palpalis collected from two distinct cameroonian foci: coordinated signatures of the midguts' remodeling as t. congolense-supportive niches. | our previous transcriptomic analysis of glossina palpalis gambiensis experimentally infected or not with trypanosoma brucei gambiense aimed to detect differentially expressed genes (degs) associated with infection. specifically, we selected candidate genes governing tsetse fly vector competence that could be used in the context of an anti-vector strategy, to control human and/or animal trypanosomiasis. the present study aimed to verify whether gene expression in field tsetse flies (g. p. palpali ... | 2017 | 28804485 |
| comparative genomics of glossina palpalis gambiensis and g. morsitans morsitans to reveal gene orthologs involved in infection by trypanosoma brucei gambiense. | blood-feeding glossina palpalis gambiense (gpg) fly transmits the single-celled eukaryotic parasite trypanosoma brucei gambiense (tbg), the second glossina fly african trypanosome pair being glossina morsitans/t.brucei rhodesiense. whatever the t. brucei subspecies, whereas the onset of their developmental program in the zoo-anthropophilic blood feeding flies does unfold in the fly midgut, its completion is taking place in the fly salivary gland where does emerge a low size metacyclic trypomasti ... | 2017 | 28421044 |