RESUMEN
We propose a taxonomic revision of the dixenous trypanosomatids currently classified as Endotrypanum and Leishmania, including parasites that do not fall within the subgenera L. (Leishmania) and L. (Viannia) related to human leishmaniasis or L. (Sauroleishmania) formed by leishmanias of lizards: L. colombiensis, L. equatorensis, L. herreri, L. hertigi, L. deanei, L. enriettii and L. martiniquensis. The comparison of these species with newly characterized isolates from sloths, porcupines and phlebotomines from central and South America unveiled new genera and subgenera supported by past (RNA PolII gene) and present (V7V8 SSU rRNA, Hsp70 and gGAPDH) phylogenetic analyses of the organisms. The genus Endotrypanum is restricted to Central and South America, comprising isolates from sloths and transmitted by phlebotomines that sporadically infect humans. This genus is the closest to the new genus Porcisia proposed to accommodate the Neotropical porcupine parasites originally described as L. hertigi and L. deanei. A new subgenus Leishmania (Mundinia) is created for the L. enriettii complex that includes L. martiniquensis. The new genus Zelonia harbours trypanosomatids from Neotropical hemipterans placed at the edge of the Leishmania-Endotrypanum-Porcisia clade. Finally, attention is drawn to the status of L. siamensis and L. australiensis as nomem nudums.
Asunto(s)
Leishmania/genética , Filogenia , Trypanosomatina/clasificación , Animales , América Central/epidemiología , Genes Protozoarios , Humanos , Leishmaniasis/epidemiología , Leishmaniasis/parasitología , Leishmaniasis/transmisión , Lagartos/parasitología , Tipificación Molecular , Puercoespines/parasitología , Psychodidae/parasitología , ARN Ribosómico/genética , Perezosos/parasitología , América del Sur/epidemiología , Trypanosomatina/genéticaRESUMEN
We characterized four Brazilian trypanosomes isolated from domestic rats and three from captive non-human primates that were morphologically similar to T. lewisi, a considered non-pathogenic species restricted to rodents and transmitted by fleas, despite its potential pathogenicity for infants. These isolates were identified as T. lewisi by barcoding using V7V8 SSU rDNA sequences. In inferred phylogenetic trees, all isolates clustered tightly with reference T. lewisi and T. lewisi-like trypanosomes from Europe, Asia and Africa and despite their high sequence conservation formed a homogeneous clade separate from other species of the subgenus T. (Herpetosoma). With the aim of clearly resolving the relationships between the Brazilian isolates from domestic rats and primates, we compared sequences from more polymorphic ITS rDNA. Results corroborated that isolates from Brazilian rats and monkeys were indeed of the same species and quite close to T. lewisi isolates of humans and rats from different geographical regions. Morphology of the monkey isolates and their behaviour in culture and in experimentally infected rats were also compatible with T. lewisi. However, infection with T. lewisi is rare among monkeys. We have examined more than 200 free-ranging and 160 captive monkeys and found only three infected individuals among the monkeys held in captivity. The findings of this work suggest that proximity of monkeys and infected rats and their exposure to infected fleas may be responsible for the host switching of T. lewisi from their natural rodent species to primates. This and previous studies reporting T. lewisi in humans suggest that this trypanosome can cause sporadic and opportunistic flea-borne infection in primates.
Asunto(s)
Haplorrinos/parasitología , Ratas Wistar/parasitología , Trypanosoma lewisi/fisiología , Tripanosomiasis/veterinaria , Animales , Brasil , ADN Protozoario , ADN Espaciador Ribosómico , Evolución Molecular , Ratones , Ratones Endogámicos BALB C , Microscopía , Filogenia , Ratas , Trypanosoma lewisi/citología , Trypanosoma lewisi/genética , Trypanosoma lewisi/crecimiento & desarrollo , Tripanosomiasis/parasitologíaRESUMEN
In this study, using a combined data set of SSU rDNA and gGAPDH gene sequences, we provide phylogenetic evidence that supports clustering of crocodilian trypanosomes from the Brazilian Caiman yacare (Alligatoridae) and Trypanosoma grayi, a species that circulates between African crocodiles (Crocodilydae) and tsetse flies. In a survey of trypanosomes in Caiman yacare from the Brazilian Pantanal, the prevalence of trypanosome infection was 35% as determined by microhaematocrit and haemoculture, and 9 cultures were obtained. The morphology of trypomastigotes from caiman blood and tissue imprints was compared with those described for other crocodilian trypanosomes. Differences in morphology and growth behaviour of caiman trypanosomes were corroborated by molecular polymorphism that revealed 2 genotypes. Eight isolates were ascribed to genotype Cay01 and 1 to genotype Cay02. Phylogenetic inferences based on concatenated SSU rDNA and gGAPDH sequences showed that caiman isolates are closely related to T. grayi, constituting a well-supported monophyletic assemblage (clade T. grayi). Divergence time estimates based on clade composition, and biogeographical and geological events were used to discuss the relationships between the evolutionary histories of crocodilian trypanosomes and their hosts.
Asunto(s)
Caimanes y Cocodrilos/parasitología , Evolución Biológica , ADN Ribosómico/genética , Gliceraldehído-3-Fosfato Deshidrogenasa (Fosforilante)/genética , Filogenia , Trypanosomatina/clasificación , África , Animales , América del Sur , Trypanosomatina/citología , Trypanosomatina/aislamiento & purificaciónRESUMEN
Trypanosoma rangeli infects several mammalian orders but has never confidently been described in Chiroptera, which are commonly parasitized by many trypanosome species. Here, we described trypanosomes from bats captured in Central Brazil identified as T. rangeli, T. dionisii, T. cruzimarinkellei and T. cruzi. Two isolates, Tra643 from Platyrrhinus lineatus and Tra1719 from Artibeus planirostris were identified as T. rangeli by morphological, biological and molecular methods, and confirmed by phylogenetic analyses. Analysis using SSU rDNA sequences clustered these bat trypanosomes together with T. rangeli from other hosts, and separated them from other trypanosomes from bats. Genotyping based on length and sequence polymorphism of PCR-amplified intergenic spliced-leader gene sequences assigned Tra1719 to the lineage A whereas Tra643 was shown to be a new genotype and was assigned to the new lineage E. To our knowledge, these two isolates are the earliest T. rangeli from bats and the first isolates from Central Brazil molecularly characterized. Rhodnius stali captured for this study was found infected by T. rangeli and T. cruzi.
Asunto(s)
Quirópteros/parasitología , ARN Lider Empalmado/genética , Trypanosoma/clasificación , Trypanosoma/aislamiento & purificación , Tripanosomiasis/veterinaria , Animales , Brasil , Análisis por Conglomerados , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genotipo , Datos de Secuencia Molecular , Filogenia , Polimorfismo Genético , Análisis de Secuencia de ADN , Homología de Secuencia , Trypanosoma/citología , Trypanosoma/genéticaRESUMEN
Parasites of wild primates are important for conservation biology and human health due to their high potential to infect humans. In the Amazon region, non-human primates are commonly infected by Trypanosoma cruzi and T. rangeli, which are also infective to man and several mammals. This is the first survey of trypanosomiasis in a critically endangered species of tamarin, Saguinus bicolor (Callitrichidae), from the Brazilian Amazon Rainforest. Of the 96 free-ranging specimens of S. bicolor examined 45 (46.8%) yielded blood smears positive for trypanosomes. T. rangeli was detected in blood smears of 38 monkeys (39.6%) whereas T. cruzi was never detected. Seven animals (7.3%) presented trypanosomes of the subgenus Megatrypanum. Hemocultures detected 84 positive tamarins (87.5%). Seventy-two of 84 (85.7%) were morphologically diagnosed as T. rangeli and 3 (3.1%) as T. cruzi. Nine tamarins (9.4%) yielded mixed cultures of these two species, which after successive passages generated six cultures exclusively of T. cruzi and two of T. rangeli, with only one culture remaining mixed. Of the 72 cultures positive for T. rangeli, 62 remained as established cultures and were genotyped: 8 were assigned to phylogenetic lineage A (12.9%) and 54 to lineage B (87.1%). Ten established cultures of T. cruzi were genotyped as TCI lineage (100%). Transmission of both trypanosome species, their potential risk to this endangered species and the role of wild primates as reservoirs for trypanosomes infective to humans are discussed.
Asunto(s)
Animales Salvajes/parasitología , Conservación de los Recursos Naturales , Enfermedades de los Monos , Saguinus/parasitología , Trypanosoma cruzi , Trypanosoma , Tripanosomiasis/veterinaria , Animales , Brasil/epidemiología , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/veterinaria , Genotipo , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/parasitología , Reacción en Cadena de la Polimerasa/métodos , Prevalencia , Árboles , Trypanosoma/clasificación , Trypanosoma/genética , Trypanosoma/aislamiento & purificación , Trypanosoma/patogenicidad , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificación , Trypanosoma cruzi/patogenicidad , Tripanosomiasis/epidemiología , Tripanosomiasis/parasitologíaRESUMEN
Blood examination by microhaematocrit and haemoculture of 459 snakes belonging to 37 species revealed 2.4% trypanosome prevalence in species of Viperidae (Crotalus durissus and Bothrops jararaca) and Colubridae (Pseudoboa nigra). Trypanosome cultures from C. durissus and P. nigra were behaviourally and morphologically indistinguishable. In addition, the growth and morphological features of a trypanosome from the sand fly Viannamyia tuberculata were similar to those of snake isolates. Cross-infection experiments revealed a lack of host restriction, as snakes of 3 species were infected with the trypanosome from C. durissus. Phylogeny based on ribosomal sequences revealed that snake trypanosomes clustered together with the sand fly trypanosome, forming a new phylogenetic lineage within Trypanosoma closest to a clade of lizard trypanosomes transmitted by sand flies. The clade of trypanosomes from snakes and lizards suggests an association between the evolutionary histories of these trypanosomes and their squamate hosts. Moreover, data strongly indicated that these trypanosomes are transmitted by sand flies. The flaws of the current taxonomy of snake trypanosomes are discussed, and the need for molecular parameters to be adopted is emphasized. To our knowledge, this is the first molecular phylogenetic study of snake trypanosomes.
Asunto(s)
Colubridae/parasitología , Filogenia , Trypanosoma/clasificación , Trypanosoma/genética , Tripanosomiasis/veterinaria , Viperidae/parasitología , Animales , Bothrops/clasificación , Bothrops/parasitología , Colubridae/clasificación , Crotalus/clasificación , Crotalus/parasitología , ADN Protozoario/análisis , ADN Ribosómico/análisis , Evolución Molecular , Interacciones Huésped-Parásitos , Datos de Secuencia Molecular , Psychodidae/parasitología , Análisis de Secuencia de ADN , Trypanosoma/fisiología , Trypanosoma/ultraestructura , Tripanosomiasis/parasitología , Tripanosomiasis/transmisión , Viperidae/clasificaciónRESUMEN
O estudo mostrou como os clínicos da rede privada de Amparo e Pedreira, no interior do estado de São Paulo, utilizam o alendronato de sódio como recurso terapêutico na osteoporose. Esta enfermidade é de alta prevalência na população idosa, sendo tratada por médicos de diferentes especialidades. Este estudo, do tipo observacional, transversal e descritivo, foi realizado pormeio de entrevistas com 32 médicos para obtenção de dados sobre indicação, forma de utilização, seguimento de tratamento, medidas não farmacológicas e referencial teórico utilizado pelos entrevistados. Os resultadosmostraram que há concordância com o preconizado em consensos e guias terapêuticos em relação à indicação,doses recomendadas e medidas não farmacológicas, porém, foram verificadas falhas no seguimento dotratamento e na orientação dada ao paciente para a administração correta do medicamento, além de descrição imprecisa de fontes de informação. Concluiu-se que a atualização científica em fontes referenciais (ensaios randomizados controlados, metanálises) é indispensável para ajudar os clínicos na promoção do uso racional do alendronato de sódio no tratamento de osteoporose.
This is a study of how physicians working in the private health system in the towns of Amparo and Pedreira (upstate São Paulo, 75 miles away from the State capital) use sodium alendronate in the treatment of osteoporosis. This disease is highly prevalent in the elderly population and is treated by consultant clinicians/various specialities. The paper describes an observational, cross-sectional study that was carried out by interviewing 32 clinicians to evaluate: indication, usage, follow-up and evaluation of treatment, non pharmacological measures and source of information used by interviewees. The results show that clinical practice is in conformity with what is recommended in clinical guidelines and the general consensus, concerning indication, doses, and nonpharmacological measures. However, some faults were found in the course of treatment and in the advice given to the patients on how to take the drug, as well as imprecise descriptions of the sources of information by the doctors interviewed. It is concluded that constant scientific updating based on sources of reference (Randomized Controlled Trial, Meta- Analysis) is an indispensable aid to these clinicians in promoting the rational use of sodium alendronate inthe treatment of osteoporosis.
Asunto(s)
Humanos , Alendronato/administración & dosificación , Alendronato/farmacología , Alendronato/provisión & distribución , Alendronato/uso terapéutico , Osteoporosis/terapia , Prescripciones de MedicamentosRESUMEN
Almost all individuals (182) belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil) were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D). The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.
Asunto(s)
Malaria Falciparum/genética , Malaria Vivax/genética , Fenotipo , Plasmodium falciparum/patogenicidad , Plasmodium vivax/patogenicidad , Adolescente , Adulto , Animales , Brasil , Distribución de Chi-Cuadrado , Niño , Preescolar , Femenino , Marcadores Genéticos , Genética de Población , Haptoglobinas/genética , Humanos , Malaria Falciparum/sangre , Malaria Vivax/sangre , Masculino , Persona de Mediana Edad , Polimorfismo GenéticoRESUMEN
Almost all individuals (182) belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil) were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D). The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings
Asunto(s)
Niño , Preescolar , Adolescente , Adulto , Persona de Mediana Edad , Humanos , Animales , Masculino , Femenino , Eritrocitos , Malaria Falciparum , Malaria Vivax , Fenotipo , Plasmodium falciparum , Plasmodium vivax , Brasil , Marcadores Genéticos , Genética de Población , Haptoglobinas , Malaria Falciparum , Malaria Vivax , Reacción en Cadena de la Polimerasa , Polimorfismo GenéticoRESUMEN
We evaluated the prevalence of, and factors associated with, Helicobacter pylori infection in 222 subjects from 3 distinct communities of native populations (Uru-Eu-Wau-Wau Indians and 2 riverine communities living on the banks of the Machado river and in Portuchuelo) living in isolation in the rainforest of Brazilian Western Amazon. The overall prevalence was 78.8% (95% CI 72.7-83.9). The prevalence was higher in the Machado river community compared with Portuchuelo (chi2 = 3.84, P = 0.05), but no significant difference was observed between the Machado river community and the Uru-Eu-Wau-Wau Indians. Logistic regression showed that residential crowding and age were factors associated with the presence of H. pylori infection. Acquisition of the bacterium started early in life and by the age of 2 years 50% of children were infected. The prevalence increased with age, reaching near universal levels during adulthood (97.9%). Residential crowding was high with a global index of 3.3 persons/room (SD = 1.8), varying significantly between the 3 communities (P = 0.001). These data provide further evidence supporting direct person-to-person spread of the bacterium.
Asunto(s)
Infecciones por Helicobacter/epidemiología , Helicobacter pylori , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Anciano , Anciano de 80 o más Años , Brasil/etnología , Niño , Preescolar , Femenino , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/etiología , Humanos , Indígenas Sudamericanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Prevalencia , Características de la Residencia , Factores de RiesgoRESUMEN
A small riverine community, Portuchuelo (8 degrees 37'S, 63 degrees 49'W), and a rural county, Monte Negro (10 degrees 15'S, 63 degrees 18'W), both in the state of Rondjnia, Brazil, were studied for the purposes of ascertaining health conditions and the causes of the variability of some infectious diseases. The sample included 181 inhabitants of Portuchuelo and 924 of Monte Negro. Data on 11 blood polymorphisms (ABO, Rh, MNSs, Kell, Fy, haptoglobin, hemoglobin, ACP1, PGM1, GLO1, and CA2) were used to determine the ethnic composition of the inhabitants of Portuchuelo and Monte Negro. The contributions of Africans, Amerindians, and Europeans to the ethnic composition of the studied populations were, respectively, 0.21 +/- 0.046, 0.44 +/- 0.064, and 0.35 +/- 0.069 in Portuchuelo; and 0.25 +/- 0.032,0.12 +/- 0.046, and 0.63 +/- 0.054 in Monte Negro.
Asunto(s)
Antígenos de Grupos Sanguíneos/genética , Etnicidad/genética , Genética de Población , Brasil , Frecuencia de los Genes , Humanos , Polimorfismo Genético , Población RuralRESUMEN
During a survey of ticks on horses in November 2000, at the University of São Paulo farm in Pirassununga county, São Paulo, Brazil, 1 gynandromorph of Amblyomma cajennense was collected from a naturally infested horse. In another survey on dogs in March 2001, in the urban area of Monte Negro, Rondônia, Brazil, a gynandromorph of Rhipicephalus sanguineus was collected from a naturally infested dog. Both specimens are described and classified as perfect bipartite protogynanders.
Asunto(s)
Perros/parasitología , Caballos/parasitología , Ixodidae/anatomía & histología , Infestaciones por Garrapatas/veterinaria , Animales , Brasil/epidemiología , Encuestas Epidemiológicas , Infestaciones por Garrapatas/epidemiologíaRESUMEN
Some demographic and epidemiological patterns of the rural population of Monte Negro, locality situated in the State of Rondônia (Brazil), Western Amazonia, are described based on a sample of 924 randomly selected individuals, approximately 10% of the whole population. The main features of this sample are (1) the illiteracy rates in the parental generation were 23% for fathers and 20% for mothers. Among children, this figure dropped to 6%; (2) housing in Monte Negro is characterized by being constructed with wood (92%), and also a floor (75%). Nevertheless, only 32% of these houses had electric energy; (3) the mean ages for the parental generation were 41.9 for males and 36.3 for females. These values for the offspring generation were 12.2 and 10.5, respectively; (4) the sex-ratio of the offspring generation was 1.32;(5) the bioassay of kinship was estimated as.033 for this long range migrant population; (6) the prevalence of some macrophage dependent infectious disease was conspicuously high; (7) the reported number of malarial episodes among males and females was statistically different, suggesting that malaria may be, in part, a "professional" disease; (8) the prevalence of serum-positive reactions against B-hepatitis is distressing. It has a strong age dependence and reaches 74% among adult males. Conversely, signs of active infection (AgHbs) rises to 16% among children.
Asunto(s)
Demografía , Morbilidad , Población Rural , Adulto , Brasil , Niño , Femenino , Humanos , Masculino , Factores SocioeconómicosRESUMEN
Some demographic and epidemiological patterns of the rural population of Monte Negro, locality situated in the State of Rondônia (Brazil), Western Amazonia, are described based on a sample of 924 randomly selected individuals, approximately 10 percent of the whole population. The main features of this sample are (1) the illiteracy rates in the parental generation were 23 percent for fathers and 20 percent for mothers. Among children, this figure dropped to 6 percent; (2) housing in Monte Negro is characterized by being constructed with wood (92 percent), and also a floor (75 percent). Nevertheless, only 32 percent of these houses had electric energy; (3) the mean ages for the parental generation were 41.9 for males and 36.3 for females. These values for the offspring generation were 12.2 and 10.5, respectively; (4) the sex-ratio of the offspring generation was 1.32;(5) the bioassay of kinship was estimated as .033 for this long range migrant population; (6) the prevalence of some macrophage dependent infectious disease was conspicuously high; (7) the reported number of malarial episodes among males and females was statistically different, suggesting that malaria may be, in part, a "professional" disease; (8) the prevalence of serum-positive reactions against B-hepatitis is distressing. It has a strong age dependence and reaches 74 percent among adult males. Conversely, signs of active infection (AgHbs) rises to 16 percent among children
Asunto(s)
Niño , Adulto , Humanos , Masculino , Femenino , Demografía , Morbilidad , Brasil , Población Rural , Población Rural , Factores SocioeconómicosRESUMEN
Assessing the diversity of the Trypanosomatidae is difficult because of the relatively small number of species that can be cultured. This same problem thwarts efforts to identify the hosts and insect vectors of Phytomonas, a genus of parasites of plants that includes species responsible for devastating epiphytotics of economically important plantations. Here, Myrna Serrano, Marta Teixeira and Erney Camargo review the studies that have led to the development of a PCR-based technique for processing insect and plant juices fixed on glass slides. The method overcomes the need for cultivation, facilitates field collections and also permits the molecular examination of archival smears of Phytomonas. In principle, the method can be adapted to any trypanosomatid as well as to any fastidious parasitic or free-living organism.
Asunto(s)
Insectos/parasitología , Plantas/parasitología , Reacción en Cadena de la Polimerasa/métodos , Trypanosomatina/clasificación , Trypanosomatina/genética , Animales , Secuencia de Bases , ADN Protozoario/análisis , Datos de Secuencia MolecularRESUMEN
A malaria control pilot project was developed in the Urupá agro-industrial farm that is situated in the State of Rondônia (Western Amazon Region, Brazil). Around 180 inhabitants had been surveyed for the past five years. The control measures were based on (1) training a community agent to perform on the spot microscopical diagnosis of malaria and to treat the uncomplicated cases of malaria; (2) limiting the use of insecticides to a short period before the high transmission season. This resulted in a significant reduction in the time between the onset of clinical symptoms and specific chemotherapy which fell from 3.5 to 1.3 days. In relation to the previous three reference years the total number of malaria cases was reduced to 50% in the first year and to 25% in the second year. The introduction of these measures coincided with pronounced reduction in the frequency of Plasmodium falciparum infections but this was less marked for P. vivax infections. In the second year of the pilot experiment there was no P. falciparum transmission on the farm. During the last decade there was a general decrease in the endemicity of malaria in the State of Rondônia. The linear regression coefficient values indicate that the decline was more pronounced in Urupá than in the general municipality and that the falciparum malaria API in Urupá farm is significantly lower than in the general municipality of Candeias were the farm is situated.
Asunto(s)
Malaria Falciparum/prevención & control , Malaria Vivax/prevención & control , Adolescente , Adulto , Distribución por Edad , Brasil/epidemiología , Niño , Preescolar , Femenino , Encuestas Epidemiológicas , Humanos , Incidencia , Lactante , Recién Nacido , Modelos Lineales , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Masculino , Proyectos Piloto , Prevalencia , Salud Rural/estadística & datos numéricos , Estaciones del Año , Distribución por SexoRESUMEN
The random amplification of polymorphic DNA was used for easy, quick and sensitive assessment of genetic polymorphism within Phytomonas to discriminate isolates and determine genetic relationships within the genus. We examined 48 Phytomonas spp., 31 isolates from plants and 17 from insects, from different geographic regions. Topology of the dendrogram based on randomly amplified polymorphic DNA fingerprints segregated the Phytomonas spp. into 5 main clusters, despite the high genetic variability within this genus. Similar clustering could also be obtained by both visual and cross-hybridization analysis of randomly amplified synapomorphic DNA fragments. There was some concordance between the genetic relationship of isolates and their plant tissue tropism. Moreover, Phytomonas spp. from plants and insects were grouped according to geographic origin, thus revealing a complex structure of this taxon comprising several clusters of very closely related organisms.
Asunto(s)
Polimorfismo Genético , Trypanosomatina/genética , Animales , Dermatoglifia del ADN , Insectos/parasitología , Hibridación de Ácido Nucleico , Filogenia , Plantas/parasitología , Técnica del ADN Polimorfo Amplificado Aleatorio , Trypanosomatina/clasificación , Trypanosomatina/aislamiento & purificaciónRESUMEN
A PCR-based method was adapted for the amplification of DNA from methanol-fixed smears of insects and plants parasitized by trypanosomatids. The PCR target was the multicopy spliced leader (SL) gene. Amplicons were hybridized with an oligonucleotide probe (SL3') specific for Phytomonas. The method has the advantage of dispensing with the cultivation of parasites, many of which are very fastidious or non-cultivable. The technique was applied to archival glass slides and to newly collected material. It proved to specific for Phytomonas spp., enabling their detection in plants and insects. Sequence comparison of the amplicons obtained revealed the existence of different strains/species of Phytomonas circulating among diseased palsms and fruit.
Asunto(s)
Genes Protozoarios/genética , Insectos/parasitología , Plantas/parasitología , ARN Lider Empalmado/genética , Trypanosomatina/genética , Animales , Secuencia de Bases , ADN Recombinante/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/métodos , Especificidad de la EspecieAsunto(s)
Malaria Vivax/diagnóstico , Plasmodium vivax , Animales , Brasil , Indígenas SudamericanosRESUMEN
Trypanosomatid parasites are fairly common in the latex, phloem, fruit sap, seed albumen, and even in the nectar, of many plant families. They are transmitted to the plants in the saliva of phytophagous hemipterous bugs (Insecta). Morphologically, plant trypanosomatids have no special characteristic, except perhaps a very twisted cell body. Most occur in plants as promastigotes and a few as choanomastigotes. It is still controversial whether or not they are pathogenic in lactiferous plants or fruit, but it is certain that the phloem parasites are pathogenic in coconut palms and coffee bushes. In these plants, they cause lethal diseases responsible for the destruction of many plantations in Central and South America, but fortunately nowhere else in the world. Probably more than one genus of Trypanosomatidae is represented among the plant parasites. The most important is certainly Phytomonas, but Leptomonas, Crithidia and Herpetomonas may also be present. The distinction between them is difficult and only recently have molecular markers become available to help in their identification. At present, Phytomonas can be identified by DNA hybridization with a specific probe (SL3') complementary to a sequence of the mini-exon or spliced leader gene. The development of a polymerase chain reaction coupled to SL3' hybridization has facilitated the detection of Phytomonas in plants. The phylogeny of Phytomonas is still being worked out. For the moment it can only be said that the genus is very close to Herpetomonas.