RESUMO
This paper provides morphological and phylogenetic analyses of two new myxobolid species found infecting Piaractus brachypomus from the Amazon basin. The fish were caught in the Tapajós River, in the municipality of Santarém, in the state of Pará, Brazil. The plasmodial development of Henneguya brachypomus n. sp. occurred in the gill lamellae while Myxobolus pirapitingae n. sp. developed in the pyloric cecum. Morphological analyses did not identify inflammatory infiltrate for either species, but H. brachypomus n. sp. induced stretching of the epithelium, compression of the adjacent tissues, and displacement and deformation of the neighboring lamellae. The mature myxospores of H. brachypomus n. sp. were ellipsoid, with a length of 11.7-13.8 µm, a width of 4.0-4.6 µm, and a thickness of 3.5-4.3 µm. The polar capsules were elongated, with a length of 5.6-7.3 µm and a width of 1.3-2.0 µm, and each contained a polar filament with 8-9 coils. The caudal process was 40.5-48.1 µm long and the total length of the myxospore was 52.4-61.6 µm. Myxobolus pirapitingae n. sp. exhibited rounded mature myxospores measuring 10.0-11.1 µm in length, 7.0-7.6 µm in width, and 5.4-6.3 µm in thickness. The polar capsules were of equal size and occupied less than half the myxospore, measuring 3.5-4.0 µm in length and 2.0-2.6 µm in width, with each containing a polar filament with 6-7 coils. Phylogenetic analysis based on partial small subunit ribosomal DNA (ssrDNA) sequences showed that H. brachypomus n. sp. clustered as a sister species of Henneguya piaractus, while M. pirapitingae n. sp. was grouped in a sub-clade together with Myxobolus matosi and Myxobolus colossomatis.
Assuntos
Doenças dos Peixes/parasitologia , Myxobolus , Myxozoa , Doenças Parasitárias em Animais/parasitologia , Animais , Brasil , Caraciformes , Feminino , Brânquias , Masculino , Tipagem Molecular , Myxobolus/classificação , Myxobolus/isolamento & purificação , Myxozoa/classificação , Myxozoa/isolamento & purificação , Filogenia , Subunidades Ribossômicas Menores , RiosRESUMO
We surveyed introduced yellow perch Perca flavescens (Mitchill, 1814) from the Willamette River, OR, USA, to determine if these fish have co-introduced myxosporean parasites. Mature parasite myxospores were observed in brains of 3/19 fish, and were morphologically and molecularly consistent with Myxobolus neurophilus (Guilford 1963), a parasite known from yellow perch in their native range. We identified another Myxobolus species from the gill filaments of 1/22 fish. The spores from the gill filaments were oval-shaped, 11.7 (10.7-12.3) µm long × 8.6 (7.7-9.0) µm wide × 5.2 (4.6-5.6) µm thick, with two oval-shaped polar capsules 5.7 (5.1-6.5) µm × 2.7 (2.4-3.2) µm, each containing a polar tubule with 8-9 turns. Small-subunit ribosomal DNA sequences from each of four plasmodia were identical, and 4.0% different (over 1800 nucleotides) from the closest known myxosporeans. Interestingly, these sequences had overlapping peaks in their chromatograms, which suggested that DNA from multiple species was present. Hence, we isolated and sequenced three individual myxospores and found that they too had mixed chromatograms, which indicated presence of at least two sequence types of small-subunit ribosomal DNA in each spore (GenBank accession MK592012, MK592013), a rare character among described myxosporeans. The spore morphology, morphometry, tissue tropism, and DNA sequence supported a diagnosis of a novel species, Myxobolus doubleae n. sp. This parasite is unknown from yellow perch in its native range, despite extensive historical surveys, which suggests that introduced yellow perch might have acquired an endemic Myxobolus species via spillback from another fish host.
Assuntos
Doenças dos Peixes/parasitologia , Myxobolus/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Percas/parasitologia , Animais , DNA de Protozoário/genética , DNA Ribossômico/genética , Brânquias/parasitologia , Filogenia , Subunidades Ribossômicas Menores/genética , Rios/parasitologia , Esporos de ProtozoáriosRESUMO
Cryptosporidiosis has been reported as an important cause of neonatal diarrhea and mortality in cattle, sheep, and other ruminants, but its impact on alpaca health has not been studied thoroughly. In this study, we have determined the prevalence and evaluated the role of cryptosporidiosis as a risk factor for diarrhea occurrence in newborn alpacas. During the calving season (January-March) of 2006, stool specimens (N = 1312) were collected from 24 herds of newborn alpacas in Puno and Cuzco, departments that account for the largest populations of alpacas in Peru. All the specimens were microscopically screened for Cryptosporidium spp. using the acid-fast technique. The association between Cryptosporidium detection and diarrhea was analyzed using χ2 test and generalized lineal model. Cryptosporidium species were determined by PCR-RFLP analysis of the small subunit rRNA gene. Cryptosporidium oocysts were detected in 159 of 1312 (12.4%) newborn alpacas. Results of the analyses demonstrated that crypstosporidiosis was significantly associated with diarrhea (PR = 3.84; CI95% 2.54-5.81; p < 0.0001). Only Cryptosporidium parvum was detected in the 153 Cryptosporidium-infected animals. Thus, there is an association of C. parvum infection with diarrhea in neonatal alpacas.
Assuntos
Camelídeos Americanos/parasitologia , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium parvum/isolamento & purificação , Diarreia/veterinária , Animais , Animais Recém-Nascidos , Cryptosporidium parvum/classificação , Cryptosporidium parvum/citologia , Cryptosporidium parvum/genética , Diarreia/epidemiologia , Diarreia/parasitologia , Fezes/parasitologia , Oocistos/citologia , Peru/epidemiologia , Prevalência , Subunidades Ribossômicas Menores/genética , Fatores de RiscoRESUMO
We investigated the involvement of oligochaetes in the life cycles of fresh water myxozoan parasites in Brazil. In a fish farm in the State of Mato Grosso do Sul, we examined 192 oligochaetes and found that two (1%) released Aurantiactinomyxon type actinospores. We identified infected oligochaetes by morphology: both were Pristina synclites, from family Naididae. This is the first report of the involvement of this species in the life cycle of myxozoans. Small-subunit ribosomal DNA sequences of Aurantiactinomyxon type 1 (1882 nt) and Aurantiactinomyxon type 2 (1900 nt) did not match any previously sequenced myxozoan in the NCBI database, with the highest BLAST search similarities of 83% with Myxobolus batalhensis MF361090 and 93% with Henneguya maculosus KF296344, respectively, and the two aurantiactinomyxons were only 75% similar to each other (over ~ 1900 bases). Phylogenetic analyses showed that Aurantiactinomyxon type 1 had closest affinities with myxozoans from fish hosts in Order Characiformes, and Aurantiactinomyxon type 2 had affinities with myxozoans from fish of Order Siluriformes.
Assuntos
Doenças dos Peixes/parasitologia , Peixes/parasitologia , Myxobolus/classificação , Myxozoa/classificação , Oligoquetos/parasitologia , Infecções Protozoárias em Animais/parasitologia , Esporos de Protozoários/classificação , Animais , Brasil , Pesqueiros , Água Doce , Estágios do Ciclo de Vida , Myxobolus/genética , Myxobolus/isolamento & purificação , Myxozoa/genética , Myxozoa/isolamento & purificação , Filogenia , Subunidades Ribossômicas MenoresRESUMO
We describe three new Henneguya spp. (Myxobolidae) found parasitizing two species of cichlid fish from the Amazon basin, Brazil: H. tucunarei n. sp. from gill filaments of Cichla monoculus and H. tapajoensis n. sp. from gill filaments of Cichla pinima, both from the Tapajós River, Pará State and H. jariensis n. sp. in the fins of Cichla monoculus from the Jari River, Amapá State. We based descriptions on myxospore morphology and small subunit ribosomal DNA sequences, and used a phylogenetic analysis to compare the new Henneguya species with known relatives. Spores of the three species had similar morphology and morphometrics, but differed molecularly 5-7.5%, and were no more than 94% similar to any other sequence in GenBank. Together with having different hosts, these data supported the diagnosis of the parasites as distinct, novel species. Maximum likelihood and Bayesian analyses showed that H. tucunarei n. sp., H. tapajoensis n. sp., and H. jariensis n. sp. plus Henneguya paraensis (which parasitizes Cichla temensis) formed a well-supported sub-clade of Henneguya parasites of cichlids from the Amazon basin, in a lineage sister to those in characiforms hosts. Our analysis was consistent with previous studies that suggest that aquatic environment and vertebrate host group are the strongest correlates with phylogenetic signals in the Myxobolidae.
Assuntos
Ciclídeos/parasitologia , Doenças dos Peixes/parasitologia , Myxozoa/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Nadadeiras de Animais , Animais , Teorema de Bayes , Brasil , Brânquias/parasitologia , Myxozoa/classificação , Filogenia , Subunidades Ribossômicas Menores , Rios , EsporosRESUMO
The genus Oxytricha Bory de Saint-Vincent in Lamouroux, Bory de Saint-Vincent and Deslongchamps, 1824 comprises about 38 species distributed worldwide and has been considered to be a nonmonophyletic group. Based on living observations, protargol preparations, and a small subunit ribosomal RNA (SSU rRNA) gene sequence, we describe a new subspecies Oxytricha granulifera chiapasensis n. subsp. This new taxon is morphologically characterized by undulating membranes basically in a Stylonychia-pattern, six dorsal kineties, size in vivo ca. 60-120 × 20-40 µm, 21-30 right and 21-31 left marginal cirri, 22-29 adoral membranelles, and spherical cortical granules arranged in longitudinal rows on the dorsal side. In terms of the SSU rRNA gene sequence, the new subspecies differs from populations of O. granulifera from GENBANK by 7-35 nucleotides. Phylogenetic analyses showed that Oxytricha granulifera gene sequences were nested into three groups, with the new subspecies included in one of them. Oxytricha granulifera chiapasensis n. subsp. is different from Oxytricha granulifera granulifera Foissner and Adam, 1983 and Oxytricha granulifera quadricirrata Blatterer and Foissner, 1988 based on: (i) undulating membranes in Stylonychia-pattern, (ii) formation of a sixth dorsal kinety during morphogenesis, (iii) the adoral membranelles number, and (iv) inhabiting freshwater habitats.
Assuntos
Lagos/parasitologia , Oxytricha/classificação , DNA de Protozoário/genética , DNA Ribossômico/genética , Ecossistema , México , Oxytricha/genética , Oxytricha/isolamento & purificação , Filogenia , Subunidades Ribossômicas Menores/genéticaRESUMO
A new species of Synthesium from the bottlenose dolphin Tursiops truncatus in South Brazilian waters is described. Morphological and molecular identification was performed, and phylogenetic analyses were carried out using the ribosomal small subunit and internal transcribed spacer 1 and the mitochondrial NDH dehydrogenase subunit 3 and cytochrome c oxidase subunit 1 genes. The main characteristics of the new species are the subterminal round-shaped oral sucker, the anterior distribution of vitellaria reaching the level of the ovary and the oval-shaped testes. The results obtained with the molecular markers supported the inclusion of the specimens into the genus Synthesium. The nucleotide divergence detected for the mitochondrial genes among the new species and others of the same genus supported the erection of a new species. This is the ninth species assigned to the genus and the third Synthesium species recorded in the South Atlantic Ocean.
Assuntos
Golfinho Nariz-de-Garrafa/parasitologia , Trematódeos/classificação , Trematódeos/isolamento & purificação , Infecções por Trematódeos/veterinária , Animais , Oceano Atlântico , Brasil , Desidrogenases de Carboidrato/genética , DNA Intergênico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Masculino , Filogenia , Subunidades Ribossômicas Menores/genética , Trematódeos/genética , Infecções por Trematódeos/parasitologiaRESUMO
In a survey of myxozoan parasites of ornamental freshwater fish from the Rio Negro river, it was found that seven of 30 (23.3 %) Corydoras melini specimens examined had plasmodia of a new Myxidium species (Myxidium amazonense n. sp.) in the gallbladder. The fish were caught in the Rio Negro river, in the municipality of Santa Isabel do Rio Negro, in the state of Amazonas, Brazil. The plasmodia had a tubular shape, which was organized as a spiral spring with several turns in the gallbladder. The development of the myxospores was asynchronic, with disporic pansporoblasts. Mature myxospores were elongated, with 17.0 ± 0.9 (16.1-17.9) µm in length and 3.7 ± 0.7 (3.0-4.4) µm in width, and lightly arcuate from the valval view, with their bodies tapering slowly until ending in rounded extremities. The valval surface had nine to ten grooves in each valve. The polar capsules, one at either end of the spore, had a length of 5.4 ± 0.5 (4.9-5.9) µm and a width of 3.4 ± 0.6 (2.8-4.0) µm. Ultrastructural analysis showed that the wall of the plasmodia had numerous microvilli-like structures, pinocytotic canals, and cytoplasmic bridges connecting the pansporoblasts to each other and to the ectoplasm zone. Phylogenetic analysis, based on a small subunit ribosomal RNA (ssrRNA), identified the new species as a sister species of Myxidiumceccarelli, the unique South American Myxidium species whose ssrRNA sequence is available in the NCBI database. This study is the first description of Myxidium species in ornamental freshwater fish from Amazon.
Assuntos
Doenças dos Peixes/parasitologia , Myxozoa/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Subunidades Ribossômicas Menores/genética , Animais , Sequência de Bases , Brasil , Peixes-Gato/parasitologia , Vesícula Biliar/parasitologia , Dados de Sequência Molecular , Myxozoa/classificação , Myxozoa/genética , Myxozoa/ultraestrutura , Filogenia , Rios/parasitologia , Esporos/classificação , Esporos/genética , Esporos/isolamento & purificação , Esporos/ultraestruturaRESUMO
During a survey of myxozoan parasites of freshwater fish from the São Francisco River in Minas Gerais State, Brazil, plasmodia of Myxidium ceccarellii n. sp. were found in gallbladders of two out of six specimens (22%) of Leporinus elongatus (Anastomidae). Parasite plasmodia were translucent and greenish, with disporic sporoblasts that develop asynchronously. Mature myxospores were ellipsoidal in frontal and lateral views, with slightly pointed ends. The surfaces of each valve had four to six longitudinal grooves. Spores dimensions were as follows: length 17.7 ± 0.5 µm (17.1-18.1), width 10.4 ± 0.47 µm (9.8-11.3), and thickness 10.1 ± 0.27 µm (9.6-10.4). Two polar capsules, one at either end of the spore, had the length of 6.3 ± 0.5 µm (5.7-7.0) and width of 6.4 ± 0.44 µm (5.7-6.9), with four to five polar filament turns. Some aberrant spores had one or three polar capsules. Partial sequencing of M. ceccarellii n. sp. small subunit ribosomal RNA (ssrRNA) gene resulted in 1,845 bp. This is the first molecular study of a Myxidium species that parasitizes a South American freshwater fish. Phylogenetic reconstruction using ssrRNA gene sequences showed that M. ceccarellii n. sp. was positioned basally in a recognized clade of myxozoans that infect the biliary systems of nonfish vertebrates.
Assuntos
Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Vesícula Biliar/parasitologia , Doenças Parasitárias em Animais/parasitologia , Filogenia , RNA Ribossômico/classificação , Animais , Brasil , Myxozoa/ultraestrutura , RNA Ribossômico/genética , Subunidades Ribossômicas Menores/genética , Rios , Análise de Sequência de DNA , Esporos/genética , Esporos/ultraestruturaRESUMO
We comparatively examined the nutritional, molecular and optical and electron microscopical characteristics of reference species and new isolates of trypanosomatids harboring bacterial endosymbionts. Sequencing of the V7V8 region of the small subunit of the ribosomal RNA (SSU rRNA) gene distinguished six major genotypes among the 13 isolates examined. The entire sequences of the SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) genes were obtained for phylogenetic analyses. In the resulting phylogenetic trees, the symbiont-harboring species clustered as a major clade comprising two subclades that corresponded to the proposed genera Angomonas and Strigomonas. The genus Angomonas comprised 10 flagellates including former Crithidia deanei and C. desouzai plus a new species. The genus Strigomonas included former Crithidia oncopelti and Blastocrithidia culicis plus a new species. Sequences from the internal transcribed spacer of ribosomal DNA (ITS rDNA) and size polymorphism of kinetoplast DNA (kDNA) minicircles revealed considerable genetic heterogeneity within the genera Angomonas and Strigomonas. Phylogenetic analyses based on 16S rDNA and ITS rDNA sequences demonstrated that all of the endosymbionts belonged to the Betaproteobacteria and revealed three new species. The congruence of the phylogenetic trees of trypanosomatids and their symbionts support a co-divergent host-symbiont evolutionary history.
Assuntos
Betaproteobacteria/classificação , Betaproteobacteria/genética , Simbiose , Trypanosomatina/classificação , Trypanosomatina/genética , Sequência de Bases , Betaproteobacteria/isolamento & purificação , Betaproteobacteria/ultraestrutura , Evolução Biológica , Código de Barras de DNA Taxonômico/métodos , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Intergênico/química , DNA Intergênico/genética , DNA de Cinetoplasto/química , DNA de Cinetoplasto/genética , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Funções Verossimilhança , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Filogenia , Polimorfismo Genético , RNA Ribossômico 16S/genética , Subunidades Ribossômicas Menores/genética , Análise de Sequência de DNA , Simbiose/genética , Trypanosomatina/isolamento & purificação , Trypanosomatina/ultraestruturaRESUMO
Paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause DNA degradation. In this study, a PCR protocol was applied to identify Leishmania strains in 33 paraffin-embedded skin samples of patients with American cutaneous leishmaniasis. DNA was obtained by the phenol-chloroform protocol following paraffin removal and then used in PCR or nested PCR based on the nucleotide sequence of the small subunit ribosomal RNA (SSU rDNA). The amplicons obtained were cloned and sequenced to determine the single nucleotide polymorphism that distinguishes between different Leishmania species or groups. This assay allowed to distinguish organisms belonging to the subgenus Viannia and identify L. (Leishmania) amazonensis and L. (L.) chagasi of the Leishmania subgenus. Of the 33 samples, PCR and nested PCR identified 91% of samples. After sequencing the PCR product of 26 samples, 16 were identified as L. (L.) amazonensis, the other 10 contain organisms belonging to the L. (Viannia) sub-genus. These results open a huge opportunity to study stored samples and promote relevant contributions to epidemiological studies.
Assuntos
DNA Ribossômico/genética , Leishmania/genética , Leishmaniose Cutânea/parasitologia , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , DNA de Protozoário/análise , DNA de Protozoário/genética , DNA Ribossômico/isolamento & purificação , Leishmania/isolamento & purificação , Inclusão em Parafina , Polimorfismo de Fragmento de Restrição , RNA Ribossômico/genética , Subunidades Ribossômicas Menores , Alinhamento de Sequência , Pele/parasitologia , Fatores de TempoRESUMO
We sequenced the small subunit (SSU) rRNA and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) genes of two trypanosomes isolated from the Brazilian snakes Pseudoboa nigra and Crotalus durissus terrificus. Trypanosomes were cultured and their morphometrical and ultrastructural features were characterized by light microscopy and scanning and transmission electron microscopy. Phylogenetic trees inferred using independent or combined SSU rRNA and gGAPDH data sets always clustered the snake trypanosomes together in a clade closest to lizard trypanosomes, forming a strongly supported monophyletic assemblage (i.e. lizard-snake clade). The positioning in the phylogenetic trees and the barcoding based on the variable V7-V8 region of the SSU rRNA, which showed high sequence divergences, allowed us to classify the isolates from distinct snake species as separate species. The isolate from P. nigra is described as a new species, Trypanosoma serpentis n. sp., whereas the isolate from C. d. terrificus is redescribed here as Trypanosoma cascavelli.
Assuntos
DNA de Protozoário/classificação , Gliceraldeído-3-Fosfato Desidrogenases/genética , Filogenia , Subunidades Ribossômicas Menores/genética , Serpentes/parasitologia , Trypanosoma/classificação , Animais , Brasil , DNA de Protozoário/análise , DNA de Protozoário/genética , Interações Hospedeiro-Parasita , Lagartos/parasitologia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , RNA Ribossômico/análise , RNA Ribossômico/classificação , RNA Ribossômico/genética , Análise de Sequência de DNA , Especificidade da Espécie , Trypanosoma/genética , Trypanosoma/ultraestruturaRESUMO
Based on molecular studies using 1760 bp of the nuSSU and 604 bp of the nuLSU rRNA genes and using morphological characters, the genera Koralionastes and Pontogeneia are assigned to the new order Koralionastetales, family Koralionastetaceae, class Sordariomycetes. Koralionastetales is a sister group to Lulworthiales; differences in morphological characters are expressed in the ascospores and the presence/absence of periphyses and paraphyses. A new species of Pontogeneia, P. microdictyi from Microdictyon sp. in the Bahamas, is described.
Assuntos
Ascomicetos/classificação , Animais , Antozoários/microbiologia , Ascomicetos/citologia , Ascomicetos/genética , Bahamas , Biologia Marinha , Oceanos e Mares , RNA Fúngico/genética , RNA Ribossômico/genética , Subunidades Ribossômicas Maiores/genética , Subunidades Ribossômicas Menores/genéticaRESUMO
BACKGROUND: Group I introns are found in the nuclear small subunit ribosomal RNA gene (SSU rDNA) of some species of the genus Porphyra (Bangiales, Rhodophyta). Size polymorphisms in group I introns has been interpreted as the result of the degeneration of homing endonuclease genes (HEG) inserted in peripheral loops of intron paired elements. In this study, intron size polymorphisms were characterized for different Porphyra spiralis var. amplifolia (PSA) populations on the Southern Brazilian coast, and were used to infer genetic relationships and genetic structure of these PSA populations, in addition to cox2-3 and rbcL-S regions. Introns of different sizes were tested qualitatively for in vitro self-splicing. RESULTS: Five intron size polymorphisms within 17 haplotypes were obtained from 80 individuals representing eight localities along the distribution of PSA in the Eastern coast of South America. In order to infer genetic structure and genetic relationships of PSA, these polymorphisms and haplotypes were used as markers for pairwise Fst analyses, Mantel's test and median joining network. The five cox2-3 haplotypes and the unique rbcL-S haplotype were used as markers for summary statistics, neutrality tests Tajima's D and Fu's Fs and for median joining network analyses. An event of demographic expansion from a population with low effective number, followed by a pattern of isolation by distance was obtained for PSA populations with the three analyses. In vitro experiments have shown that introns of different lengths were able to self-splice from pre-RNA transcripts. CONCLUSION: The findings indicated that degenerated HEGs are reminiscent of the presence of a full-length and functional HEG, once fixed for PSA populations. The cline of HEG degeneration determined the pattern of isolation by distance. Analyses with the other markers indicated an event of demographic expansion from a population with low effective number. The different degrees of degeneration of the HEG do not refrain intron self-splicing. To our knowledge, this was the first study to address intraspecific evolutionary history of a nuclear group I intron; to use nuclear, mitochondrial and chloroplast DNA for population level analyses of Porphyra; and intron size polymorphism as a marker for population genetics.