RESUMO
Two of 19 roe deer (Capreolus capreolus) in northern Spain were infested with Cephenemyia stimulator and one individual with Oestrus ovis. Three larvae of O. ovis were recovered from the nasopharynx of an adult female deer examined in February 2017, during the hunting season in the province of Burgos. The larvae were identified by morphology, and DNA sequencing from cytochrome oxidase subunit I and 28S rDNA confirmed the identification of both species of larvae. The possibility of O. ovis parasitizing roe deer should be considered in the diagnosis of nasal bots in cervids.
RESUMO
Phylogenetic relationships among the mammal-parasitic lungworms (Metastrongyloidea) were inferred using small- and large-subunit ribosomal DNA sequences together with 12S ribosomal mtDNA sequences. Maximum parsimony and Bayesian inference methods were used from optimal alignments and those filtered for alignment ambiguity. Analysis of 30 ingroup sequences using ribosomal DNA sequences yielded a single most parsimonious tree. Monophyly of the Metastrongyloidea was supported, but there was no support for monophyly of any of the 7 families as they have been traditionally defined. Parafilaroides decorus, an abursate lungworm of pinnipeds currently classified in the Filaroididae, was nested within a clade containing members of the Pseudaliidae, parasites of cetaceans. The tree also shows clades somewhat resembling the traditional familial divisions of the Metastrongyloidea, but in all groups, paraphyletic relationships were recovered. In a combined analysis of nuclear rDNA and 12S mtDNA, maximum parsimony and Bayesian analyses showed similar patterns to those observed with only nuclear rDNA sequences. Based on the phylogeny, the respiratory tract was inferred to be the ancestral predilection site for Metastrongyloidea, with multiple evolutionary invasions of extrapulmonary sites such as sinuses, circulatory system, and meninges. Similarly, the ancestral host was inferred to be a carnivore with subsequent colonization events into marsupial, rodent, artiodactyl, pinniped, and cetacean hosts.
Assuntos
Carnívoros , Metastrongyloidea , Animais , Teorema de Bayes , DNA Mitocondrial/genética , DNA Ribossômico/genética , FilogeniaRESUMO
Protrelleta floridana Chitwood, 1932 and Cranifera cranifera (Chitwood, 1932) (Oxyuridomorpha: Thelastomatoidea: Protrelloididae, Thelastomatidae) are recorded for the first time in Cuba. These nematodes were found to parasitize the cockroach Blaberus discoidalis Serville (Blattaria: Blaberidae), constituting a new host record for them. Both species are redescribed with the aid of scanning electron microscopy and the arrangement of the copulatory papillae of the males of P. floridana is amended. The present specimens coincide in their morphology and most of the measurements with the type populations from USA and the records from Costa Rica, with only minor differences. The molecular phylogeny was inferred by mean of the D2-D3 domain of the 28S rDNA and the Cuban P. floridana and C. cranifera form monophyletic clades with sequences of both taxa from Costa Rica as well as a sequence of C. cranifera from Russia. In the case of C. cranifera its phylogeny and that of its blaberid hosts reveal coevolutionary relationships.
Assuntos
Baratas , Nematoides , Oxyurida , Parasitos , Masculino , Animais , Baratas/parasitologia , Cuba , DNA Ribossômico , FilogeniaRESUMO
Buzionema lutgardae n. sp. (Nematoda: Oxyuridomorpha: Thelastomatidae) is described from the cockroach Byrsotria sp. (Blattaria: Blaberidae), endemic to Cuba. Females of B. lutgardae n. sp. are shorter than those of B. validum Kloss, 1966 (16002150 µm vs. 31313378 µm), but the oesophagus is comparatively longer (b = 2.963.77 vs. 4.654.87). The lateral alae of the new species extend from ca. the midpoint of the cylindrical part of the procorpus to the level of the anus in contrast to the base of the basal bulb to the level of the anus in B. validum. The males of B. lutgardae n. sp. are shorter than those of B. validum (780940 µm vs. 11771423 µm) and their lateral alae end at some distance before the cloaca instead the level of the cloaca in B. validum. The phylogeny of B. lutgardae n. sp. is inferred by the D2-D3 domains of the 28S rDNA. B. lutgardae n. sp. and B. validum form a monophyletic clade with strong nodal support, as sister-group of the genus Leidynema Schwenck in Travassos, 1929.
Assuntos
Baratas/parasitologia , Oxyurida/anatomia & histologia , Oxyurida/classificação , Animais , Cuba , DNA Ribossômico , Feminino , Masculino , FilogeniaRESUMO
Three new genera and three new species of hystrignathid nematodes were collected from the hindgut of passalid beetles in the Yunnan Province, China. Huntia morffei gen. n. et sp. n. from Ceracupes fronticornis (Westwood) differs from related genera in the shape of the stoma, in the cephalic structure, and in the lack of annulation in the cervical region. Parakongonema sinica gen. n. et sp. n. from Aceraius grandis (Burmeister) and C. fronticornis can be easily distinguished from related genera in having the oral opening surrounded by a cuticular ring, the ring being surrounded by a cuticular flap, in the shape of the oesophagus, and in the cephalic structure. Parahystrignathus tongbiguanensis gen. n. et sp. n. from C. fronticornis and A. grandis differs from related genera by having the cervical region armed with alternating rows of spines, with 16 spines in the first row, and by lacking the first cephalic annule. In addition, the 18S and 28S rDNA partial sequences of three new species were obtained. The phylogeny of Hystrignathidae was inferred using partial sequences of the 28S rDNA and revealed patterns that suggest that the shape of the parasite digestive tract may reflect the evolutionary relationships of hystrignathid nematodes.
Assuntos
Besouros , Nematoides , Animais , China , Besouros/genética , Insetos , Nematoides/genética , FilogeniaRESUMO
Aoruroides chubudaigaku n. sp. (Nematoda: Oxyuridomorpha: Thelastomatidae) is described from the wood-burrowing cockroach Panesthia angustipennis spadica (Shiraki, 1906) (Blattodea: Blaberidae: Panesthiinae) from Aichi prefecture, Japan. Females of A. chubudaigaku n. sp. are similar to A. costaricensis Carreno Tuhela, 2011 by the position of the nerve ring at level of the first third of the isthmus, the body length and the comparative measurements of the oesophagus and tail. They differ by the position of the excretory pore and the vulva. The males of A. chubudaigaku n. sp. are characterized by the absence of ornamentations in the cervical cuticle and the nerve ring located at the posterior third of the corpus. In addition, the males of the new species can be differentiated by the length of the body and the comparative lengths of the oesophagus and the tail. The phylogeny of A. chubudaigaku n. sp. is inferred by the D2-D3 domains of the LSU rDNA and the validity of the genus Aoruroides Travassos Kloss, 1958 is discussed on the basis of both molecular and morphological data. This constitutes the first species of the genus Aoruroides described from the Japanese archipelago.
Assuntos
Baratas , Nematoides , Parasitos , Animais , Feminino , Japão , Masculino , Filogenia , MadeiraRESUMO
The females of Xyo pseudohystrix Travassos Kloss, 1958 (Nematoda: Oxyuridomorpha: Hystrignathidae) are redescribed and illustrated with the aid of SEM. New features of the cephalic end, arrangement of the cervical spines and genital tract were observed. The taxonomic status of the species is discussed on the basis of discrepancies with the generic diagnosis of Xyo Cobb, 1898. Due to the lack of proper information on the genus the status of incertae sedis is proposed. The identity of the males was confirmed by molecular studies and the morphology of the specimens previously assigned by Christie (1932) as males of Hystrignathus rigidus Leidy, 1858 correspond to the current species. New locality records are given for the states of Georgia and Ohio, USA. The phylogenetic position of the species is inferred on the basis of the D2-D3 segment of the LSU rDNA and SSU rDNA.
Assuntos
Besouros , Nematoides , Animais , DNA Ribossômico , Feminino , Georgia , Masculino , Ohio , FilogeniaRESUMO
Blattophila peregrinata Carreno, 2017 (Nematoda: Oxyuridomorpha: Thelastomatidae) is proposed as a junior synonym of Suifunema peregrinatum (Carreno, 2017) n. comb., based on the revision of the type material of S. caudelli Chitwood, 1932, the type and only species of the genus. The revision permitted the emendation of some features of the original descriptions, namely the position of the nerve ring at level of the corpus instead the isthmus and the female genital tract didelphic-prodelphic instead didelphic-amphidelphic. The males of S. peregrinatum n. comb. are the only ones known for the genus. Thus, an amended generic diagnosis is given, including information on the males. Both S. peregrinatum n. comb. and S. caudelli differ by having a more slender body, a longer tail, and the vulva farther from the anterior end in the former. S. peregrinatum n. comb. is recorded for the first time from Pycnoscelus indicus Fabricius, 1775 (Blattodea: Blaberidae) from Japan. The specimens from Japan are morphologically consistent with other populations of the species from the USA and the Galapagos Islands of Ecuador. Only some morphometrics vary slightly, but these are within the range of the species. The phylogenetic position of the genus among the family Thelastomatidae is discussed, including sequences of the D2-D3 LSU rDNA of specimens from both the type population (Ohio, USA) and Japan.
Assuntos
Nematoides , Animais , Equador , Feminino , Japão , Masculino , Ohio , FilogeniaRESUMO
A die-off occurred in a captive colony of blue-winged grasshoppers (Tropidacris collaris) at the Toronto Zoo. One fourth of the colony died within a year due to infection with worms initially mistaken for nematomorphs but later identified as nematodes belonging to the Mermithidae, genus Mermis. Mortality persisted and the grasshopper population dwindled over the following years. Mermithid larvae developed in the hemocoel of the insects until they eventually emerged from a hollowed-out exoskeleton. Circumstantial evidence suggests that the parasites were introduced with raspberry browse that was grown on site and contaminated with mermithid eggs.
Assuntos
Gafanhotos/parasitologia , Interações Hospedeiro-Parasita , Mermithoidea/patogenicidade , Animais , Animais de Zoológico/parasitologia , Surtos de Doenças/veterinária , Mermithoidea/crescimento & desenvolvimentoRESUMO
Thelastomatoid nematodes from the hindguts of several species of insects were collected in 4 localities in Mississippi, U.S.A. Protrellus browni n. sp. is described from Ischnoptera deropeltiformis (Blattaria: Ectobiidae) using light and scanning electron microscopy. This species is distinguished on the basis of its large size as well as its large eggs having one broad end tapering toward the opposite pole and with the presence of small spines on part of the shell. Protrellus aurifluus (Chitwood, 1932) Basir, 1956 was found in Parcoblatta fulvescens (Blattaria: Ectobiidae). Four other species of blattarians sampled were negative for pinworms. Additional nematodes recovered from other hosts included Zonothrix columbianus Adamson Buck 1989 (Thelastomatoidea: Pseudonymidae) from Tropisternus blatchleyi blatchleyi and Tropisternus collaris (Coleoptera: Hydrophilidae), Hystrignathus rigidus Leidy, 1850 and Xyo pseudohystrix Travassos Kloss, 1958 (Thelastomatoidea: Hystrignathidae) from Odontotaenius disjunctus (Coleoptera: Passalidae). These findings include several new host and geographical records.
Assuntos
Blattellidae , Enterobius , Nematoides , Animais , Enterobius/isolamento & purificação , Insetos , Mississippi , ÓvuloRESUMO
Two new species of thelastomatid nematodes parasitic in the hindgut of cockroaches are described. Hammerschmidtiella keeneyi n. sp. is described from a laboratory colony of Diploptera punctata (Eschscholtz, 1822) from a facility in Ohio, U. S. A. This species is characterized by having females with a short tail and males smaller than those described from other species. The new species also differs from others in the genus by a number of differing measurements that indicate a distinct identity, including esophageal, tail, and egg lengths as well as the relative position of the excretory pore. Blattophila peregrinata n. sp. is described from Periplaneta australasiae (Fabricius, 1775) and Pycnoscelus surinamensis (Linnaeus, 1758) in a greenhouse from Ohio, U.S.A. and from wild P. surinamensis in southern Florida, U.S.A. This species differs from others in the genus by having a posteriorly directed vagina, vulva in the anterior third of the body, no lateral alae in females, and eggs with an operculum. In P. surinamensis from southern Florida, an additional species, Severianoia annamensis Van Luc & Spiridonov, 1993 was found and did not co-parasitize the host with B. peregrinata n. sp. Blattophila peregrinata n. sp. and S. annamensis also occur in the Galápagos Islands, Ecuador, indicating that these have a widespread global range.
Assuntos
Baratas , Oxyurida , Animais , Equador , Feminino , Florida , Masculino , Nematoides , Ohio , ÓvuloRESUMO
The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.
Assuntos
Babesia/classificação , Babesiose/parasitologia , Animais , Babesia/genética , Babesia/ultraestrutura , Sequência de Bases , DNA de Protozoário/imunologia , DNA Espaçador Ribossômico/genética , Genes de Protozoários , Humanos , Microscopia Eletrônica , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , RNA de Protozoário/genética , RNA Ribossômico 18S/genéticaRESUMO
Small piroplasms as a cause of canine babesiosis have usually been identified as Babesia gibsoni. Recent genetic studies suggested that small piroplasms are more likely comprised of at least three genotypically distinct species. In southern California, canine babesiosis caused by a small piroplasm has been documented since 1990. Morphological characteristics of this parasite include a small (0.3-3.0 microm) intraerythrocytic merozoite stage with predominantly ring, piriform, tetrad, amoeboid, or anaplasmoid forms. Transmission electron microscopic images of merozoites demonstrate the presence of an apical complex consisting of an inner subplasmalemmal membrane and rhoptries. Based on phylogenetic analyses of the 18S rRNA and the ITS-2 genes, the Californian small piroplasm isolate is more closely related to piroplasm isolates from wildlife and humans in the western United States than it is to B. gibsoni. Molecular and morphologic evidence supports naming the small piroplasm from southern California as a distinct species, Babesia conradae.
Assuntos
Babesia/classificação , Babesia/isolamento & purificação , Babesiose/veterinária , Doenças do Cão/parasitologia , Eritrócitos/parasitologia , Animais , Babesia/genética , Babesia/ultraestrutura , Babesiose/parasitologia , California , Primers do DNA/química , DNA de Protozoário/química , DNA Ribossômico/química , DNA Espaçador Ribossômico/genética , Cães , Eritrócitos/patologia , Microscopia Eletrônica de Transmissão/veterinária , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 18S/genéticaRESUMO
Skrjabingylus santaceciliae n. sp. is described based on specimens from the frontal sinuses of a hooded skunk, Mephitis macroura, collected from the Area de Conservación Guanacaste, Costa Rica. Skrjabingylus santaceciliae n. sp. differs from the other 5 species in the genus in having pointed spicule tips that lack a rounded or lobed formation and by lacking a prominent distal projection at the tail tip. Morphometric comparisons show that S. santaceciliae n. sp. is much smaller than the only other valid species from Mephitis, Skrjabingylus chitwoodorum Hill, 1939. Likewise, morphometric comparisons also distinguish S. santaceciliae n. sp. from other described Skrjabingylus species.
Assuntos
Seio Frontal/parasitologia , Mephitidae/parasitologia , Metastrongyloidea/classificação , Infecções por Strongylida/veterinária , Animais , Costa Rica , Feminino , Masculino , Metastrongyloidea/anatomia & histologia , Metastrongyloidea/isolamento & purificação , Metastrongyloidea/ultraestrutura , Microscopia Eletrônica de Varredura/veterinária , Infecções por Strongylida/parasitologiaRESUMO
The thelastomatoid pinworm fauna (Nematoda: Oxyurida: Thelastomatoidea) was surveyed in 3 endemic species and 6 introduced species of cockroach hosts (Insecta: Blattaria) in the Galápagos Islands, Ecuador. A total of 658 host specimens were examined from preserved collections that had been collected between 1966 and 2003 from 7 islands in the archipelago. Eight species of pinworms were identified from these cockroach hosts, including the dominant species Cephalobellus ovumglutinosus and a Severianoia sp. as well as Leidynema appendiculata, Hammerschmidtiella diesingi, an unidentified Cephalobellus species resembling Cephalobellus magalhaesi, an unidentified Protrellus species closely resembling Protrellus shamimi, and an undescribed Blattophila sp. Five new host records are identified for C. ovumglutinosus including the endemic Galápagos cockroaches Chorisoneura carpenteri, Ischnoptera snodgrassii, and Ischnoptera santacruzensis. These endemics were also infected with an undescribed Blatticola sp. Other species recorded resemble known pinworms from other hosts around the world. Prevalence between islands and between host species was variable, but total prevalence for individual pinworm species was consistently low (<10%). A single host specimen examined was infected with more than 1 pinworm species; otherwise only a single species was observed in each infected host. At least 1 introduced pinworm species carried to the islands via invasive cockroach hosts was present in endemic host species, but several globally widespread introduced pinworm species were absent from endemic cockroaches. Santa Cruz was inhabited by the greatest number of pinworm species, likely due to a higher rate of invasive host introduction. This survey, the first from this region, showed that the distribution and transmission of pinworms in the Galápagos Islands is complex and may provide future models of invertebrate dispersal and speciation in an ecosystem already rich with examples of evolution.
Assuntos
Baratas/parasitologia , Oxyurida/classificação , Animais , Evolução Biológica , Equador , Feminino , Espécies Introduzidas , Masculino , Oxyurida/anatomia & histologia , Oxyurida/isolamento & purificaçãoRESUMO
Phylogenetic relationships among six isolates of Halicephalobus gingivalis (Stefanski, 1954), a species with pathogenic potential in horses and humans, were evaluated using DNA sequences from the nuclear large-subunit ribosomal RNA (LSU rDNA) gene. Sequences from nematodes obtained from in vitro cultures (soil or clinical sources), or isolated from infected horse tissues, were compared. Gene sequences from a fatal equine clinical case from southern California and a free-living isolate recovered from southern California soil showed no fixed differences. Sequences from isolates representing two fatal equine cases from North America, one from Ontario, Canada and another from Tennessee also showed no fixed differences. In contrast, two equine cases from Tennessee had 18 fixed differences for this LSU region, the greatest observed among isolates from horses. Phylogenetic analysis of six Halicephalobus sequences and four outgroup taxa by maximum parsimony yielded one tree with five well-supported clades. This phylogeny did not group isolates of Halicephalobus strictly by region of geographic isolation or source of sample, and depicted one clinical and one soil isolate as sister taxa. These results confirm that free-living environmental isolates are potential sources of infection for horses. The phylogeny also reveals that diverse isolates can cause infections in horses within a relatively limited geographic region, and conversely that genetically similar sister taxa can be recovered from geographically distant localities. PCR primers that selectively amplify Halicephalobus DNA were designed and tested based on comparison of closely related nematodes as inferred from phylogenetic analysis.
Assuntos
Doenças dos Cavalos/diagnóstico , Infecções Oportunistas/veterinária , Infecções por Rhabditida/veterinária , Rabditídios/classificação , Solo/parasitologia , Animais , Sequência de Bases , DNA de Helmintos/genética , DNA Ribossômico/genética , Doenças dos Cavalos/parasitologia , Cavalos , Dados de Sequência Molecular , Infecções Oportunistas/diagnóstico , Infecções Oportunistas/parasitologia , Filogenia , Reação em Cadeia da Polimerase/métodos , Rabditídios/genética , Infecções por Rhabditida/diagnóstico , Infecções por Rhabditida/parasitologia , Alinhamento de SequênciaRESUMO
Phylogenetic relationships among nematodes of the strongylid superfamily Metastrongyloidea were analyzed using partial sequences from the large-subunit ribosomal RNA (LSU rRNA) and small-subunit ribosomal RNA (SSU rRNA) genes. Regions of nuclear ribosomal DNA (rDNA) were amplified by polymerase chain reaction, directly sequenced, aligned, and phylogenies inferred using maximum parsimony. Phylogenetic hypotheses inferred from the SSU rRNA gene supported the monophyly of representative taxa from each of the 7 currently accepted metastrongyloid families. Metastrongyloid taxa formed the sister group to representative trichostrongyloid sequences based on SSU data. Sequences from either the SSU or LSU RNA regions alone provided poor resolution for relationships within the Metastrongyloidea. However, a combined analysis using sequences from all rDNA regions yielded 3 equally parsimonious trees that represented the abursate Filaroididae as polyphyletic, Parafilaroides decorus as the sister species to the monophyletic Pseudaliidae, and a sister group relationship between Oslerus osleri and Metastrongylus salmi. Relationships among 3 members of the Crenosomatidae, and 1 representative of the Skrjabingylidae (Skrjabingylus chitwoodorum) were not resolved by these combined data. However, members of both these groups were consistently resolved as the sister group to the other metastrongyloid families. These relationships are inconsistent with traditional classifications of the Metastrongyloidea and existing hypotheses for their evolution.
Assuntos
DNA Ribossômico/química , Metastrongyloidea/classificação , Metastrongyloidea/genética , Filogenia , RNA Ribossômico/genética , Animais , Sequência de Bases , DNA de Helmintos/química , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA de Helmintos/genética , Alinhamento de SequênciaRESUMO
A species of Ashworthius is reported for the first time in the Western Hemisphere, and A. patriciapilittae n. sp. is described on the basis of specimens in white-tailed deer Odocoileus virginianus from Costa Rica. Among 8 known species, A. patriciapilittae is morphologically similar to A. tuyenquangi in red muntjac Muntjacas muntjak from northern Vietnam. The synlophe in A. patriciapilittae is composed of 26 ridges in the cervical zone and is continuous to the caudal extremity in males and females. Males are characterized by a complex dorsal ray and narrow trifurcate spicules (351-356 microm long) lacking an "eyelet." with dissimilar ventral and dorsal processes; the gubernaculum is 45-48% of the spicule length. Females have a prominent linguiform flap at the vulva and large eggs (108-142 microm long). The presence of A. patriciapilittae in Costa Rica is examined in the context of competing hypotheses for cospeciation or contemporary host-switching in cervids: either A. patriciapilittae is a component of an endemic Central and South American fauna that has diversified through coevolution of Ashworthius and cervid hosts or it has been introduced. Among haemonchines in the Western Hemisphere, specimens of A. patriciapilittae may be confused with 3 species of Haemonchus, including H. contortus, H. placei, and H. similis, that occur in both domestic and wild ruminants. Discovery of A. patriciapilittae emphasizes the continued need for survey and inventory to define the structure and distribution of parasite faunas in wild and domestic ruminants from the Nearctic and Neotropical regions.
Assuntos
Cervos/parasitologia , Trichostrongyloidea/classificação , Tricostrongiloidíase/veterinária , Abomaso/parasitologia , Animais , Costa Rica , Feminino , Masculino , Microscopia de Interferência/veterinária , Trichostrongyloidea/anatomia & histologia , Tricostrongiloidíase/parasitologiaRESUMO
Cryptosporidium parvum oocysts were stored in 1-ml aliquots of filtered river water at -20, 4, 10, and 21-23 C in the dark. Oocysts were also added to filter-sterilized river water samples and stored at 21-23 C. The infectivity of oocysts stored under different conditions was assayed at weekly intervals through infection of human adenocarcinoma ileocecal (HCT-8) cell monolayers. Wells containing between 10 and 100 foci of infection were enumerated by immunofluorescent microscopy, and the number of infective oocysts was calculated. No infectious oocysts were detected after 1 wk at -20 C. The number of infective oocysts stored at 4 C decreased 5-fold, and the number of those stored at 10 C decreased 2.5-fold after 14 wk. The infectivity of oocysts stored in potassium dichromate (positive control) at 4 C decreased 2-fold over 14 wk. The number of infective oocysts in filter-sterilized and non-filter-sterilized river water stored at 21-23 C decreased by 3.3 and 2.6 log units, respectively, over 12 wk, and no foci of infection were detected at 14 wk. The results show that as temperature increased from 4 to 23 C, the duration of oocyst infectivity decreased.
Assuntos
Cryptosporidium parvum/patogenicidade , Água Doce/parasitologia , Animais , Temperatura Baixa , Criptosporidiose/parasitologia , Cryptosporidium parvum/crescimento & desenvolvimento , Corantes Fluorescentes/química , Humanos , Microscopia de Fluorescência , Ontário , Células Tumorais Cultivadas , Abastecimento de ÁguaRESUMO
The nematode order Oxyurida is unique in including species for which definitive host ranges are broad and may include vertebrate or invertebrate hosts. The superfamily Thelastomatoidea is a highly diverse assemblage of oxyurids occurring in cockroaches, diplopods, hydrophilid beetles, passalid beetles, several other coleopteran larvae, mole crickets, and, with few representative species documented, other arthropod hosts. Published research and revision of the Thelastomatoidea, particularly in the 1980s and 1990s, provided several interesting hypotheses on the systematics and evolution of this group. In this review, these hypotheses are examined in the context of recent advances in taxonomy, discovery of additional species diversity and distribution, and preliminary phylogenetic hypotheses that have been proposed. There continues to remain a paucity of phylogenetic data that explore the phylogenetic relationships of the Thelastomatoidea and their relationships to vertebrate-parasitizing pinworms. A combination of mitochondrial and nuclear DNA sequences for representative species across all of the major lineages will be important for more robust phylogenetic hypotheses. Much broader geographical and host taxon sampling is necessary to determine true diversity of the Thelastomatoidea. Modern approaches to species descriptions, such as improvements in light and scanning electron microscopy and the use of molecular approaches to matching male and female nematodes, can also be applied to improve our understanding of the evolution of these fascinating parasites.