Dipetalonema graciliformis (Freitas, 1964) from the red-handed tamarins (Saguinus midas, Linnaeus, 1758) in French Guiana.

Six Dipetalonema species have been reported from Neotropical monkeys, Dipetalonema gracile, Dipetalonema graciliformis and Dipetalonema caudispina being the dominant species found in French Guiana primates. Adult filarioids isolated from the abdominal cavity of tamarins (Saguinus midas) in French Guiana were morphologically and molecularly identified as D. graciliformis. Phylogenetic analysis based on DNA and amino acid sequences of the cox1 gene as well as the concatenated sequences of the cox1 and the 18S genes indicated that D. graciliformis belongs to the clade 4 (ONC4) of Onchocercidae. Blast analysis of the 18S rDNA revealed that D. graciliformis in the studied tamarins is conspecific with the filarioid circulating in howler monkeys (Alouatta macconnelli) in French Guiana, previously referred to as unidentified Onchocercidae species.

Co-infection with filarial nematodes in Sapajus macrocephalus and Cebus albifrons (Primates: Cebidae) from the Peruvian Amazon.

Dipetalonema caudispina (Molin, 1858) and D. gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) are two of six known species of filarial nematodes that parasitize Neotropical non-human primates. Adult filariae were collected from the thoracic and abdominal cavities of 38 of 44 specimens of Sapajus macrocephalus (Spix, 1823) and nine of ten specimens of Cebus albifrons (Humboldt, 1812) (Primates: Cebidae), distributed in the Yavarí-Mirín river basin and used locally for human consumption. Co-occurrence of D. caudispina and D. gracile is reported for the first time, with a prevalence of 18.5% (10 of 54 hosts examined). Our finding of D. caudispina and D. gracile in cebids from the Peruvian Amazon constitutes a new geographical record for both filariae, two new host records for D. caudispina, and the first report of D. gracile in S. macrocephalus. In addition, we provide morphometric data for D. caudispina, complementing the original description, as well as scanning electron microscopy details on the structure of the area rugosa and number of caudal papillae in males.

The mitochondrial genome of Dipetalonema gracile from a squirrel monkey in China.

Dipetalonema gracile is a common parasite in squirrel monkeys (Saimiri sciureus), which can cause malnutrition and progressive wasting of the host, and lead to death in the case of massive infection. This study aimed to identify a suspected D. gracile worm from a dead squirrel monkey by means of molecular biology, and to amplify its complete mitochondrial genome by polymerase chain reaction (PCR) and sequence analysis. The results identified the worm as D. gracile, and the full length of its complete mitochondrial genome was 13,584 bp, which contained 22 tRNA genes, 12 protein-coding genes, two rRNA genes, one AT-rich region and one small non-coding region. The nucleotide composition included A (16.89%), G (20.19%), T (56.22%) and C (6.70%), among which A + T = 73.11%. The 12 protein-coding genes used TTG and ATT as start codons, and TAG and TAA as stop codons. Among the 22 tRNA genes, only trnS1AGN and trnS2UCN exhibited the TΨC-loop structure, while the other 20 tRNAs showed the TV-loop structure. The rrnL (986 bp) and rrnS (685 bp) genes were single-stranded and conserved in secondary structure. This study has enriched the mitochondrial gene database of Dipetalonema and laid a scientific basis for further study on classification, and genetic and evolutionary relationships of Dipetalonema nematodes.

Characterization of the heartworm Acanthocheilonema spirocauda (Leidy, 1858) Anderson, 1992 (Nematoda: Onchocercidae) in Scandinavia.

The heartworm Acanthocheilonema spirocauda (Leidy, Proc Acad Nat Sci Philadelphia 10:110-112, 1858) Anderson, 1992 is described from material collected from harbour seals in Scandinavia and compared with types and other specimens described by Anderson (Can J Zool 37:481-493, 1959) from harbour seals in eastern USA. Most morphometric characters of the material from USA fall within the ranges established for the Scandinavian one. Some intraspecific variability in the organisation of papillae on the male tail was detected among the Scandinavian specimens. Differences between the specimens from Scandinavia and Eastern USA are also found in the organisation of papillae on the tail of males and females. An excretory pore was not discernible, but a clearly hemizonid-like structure is described. For the first time, scanning electron micrographs present external morphological structures of the species.

Prevalence and molecular phylogenetic characterization of Trypanosoma (Megatrypanum) minasense in the peripheral blood of small neotropical primates after a quarantine period.

Neotropical primates of the Cebidae and Callitrichidae, in their natural habitats, are frequently infected with a variety of trypanosomes including Trypanosoma cruzi, which causes a serious zoonosis, Chagas' disease. The state of trypanosome infection after a 30-day quarantine period was assessed in 85 squirrel monkeys (Saimiri sciureus) and 15 red-handed tamarins (Saguinus midas), that were wild-caught and exported to Japan as companion animals or laboratory animals, for biomedical research, respectively. In addition to many microfilariae of Mansonella (Tetrapetalonema) mariae at a prevalence of 25.9%, and Dipetalonema caudispina at a prevalence of 3.5%, a few trypomastigotes of Trypanosoma (Megatrypanum) minasense were detected in Giemsa-stained thin films of blood from 20 squirrel monkeys at a prevalence of 23.5%. Although few T. minasense trypomastigotes were found in Giemsa-stained blood films from tamarins, a buffy-coat examination detected trypanosomes in 12 red-handed tamarins (80.0%), and PCR amplification of a highly variable region of the small subunit ribosomal RNA genes (SSU rDNA) for Trypanosoma spp. detected the infection in 14 of the 15 tamarins (93.3%). Nucleotide sequences of the amplicons were identical for trypanosomes from tamarins and squirrel monkeys, indicating a high prevalence but low parasitemia of T. minasense in imported Neotropical nonhuman primates. Based on the SSU rDNA and 5.8S rDNA, the molecular phylogenetic characterization of T. minasense indicated that T. minasense is closely related to trypanosomes with Trypanosoma theileri-like morphology and is distinct from Trypanosoma (Tejeraia) rangeli, as well as from T. cruzi. Using some blood samples from these monkeys, amplification and subsequent sequencing of the glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene fragments detected 4 trypanosome genotypes, including 2 types of T. cruzi clade, 1 type of T. rangeli clade, and 1 T. rangeli-related type, but failed to indicate its phylogenetic position based on the gGAPDH gene. Furthermore, species ordinarily classified in the Megatrypanum by morphological criteria do not form a clade in any molecular phylogenetic trees based on rDNA or gGAPDH genes.

A new species of Dipetalonema (Filarioidea: Onchocercidae) from Ateles chamek from the Beni of Bolivia.

We describe a new species of Dipetalonema occurring in the body cavity of Ateles chamek (Humboldt, 1812) from north-central Bolivia. Morphologic characters serving to separate Dipetalonema yatesi n. sp. from known forms include a vagina vera with a simple tube and thin walls and a left spicule, which possesses a handle shorter than the lamina (ratio 2.7); the latter displays an anterior membranous alae similar in length to the terminal flagellum, a distal extremity of the left spicule within a simple hook and a membrane, phasmids at the basis of the lappets, and heterogeneous muscles occupying the whole cavity. Dipetalonema yatesi n. sp. can be separated from Dipetalonema robini, Dipetalonema gracile, and Dipetalonema graciliformis, between other characters, in having a simple vagina vera instead of a sinuous one, and from Dipetalonema caudispina and Dipetalonema freitasi in having the lamina of the left spicule divided in a membranous alae and a terminal flagellum.

Histochemical differentiation of Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema dracunculoides microfilariae by staining with a commercial kit, Leucognost-SP.

The diagnosis of canine heartworm infection is based upon the presence of circulating Dirofilaria immitis microfilariae or on techniques for the detection of serum antibodies or antigens. In the first of these, discrimination between D. immitis, D. repens and Acanthocheilonema dracunculoides microfilariae is based upon the acid phosphatase histochemical stain. In this paper, we propose an alternative technique for histochemical staining using a commercial kit test of naphthol-AS-OL (Leucognost-SP). This offers the advantages of speed and simplicity as compared to the standard Barka procedure.

[Imported parasites in dogs: Dirofilaria repens and Dipetalonema reconditum]. / Eingeschleppte Parasiten bei Hunden: Dirofilaria repens und Dipetalonema reconditum.

Between June 1993 and May 1996 infections with filariae were diagnosed in 80 dogs. Five animals were infected with Dirofilaria repens and three other dogs with Dipetalonema reconditum. One of the D. reconditum positive dogs was also infected with Dirofilaria immitis. An epidemiological analysis of the cases was possible for three D. repens and two D. reconditum infected dogs. Two of the dogs with D. repens infections had been imported from Italy or Greece, the third dog had been taken by its owner to Hungary and former Yugoslavia. The dogs infected with D. reconditum were imported from Corse or Spain. Regarding the other 72 dogs with filariae, 45 animals were infected with D. immitis. For 27 dogs being negative in the D. immitis ELISA, microfilariae have been demonstrated. However, a histochemical species differentiation of the microfilariae was not possible because fresh blood smears were not available.

[A 5th filaria of the genus Dipetalonema, parasite of South American monkeys]. / Une cinquième filaire du genre Dipetalonema, parasite de singes Sud-Américains.

Description of D. freitasi n. sp., a parasite of Cebus capucinus: this species, close to D. caudispina, is distinguished by the slightly more complex structure of the vagina and right spicule, the lack of area rugosa on the tail and by the shorter microfilaria. Additional morphological data on the male of D. robini Petit et al., 1985 are given. A comparative table of 4 principal evolutive characters of the genus Dipetalonema (vagina, left and right spicules, epithelio-muscular body wall) is given. D. caudispina and D. freitasi n. sp. represent a small primitive group opposed to the more evolved one made up of D. robini, D. gracile and D. graciliformis.

Acanthocheilonema sabanicolae n. sp. (Filarioidea: Onchocercidae) from the savanna armadillo (Dasypus sabanicola) in Venezuela, with comments on the genus Acanthocheilonema.

A new species of Acanthocheilonema, Acanthocheilonema sabanicolae n. sp., is described from the subcutaneous tissues of the savanna armadillo (Dasypus sabanicola) in Venezuela. The adults (females 25-30.6 mm long by 61-78 micron wide; males 10.9-15.3 mm long by 42-44 micron wide) and the microfilariae (112-131 micron long by 3-5 micron wide) are the smallest within the genus. The microfilaria, a skin dweller, assumes a characteristic C-shaped curve, when fixed in 2% formalin, which serves to distinguish A. sabanicolae from others in the genus. Moreover, the spicules are notably smaller than any others in the Acanthocheilonema. Acanthocheilonema sabanicolae is the first species in this genus to be described from edentates, and, along with A. reconditum of dogs and A. pricei of opossums, is the third species of Acanthocheilonema to be reported from South America. Morphological features, vectors, and vertebrate hosts of the genus Acanthocheilonema are reviewed.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. (Nematoda: Filarioidea) from Colombian capybaras.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. is described from specimens recovered from skeletal muscle fascia of the capybara, Hydrochoerus hydrochacris, from several localities in Colombia, South America. The microfilaria, which is found in the skin of the host, is also described for the first time. The monotypic species of the subgenus Alafilaria can be distinguished from existing Dipetalonema subgenera and all filariae known to us, on the basis of numerous preanal caudal papillae in males, small size of petals on the caudal extremity of each sex, and low, bluntly-rounded lateral alae in the cuticle of adult worms of both sexes. Unusual and distinctive features of the microfilaria include conspicuous lateral cuticular alae and a caudal extremity devoid of nuclei.

Dipetalonema (Dasypafilaria) averyi subgen. et sp. n. (Nematoda: Filarioidea) from the nine-banded armadillo, Dasypus novemcinctus in Louisiana.

A new filarial nematode, Dipetalonema (Dasypafilaria) averyi subgen. et sp. n., is described from the omentum of armadillos (Dasypus novemicinctus) for southern Louisiana. Within the genus, the large buccal cavity, the absence of a gubernaculum, the reduced number of caudal papillae, the large caudal lappets, and the sheathed microfilaria serve to distinguish the subgenus Dasypafilaria from other subgenera. The small size of D. averyi (females 5.3-9.5 mm long by 70-90 micrometers wide; males 3.8-5.5 mm long by 46-70 micrometers wide) readily distinguishes it from other species in the genus. It also is distinguished by its rounded cephalic extremity, the location of the vulva at the level of the base of the esophagus, the morphology of the spicules, and the size and configuration of the microfilaria.

[New data on the Dipetalonema lineage (Filarioidea, Nematoda)]. / Nouvelles données sur la lignée Dipetalonema (Filarioidea, Nematoda).

The evolutionary line of Dipetalonema can apparently be divided into four groups: I: Australian species; II: paleoendemic South American species; III: the Tetrapetalonema group; IV: the Acanthocheilonema group. Loxodontofilaria at present insufficiently known to be classified and several species belonging to the Acanthocheilonema group are the object of the present study. Descriptions are given of Loxodontofilaria asiatica n. sp., parasite of Elephas indicus in Burma, Cercopithifilaria degraaffi n. sp., parasites of Papio ursinus in South Africa, C. cephalophi n. sp., parasite of Cephalophus dorsalis and C. gabonensis n. sp., parasite of Atherurus africanus in Gabon. Additional morphological data are given on Cercopithifilaria didelphis, C. rugosicauda, Acanthocheilonema pachycephalum, A. viteae, Molinema dessetae, Dipetalonema gracile, Orihelia sp., Skrjabinofilaria skrjabini, Breinlia (B.) spratti, Litomosa sp., Loxodontofilaria hippopotami. Yatesia n. gen. with type species Yatesia hydrochoerus (Yates, 1980), is proposed, distinguished by specialized characters of the posterior extremity. The genus Cercopithifilaria is used to accomodate species considered as specialized Acanthocheilonema. Chenofilaria is placed in synonymy with Acanthocheilonema. Loxodontofilaria includes the three filarid species from elephants, L. loxodontis, L. gossi, L. asiatica n. sp. and the species from the Hippopotamus, L. hippopotami; D. okapiae is considered a species inquirenda. The interpretation given for the neotropical fauna is the following: --Skrjabinofilaria, Orihelia, Dasypafilaria and Dipetalonema may be true paleoendemics in South America. --Molinema and Ackertia on the one hand and Yatesia on the other may be forms of African origin introduced at the end of the Eocene during the migration of African rodents into South America. The cpature in American reptiles (the genus Macdonaldius) could have occurred during this period. --Surprisingly, the two species of Dipetalonema in Didelphis may be late captures of neartic origin: A. pricei from Acanthocheilonema in carnivores and C. didelphis from a Cercopithifilaria in eutherian mammals.

[Presence, in ticks from the Geneva region, of infective larvae which may be related to the dog filaria Dipetalonema grassii]. / Présence, chez des tiques de la région de Genève, de larves infestantes qui pourraient se rapporter à la filaire de chien Dipetalonema grassii.

About forty infective filarial larvae were collected from Rhipicephalus sanguineus (two ticks positive out of about 50 examined) living inside a house and presumably originally transported from the south of France or Toscana. The larvae are of the genus Dipetalonema; they are distinct from infective stages of the three most common European species, D. dracunculoides and D. reconditum from dogs and D. rugosicauda from roe deer. They may however be larvae of D. arassii (Noé, 1907), a dog filarid which has not been reported since its original descovery in Italy.

Dipetalonema (Cercopithifilaria) kenyensis subgen. et sp. n. (Nematoda: Filarioidea) from African baboons, Papio anubis.

Dipetalonema (Cercopithifilaria) kenyensis subgen. et sp. n. is described from the subcutaneous connective tissues of Papio anubis, from Kenya, Africa. Of the six recognized subgenera of the genus Dipetalonema, Cercopithifilaria most closely resembles Loxodontofilaria and Chenofilaria in having an undividied esophagus. The appearance of the female tail and the number and arrangement of the caudal papillae in the male distinguish it from these two subgenera. The species kenyensis is distinct from all other species by its body size, its microfilaria, and the size and shape of the spicules. This is the first species of Dipetalonema to be described from an African primate.

Dipetalonema (Acanthocheilonema) didelphis sp. n. (Nematoda: Filarioidea) from opossums, with a redescription of D. (A.) pricei (Vaz and Pereira 1934).

Dipetalonema (Acanthocheilonema) didelphis sp. n. recovered from the subcutaneous and periesophageal connective tissues of Didelphis virginiana from several localities in the United States and of D. marsupialis from Colombia is described. Dipetalonema didelphis sp. n. resembles D reconditum and D. mansonbahri in size, in lacking a two-segmented buccal capsule, and in the female having a long, digitiform tail. Dipetalonema reconditum, however, has a much longer glandular esophagus and D. mansonbahri has a rounded cephalic extremity delimited by a necklike region. The male of D. didelphis sp. n. differs from both in the structural details of the spicules and in having a higher spicular ratio. The microfilaria is much shorter than that of either D. reconditum or D. mansonbahri. Dipetalonema (A.) pricei adults are redescribed from the paratype specimens, and the microfilaria is also described. Dipetalonema pricei most closely resembles D. dracunculoides in size and in the presence of a well-developed, two-segmented buccal capsule, but the latter species has a much longer glandular esophagus. These two species also differ in the appearance of the spicules.

Development of Dipetalonema gracile and D. caudispina to the infective stage in Culicoides hollensis.

The microfilariae of 2 species of Dipetalonema (i.e., D. gracile and D. caudispina), common parasites of South American monkeys, develop to the third (infective) stage in the biting midge, Culicoides hollensis. Development of both species occurs in the abdominal fat body; D. gracile requires 13 days and D. caudispina 9 days. Despite similarities in the patterns of development of both species, the third-stage larvae of each is morphologically distinct.

Circulating non-human microfilaria in a patient with systemic lupus erythematosus.

A 12-yr-old girl with systemic lupus erythematosus requiring steroid therapy was found to have a circulating microfilaria during an exacerbation of her illness. Morphologically, the microfilaria does not correspond precisely with any previously described species, though similarities exist between the patient's microfilaria and those of Dipetalonema reconditum of the dog and D. interstitium of the grey squirrel. The organism reported here is probably an undescribed species from a wild mammal. Although the association may be merely coincidental, this case suggests that compromised immunity might have led to this unusual infection with a non-human filaria.