Hermes Ribeiro Luz

Ornithodoros faccinii n. sp. (Acari: Ixodida: Argasidae) parasitizing the frog Thoropa miliaris (Amphibia: Anura: Cycloramphidae) in Brazil

BackgroundMost argasid ticks from the Neotropical region are parasites of mammals and birds, with a few records from reptiles. Many species of the genus Ornithodoros are known only through larval descriptions, and their chaetotaxy and morphological characteristics have been used to separate the taxa. In the present study, we describe the larva and the nymph of first instar of a new species of the genus Ornithodoros that was collected from frogs of the species Thoropa miliaris.MethodsLarvae of Ornithodoros were collected from frogs of the species T. miliaris at waterfalls in the state of Rio de Janeiro, southeastern Brazil. The larval and nymphal description was based on optical and scanning electron microscopy. Molecular analysis using the argasid 16S rRNA sequences available in GenBank was also conducted.ResultsOrnithodoros faccinii sp. n. is closely related to Ornithodoros clarki Jones & Clifford, Ornithodoros marinkellei Kohls, Clifford & Jones, Ornithodoros capensis Neumann and Ornithodoros sawaii Kitaoka & Susuki. However, the larval morphology of the new species is unique. The mitochondrial 16S rDNA partial sequence of O. faccinii generated in the present study was deposited in GenBank under the number KP861242.ConclusionsThe larvae collected from Thoropa miliaris are a new species, Ornithodoros faccinii n. sp. This is the first report of argasid ticks on frogs in Brazil, the second on frogs and the third on Amphibia in the Neotropical region.

Isosporoid Coccidia (Apicomplexa: Eimeriidae) parasites of tanagers (Passeriformes: Thraupidae) from the Marambaia Island, Brazil

In recent years some coccidian parasites of birds were recorded in Marambaia Island, which is a protected environment with a great biodiversity of birds, mainly tanagers. In this current study Isospora tiesangui, I. sepetibensis, I. ramphoceli, I. navarroi, I. cadimi and I. marambaiensis were identified according to their respective thraupid hosts of the Marambaia Island. These species were characterized with histograms, linear regression and analysis of variance (ANOVA). The main feature of identification was the morphology of the sporocyst, mainly Stieda and substieda bodies, since the morphometry did not provide sufficient differentiation. Besides, Dacnis cayana and Thraupis palmarum were reported as new hosts to I. sepetibensis and I. navarroi respectively.

Detection of Rickettsia bellii and Rickettsia amblyommii in Amblyomma longirostre (Acari: Ixodidae) from Bahia state, Northeast Brazil

Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auriculariumcollected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.

Isospora massardi sp. nov. (Apicomplexa: Eimeriidae) from the white-necked thrush Turdus albicollis (Passeriformes: Turdidae) from Brazil

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) are reported from the white-necked thrush Turdus albicollis Vieillot, 1818, a very common species in South America. Isospora massardi sp. nov. oocysts are subspherical, 18.6 × 17.7 μm, with smooth, bilayered wall, ∼0.9 μm. Micropyle, oocyst residuum are absent, but two polar granules are frequently present. Sporocysts are ovoidal, 14.8 × 9.3 μm. Stieda body is knob-like to rounded and substieda body is rounded. Sporocyst residuum is composed of scattered spherules of different sizes. Sporozoites are vermiform with posterior and anterior refractile bodies and a nucleus. This is the sixth description of an isosporoid coccidium infecting a New World turdid bird.

Isospora mionectesi sp. nov. (Apicomplexa, Eimeriidae) from the grey-hooded flycatcher, Mionectes rufiventris in Brazil

A new isosporoid coccidian (Apicomplexa, Eimeriidae) species from the grey-hooded flycatcher, Mionectes rufiventris, from Brazil, is reported in the current study. Isospora mionectesi sp. nov. oocysts are ellipsoidal, 28.3 × 21.2 µm, with smooth, bilayered wall, ∼1.3 µm. Micropyle and oocyst residuum are absent, but one or two polar granules are present. Sporocysts are elongate ellipsoidal, 19.7 × 11.7 µm. Stieda body rounded and substieda body prominent. Sporocyst residuum is subspherical and compact. Sporozoites are vermiform with one refractile body and a nucleus.

Isospora coerebae n. sp. (Apicomplexa: Eimeriidae) from the bananaquit Coereba flaveola (Passeriformes: Coerebidae) in South America

The present study describes a new isosporoid coccidian parasite from the bananaquit Coereba flaveola, in Brazil. This new species is similar to I. cagasebi, but it can be distinguished by the size and shape of Stieda and susbstieda bodies. Isospora coerebae n. sp. oocysts are spheroidal to sub-spheroidal, 24.8 × 23.3 μm, with a smooth and bi-layered wall, ~1.2 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are elongate ovoidal, 17.9 × 10.9 μm. Stieda and substieda bodies are present. Sporocyst residuum is present and sporozoites have a posterior refractile body.

Molecular analyses reveal an abundant diversity of ticks and rickettsial agents associated with wild birds in two regions of primary Brazilian Atlantic Rainforest

Brazilian wild birds are recognized as frequent and important hosts for immature stages of more than half of the 32 recognized species of Amblyomma ticks recorded in that country. Several species of Amblyomma harbor rickettsial agents, including members of the spotted fever group (SFG). Most studies on this topic relied primarily on morphological characterization and reported large portions of the collected ticks at the genus rather than species level. Clearly, this factor may have contributed to an underestimation of tick diversity and distribution and makes comparisons between studies difficult. The current investigation combined morphological and molecular analyses to assess the diversity of ticks and rickettsial agents associated with wild birds, captured in two regions of native Atlantic rainforest, in the state of Rio de Janeiro, Brazil. A total of 910 birds were captured, representing two orders, 34 families and 106 species, among which 93 specimens (10.2%), were parasitized by 138 immature ticks (60 larvae and 78 nymphs), representing 10 recognized species of the genus Amblyomma; together with two reasonably well classified haplotypes (Amblyomma sp. haplotype Nazaré and Amblyomma sp. strain USNTC 6792). Amplification by PCR and sequencing of rickettsial genes (htrA, gltA, ompA and ompB), demonstrated the presence of Rickettsia DNA in 48 (34%) of the ticks. Specifically, Rickettsia bellii was detected in a single larva and a single nymph of A. aureolatum; R. amblyomatis was found in 16 of 37 A. longirostre and was recorded for the first time in three nymphs of A. calcaratum; R. rhipicephali was detected in 9 (47%) of 19 Amblyomma sp. haplotype Nazaré ticks. The remaining ticks were infected with genetic variants of R. parkeri, namely strain ApPR in 12 A. parkeri and seven Amblyomma sp. haplotype Nazaré ticks, with the strain NOD found in two specimens of A. nodosum. Interestingly, a single larvae of A. ovale was shown to be infected with the emerging human pathogen Rickettsia sp. strain Atlantic rainforest (ARF), suggesting a possible role for birds in the dispersal of ticks infected with this variant of R. parkeri. The diversity of ticks and Rickettsia recorded in this study is, to our knowledge, the most abundant recorded to date in Brazil and highlighted the value of employing methods capable of providing species level identification of the ixodofauna of wild birds.

Ticks on birds caught on the campus of the Federal Rural University of Rio de Janeiro, Brazil

The prevalence of parasitic infections, particularly those caused by ectoparasites, may influence the biology and ecology of wild birds. The aim of this study was to investigate occurrences and identify the species of ticks collected from wild birds caught on the campus of the Federal Rural University of Rio de Janeiro. The birds were caught using mist nets between October 2009 and December 2010. In total, 223 birds were caught, represented by 53 species and 19 families in nine orders. Nineteen birds (n = 7 species) were parasitized by immature ticks (prevalence of 8.5%). Forty-four ticks were collected, of which 23 were nymphs and 21 were larvae. There were associations between parasitism by ticks and non-Passeriformes birds, and between parasitism and ground-dwelling birds, which was possibly due to the presence (or inclusion among the captured birds) of Vanellus chilensis (Charadriiformes: Charadriidae). All the nymphs collected were identified as Amblyomma cajennense. In general terms, we must emphasize that wild birds in the study area may play the role of dispersers for the immature stages of A. cajennense, albeit non-preferentially.

Isospora cagasebi sp. nov. (Apicomplexa, Eimeriidae) from the bananaquit, Coereba flaveola of Brazil

Isospora cagasebi sp. nov. (Apicomplexa, Eimeriidae) is reported from a bananaquit, Coereba flaveola from Brazil. Oocysts are sub-spherical, 24.9 × 24.5 (23.0–26.1 × 22.6–25.4), with a smooth, bilayered wall ∼1.4 and mean L:W ratio 1.0; micropyle, oocyst residuum and polar granule are absent. Sporocysts are elongate ovoidal, 18.7 × 11.5 (17.6–19.4 × 10.4–12.3), with both Stieda and substieda bodies and mean L:W ratio 1.6; sporocyst residuum present and sporozoites each with 2 refractiles bodies.

Parasitism by Ornithodoros faccinii (Ixodida: Argasidae) on Thoropa miliaris (Anura: Cycloramphidae) in Brazil

ABSTRACT Ornithodoros faccinii Barros-Battesti, Landulfo & Luz 2015, a recently described species of soft tick, was collected from Thoropa miliaris (Spix, 1824), an amphibian of the family Cycloramphidae, in the municipality of Itaguaí, in the state of Rio de Janeiro. Primary aspects of the ecology of O. faccinii and its relationship with T. miliaris are still largely unknown. The aims of this study were to verify the distribution range, the presence of other stage and site preference for parasitism of O. faccinii on the anuran’s body. To this end, 1026 specimens of T. miliaris from five important herpetological collections in Brazil were examined, 97 of which were parasitized by 433 larvae of O. faccinii. The geographical distribution of O. faccinii appears to be associated with that of T. miliaris, and several hypotheses are proposed regarding the behaviour of the larvae and the absence of parasitizing nymphs and adults. Thirteen municipalities in the state of Rio de Janeiro and other municipalities in the states of Minas Gerais, Espírito Santo and Bahia were added to the list of distribution of O. faccinii. No significant differences (p > 0.05) in parasitism were found among the categories of subadult, male and female. Twelve attachment sites were found for O. faccinii larvae, and the most frequently parasitized site on the body of T. miliaris was the inguinal region, followed by the lateral ventral and axillary regions. Parasitism by O. faccinii is highly aggregated in the regions under study in the state of Rio de Janeiro.