Development of Hepatozoon caimani (Carini, 1909) Pess a, De Biasi & De Souza, 1972 in the Caiman Caiman c. crocodilus, the frog Rana catesbeiana and the mosquito Culex fatigans

Molecular detection of Hepatozoon species (Apicomplexa: Hepatozoidae) infecting snakes in the Northeastern region of Argentina

The genus Hepatozoon Miller (1908) contains a wide range of obligate parasitic organisms with complex life cycles involving vertebrates and hematophagous invertebrates. Despite over 300 species being described, only a small percentage has been characterized in snakes using morphological and molecular techniques. The prevalence of these parasites in snakes is significant, highlighting the need for molecular descriptions in such elusive hosts. Thus, the objective of this study was to determine molecularly the presence of Hepatozoon species in snakes from the Northeastern region of Argentina. Thirty-two specimens of eight snake species (Bothrops alternatus, Dryophylax hypoconia, Erythrolamprus jaegeri coralliventris, Erythrolamprus poecilogyrus, Erythrolamprus semiaureus, Philodryas olfersii latirostris, Pseudablabes (ex Philodryas) patagoniensis and Palusophis (ex Mastigodryas) bifossatus were collected and examined. PCR analysis of the 18S rRNA locus detected four samples (12% prevalence) positive for the presence of Hepatozoon DNA. Phylogenetic analysis positioned the 18S rRNA Hepatozoon sequences obtained in three different clades, one with Hepatozoon musa, another with sequences of Hepatozoon cuestensis, while the third was placed as a sister taxon to a clade including Hepatozoon cevapii and Hepatozoon massardi. This study presents the first documentation of Hepatozoon infecting snakes in Argentina, thereby expanding their distribution within southern South America. Additionally, B. alternatus and Pa. bifossatus are reported as new hosts of Hepatozoon.

Description of an intramonocytic haemoparasite, Hepatozoon lainsoni sp. nov. (Apicomplexa: Adeleorina: Hepatozoidae), infecting Ameiva ameiva lizard (Reptilia: Squamata: Teiidae) in northern Brazil

Haemogregarine (Apicomplexa: Adeleorina) parasites are considered to be the most common and widespread haemoparasites in reptiles. The genus Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) can be found parasitizing a broad range of species and, in reptiles, they infect mainly peripheral blood erythrocytes. The present study detected and characterized a haemogregarine isolated from the lizard species, Ameiva ameiva, collected from the municipality of Capanema, Pará state, north Brazil. Blood smears and imprints from lungs, brain, heart, kidney, liver, bone marrow and spleen were observed using light microscopy and the parasite was genetically identified by molecular analysis. Morphological, morphometric and molecular data were obtained. Parasite gamonts were found in 49.5% (55/111) of the blood smears from A. ameiva, and were characterized as oval, averaging 12.0 ± 0.8 × 5.9 ± 0.6 μm2 in size, which displaced the nuclei of parasitized monocytes laterally. Parasite forms resembling immature gamonts were observed in the spleen and bone marrow of the lizards. Furthermore, phylogenetic analyses of 18S rRNA sequences did not reveal gene similarity with other Hepatozoon spp. sequences from reptiles. Thus, morphological and molecular analyses have identified a new species of Hepatozoon parasite, Hepatozoon lainsoni sp. nov., which infects monocytes of the A. ameiva lizard.

The amphibian's spleen as a source of biomarkers for ecotoxicity assessment: Historical review and trends

Amphibians are very sensitive to many environmental changes, so these animals are considered good bioindicator models for ecotoxicology. Given the importance of the amphibian spleen for hematopoietic and immune responses, this can be a key organ for the evaluation of biomarkers to monitor the health of individuals in nature or in captivity. In this systematic review, we searched databases and summarized the main findings concerning the amphibian spleen as a source of possible biomarkers applied in different scientific fields. The searches resulted in 83 articles published from 1923 to 2022, which applied the use of splenic samples to evaluate the effects of distinct stressors on amphibians. Articles were distributed in more than twenty countries, with USA, Europe, and Brazil, standing out among them. Publications focused mainly on anatomical and histomorphological characterization of the spleen, its physiology, and development. Recently, the use of splenic biomarkers in pathology and ecotoxicology began to grow but many gaps still need to be addressed in herpetological research. About 85 % of the splenic biomarkers showed responses to various stressors, which indicates that the spleen can provide numerous biomarkers to be used in many study fields. The limited amount of information on morphological description and splenic anatomy in amphibians may be a contributing factor to the underestimated use of splenic biomarkers in herpetological research around the world. We hope that this unprecedented review can instigate researchers to refine herpetological experimentation, using the spleen as a versatile and alternative source for biomarkers in ecotoxicology.

Hepatozoon Miller, 1908 parasites in the Colubridae snakes Clelia clelia (Daudin, 1803) and Drymarchon corais (Boie, 1827) from the Eastern Amazonia

Based on the genetic, morphological, and morphometric data of blood gamonts, we identified Hepatozoon parasites in colubrid snakes sampled in the Eastern Amazon region. Hepatozoon trigeminum was detected in the mussurana snake Clelia clelia and exhibited wide and elongated gamonts (mean dimensions: 14.25±0.65 × 4.31±0.43 μm) with an evident parasitophorous vacuole. Hepatozoon odwyerae sp. nov. was described in the indigo snake Drymarchon corais, whose gamonts have elongated and thin bodies (mean dimensions: 13.41±0.79 × 3.72±0.35 μm) with one end more tapered than the other. Phylogenetic analyses, based on the amplification of a 441 bp fragment of the 18S rRNA gene, revealed that the novel sequences of Hepatozoon spp. from our study were closely related to hemogregarine lineages found in lizards and snakes from Brazil, forming a well-supported monophyletic clade with them. The present study provides the first species description of Hepatoozon in D. corais and a new record of a host species for C. clelia using the integrated taxonomic data. We also highlight the importance of further investigations into the diversity of Hepatozoon in snakes, a rich but underestimated group of parasites, especially in the Amazonian biome.

Diversity of Hepatozoon species in wild mammals and ticks in Europe

BACKGROUND

Hepatozoon spp. are tick-borne parasites causing subclinical to clinical disease in wild and domestic animals. Aim of this study was to determine Hepatozoon prevalence and species distribution among wild mammals and ticks in Europe.

METHODS

Samples of wild mammals and ticks, originating from Austria, Bosnia and Herzegovina, Croatia, Belgium and the Netherlands, were tested with PCR to amplify a ~ 670-bp fragment of the small subunit ribosomal RNA gene.

RESULTS

Of the 2801 mammal samples that were used for this study, 370 (13.2%) tested positive. Hepatozoon canis was detected in samples of 178 animals (3 Artiodactyla, 173 Carnivora, 1 Eulipotyphia, 1 Lagomorpha), H. martis in 125 (3 Artiodactyla, 122 Carnivora), H. sciuri in 13 (all Rodentia), Hepatozoon sp. in 47 (among which Hepatozoon sp. Vole isolate, all Rodentia) and H. ayorgbor in 4 (all Rodentia). Regarding origin, 2.9% (6/208) tested positive from Austria, 2.8% (1/36) from Bosnia and Herzegovina, 14.6% (173/1186) from Croatia and 13.9% (190/1371) from Belgium/the Netherlands. Of the 754 ticks collected, 0.0% (0/35) Hyalomma sp., 16.0% (4/25) Dermacentor spp., 0.0% (0/23) Haemaphysalis spp., 5.3% (24/50) Ixodes and 1.4% (3/221) Rhipicephalus spp. tested positive for Hepatozoon (4.2%; 32/754), most often H. canis (n = 22).

CONCLUSIONS

Hepatozoon canis is most present in mammals (especially in Carnivora such as gray wolves and golden jackals) and ticks, followed by H. martis, which was found merely in stone martens and pine martens. None of the rodent-associated Hepatozoon spp. were detected in the ticks, suggesting the possible implication of other arthropod species or non-vectorial routes in the transmission cycle of the hemoprotozoans in rodents. Our findings of H. canis in ticks other than R. sanguineus add to the observation that other ticks are also involved in the life cycle of Hepatozoon. Now that presence of Hepatozoon has been demonstrated in red foxes, gray wolves, mustelids and rodents from the Netherlands and/or Belgium, veterinary clinicians should be aware of the possibility of spill-over to domestic animals, such as dogs.

A 50-year-old redescription: molecular and morphometric characterization of Hepatozoon carinicauda Pessôa and Cavalheiro, 1969 in the brown-banded water snake Helicops angulatus (Linnaeus, 1758)

The combined use of molecular and microscopic techniques has become an increasingly common and efficient practice for the taxonomic and evolutionary understanding of single-celled parasites such as haemogregarines. Based on this integrative approach, we characterized Hepatozoon found in Helicops angulatus snakes from the Eastern Amazonia, Brazil. The gamonts observed caused cell hypertrophy and were extremely elongated and, in some cases, piriform (mean dimensions: 25.3 ± 1.9 × 8.6 ± 1.3 μm). These morphological features correspond to Hepatozoon carinicauda, described 50 years ago in the snake Helicops carinicaudus in the southeast region of Brazil. Phylogenetic and genetic divergence analyses, performed with the sequence obtained from the amplification of a 590 bp fragment of the 18S rRNA gene, revealed that Hepatozoon in He. angulatus differed from the other lineages retrieved from GenBank, and was clustered singly in both the phylogenetic tree and the haplotype network. The integration of these data allowed the identification of H. carinicauda in a new aquatic host, and increased the knowledge of its geographical distribution. Therefore, the present study included the first redescription of a Hepatozoon species in a snake from the Brazilian Amazon.

Hepatozoon parasites (Apicomplexa: Hepatozoidae) in fish Hoplias aimara (Characiformes, Erythrinidae) from the Eastern Amazon, Brazil

This study reports the occurrence of parasites belonging to the Hepatozoon genus in fish Hoplias aimara from the Eastern Amazon. Fish (n = 54) were sampled from the Falsino River, located in the Amapá National Forest (FLONA), in the state of Amapá, northern Brazil. Fresh liver preparations were examined in the field between a slide and a coverslip under a light microscope. Cysts containing Hepatozoon cystozoites were observed in the liver of 5 (9%) out of 54 H. aimara individuals. The cysts were ovoid (mean dimensions 10.28 × 9.8 μm), presenting up to four elongated cystozoites (mean dimensions 11.04 × 1.68 μm), containing 1 to 4 residual bodies of different sizes. A single liver sample containing cysts was submitted to DNA extraction and PCR analyses based on a fragment of the 18S rRNA gene. The sequencing revealed a 465 bp fragment exhibiting 99% query coverage, 0.0 E-value, and 98.7% identity with Hepatozoon caimani (MF322538 and MF322539), detected in caimans (Caiman yacare) from Brazil. This is the first report of the occurrence of cysts containing Hepatozoon cystozoites in free-living fishes.

Genetic diversity of Hepatozoon spp. in rodents from Chile

This study aimed to investigate the genetic diversity of Hepatozoon spp. in rodents from Valdivia, Chile. A total of 74 rodents (synanthropic n=38; wild n=36) were trapped in Valdivia. We performed conventional PCR assays for Apicomplexa organisms targeting two overlapping 18S rDNA gene fragments (600 bp and 900 bp) followed by sequencing of selected amplicons. Hepatozoon spp. occurrence was 82.43% (61/74). Twelve sequences obtained from the 600 bp and ten from the 900 bp 18S rDNA fragments were identified as Hepatozoon sp. Six sequences obtained from 18S rDNA-based overlapping PCR protocols were used for concatenated (1,400 bp) phylogenetic, haplotype and distance analyses. Hepatozoon spp. 18S rDNA concatenated sequences from the present study were detected in Oligoryzomys longicaudatus, Rattus norvegicus, Mus musculus, and Abrothrix longipilis grouped with Hepatozoon species earlier described in rodents and reptiles from Chile and Brazil. Nucleotide polymorphism of the six 18S rDNA sequences (1,400 bp) from this study, and other Chilean sequences from rodents and rodent's ticks, showed high diversity with a total of nine Chilean haplotypes. Three haplotypes from Valdivia were identified for the first time in this study, suggesting the circulation of novel haplotypes in rodents from southern Chile.

Vector-borne zoonotic blood parasites in wildlife from Ecuador: A report and systematic review

Background and Aim:

Ecuador is a hugely diverse country, but information on infectious diseases in local wild animals is scarce. The aim of this study was to screen the presence of blood parasites in free-ranging wild animals admitted to the Wildlife Hospital at Universidad San Francisco de Quito, from April 2012 to January 2019.

Materials and Methods:

We identified blood parasites by microscopic observation of blood smears from free-ranging wildlife species that attended the Wildlife Hospital of Universidad San Francisco de Quito (Ecuador) from April 2012 to January 2019.

Results:

The microscopic evaluations of animals as potential reservoirs for vector-borne zoonotic blood parasites revealed the presence of Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., microfilaria, Mycoplasma spp., and Trypanosoma spp. in previously unreported wildlife species. In addition, we performed a systematic review to understand the current knowledge gaps in the context of these findings.

Conclusion:

Our data contribute to the knowledge of blood parasites in wildlife from Ecuador. Furthermore, the potential transmission of these parasites to humans and domestic animals, current anthropogenic environmental changes in the region, and the lack of information on this suggest the importance of our results and warrant further investigations on infectious diseases in animals and humans and their relationship with environmental health as key domains of the One Health concept.

New insights on the diversity of Brazilian anuran blood parasites: With the description of three new species of Hepatozoon (Apicomplexa: Hepatozoidae) from Leptodactylidae anurans

The Amphibia are considered the most threatened vertebrate class globally, yet in Brazil they are also one of the more diverse and species rich groups. Although, in recent years there has been strong focus on amphibian related research, their parasites have not received the same attention. In Brazil, only a single species of Hepatozoon, namely H. leptodactyli (Lesage, 1908) Pessoa, 1970, has been described from anuran hosts. The present study aimed to describe three new species of Hepatozoon parasitising Leptodactylus labyrinthicus and Leptodactylus latrans from Mato Grosso State, Brazil. From 66 anurans screened for haemogregarines, four belonging to the Leptodactylidae were found positive for species of Hepatozoon. Based on the morphological analysis of peripheral blood gamonts and spleen and liver tissue meronts, three different morphotypes of Hepatozoon spp. were identified. Morphotype 1 (M1) and morphotype 2 (M2) in L. labyrinthicus and morphotype 3 (M3) in L. latrans. Molecular data based on partial 18S rDNA sequences revealed an interspecific divergence, between the species ranging from 0.43% to 1.16%. Phylogenetic analysis recovered isolates from the present study monophyletic with other isolates from Brazilian reptile and anuran hosts, sister to a clade comprising species isolated from African, North American and European reptile and anuran host species. Thus, using morphological and molecular analysis three new species infecting Brazilian Leptodactylidae anurans were identified and described. This study increases the knowledge of Brazilian anurans blood parasites and demonstrates the importance of using integrative approaches for diagnosis of hemoparasites.

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Diversity and phylogenetic relationship of haemogregarines from Brazilian anurans.

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Description of a three new species of Hepatozoon from Brazilian anurans.

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First report of species of Hepatozoon descriptions using both morphological and molecular approaches from Brazilian anurans.

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Merogonic data of Hepatozoon spp. infection on Brazilian anurans.

Haemogregarines and Criteria for Identification

Simple Summary

Taxonomic classification of haemogregarines belonging to Apicomplexa can become difficult when the information about the life cycle stages is not available. Using a self-reporting, we record different haemogregarine species infecting various animal categories and exploring the most systematic features for each life cycle stage. The keystone in the classification of any species of haemogregarines is related to the sporogonic cycle more than other stages of schizogony and gamogony. Molecular approaches are excellent tools that enabled the identification of apicomplexan parasites by clarifying their evolutionary relationships.

Abstract

Apicomplexa is a phylum that includes all parasitic protozoa sharing unique ultrastructural features. Haemogregarines are sophisticated apicomplexan blood parasites with an obligatory heteroxenous life cycle and haplohomophasic alternation of generations. Haemogregarines are common blood parasites of fish, amphibians, lizards, snakes, turtles, tortoises, crocodilians, birds, and mammals. Haemogregarine ultrastructure has been so far examined only for stages from the vertebrate host. PCR-based assays and the sequencing of the 18S rRNA gene are helpful methods to further characterize this parasite group. The proper classification for the haemogregarine complex is available with the criteria of generic and unique diagnosis of these parasites.

Morphometric and molecular characterisation of Hepatozoon bashtari n. sp. in painted saw-scaled viper, Echis coloratus (Ophidia, Viperidae)

Hepatozoon species are the most widely known haemogregarines infecting a wide range of vertebrates, although predominately snakes. Herein, Hepatozoon bashtari n. sp., originally infecting the painted saw-scaled viper, Echis coloratus, in Saudi Arabia is described using both morphological features and molecular data from 18S rDNA sequences. The overall prevalence of infection was 60% (9/15) with parasitaemia ranging from 52 to 60%. Gamonts were entirely intraerythrocytic and were observed to cause considerable hypertrophy within the host cell. The mean size of mature gamonts was 15.4 × 3.3 μm. Merogonic stages were confined to the lung endothelial cells with monomorphic meronts. The average size of mature meronts was 32 × 12 μm and they were estimated to produce 13-16 merozoites each. The phylogenetic tree generated from SSU rDNA sequences revealed that Hepatozoon bashtari sp. n. clusters with the vast majority of other Hepatozoon species infecting snakes, lizards and geckos in various regions of the world, which would appear to support the hypothesis of prey-predator transmission of the genus Hepatozoon. Through a combination of morphological comparison with closely related Hepatozoon spp. and 18S rRNA gene sequence analysis, it is possible to confirm Hepatozoon bashtari sp. n. as a new species.

Molecular detection of Apicomplexan hemoparasites in anurans from Brazil

Amphibians are among the most threatened vertebrate groups in the world, and the main causes include climate change, habitat destruction, and emerging diseases. Herein, we investigated the occurrence and characterized molecularly Apicomplexa in anurans from southeastern Brazil. Forty individuals from seven anuran species were sampled in São Paulo state. In the molecular analyses, one Leptodactylus latrans and one Rhinella diptycha were positive in PCR assays for species of Hepatozoon. Two L. latrans were also positive for coccidian infections (Lankesterella sp. and an unidentified coccidian species). Phylogenetic analysis based on 18S rDNA clustered the sequences detected in anurans from the present study with Hepatozoon spp. detected in reptiles and other anurans from Brazil, albeit they were separate from Hepatozoon haplotypes detected in frogs from Africa and North America. Our study showed, for the first time, the molecular detection of Lankesterella sp. and another coccidian in L. latrans. Additionally, co-infection by different species of Hepatozoon haplotypes and an unidentified coccidian in anurans from Brazil was documented.

Molecular detection of Hepatozoon spp. in non-hematophagous bats in Brazil

Even though Hepatozoon spp. has been molecularly detected in several wild animals in Brazil, there is no report on the occurrence of Hepatozoon spp. DNA in bats in Brazil. This study aimed at detecting Hepatozoon, in addition to ectoparasites, in non-hematophagous bats sampled in central-western Brazil using blood smears, hematoxylin-eosin (HE)-staining liver/spleen preparations and molecular and phylogenetic techniques. A total of 135 spleen, 127 liver, and 133 blood samples were collected from 135 non-hematophagous bats from 12 different species in two different sites in Campo Grande, Mato Grosso do Sul state, in the Brazilian Cerrado region. Spleen and blood DNA samples were submitted to two conventional PCR protocols for Hepatozoon spp. based on 18S rRNA. No Hepatozoon spp. gamonts or meronts were observed in blood smears and HE-stained-liver preparations, respectively. While none of the spleen samples was positive for Hepatozoon spp. in the PCR assays, 5 (3 %) blood samples contained 18S rRNA Hepatozoon DNA, including 2/37 (5 %) Artibeus lituratus, 2/32 (6 %) A. planirostris, and 1/23 (4 %) Platyrrhinus lineatus. Out of 5 bats positive for Hepatozoon spp., 3 were parasitized by either Macronyssidae/Spinturnicidae mites or Streblidae flies. BLAST analysis showed that the sequences detected in bats had >99 % identity with Hepatozoon sequences detected in amphibians and reptiles from Brazil, including Hepatozoon caimani detected in Caiman crocodilus. The phylogenetic inferences estimated by the Maximum Likelihood and Bayesian methods clustered the Hepatozoon sequences detected in Brazilian bats with those detected in reptiles and amphibians.

Hepatozoon milleri sp. nov. (Adeleorina: Hepatozoidae) in Akodon montensis (Rodentia: Cricetidae: Sigmodontinae) from southeastern Brazil

Members of the genus Hepatozoon (Miller, 1908) are blood parasites found in a wide range of host species, including wild rodents; however, information about the life cycle, distribution and Hepatozoon species diversity infecting these mammals are lacking. We studied the parasite stages and DNA sequences of Hepatozoon sp. of 11 naturally infected Akodon montensis. Thin blood smears, tissue samples and whole blood were obtained for morphology, morphometry and molecular analyses. Seven of the 11 rodents had gamonts on the blood smears. Biological and morphological features of the parasite such as tissue tropism, gamonts and meronts size and morphology, as well as the DNA sequence comparison and phylogenetic analysis, indicated that the Hepatozoon sp. detected in this study is distinct from those species previously reported in small rodents. Herein, we propose a new species, named Hepatozoon milleri sp. nov. This is the first description of a new Hepatozoon species from wild small rodents in Brazil, based on morphological and molecular characteristics.

Hepatozoon caimani in Caiman crocodilus yacare (Crocodylia, Alligatoridae) from North Pantanal, Brazil

Hepatozoon species are the most common intracellular hemoparasite found in reptiles. Hepatozoon caimani, whose vectors are Culex mosquitoes, has been detected in a high prevalence among caimans in Brazil by blood smears examinations. The present work aimed to detect and characterize the Hepatozoon spp. found in 33 caimans (24 free-ranging and 9 captive; 28 males and 5 females) (Caiman crocodilus yacare) sampled at Poconé, North Pantanal, state of Mato Grosso, Brazil, using blood smears examinations and molecular techniques. Hepatozoon spp.-gametocytes were found in 70.8% (17/24) and 88.8% (8/9) of blood smears from free-ranging and captive caimans, respectively. Hepatozoon spp. 18S rRNA DNA was found in 79.2% (19/24) and 88.8% (8/9) of free-ranging and captive caimans, respectively. Comparative analysis of parasitized and non-parasitized erythrocytes showed that all analyzed features were significantly different (P<0.05) for both linear and area dimensions. Phylogenetic analysis based on 18S rRNA sequences grouped the Hepatozoon spp. sequences detected in the present study together with H. caimani, recently detected in caimans in southern Pantanal.

Novel piroplasmid and Hepatozoon organisms infecting the wildlife of two regions of the Brazilian Amazon

During 2009–2012, wild animals were sampled in two areas within the Amazon biome of Brazil, in the states of Mato Grosso and Pará. Animal tissues and blood were molecularly tested for the presence of Piroplasmida (genera Babesia, Theileria, Cytauxzoon) or Hepatozoon DNA. Overall, 181 wild animals comprising 36 different species (2 reptiles, 5 birds, and 29 mammals) were sampled. The following Piroplasmida agents were detected: Cytauxzoon felis in one ocelot (Leopardus pardalis), Theileria cervi in two red brocket deer (Mazama americana), Theileria spp. in three nine-banded-armadillos (Dasypus novemcinctus), one agouti (Dasyprocta sp.), and four lowland pacas (Cuniculus paca), Babesia spp. in one common opossum (Didelphis marsupialis) and one white-lipped peccary (Tayassu pecari). The following Hepatozoon agents were detected: Hepatozoon sp. (possibly Hepatozoon caimani) in three spectacled caimans (Caiman crocodilus), Hepatozoon felis in an ocelot (Leopardus pardalis), and Hepatozoon spp. in one scorpion mud turtle (Kinosternon scorpioides) and one lowland paca (Cuniculus paca). Phylogenetic analyses inferred by the 18S rRNA gene partial sequences supported these results, highlighting at least five novel Piroplasmida agents, and two novel Hepatozoon agents. This study screened the presence of tick-borne protozoa in a number of wildlife species from the Amazon for the first time. Our results indicate that a variety of genetically distinct Piroplasmida and Hepatozoon organisms circulate under natural conditions in the Amazonian wildlife.

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We detected Babesia and Theileria genotypes in Amazon wildlife for the first time.

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Cytauxzoon felis and Hepatozoon felis is reported from ocelot (Leopardus pardalis).

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We detected novel Hepatozoon genotypes from reptiles and the rodent Cuniculus paca.

Molecular diagnosis of Hepatozoon canis in symptomatic dogs in the city of Goiania, Goiás, Brazil

ABSTRACT More than 300 species have been described in the genus Hepatozoon, occurring in different vertebrates. Among these, only Hepatozoon canis and Hepatozoon americanum are seen in dogs. Different methods may be used for laboratory diagnosis. The most common of these is direct parasitological examination of parasite stages in blood smears. The aim of this investigation was to conduct a phylogenetic study on Hepatozoon isolates from symptomatic dogs in the city of Goiânia, Goiás, Brazil. Blood samples were obtained from 40 symptomatic dogs that had been referred to the Veterinary Hospital of the Federal University of Goiás. Among these, only two samples were positive for Hepatozoon spp. using the direct parasitological method. These samples were then subjected to a DNA extraction process and amplification of a fragment of the 18S rRNA by means of PCR. Subsequently, the PCR products from each sample were purified and sequenced. The sequences obtained were then analyzed using the BLASTn algorithm, which identified both sequences of this study as Hepatozoon canis. By applying the Mega4 software, it was confirmed that these isolates of H. canis from dogs in Goiânia are similar to other reference isolates of the same species from other regions of Brazil and worldwide.

Hepatozoon spp. infections in wild rodents in an area of endemic canine hepatozoonosis in southeastern Brazil

Hepatozoon canis is a tick-borne parasite that occurs worldwide. In rural areas of Brazil, H. canis vectors remain unknown, which has led to speculation about alternative routes of transmission. Small rodents can play a role in the transmission (via predation) of Hepatozoon americanum, which led us to question whether predation might be an alternative mode of transmission for H. canis. Thus, this study investigated whether Hepatozoon spp. are present in wild small rodents in forest fragments that surround rural areas in Botucatu County, São Paulo, Brazil, where canine hepatozoonosis is endemic. The study included blood samples from 158 dogs, which were screened by microscopy and molecular analysis. Blood samples and tissues from 67 rodents were obtained for histopathology and molecular detection. The prevalence of H. canis was high (66.45%) in dogs from rural areas of Botucatu, São Paulo, Brazil. The molecular analysis showed that wild rodent species in Brazil were infected with Hepatozoon spp. other than H. canis. Therefore, although the hypothesis that sylvatic rodents act as reservoirs for H. canis was not supported, the presence of monozoic cysts in the rodents suggests that, in addition to intermediate hosts, wild small rodents in Brazil might act as paratenic hosts of Hepatozoon spp. because they harbor infective stages for intermediate host predators.

Paleoparasitological evidence of pinworm (Enterobius vermicularis) infection in a female adolescent residing in ancient Tehran (Iran) 7000 years ago

BACKGROUND

The Molavi street archeological site south of Tehran accidentally provided a unique opportunity for paleoparasitological studies in Iran. A female skeleton was unearthed and evaluated to be 7000 years old. Soil samples were collected around the pelvic and sacrum bones.

FINDINGS

Careful microscopic investigation of rehydrated soil samples revealed the presence of one Enterobius vermicularis egg attached to the skeleton sacral region.

CONCLUSION

The present finding likely represents the oldest evidence of a human pinworm infection in Asia.

Cardiovascular disease and type 2 diabetes in evolutionary perspective: a critical role for helminths?

Heart disease and type 2 diabetes are commonly believed to be rare among contemporary subsistence-level human populations, and by extension prehistoric populations. Although some caveats remain, evidence shows these diseases to be unusual among well-studied hunter-gatherers and other subsistence populations with minimal access to healthcare. Here we expand on a relatively new proposal for why these and other populations may not show major signs of these diseases. Chronic infections, especially helminths, may offer protection against heart disease and diabetes through direct and indirect pathways. As part of a strategy to insure their own survival and reproduction, helminths exert multiple cardio-protective effects on their host through their effects on immune function and blood lipid metabolism. Helminths consume blood lipids and glucose, alter lipid metabolism, and modulate immune function towards Th-2 polarization - which combined can lower blood cholesterol, reduce obesity, increase insulin sensitivity, decrease atheroma progression, and reduce likelihood of atherosclerotic plaque rupture. Traditional cardiometabolic risk factors, coupled with the mismatch between our evolved immune systems and modern, hygienic environments may interact in complex ways. In this review, we survey existing studies in the non-human animal and human literature, highlight unresolved questions and suggest future directions to explore the role of helminths in the etiology of cardio-metabolic disease.

Evolutionary History of Terrestrial Pathogens and Endoparasites as Revealed in Fossils and Subfossils

The present work uses fossils and subfossils to decipher the origin and evolution of terrestrial pathogens and endoparasites. Fossils, as interpreted by morphology or specific features of their hosts, furnish minimum dates for the origin of infectious agents, coevolution with hosts, and geographical locations. Subfossils, those that can be C14 dated (roughly under 50,000 years) and are identified by morphology as well as molecular and immunological techniques, provide time periods when humans became infected with various diseases. The pathogen groups surveyed include viruses, bacteria, protozoa, fungi, and select multicellular endoparasites including nematodes, trematodes, cestodes, and insect parasitoids in the terrestrial environment.

The enigma of the dog mummy from ancient Egypt and the origin of 'Rhipicephalus sanguineus'

BACKGROUND

Ticks belonging to the Rhipicephalus sanguineus group are amongst the most important vectors of pathogenic microorganisms to dogs and humans. However, the taxonomy of this species group is still the subject of debate, especially because there is no type specimen or reliable morphological description for Rhipicephalus sanguineus sensu stricto. Recently, a comprehensive morphological and genetic study on representative tick specimens from Europe, Africa, Americas, and Oceania, revealed the existence of at least four morphologically and genetically distinct species under the name 'R. sanguineus' infesting dogs from different countries.

METHODS

Herein, we examined morphologically tick specimens retrieved on a dog mummy from Ancient Egypt (ca. 1st century - 4th century A.D.). The dog mummy and associated ticks were found during an archaeological expedition conducted in El Deir.

RESULTS

Scanning electron micrographs allowed us to assess their identity as belonging to the R. sanguineus group. In addition on the basis of the scutal punctation pattern, spiracular plates, width of dorsal tail of spiracular plates relative to the adjacent festoon, female genital aperture, male adanal plates and accessory shields, these ticks were tentatively identified as Rhipicephalus sp. II (=temperate species).

CONCLUSIONS

It can be concluded that R. sanguineus group ticks have infested dogs living in the Mediterranean region since ancient times. This finding represents the oldest record of ticks on any animal species and adds a new piece in the complex puzzle regarding tick parasitism on dogs and humans and their role as vectors of pathogens.

Are fish paratenic natural hosts of the caiman haemoparasite Hepatozoon caimani?

The susceptibility of two fish and four mosquito species to the Caiman yacare haemoparasite Hepatozoon caimani was experimentally investigated. Mosquitoes belonging to four species (Aedes fluviatilis, Aedes albopictus, Aedes aegypti and Culex quinquefasciatus) were blood-fed on two naturally infected C. yacare from the Central-West Region of Brazil that exhibited distinct levels of parasitaemia: caimans A (11.05%) and B (1.25%). None of the engorged A. fluviatilis, A. albopictus or A. aegypti mosquitoes fed on caiman A survived for the duration of the sporogonic cycle; the great majority of the engorged mosquitoes died within 48 h of the blood meal. All A. aegypti fed on caiman B were negative, whereas 91.3% of dissected C. quinquefasciatus fed on the same caiman contained oocysts. Characid fish-Metynnis sp. and Astyanax sp.-were individually fed with C. quinquefasciatus females previously engorged (21-23 days) on caiman B. No parasite was found in the Astyanax fish. By contrast, 100% of the Metynnis fish depicted numerous cysts harbouring cystozoites identical to those of H. caimani, even more than 8 months after the ingestion of the infected mosquitoes. The cysts were located near the veins of the liver and, in some cases, close to the tunica intima of these vessels. No inflammatory reaction was observed. Gametocytes were observed in the blood smears of juvenile caimans that had ingested infected fish 9-12 weeks earlier. The potential role of fish as paratenic vertebrate hosts of H. caimani in nature is discussed.

The changing pattern of parasitic infection among Korean populations by paleoparasitological study of Joseon Dynasty mummies

In the coprolites of 4 recently discovered Joseon mummies of Korea, we found Ascaris lumbricoides , Trichuris trichiura , Metagonimus yokogawai , Paragonimus westermani , and Clonorchis sinensis eggs. The current finding was compared with previous paleoparasitological data, and with recent national survey data from Korea. For A. lumbricoides and T. trichiura , similar patterns of infection prevalence were observed between the national survey of 1961 and our current Joseon data. Some of the trematode species (C. sinenesis and P. westermani) showed much higher infection prevalences among the Joseon Koreans than among their 1960s descendants. The present results indicate that the decrease in trematode infection rates might have begun earlier than was the case for nematode infection.

A redescription of Haemogregarina damiettae Ramadan et al. 1996 naturally infecting the Acanthodactylus boskianus from Egypt, with new merognic data

Haemogregarina damiettae was previously described form Acanthodactylus boskianus in Egypt, and the description was base only on the blood stages with no data on the tissue stages. In the present study, both blood and tissue stages were encountered. The prevalence of infection was found to be 60 % (30/50). The blood stages were found to be confined to the erythrocytes and none in the leucocytes. The erythrocytic stages could be differentiated into small and large forms. The small form, trophozoite, measured 10 × 3 μm, while the large form, mature gamontocyte, measured 18 × 5 μm. The cytoplasm of the mature gamontocyte was finely granular and faintly stained with Giemsa, while the nucleus was relatively large and occupied about one third of the body length and was formed of a network of chromatin filaments. Infected erythrocytes were hypertrophied and their nuclei either longitudinally stretched or split into two fragments. The tissue stages were observed in the lungs and hearts of the infected lizards. The merogonic stages were evident as multinucleated ovoid to subspherical bodies enclosed by parasitophorous vacuoles. Mature meronts measured 16 × 12 μm and estimated to produce 15-25 merozoites.

Zoonotic and human parasites of inhabitants of Cueva de los Muertos Chiquitos, Rio Zape Valley, Durango, Mexico

We present the first reconstruction of the parasitoses among the people of the Loma San Gabriel culture, as represented by 36 coprolites excavated from the Cueva de los Muertos Chiquitos in Durango, Mexico. The coprolites date to approximately 1,400-yr-ago. Species identified based on eggs recovered include the trematode Echinostoma sp., the tapeworms Hymenolepis sp. and Dipylidium caninum , and the nematodes Ancylostoma duodenale, Enterobius vermicularis, and Trichuris trichiura. After rehydration and screening, 2 methods were used to recover eggs from these samples including spontaneous sedimentation and flotation. Samples were analyzed by 3 different laboratories for independent verification and comparison of methods. Spontaneous sedimentation resulted in the discovery of hymenolepidid eggs that were not found with flotation. Sedimentation was a more-sensitive indicator of prevalence as well. The modified method of flotation permitted estimation of egg concentration and resulted in the detection of a few specimens not found by sedimentation. The results of both methods showed that 19 (of 36) coprolites contained helminth eggs. Our results detected the presence of pathogenic helminths including hookworms and whipworms. The cestodes found do not cause severe pathology in humans. The early dates of hookworm and whipworm, relative to other findings in the southwest United States, indicate that these parasites arrived relatively late in prehistory in Arizona and New Mexico, probably moving into the area with travelers from Mesoamerica.

Anurans as paratenic hosts in the transmission of Hepatozoon caimani to caimans Caiman yacare and Caiman latirostris

Prevalence of Hepatozoon caimani has been reported in 76% of caimans Caiman yacare from the Pantanal region. Culex (Melanoconion) spp. mosquitoes were recently identified as natural vectors of this parasite. However, culicids are not typically eaten by crocodilians, suggesting that the main transmission route is through ingestion of insectivorous vertebrates, such as anurans. The susceptibility of wild frogs Leptodactylus chaquensis, Leptodactylus podicipinus and Scinax nasicus to infection by H. caimani was verified. Wild-caught anurans were force fed with sporulated oocysts from laboratory-bred Culex (Melanoconion) mosquitoes. Frogs were killed 30 days postinfection, and their internal organs were fed to caimans C. yacare and Caiman latirostris. Cystozoites were identified in fresh liver impression smears of L. chaquensis. C. yacare fed on anuran organ presented gametocytes in peripheral blood circulation between 74 and 80 days postinoculation (dpi). Gametocytes were also verified in C. latirostris fed on the internal organs of L. podicipinus and S. nasicus between 60-70 and 69-75 dpi, respectively. Since frogs used in experiment are sympatric with C. yacare and C. latirostris and may occur in the diet of these caimans, the results suggest these amphibians are paratenic hosts in the natural transmission cycle of H. caimani in Pantanal.

First paleoparasitological results from late Holocene in Patagonian coprolites

These are the first paleoparasitological results from the Late Holocene in Patagonian coprolites. Coprolites collected from layers dated at 3,480 and 2,740 yr before present (B.P.), from the archaeological site Cerro Casa de Piedra, were examined. The site is a hill located in a forest steppe ecotone in Perito Moreno National Park. The coprolites could belong to humans or to other carnivores such as canids. After rehydration and spontaneous sedimentation of the samples, the parasite contents were examined. Results obtained showed the common presence of eggs of a Calodium sp., eggs of other capillariids and trichostrongylids, oocysts of Eimeria macusaniensis (Apicomplexa), and eggs of taeniids (Cestoda). Although the generic identification of some parasites could not be provided, the presence of tapeworm eggs represents the first record for the Late Holocene in Patagonia and shows that parasitism by cestodes existed in the region in pre-Columbian times. Results indicate that in the Late Patagonic Holocene, zoonotic helminths may have been commonly present in the inhabitants of Patagonia. The parasites found in the coprolites allow us to deduce what these people were eating and, thus, indicate what other pathogens, such as viruses, bacteria, and parasitic protozoans, may have infected them via the same sources.

Biological risks associated with consumption of reptile products

The consumption of a wide variety of species of reptiles caught from the wild has been an important source of protein for humans world-wide for millennia. Terrapins, snakes, lizards, crocodiles and iguanas are now farmed and the consumption and trade of their meat and other edible products have recently increased in some areas of the world. Biological risks associated with the consumption of products from both farmed and wild reptile meat and eggs include infections caused by bacteria (Salmonella spp., Vibrio spp.), parasites (Spirometra, Trichinella, Gnathostoma, pentastomids), as well as intoxications by biotoxins. For crocodiles, Salmonella spp. constitute a significant public health risk due to the high intestinal carrier rate which is reflected in an equally high contamination rate in their fresh and frozen meat. There is a lack of information about the presence of Salmonella spp. in meat from other edible reptilians, though captive reptiles used as pets (lizards or turtles) are frequently carriers of these bacteria in Europe. Parasitic protozoa in reptiles represent a negligible risk for public health compared to parasitic metazoans, of which trichinellosis, pentastomiasis, gnathostomiasis and sparganosis can be acquired through consumption of contaminated crocodile, monitor lizard, turtle and snake meat, respectively. Other reptiles, although found to harbour the above parasites, have not been implicated with their transmission to humans. Freezing treatment inactivates Spirometra and Trichinella in crocodile meat, while the effectiveness of freezing of other reptilian meat is unknown. Biotoxins that accumulate in the flesh of sea turtles may cause chelonitoxism, a type of food poisoning with a high mortality rate in humans. Infections by fungi, including yeasts, and viruses widely occur in reptiles but have not been linked to a human health risk through the contamination of their meat. Currently there are no indications that natural transmissible spongiform encephalopathies (TSEs) occur in reptilians. The feeding of farmed reptiles with non-processed and recycled animal products is likely to increase the occurrence of biological hazards in reptile meat. Application of GHP, GMP and HACCP procedures, respectively at farm and slaughterhouse level, is crucial for controlling the hazards.

Colonization with Heligmosomoides polygyrus suppresses mucosal IL-17 production

Helminth exposure appears to protect hosts from inappropriate inflammatory responses, such as those causing inflammatory bowel disease. A recently identified, strongly proinflammatory limb of the immune response is characterized by T cell IL-17 production. Many autoimmune type inflammatory diseases are associated with IL-17 release. Because helminths protect from these diseases, we examined IL-17 production in helminth-colonized mice. We colonized mice with Heligmosomoides polygyrus, an intestinal helminth, and analyzed IL-17 production by lamina propria mononuclear cells (LPMC) and mesenteric lymph node (MLN) cells. Colonization with H. polygyrus reduces IL-17A mRNA by MLN cells and inhibits IL-17 production by cultured LPMC and MLN cells. Helminth exposure augments IL-4 and IL-10 production. Blocking both IL-4 and IL-10, but not IL-10 alone, restores IL-17 production in vitro. Colonization of colitic IL-10-deficient mice with H. polygyrus suppresses LPMC IL-17 production and improves colitis. Ab-mediated blockade of IL-17 improves colitis in IL-10-deficient mice. Thus, helminth-associated inhibition of IL-17 production is most likely an important mechanism mediating protection from inappropriate intestinal inflammation.

Minimum requirements for ookinete to oocyst transformation in Plasmodium

During their passage through a mosquito vector, malaria parasites undergo several developmental transformations including that from a motile zygote, the ookinete, to a sessile oocyst that develops beneath the basal lamina of the midgut epithelium. This transformation process is poorly understood and the oocyst is the least studied of all the stages in the malaria life cycle. We have used an in vitro culture system to monitor morphological features associated with transformation of Plasmodium berghei ookinetes and the role of basal lamina components in this process. We also describe the minimal requirements for transformation and early oocyst development. A defined sequence of events begins with the break-up of the inner surface membrane, specifically along the convex side of the ookinete, where a protrusion occurs. A distinct form, the transforming ookinete or took, has been identified in vitro and also observed in vivo. Contrary to previous suggestions, we have shown that no basal lamina components are required to trigger ookinete to oocyst transformation in vitro. We have demonstrated that transformation does not occur spontaneously; it is initiated in the presence of bicarbonate added to PBS, but it is not mediated by changes in pH alone. Transformation is a two-step process that is not completed unless a range of nutrients are also present. A minimal medium is defined which supports transformation and oocyst growth from 7.8 to 11.4 μm by day 5 with 84% viability. We conclude that ookinete transformation is mediated by bicarbonate and occurs in a similar manner to the differentiation of sporozoite to the hepatic stage.

Haematozoan parasites of the lizard Ameiva ameiva (Teiidae) from Amazonian Brazil: a preliminary note

Three different haematozoan parasites are described in the blood of the teiid lizard Ameiva ameiva Linn. from North Brazil: one in the monocytes and the other two in erythrocytes. The leucocytic parasite is probably a species of Lainsonia Landau, 1973 (Lankesterellidae) as suggested by the presence of sporogonic stages in the internal organs, morphology of the blood forms (sporozoites), and their survival and accumulation in macrophages of the liver. One of the erythrocytic parasites produces encapsulated, stain-resistant forms in the peripheral blood, very similar to gametocytes of Hemolivia Petit et al., 1990. The other is morphologically very different and characteristically adheres to the host-cell nucleus. None of the parasites underwent development in the mosquitoes Culex quinquefasciatus and Aedes aegypti and their behaviour in other haematophagous hosts is under investigation. Mixed infections of the parasites commonly occur and this often creates difficulties in relating the tissue stages in the internal organs to the forms seen in the blood. Concomitant infections with a Plasmodium tropiduri-like malaria parasite were seen and were sometimes extremely heavy.