Phylogenetic relationships and systematics of tapeworms of the family Davaineidae (Cestoda, Cyclophyllidea), with emphasis on species in rodents.

The present study aims at clarifying the poorly known phylogenetic relationships and systematics of cestodes of the family Davaineidae Braun, 1900 (Cyclophyllidea), primarily the genus Raillietina Fuhrmann, 1920 and of the subfamily Inermicapsiferinae (Anoplocephalidae) from mammals (mostly rodents, 31 new isolates) and birds (eight new isolates). Phylogenetic analyses are based on sequences of the large subunit ribosomal RNA gene (28S) and mitochondrial NADH dehydrogenase subunit 1 gene (nad1). The main phylogenetic pattern emerging from the present analysis is the presence of three independent lineages within the main clade of the subfamily Davaineinae, one of which is almost entirely confined to species from rodents and the other two show a mixture of species from birds and mammals. It is suggested that the major diversification of the main clade took place in birds, possibly in galliforms. The subsequent diversification included repeated host shifts from birds to mammals and to other birds, and from rodents to other mammals, showing that colonisation of new host lineages has been the main driver in the diversification of davaineine cestodes. It is also shown that all isolates of Inermicapsifer Janicki, 1910, mainly from rodents, form a monophyletic group positioned among Raillietina spp. in the "rodent lineage", indicating that the genus Inermicapsifer is a member of the family Davaineidae. This means that the subfamily Inermicapsiferinae and the family Inermicapsiferidae should be treated as synonyms of the Davaineidae, specifically the subfamily Davaineinae. Three additional genera generally included in the Inermicapsiferinae, i.e. Metacapsifer Spasskii, 1951, Pericapsifer Spasskii, 1951 and Thysanotaenia Beddard, 1911, are also assigned here to the Davaineidae (subfamily Davaineinae). Raillietina spp. were present in all three main lineages and appeared as multiple independent sublineages from bird and mammalian hosts, verifying the non-monophyly of the genus Raillietina and suggesting a presence of multiple new species and genera.

Data on New Intermediate and Accidental Hosts Naturally Infected with Angiostrongylus cantonensis in La Gomera and Gran Canaria (Canary Islands, Spain).

Angiostrongylus cantonensis is a metastrongyloid nematode and the etiologic agent of angiostrongyliasis, a disease characterized by eosinophilic meningitis. This emerging zoonotic parasite has undergone great expansion, including in some regions of Europe and America. In the Canary Islands, the parasite was first discovered parasitizing Rattus rattus on the island of Tenerife in 2010. To date, the distribution of this parasite in the Canary Islands has been restricted to the northern zone and the main cities of Tenerife. Using molecular tools for the sentinel species present in the Canary Islands, this study confirmed the presence of the nematode on two other islands in the Canary Archipelago: La Gomera and Gran Canaria. Furthermore, this emerging parasite was detected, besides in the common definitive host R. rattus, in wild Mus musculus and Felis catus and in four terrestrial gastropod species, Limacus flavus, Milax gagates, Insulivitrina emmersoni, and Insulivitrina oromii, two of them endemic to La Gomera, for the first time, increasing the number of non-definitive host species. This study reinforces the expansion character of A. cantonensis and highlights the importance of knowledge about sentinel species for identifying new transmission locations that help prevent and control the transmission of the parasite and, thus, prevent public health problems.

Multiple Lineages of Hantaviruses Harbored by the Iberian Mole (Talpa occidentalis) in Spain.

The recent detection of both Nova virus (NVAV) and Bruges virus (BRGV) in European moles (Talpa europaea) in Belgium and Germany prompted a search for related hantaviruses in the Iberian mole (Talpa occidentalis). RNAlater®-preserved lung tissue from 106 Iberian moles, collected during January 2011 to June 2014 in Asturias, Spain, were analyzed for hantavirus RNA by nested/hemi-nested RT-PCR. Pairwise alignment and comparison of partial L-segment sequences, detected in 11 Iberian moles from four parishes, indicated the circulation of genetically distinct hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, demonstrated three distinct hantaviruses in Iberian moles: NVAV, BRGV, and a new hantavirus, designated Asturias virus (ASTV). Of the cDNA from seven infected moles processed for next generation sequencing using Illumina HiSeq1500, one produced viable contigs, spanning the S, M and L segments of ASTV. The original view that each hantavirus species is harbored by a single small-mammal host species is now known to be invalid. Host-switching or cross-species transmission events, as well as reassortment, have shaped the complex evolutionary history and phylogeography of hantaviruses such that some hantavirus species are hosted by multiple reservoir species, and conversely, some host species harbor more than one hantavirus species.

Morphologic and genetic characterization of Pterygodermatites (Mesopectines) valladaresi n. sp. (Nematoda, Rictulariidae), a parasite of the mouse Mus musculus (Rodentia, Muridae) from the Canary Islands (Spain).

A new rictulariid nematode Pterygodermatites (Mesopectines) valladaresi n. sp., parasite of the house mouse Mus musculus (Rodentia: Muridae) in the Canary Islands (Spain) is described by means of light and scanning electron microscopy. The new species belongs to the subgenus Mesopectines characterized by a more or less dorsal orientation of the buccal capsule, the presence of three oesophageal teeth, the morphology of the oral denticles and the Spirurida type of arrangement of caudal papillae in males. The most discriminant characteristics between the new species and the existing species in the subgenus Mesopectines are (a) the number of cuticular projection pairs (62-64), (b) the size of right and left spicules (respectively, 62-90 µm and 123-139 µm), (c) the number of midventral fans in males (3-4), (d) the number of prevulvar/total cuticular projection pairs (38-42/63-71), (e) the posterior differentiation of combs into spines in relation to the position of the vulva and (f) the anterior position of the vulva in relation to the oesophagus-intestine junction in females. Parasitized hosts and geographical distribution are also useful criteria to distinguish P. (Me.) valladaresi n. sp. from the remaining species of the subgenus. In addition, the cox1 sequence of the new species is provided and compared with available data of related species.

Title: Caractérisation morphologique et génétique de Pterygodermatites (Mesopectines) valladaresi n. sp. (Nematoda, Rictulariidae), un parasite de la souris Mus musculus (Rodentia, Muridae) des îles Canaries (Espagne). Abstract: Un nouveau nématode rictulaire, Pterygodermatites (Mesopectines) valladaresi n. sp., parasite de la souris domestique Mus musculus (Rodentia, Muridae) aux îles Canaries (Espagne) est décrit par microscopie optique et électronique à balayage. La nouvelle espèce appartient au sous-genre Mesopectines caractérisé par une orientation plus ou moins dorsale de la capsule buccale, la présence de trois dents œsophagiennes, la morphologie des denticules buccaux et le type Spirurida d'arrangement des papilles caudales chez les mâles. Les caractéristiques les plus discriminantes entre la nouvelle espèce et les espèces existantes du sous-genre Mesopectines sont (a) le nombre de paires de projections cuticulaires (62­64), (b) la taille des spicules droit et gauche (respectivement, 62­90 µm et 123­139 µm), (c) le nombre de bourrelets cuticulaires médio-ventraux chez les mâles (3­4), (d) le nombre de peignes prévulvaires par rapport au nombre total de peignes (38­42/63­71), (e) la transformation en épines des peignes après la vulve et (f) la position antérieure de la vulve par rapport à la jonction œsophage-intestin chez les femelles. Les hôtes parasités et la répartition géographique sont également des critères utiles pour distinguer P. (Me.) valladaresi n. sp. des autres espèces du sous-genre. De plus, la séquence du cox1 de la nouvelle espèce est fournie et comparée aux données disponibles sur les espèces apparentées.

New Data on Pterygodermatites (Pterygodermatites) plagiostoma Wedl, 1861 (Nematoda, Rictulariidae) Parasite of the Algerian Hedgehog Atelerix algirus Linnaeus, 1758 (Eulipotyphla: Erinaceidae) from the Canary Islands.

A redescription of the rictulariid nematode Pterygodermatites (Pterygodermatites) plagiostoma Wedl, 1861, is made by means of light and scanning electron microscopy, including the first data on male specimens. The morphologic study was based on specimens recovered from two Algerian hedgehogs (Atelerix algirus) from Tenerife and Gran Canaria islands (Canary Archipelago, Spain). The main characteristics of P. (P.) plagiostoma males are the presence of 49-53 pairs of cuticular projections, the presence of one or two midventral precloacal fans (generally one), and the size of two unequal spicules, measuring 98-123 µm (right spicule) and 185-236 µm (left spicule). The cloacal papillae are arranged according to the Ascaridida type. They include two precloacal pairs, an unpaired precloacal papilla, one pair lateral to the cloaca, six postcloacal pairs, and a pair of phasmids near the tail tip. Females are mainly characterized by the presence of 71-77 pairs of cuticular projections, with 43-46 pairs of prevulvar combs, by the differentiation from combs to spines at the level of or slightly posterior to the vulva and by the position of the vulva, located posteriorly to the esophagus-intestine junction. Clear differences were found between P. (P.) plagiostoma and related species of the subgenus P. (Pterygodermatites).

Myiasis by Cordylobia anthropophaga (Calliphoridae) in rodents from Cape Verde.

PURPOSE: The tumbu fly, Cordylobia anthropophaga (Diptera: Calliphoridae), is widely distributed in continental tropical and subtropical Africa, being the most common cause of furuncular myiasis in Sub-Saharan Africa. The aim of the present work was to analyze the role of rodents as possible reservoirs of C. anthropophaga in Cape Verde, considering the zoonotic character of this fly species. MATERIALS AND METHODS: A total of 150 peridomestic rodents were studied in Santiago island. For the obtained larvae, morphological and molecular characters were analyzed. RESULTS: Cordylobia anthropophaga was found in 6.4% of the peridomestic Rattus rattus analyzed. The present work unveils the presence of C. anthropophaga in rodents of the African archipelago of Cape Verde, introduced probably with West African humans and/or animals. CONCLUSION: The presence in peridomestic animals, and the wide range of species that this fly can affect, entails a zoonotic risk of myiasis by tumbu fly.

Human parasites as tracers of the evolution of their hosts.

Because parasite data reveal essential information about the behavior and history of their hosts, it is possible to use them as tracers of host evolution. A table built from the analysis of the data contained in the book by Ashford and Crewe "The Parasites of Homo sapiens" allows counting and cross comparing the parasites according to the main descriptors used by the authors: Taxonomic groups, for each group number of parasites species identified in humans; Status, numbers of reported human cases and their dispersion; Geographic distribution, parasite specific richness recorded in biogeographic regions; Habitat, parasite location in or on the human body; Transmission, contamination pathways to man; Hosts, non-human hosts, which have a role in the maintenance of a parasite; Host-specificity status, relative role of man or other hosts in the maintenance of parasite populations. A strong positive correlation is observed between the number of parasites species recorded in humans and the global parasite species richness for each taxonomic group. About 74% of the parasites recorded in humans are rare, sporadic or nowhere common; 10% only are common or abundant worldwide. The Palearctic exhibits the highest parasite species diversity; the Oriental, Nearctic, Neotropical and Aethiopian regions have roughly similar richness values; the Australian Region is the poorest. Earliest domesticated animals, such as dog, cat, cattle or pig, share more parasite species with Humans than tardily domesticated as horse, rabbit or camel. More than one third of our parasites have elected our alimentary canal as a home and about two third are using the digestive tract path for contamination. Time of occupancy of new territories, diversity in feeding habits and commensalism with other animals, widely explain Human particular parasite richness. As suggested by the authors: "There must be few parasitic species which have never had the opportunity to infect a human".

Cryptosporidium spp. in wild murids (Rodentia) from Corsica, France.

Cryptosporidium spp. are worldwide protozoan parasites that can affect to a broad range of vertebrate hosts, including rodents. In the island of Corsica (France), there are no previous data about these protozoa infecting wild rodents. To estimate the distribution and occurrence, a total of 117 wild murine rodents of the species Rattus rattus (84), Mus musculus domesticus (21), Apodemus sylvaticus (11), and Rattus norvegicus (1) were captured in 24 different biotopes. Fecal samples were screened for Cryptosporidium spp. by nested PCR to amplify an 830 bp fragment of the 18S rRNA gene. As general occurrence, 15.4% of the rodents analyzed were positive for Cryptosporidium spp., being detected widely distributed along the island in R. rattus (17.6%) and M. m. domesticus (14.3%). Cryptosporidium viatorum, Cryptosporidium sp. rat genotype II, and Cryptosporidium sp. rat genotype III were successfully identified in R. rattus. The results herein reported provide the first data on Cryptosporidium spp. in wild murine species from a Mediterranean island and constitute the first report of the zoonotic species C. viatorum in R. rattus. Although a low occurrence of Cryptosporidium spp. in murids was obtained and only in one animal the zoonotic species C. viatorum was identified, our results highlight that wild murine rodents from Corsica could mediate in the maintenance and transmission of this protozoan to the environment and other hosts including humans and animals. Further studies are required to better understand the epidemiology of Cryptosporidium spp. in wild rodents from Corsica and their possible public health repercussions.

A Peculiar Distribution of the Emerging Nematode Angiostrongylus cantonensis in the Canary Islands (Spain): Recent Introduction or Isolation Effect?

Angiostrongylus cantonensis is an emerging zoonotic nematode recognized as the leading cause of eosinophilic meningitis in the word. After its discovery in China, it was recorded in 30 countries worldwide. Recently, it has expanded to new areas such as South America and it has been recently found in the Atlantic island of Tenerife (Canary Islands). In order to characterize the distribution of A. cantonensis in the Canary Islands, the lungs of 1462 rodents were sampled in eight islands of the archipelago over 13 years and were then analyzed for A. cantonensis. Remarkably, the parasite was detected only in Tenerife, in Rattus rattus (19.7%) and Rattus norvegicus (7.14%). They were concretely in the northern part of the island, which had a warmer and more humid climate than the south and main cities. The absence of this nematode in other islands with similar environmental conditions could be explained by an isolation effect or by a recent introduction of the parasite in the islands. Besides, the presence in Tenerife of the most invasive lineage of A. cantonensis reinforced the hypothesis of a recent introduction on this island. This study highlights the need to implement control measures to prevent the expansion to other areas in order to avoid the transmission to humans and other animals.

Pathogenic Leptospira species in rodents from Corsica (France).

Leptospirosis is a worldwide emerging zoonotic disease caused by Leptospira species, that in some patients develop severe forms with high mortality. In France, Corsica is the area where the highest incidences have been reported. The present study was focused on the analysis of pathogenic Leptospira species in rodents of Corsica, as these micromammals are the main natural reservoirs of the bacteria, in order to identify the circulating species and to locate possible risk focuses of transmission, as no previous study on the presence of Leptospira species has been carried out in the island. Rattus rattus, Rattus norvegicus, Apodemus sylvaticus and Mus musculus domesticus were captured in the proximity of water sources along Corsica, the detection of pathogenic Leptospira species was carried out by amplification of the LipL32 gene. The bacteria were found in all the rodent species analyzed and widely. The general prevalence was 10.4%, reaching the maximum value in Bastia (45%). Leptospira interrogans and Leptospira borgpetersenii were identified by phylogenetic analysis, but also two sequences which corresponded to an unnamed Leptospira species, only previously found in rodents of New Caledonia. The high incidence of human leptospirosis in Corsica could be partially explained by the wide distribution of pathogenic Leptospira species identified in this study. Also, the presence of an unknown pathogenic species of Leptospira in an area with high prevalence, may be involved in the higher incidence of Leptospirosis in this island, however, the zoonotic capacity of this species remains unknown. The results obtained are interesting for public health since all positive samples were found near water sources and one of the routes of transmission of leptospirosis is contact with contaminated water. This information could help the competent entities to take preventive measures, reducing the incidence of human leptospirosis in Corsica.

Rodents as Reservoirs of the Zoonotic Pathogens Coxiella burnetii and Toxoplasma gondii in Corsica (France).

Coxiella burnetii and Toxoplasma gondii are intracellular pathogens that cause important reproductive disorders in humans and animals worldwide, which translates into high economic losses. The aim of this study was to analyze the possible role of peridomestic small mammals in the maintenance and transmission of C. burnetii and T. gondii in the Mediterranean island of Corsica, by the analysis of the seroprevalence in rodents. Our results showed a wide distribution of C. burnetii and T. gondii in Corsica in Rattus rattus and Mus musculus domesticus. The overall seroprevalence of anti-C. burnetii was 9.32%, being 8.73% from R. rattus and 13.33% from M. m. domesticus. With respect to T. gondii, seropositive rodents were observed in 12.96% of total animals, being 12.76% from rats and 14.29% from mice. Taking into consideration the large range of host these pathogens can infect, including humans and livestock, and their pathologies, the results provided by this study are relevant for public health and veterinary, and could help the governmental entities to prevent possible infectious focuses of Q fever and toxoplasmosis.

First ocular report of Gurltia paralysans (Wolffhügel, 1933) in cat.

A two-year-old cat from Tenerife, Canary Islands (Spain), presented with two months history of uveitis in the left eye. It had been treated for two months but still showed an active uveitis. After new treatment, eye examination showed a mobile worm in the anterior chamber. Following surgical removal, the worm was obtained. Morphological study revealed that it was a male metastrongyloid nematode (Nematoda: Metastrongyloidea) with caudal bursa and two similar spicules. Molecular tools based on the 18Sr RNA gene sequence identified the parasite as Gurltia paralysans, which is a neurotropic nematode previously found in South America. Therefore, this article describes the first report of ophthalmic case of parasitism by G. paralysans, and cites for first time this species out of South America.

Bartonella in Rodents and Ectoparasites in the Canary Islands, Spain: New Insights into Host-Vector-Pathogen Relationships.

Bartonella genus is comprised of several species of zoonotic relevance and rodents are reservoirs for some of these Bartonella species. As there were no data about the range of Bartonella species circulating among rodents in the Canary Islands, our main aim was to overcome this lack of knowledge by targeting both the citrate synthase (gltA) and the RNA polymerase beta subunit (rpoB) genes. A total of 181 small mammals and 154 ectoparasites were obtained in three of the Canary Islands, namely Tenerife, La Palma, and Lanzarote. The overall prevalence of Bartonella DNA in rodents was 18.8%, whereas the prevalence in ectoparasites was 13.6%. Bartonella sequences closely related to the zoonotic species Bartonella elizabethae, Bartonella tribocorum, and Bartonella rochalimae were identified in rodents, whereas two different gltA haplotypes similar to B. elizabethae were also detected in fleas. Furthermore, Bartonella queenslandensis DNA was also identified in rodents. A strong host specificity was observed, since B. elizabethae DNA was only found in Mus musculus domesticus, whereas gltA and rpoB sequences closely related to the rest of Bartonella species were only identified in Rattus rattus, which is probably due to the host specificity of the arthropod species that act as vectors in these islands. Our results indicate that humans may contract Bartonella infection by contact with rodents in the Canary Islands.

Leptospira interrogans in Rodents from Cape Verde.

Leptospirosis is an important worldwide zoonotic disease that can infect both animals and humans. In most cases, leptospirosis is a nonspecific self-limiting illness, but some patients can develop a severe form with a high mortality. This study was carried out in Santiago Island, Cape Verde, in 2012-2013. A total of 62 wild rodents (Rattus rattus and Mus domesticus) were analyzed. The lipL32 gene, present only in pathogenic Leptospira spp., was amplified by PCR, and 16 samples were positive (25.8%). In both rodent species, Leptospira interrogans was identified. The results show the presence of pathogenic Leptospira in the three localities analyzed in Santiago. The presence of L. interrogans demonstrates a serious health risk for the population, since this species has been associated with the most severe form of leptospirosis, the Weil's disease in humans, a severe infection with jaundice, renal failure, and hemorrhage.

Spermatozoon ultrastructure of Thysanotaenia congolensis (Cyclophyllidea, Anoplocephalidae, Inermicapsiferinae): phylogenetic implications.

The mature spermatozoon of Thysanotaenia congolensis, an intestinal parasite of black rat Rattus rattus from Cape Verde, is described by means of transmission electron microscopy. The ultrastructural organization of the sperm cell of T. congolensis follows Levron et al.'s type VII of the Eucestoda. It corresponds to a uniflagellate spermatozoon that presents crested bodies, periaxonemal sheath and intracytoplasmic walls, spiralled cortical microtubules and nucleus spiralled around the axoneme. These characteristics are also present in the spermatozoa of other inermicapsiferines and differ from the characters found in species belonging to the remaining subfamilies of anoplocephalids, namely Anoplocephalinae, Linstowiinae and Thysanosomatinae. Several authors consider the family Anoplocephalidae as a polyphyletic group, and its relationships with the Davaineidae are a matter of controversy. The phylogenetic implications of spermatological ultrastructural features present in inermicapsiferines and in the remaining anoplocephalids are discussed, and the available data on anoplocephalids are compared to similar results in davaineids in order to contribute to a better knowledge of relationships between these cyclophyllidean families.

Bartonella spp. in Small Mammals, Benin.

This study aimed to investigate the prevalence and genetic diversity of Bartonella organisms in small mammals in Cotonou, Benin. We captured 163 rodents and 12 insectivores and successfully detected Bartonella DNA from 13 of the 175 small mammal individuals. Bartonella spp., identical or closely related to Bartonella elizabethae, Bartonella tribocorum, and Bartonella rochalimae, was detected. A potential new Bartonella species, proposed as Candidatus Bartonella mastomydis, was found in three Mastomys individuals and genetically characterized by targeting two housekeeping genes (rpoB and gltA) and the intergenic species region. However, 20.8% of gray rats were found to be infected with Bartonella spp., and none of the black rats analyzed was positive. This work may be important from a public health point of view due to the zoonotic nature of the Bartonella species detected and warrants further investigation on the unknown zoonotic potential of this newly proposed Bartonella species.

First spermatological study in the Atractotrematidae (Digenea, Haploporoidea): the case of Atractotrema sigani, intestinal parasite of Siganus lineatus.

The ultrastructural organization of the mature spermatozoon of the digenean Atractotrema sigani (from Siganus lineatus off New Caledonia) was investigated by transmission electron microscopy. The male gamete of A. sigani exhibits the general morphology described in digeneans with the presence of two axonemes of different lengths showing the 9 + "1" pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies and granules of glycogen. However, the mature spermatozoon of A. sigani has some specific characters such as the morphology of its anterior region and the submembranous electron-dense material. Although similar structures have been reported in some digenean species, the presence of a submembranous electron-dense material describing a complete ring is reported here for the first time in the mature spermatozoon of A. sigani. In addition, sperm characteristics are compared between the Haploporoidea and their supposed close superfamilies, and possible phylogenetic implications of these findings for the Digenea are discussed.

Serological survey of antibodies to Toxoplasma gondii and Coxiella burnetii in rodents in north-western African islands (Canary Islands and Cape Verde).

Coxiella burnetii and Toxoplasma gondii are intracellular parasites that cause important reproductive disorders in animals and humans worldwide, resulting in high economic losses. The aim of the present study was to analyse the possible role of peridomestic small mammals in the maintenance and transmission of C. burnetii and T. gondii in the north-western African archipelagos of the Canary Islands and Cape Verde, where these species are commonly found affecting humans and farm animals. Between 2009 and 2013, 108 black rats (Rattus rattus) and 77 mice (Mus musculus) were analysed for the presence of Coxiella and Toxoplasma antibodies by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IFA), respectively. Our results showed a wide distribution of C. burnetii and T. gondii, except for T. gondii in Cape Verde, in both rodent species. The overall seroprevalence of C. burnetii antibodies was 12.4%; 21.1% for Cape Verde and 10.2% for the Canary Islands. With respect to T. gondii, seropositive rodents were only observed in the Canary Islands, with an overall seroprevalence of 15%. Considering the fact that both pathogens can infect a large range of hosts, including livestock and humans, the results are of public health and veterinary importance and could be used by governmental entities to manage risk factors and to prevent future cases of Q fever and toxoplasmosis.

Intermediate hosts of Angiostrongylus cantonensis in Tenerife, Spain.

The nematode Angiostrongylus cantonensis is the causative agent of human angiostrongyliasis, the main clinical manifestation of which is eosinophilic meningitis. Although this parasite has been found recently in its definitive rat host in Tenerife (Canary Islands, Spain), showing a widespread distribution over the north-east part of the island, there are no available data regarding which snail and/or slug species are acting as intermediate hosts on this island. Consequently, the objective of this work was to determine the possible role of three mollusc species, Plutonia lamarckii, Cornu aspersum and Theba pisana, as intermediate hosts of A. cantonensis in Tenerife. Between 2011 and 2014, 233 molluscs were collected from five biotopes where rats had been found previously to harbor either adult worms or antibodies against A. cantonensis, and the identification was carried out on the basis of morphological features and a LAMP technique. The prevalence of A. cantonensis larvae in the mollusc samples, based on morphological identification, was 19.3%, whereas 59 out of the 98 individuals (60.2%) analyzed by LAMP were positive. Positive results were obtained for the three mollusc species analyzed and two of the positive samples, both obtained from P. lamarckii, were confirmed as positive by 18S rRNA and ITS1 PCR. Sequence analysis of 18S rRNA PCR products showed 100% similarity with previously published A. cantonensis sequences. These results may be relevant from a public health point of view, since all the biotopes from which the samples were obtained were in inhabited areas or areas with human activity, but it is also important from the perspective of a possible transmission to other accidental hosts, such as dogs and horses, animals that are present in some of the areas analyzed.

Functional ultrastructure of the parenchymatic capsules of the cestode Thysanotaenia congolensis (Cyclophyllidea, Anoplocephalidae, Inermicapsiferinae).

Proglottids from adult Thysanotaenia congolensis from naturally infected black rats Rattus rattus from Santiago Island, Cape Verde, were examined by transmission electron microscopy (TEM). The uterus in mature proglottids is composed of an ephemeral transverse tube or sac that breaks down, releasing eggs into the parenchyma where they are sequestered in groups and encapsulated by parenchymatous layers. In gravid proglottids, eggs accumulate in groups of 6-12 at the distal end of sac-like uterine ducts. As eggs accumulate, the end of the uterine ducts expands until it pinches off, releasing groups of eggs into the parenchyma surrounded by remnants of uterine epithelium. These epithelium-bound groups of eggs remain in the parenchyma until they are encapsulated with several parenchymatous layers, forming parenchymatic egg capsules, typical for mature and gravid proglottids of Inermicapsiferinae. The parenchymatic capsules originate from the medullary parenchyma of immature proglottids, which undergoes differentiation into the three layers of gravid proglottids: (1) an outer connective tissue layer composed of long delicate filaments of unknown chemical nature embedded in a granular extracellular matrix; (2) a middle layer appearing as an accumulation of large closely packed PAS-positive mucous goblets that are intensely metachromatic after toluidine blue staining and (3) an inner compact layer composed of lipid-containing cells, muscle cells with elongated muscle fibres and cells of various sizes and shapes forming or containing calcareous corpuscles. The mature hexacanths of T. congolensis are surrounded by reduced oncospheral envelopes consisting of remnants of a very thin membranous layer of degenerating embryophore with long, irregularly shaped cytoplasmic processes and by remnants of uterine epithelium extending as numerous apical microlamellae into the parenchymatic capsule lumen.