Volume 57, Issue 1

Although Giardia duodenalis is considered a parasite of mammals, different genotypes have been identified as infecting several species of freshwater and marine fish in Australia. Establishment of G. duodenalis infection in common laboratory zebrafish (Danio rerio), could provide an excellent tool for a range of studies on Giardia. We conducted preliminary experiments to investigate this possibility. Zebrafish were inoculated with viable G. duodenalis cysts from two different Assemblages (A and D) using a modified oro-gastric tube. Direct microscopy and immunofluorescent antibody test were used to check for Giardia cysts/trophozoites in the intestine, and histology was performed on intestinal mucosa to evaluate possible pathological changes. Giardia cysts were successfully deposited in the zebrafish alimentary tract using a modified oro-gastric tube, and were maintained in the fish gut for at least 8 days. Although a single trophozoite was observed in one fish three days post-exposure, we were unable to demonstrate established, propagative infection under the conditions tested.

Toxoplasma gondii and Neospora caninum are closely related protozoan parasites, they share many common hosts, and can cause neurological diseases in dogs. Dogs can have close contacts with humans and livestock and therefore they can act as reservoirs of these parasites. The aim of this study was to survey the seroprevalence of antibodies against T. gondii and N. caninum and their co-infection rate in dogs in Korea. In total, sera from 553 domestic dogs were collected from different breeds, sexes, and ages of dogs from nine provinces across the country of Korea during 2006 and 2007. The presence of antibodies against T. gondii and N. caninum was analyzed using the latex agglutination test (LAT) with a cut-off value of 1:32, and the indirect fluorescent antibody test (IFAT) using a serum titer of 1:100. In the total dog population, 71 (12.8%) dogs were positive for anti-T. gondii antibodies and only 20 (3.6%) were positive for anti-N. caninum antibodies. Relatively higher seropositive frequencies of antibodies against T. gondii (20.1%) and N. caninum (4.9%) were detected in the dog population from the Gyeonggi. A higher proportion of animals seropositive for anti-T. gondii antibodies was found in stray dog populations as compared to household dog populations: 18.5% (59/319) vs 5.1% (12/234), respectively. The Chi-square tests revealed significant differences in the seropositive frequencies of antibodies against T. gondii between stray and household dogs in the total population (p<0.0001), and in dogs from the Gyeonggi (p<0.01). No significant differences were observed for the presence of antibodies against T. gondii or N. caninum when compared across the sex or age (p>0.05). The first serological survey on antibodies against both T. gondii and N. caninum parasites across the entire country showed that co-infection was not common in these canine populations with a seropositive level of 0.72%. The significantly higher positive frequency of T. gondii antibodies in stray dogs in both, Gyeonggi and in the total dog populations suggests that further investigation on the seroprevalence of parasites should focus on stray dogs.

Cryptosporidium is an intestinal protozoan parasite prevalent in a wide range of mammals. Although it has been recorded in many hosts, its impact on endangered species is poorly understood. Here we present a preliminary study of four populations of the highly threatened spotted souslik (Spermophilus suslicus), living in the westernmost part of the species range. The populations inhabit fragmented habitats and suffer from loss of genetic variation. An IFA test revealed that 35.9% of sampled animals (41/114) was infected with Cryptosporidium and none with Giardia. The prevalence and infection intensity differed among the populations. In areas grazed by cattle it was about 3 folds higher, which suggests a possible transmission route. To the authors best knowledge the present study is the first report of Cryptosporidium infections in S. suslicus.

The ultrastructure of gamonts and sporulated oocysts of Goussia metchnikovi in the spleen of gudgeon, Gobio gobio from the river Lee, England is described. In developing microgamonts, small amylopectin granules were grouped centrally and nuclei were often arranged peripherally, close to the surface membrane. Nuclear chromatin condensed into peripheral dense portions that became the nuclei of flagellated microgametes, released to the parasitophorous vacuole. The cytoplasm of macrogametes had larger, scattered amylopectin granules, lipid globules and small electron-dense bodies, but no obvious wall forming bodies; peripheral vesicular structures with the appearance of mitochondria were also present and the parasitophorous vacuole contained flocculent material, but was otherwise free of structures. Sporulated oocysts contained four sporocysts and oocyst walls appeared to consist of a single membrane. Sporocyst walls showed a dehiscence suture, characteristic of the genus Goussia, which had filamentous extensions in places. The sporocyst wall comprised a dense inner layer and a thin outer layer with a fuzzy coat, separated by an electron lucent layer. Groups of oocysts were encapsulated by fibrous layers and inflammatory cells, and many sporocysts and their contained sporozoites showed evidence of elimination by the host.

A new strigeid digenean, Strigea inflecta sp. nov., is described from the small intestine of the Red-legged Seriema, Cariama cristata (L.) (Gruiformes, Cariamidae) from Formosa Province, Argentina. This species is characterized by having a body plump, a cup-shaped forebody with a large opening, a sacciform hindbody, without a neck region and strongly curved dorsally, a poorly delimited copulatory bursa, wider than longer, a shallow and asymmetrical genital atrium, and a genital cone well delimited from body parenchyma, strongly muscular, inclined towards the surface ventral of the body. Another digenean species collected from Red-legged Seriema, Brachylaima yupanquii Freitas, Kohn et Ibáñez, 1967 (Brachylaimidae) is described with the addition of new morphological characters and morphometrical data. This species is reported for the first time in Argentina and C. cristata represents a new host record.

The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + “1” trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two lateral expansions accompanied by external ornamentation of the plasma membrane and spinelike bodies characterize the mature sperm. Moreover, a new spermatological character is described for the first time, the so-called cytoplasmic ornamented buttons.

The lectin binding properties of Fasciola hepatica miracidia were studied by a panel of fluorescein- and gold-conjugated lectins (ConA, LCA, WGA, LEA, SBA, HPA and UEA-I). The presence of mannose and/or glucose residues was demonstrated with ConA and LCA as weak diffuse fluorescence of the miracidial surface, which was more intense at the anterior part of the larva. The N-acetylglucosamine-binding lectins WGA and LEA reacted intensely with the whole miracidial surface. No labelling with N-acetylgalactosamine and/or galactose-specific (SBA and HPA) and fucose-specific UEA-I lectins was observed. The possibility that the specific recognition of the miracidial surface carbohydrates by lectins may initiate the process of transformation of the miracidia into sporocysts was examined in vitro in physiological saline for Galba truncatula. Incubation in the presence of ConA and WGA resulted in facilitation of the transformation process. Facilitation was absent in the presence of inhibitor sugars. Incubation in the presence of SBA or UEA-I had no effect. The results suggested a possible impact of carbohydrate-lectin interactions in transformation of miracidia of F. hepatica to sporocysts in vivo.

Sixty-one specimens of the piranha Serrasalmus marginatus Valenciennes, 1837 were analyzed, aiming at assessing the community structure of their gill parasites. The samples were collected in lagoons of the Paraná, Ivinheima and Baia Subsystems within the Upper Paraná River Floodplain (Brazil). Host size and sex had little or no influence on the abundance and prevalence of parasites. The organization of the gill parasite infracommunities of S. marginatus was significantly non-random according to null models and ordination analyses. In general, parasite infrapopulations were not affected by interspecific associations or host characteristics (e.g. size, sex), what highlights the importance of local habitat characteristics to community organization of gill parasites of S. marginatus in the Upper Paraná River Floodplain.

A new species of the genus Hammerschmidtiella, H. eltalaensis sp. nov. parasitizing a brown cockroach Periplaneta brunnea Burmeister from El Tala river, Catamarca, Argentina, is described and illustrated. It is characterized by having the cuticle striated, without lateral alae, mouth with three toothed lips and eight labial papillae, amphids small and pore shaped, buccal capsule short, wide, with four mobile teeth, oesophagus with metacorpus valvate, isthmus cylindrical and thin surrounded by nerve ring, and a rounded basal bulb heavily muscled and valvate, the vulva is slightly protruding and lies in the anterior third of the body, didelphic, prodelphic, eggs small and elongate, the male with one spicule, without gubernaculum, the genital papillae arranged in one pair of small preanal papillae, and two postanal papillae, one pair is the base of the tail appendage. Tail appendage very long, thin, and reaching almost one third of the length of the body in the female. In the male the posterior end of the body abruptly truncated posterior to anus with spine-like long tail appendage.

The objective of this study was to investigate the ascarid infection in Asiatic lions using scat samples, based on microscopic analysis, PCR amplification of the ITS-2 region of ribosomal DNA and sequence analysis of the amplicons. Microscopic analysis indicated the presence of eggs of Toxascaris leonina in eleven of the sixteen scat samples analysed and in one of these eleven scats eggs of Toxocara cati were also detected. In five of the scats eggs were not detectable. The presence of T. leonina in all the infected samples was also confirmed by PCR amplification of the ITS-2 of ribosomal RNA gene and five of these also showed amplicons corresponding to T. cati, respectively. Toxocara canis infection was not observed in any of the scat samples. Nucleotide sequence analysis of the ITS-2 region indicated 97% to 99% similarity with T. leonina and T. cati, respectively. To our knowledge, this is the first molecular characterization of ascarid infection in captive Asiatic lions from a zoological garden of India. This study also indicates that Asiatic lions are more prone to infection either with T. leonina or T. cati and the parasite is not host specific.

A new species of parasitic nematode, Rhabdochona (Rhabdochona) keralaensis sp. nov., is described based on specimens recovered from the intestine of Anguilla bengalensis bengalensis (Gray) collected from the freshwater bodies of Kerala State, southern India. It is characterized mainly by the presence of ten anterior prostomal teeth, absence of basal teeth, simple deirids, length of spicules, number and arrangement of preanal papillae and non-filamented eggs. Two species of camallanid nematodes, adults of Camallanus cotti Fujita, 1927 and a single Procamallanus (Spirocamallanus) sp. fourth-stage larva, were also recorded from A. bengalensis. Camallanus cotti, a pathogenic parasite of many species of wild and aquarium-reared fishes in many countries of South and East Asia, Europe, South and North America, West Indies and Australia, is reported for the first time from a representative of the fish family Anguillidae. Descriptions of R. (R.) keralaensis and Indian specimens of C. cotti, based on light and scanning electron microscopical examinations, are provided. Camallanus oxygasterae Gupta et Bakshi, 1983 is considered a junior synonym of C. cotti.

Increasing knowledge of the biodiversity of parasitic copepods in the Argentinean Sea will provide a baseline against which changes in the distribution of marine biota can be detected. We provide new information on the distribution of 13 known species of parasitic copepods gathered from 11 species of marine fishes from Argentinean Sea, including 7 new host records and 9 new locality records. These species are: Bomolochus globiceps (Vervoort et Ramírez, 1968) and Nothobomolochus cresseyi Timi et Sardella, 1997 (Bomolochidae Sumpf, 1871); Brasilochondria riograndensis Thatcher et Pereira, 2004 (Chondracanthidae Milne Edwards, 1840); Taeniacanthus lagocephali Pearse, 1952 (Taeniacanthidae Wilson, 1911); Caligus rogercresseyi Boxshall et Bravo, 2000 and Metacaligus uruguayensis (Thomsen, 1949) (Caligidae Burmeister, 1835); Hatschekia conifera Yamaguti, 1939 (Hatschekiidae Kabata, 1979); Clavellotis pagri (Krøyer, 1863), Clavella adunca (Strøm, 1762), Clavella bowmani Kabata, 1963 and Parabrachiella amphipacifica Ho, 1982 (Lernaeopodidae Milne Edwards, 1840), and Lernanthropus leidyi Wilson, 1922 and Lernanthropus caudatus Wilson, 1922 (Lernanthropidae Kabata, 1979). A list of host species lacking parasitic copepods, for which large samples were investigated by the authors, is also provided in order to compare in future surveys.

A total of 170 wild birds from Senegal, belonging to 48 species and 9 orders, were searched for lice in 2005 and 2007. Chewing lice were found on 58 birds of 18 species and 5 orders (Columbiformes, Cuculiformes, Coraciiformes, Galliformes and Passeriformes). Twenty-two species of chewing lice of 13 genera were determined. Other nine samples of chewing lice that represent a new host-parasite association were determined at generic level only, because only one sex or nymph of these lice were found. Our records represent the first louse records from passerines Camaroptera brachyura (Cisticolidae), Chalcomitra senegalensis (Nectariniidae), Corvinella corvina (Laniidae), Laniarius barbarus (Malaconotidae), Prinia erythroptera (Cisticolidae) and Turdus pelios (Turdidae). Descriptions and illustrations are given for Brueelia chalcomitrae Najer et Sychra sp. nov. ex Chalcomitra senegalensis (Nectariniidae), Brueelia priniae Najer et Sychra sp. nov. ex Prinia subflava (Cisticolidae), and Philopteroides terpsiphoni Najer et Sychra sp. nov. ex Terpsiphone viridis (Monarchidae).

In the present study we compared the prevalence of Demodex mites in patients with rheumatoid arthritis and in one control group involving individuals of similar mean age. From each person we epilated 3–4 lashes from each eyelid and examined them under a microscope to find Demodex mites. In total 147 patients were examined. The prevalence of Demodex mites was 33% in rheumatoid arthritis (RA) patients and 31% in the control group. Our results demonstrated that the prevalence of Demodex mites was similar in RA patients as compared to the control group.