We studied patterns of variation in cestode communities of 3 abundant rodent species that live in sympatry in the Niayes of the Retba Lake, Western Senegal. We evaluated whether the host species have the same parasites and, within host species, whether the variability in parasite community is related to intrinsic (sex, age of the host individual) or extrinsic (habitat, season) factors. Arvicanthis niloticus was parasitized by 2 cestode species, namely Inermicapsifer madagascariensis and the highly dominant Raillietina trapezoïdes. Raillietina baeri was the only cestode species found in Mastomys erythroleucus, and there was no cestode in M. huberti. Prevalence and abundance levels of cestodes were very high in A. niloticus, especially in adults. Seasonal and habitat effects were found in both cestode communities of M. erythroleucus and A. niloticus. Local host specificity and abundance/prevalence levels suggested variations in the interaction between rodents and cestode intermediate host species among habitats and seasons.

Gyrocerviceanseris passamaquoddyensis n. gen., n. sp. is described from the gills of silver hake, Merluccius bilinearis, in Passamaquoddy Bay, southwestern New Brunswick, Canada. Diagnostic features include an oval haptor with asymmetrically distributed marginal hooks (3 pairs anterior, 5 pairs posterior) and a prominent muscular flange on the lateral margins, between the anterior and posterior groups of hooks. The hamuli are well developed, with a straight point, a short shaft, and an elongate, blade-like ventral root having a ventrally directed, gooseneck-shaped tip. The ventral bar is rectangular, with a small, hourglass-shaped posterior membrane. There is no dorsal bar. The marginal hook sickle is sharply curved, with a long fine point, an upturned toe, a small heel, and a straight handle. A partial DNA sequence from 18S rDNA was generated and found to be over 11% divergent from its closest matches in GenBank. However, it was less divergent (7.8%) from a previously unpublished sequence of Gyrodactylus emembranatus Malmberg, 1970, suggesting this species is its closest known relative. Interestingly, both species have almost identical marginal hook sickles and a male copulatory organ (MCO) with small spines in multiple arched rows. Gyrocerviceanseris n. gen. is the sixth genus of viviparous monogeneans to be described from marine and estuarine fishes of the northwestern Atlantic Ocean.

The first case of myiasis in the anuran Hypsiboas beckeri Caramaschi and Cruz by Lepidodexia centenaria n. sp. (subgenus Notochaeta) is reported, from the Serra da Pedra Branca, Minas Gerais, in southeastern Brazil. The new species differs from closely related species mainly by the straight apex of the phallus, the ventrally broader vesica, and the shape of the juxta and median and lateral styli. The new species appears to be host-specific to H. beckeri and endemic to high-altitude regions of the Brazilian Atlantic Forest, in contrast to the habitat- and host-generalist Lepidodexia (N.) bufonivora.

Four new species of Peniculisa Wilson, 1917, are described from marine fishes caught in coastal waters of southwestern Japan. Peniculisa elongata n. sp., Peniculisa crassa n. sp., and Peniculisa uchinah n. sp. are distinguishable from Peniculisa furcata (Krøyer, 1863), Peniculisa bellwoodi Boxshall, 1989, and Peniculisa wilsoni Radhakrishnan, 1977, in the lack of rami on legs 1 to 4, the lack of leg 5, and the possession of a trunk with prominent anterior shoulders. Peniculisa elongata n. sp. is separated from the remaining 2 known and 3 new congeners, Peniculisa bicaudata Shiino, 1956, Peniculisa shiinoi Izawa, 1965, P. crassa n. sp., Peniculisa ohirugi n. sp., and P. uchinah n. sp. by a pair of long, slender caudal processes, a compact cephalothorax, and its trunk with posteroventral lobes projecting posteriorly. Peniculisa crassa n. sp. can be discriminated from them by its pair of short, thick caudal processes, a comparatively large and thick cephalothorax in relation to its body, and its abdominal processes widest at base. Peniculisa uchinah n. sp. is distinguished from all other congeners by the possession of a pair of relatively long, slender, and proportionately long caudal processes, and a long abdominal process widest near the posterior end. Peniculisa ohirugi n. sp. is identified by a pair of long, divergent abdominal processes extending the tip of caudal rami, and by the location of leg 4 on the neck region.

In some regions of the world, co-existence of schistosomiasis and hepatitis C (HCV) infection is common. Because the morbidity in human schistosomiasis is primarily due to host cell-mediated immune response, it was of interest to determine the effects on Schistosoma mansoni infection of an immune stimulator used in the standard treatment of HCV infection. Schistosoma mansoni-infected mice were treated with PEG-interferon-α-2a (PEG-IFN-α) by subcutaneous injection. Groups 1, 2, and 3 received 0.2 µg, 0.6 µg, and 1 µg PEG-IFN-α/wk, respectively, while group 4 received saline. The total worm burden was lower in all treated groups, with a maximal reduction of 35% after 9 wk of treatment with 1 µg PEG-IFN-α. Interferon treatment also increased the proportion of single worms over pairs. Ova counts in intestine and liver, as well as the number of liver granulomas, were greatly decreased at all time points for all treated groups. PEG-IFN-α also had inhibitory effects on the size of granulomas after 4 wk of treatment. The results suggest that PEG-IFN-α may be worth investigating for the treatment of human schistosomiasis when standard oral agents cannot be used, or when rapid inhibition of granuloma formation may be a priority.

Worldwide comparison of Toxoplasma gondii isolates from free-range chickens (Gallus domesticus) has indicated that T. gondii isolates from Brazil are phenotypically and genetically different from isolates from other countries; most strains from Brazil are pathogenic to mice, there is great genetic variability, most isolates are nonclonal, and Type II is absent or rare. The prevalence of T. gondii in 50 free-range chickens from the island of Fernando de Noronha, Brazil (this island is 350 km from the mainland) was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT); 42 (84%) chickens had titers of 1∶5 in 2, 1∶10 in 4, 1∶20 in 3, 1∶40 in 6, 1∶80 in 6, 1∶160 in 5, 1∶320 in 3, and 1∶640 or higher in 13 chickens. Hearts of 40 seropositive chickens were bioassayed individually in mice. Toxoplasma gondii was isolated from 24 chickens with MAT titers of 1∶5 or higher; the isolates were designated TgCKBr210-233. None of the isolates was pathogenic for mice. The restricted fragment length polymorphism using 10 markers revealed 6 genotypes, including the Type II, Type III, and 4 new chicken genotypes (#59–#62) that were different from genotypes so far reported in Brazil. All 24 isolates were successfully genotyped; 15 isolates were Brazil chicken type #59, 1 type #60, 1 type #61, 1 type #62; 5 were Type II (with Type I allele at the Apico locus); and 1 isolate was clonal Type III. Results in this study indicate that T. gondii on this island consists of unique genotypes as well as clonal genotypes that are dominant in Europe and North America.

Most strains of Toxoplasma gondii isolated in North America and Europe are grouped into 3 (Types I, II, III) genotypes and are considered clonal. Recent evidence suggests that illness due to toxoplasmosis in immunocompetent persons may be related to infection with an atypical genotype; these strains are mouse virulent. In the present study, a new mouse-virulent atypical T. gondii genotype was isolated from an asymptomatic black bear (Ursus americanus) from Alaska. The bear had a titer of 1∶1,600 using the modified agglutination test for T. gondii. Swiss Webster out-bred mice inoculated with bear heart homogenate died of acute toxoplasmosis, 12 days post-inoculation (PI). Cats fed tissues from chronically infected animals (day 30 PI) shed oocysts, but only 1 of 3 cats fed acutely infected mice (12, 16, 18 days PI) shed oocysts. The isolate (designated TgBbUS1) was mouse virulent; mice inoculated with 1 oocyst or 1 tachyzoite died of acute toxoplasmosis. The restricted fragment length polymorphism using 10 markers revealed that the strain possessed an atypical genotype: type I allele at loci SAG1, (5′-3′)SAG2, SAG3, c22-8, c29-2, L358, and Apico; type II allele at locus alt.SAG2; and type III allele at loci BTUB, GRA6, and PK1. DNA sequencing at intron loci EF1, HP2, and UPRT1 revealed that the TgBbUS1 is a divergent T. gondii strain. These results indicate that mouse-virulent atypical T. gondii genotypes are also circulating in wildlife in North America.

Neospora caninum is an intracellular protozoan pathogen that causes abortion in cattle. This parasite elicits a typical type 1 immune response in host animals, and it is widely believed that the strong type 1 immune response during pregnancy may result in fetal death. Pro-inflammatory and/or inflammatory cytokines produced during either primary or secondary pathogen exposure are supposed to be the mediators of abortion. The present study defined cytokine production by murine naïve dendritic cells and spleen cells in response to whole Neospora tachyzoites (live, heat-killed, freeze-killed) or whole-cell tachyzoite lysate in the form of total (NcAg), soluble (sNcAg), or insoluble antigen (isNcAg). All tachyzoite and antigen preparations at high doses stimulated high levels of interleukin (IL) -12, interferon (IFN) -γ, and tumor necrosis factor (TNF) -α, except for heat-killed tachyzoites and sNcAg, which induced moderate level of IL-12 and very low levels of IFN-γ and TNF-α. In general, whole N. caninum tachyzoites were more effective in inducing IL-12, IFN-γ, and TNF-α than the lysate antigen preparations. It appears that the heat-killed N. caninum tachyzoites were less potent in eliciting IFN-γ or IL-10, but more effective in inducing IL-4. Thus, heat-inactivated tachyzoites or sNcAg alone may not be powerful enough to elicit strong type 1 immune responses against the disease. The present study comprehensively studied the production of critical cytokine by the murine dendritic cells and spleen cells in response to N. caninum; these results may facilitate a better understanding of antigen priming and aid in the design of vaccines/adjuvants against neosporosis.

Halipegus eccentricus is a common hemiurid trematode in the eustachian tubes of North America frogs. However, the life cycle of this species has never been completely elucidated. Studies on H. eccentricus suggest that it has a 3-host life cycle. Here, we show through fieldwork and host specificity experimental infections that the life cycle of Halipegus eccentricus utilizes 4 hosts. Metamorphosed anurans become infected with H. eccentricus by feeding on infected damselflies; worms reside in the stomach of anurans, migrate to the eustachian tubes within 32–39 days post-exposure (DPE), and release eggs 50–60 DPE. Cystophorous cercariae develop in Physa gyrina snails within 32–35 DPE, infect ostracod (Cypridopsis sp.) second intermediate hosts, and develop to metacercariae. Fifteen- to 19-day-old metacercariae from ostracods are infective to both damselfly larvae and metamorphosed anurans. Field surveys of damselflies and tadpoles, along with laboratory exposure of damselfly larvae, metamorphosed anurans, and tadpoles with infected ostracods, indicated that only metamorphosed anurans and damselflies become infected with H. eccentricus, whereas field-collected tadpoles and laboratory-exposed tadpoles were never infected with H. eccentricus. Because little morphological change occurred in the metacercaria stage of H. eccentricus between the ostracod second intermediate host and damselfly host, and metamorphosed anurans became infected with H. eccentricus metacercariae recovered from both host groups, we suggest that odonates serve as paratenic hosts in this life cycle. Additionally, our field work and experimental infections provide data on the use of odonates as the route of infection by another North American Halipegus sp. that matures in the stomach of frogs. Our data indicate that when the life cycles are known, the use of odonates as the route of infection to anurans is common in the life cycles of Halipegus spp., and all species exhibit remarkable infection site fidelity in their amphibian hosts.

The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans (Clinostomum sp., Glypthelmins quieta, Haematoloechus sp., and Langeronia macrocirra), 5 nematodes (Aplectana itzocanensis, Cosmocerca podicipinus, Foleyellides striatus, Oswaldocruzia subauricularis, and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta, L. macrocirra, and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana, Cosmocerca, Foleyellides, and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins, Haematoloechus, and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

Maritrema madrynensis n. sp. is described from the Patagonian coast, Argentina, based on naturally obtained adults from the kelp gull Larus dominicanus and cultured metacercariae from the crab Cyrtograpsus altimanus. The new species fits into the “eroliae complex” and can be distinguished from other related species mainly in shape, size, and distribution of the spines on the cirrus and vitellarium in a complete ring in all specimens. Based on morphological and morphometric features of the naturally and experimentally obtained specimens and the trophic relationship between invertebrate and vertebrate hosts, we suggest that the crab C. altimanus acts as a second intermediate host of M. madrynensis n. sp. This is the first report of a Maritrema species in Patagonia and the southernmost record for the genus.

Single individuals of 2 little-known cetacean species, Mesoplodon hectori and Phocoena dioptrica, stranded and died on the coast of Argentina (Buenos Aires and Chubut provinces, respectively) and were studied for the presence of helminths. The cestodes found were described and illustrated using light microscopy. The following cestode taxa were recovered: Tetrabothrius (Tetrabothrius) hobergi n. sp. (several fragmented specimens, at least 1 gravid) and Tetrabothrius (s.l.) sp. 1 (several fragmented immature specimens) from M. hectori, and Tetrabothrius (s.l.) sp. 2 (single fragmented immature specimen) and 2 morphotypes of tetraphyllidean larvae from P. dioptrica. Tetrabothrius (T.) hobergi n. sp. can be distinguished from Tetrabothrius (T.) forsteri by the greater number of testes and larger eggs and oncospheres, from Tetrabothrius (T.) curilensis by the smaller testes and vitellarium, the shape and size of the ovary, and the larger oncospheres and longer embryonic hooks, and from Tetrabothrius (T.) sp. from Ziphius cavirostris by the narrower strobila, smaller scolex, and smaller number of testes. The generic designations of Tetrabothrius (s.l.) sp. 1 and Tetrabothrius (s.l.) sp. 2 were based on the scolex morphology. Tetrabothrius (s.l.) sp. 1 is closest to Tetrabothrius (T.) forsteri and Tetrabothrius (Biamniculus) innominatus based on the number of testes, while the scolex size of Tetrabothrius (Tetrabothrius) sp. 2 is within the variability range reported for Tetrabothrius (T.) forsteri. More definite identification of the 2 species was not possible due to the condition of the available material. The present study provides the first descriptions of cestodes from M. hectori and P. dioptrica, thus enriching the knowledge regarding the helminths of insufficiently studied marine mammals.

Marine spirorchiid trematodes are associated with morbidity and mortality in sea turtles worldwide. The intermediate hosts remain unknown, and discovery efforts are hindered by the large number and great diversity of potential hosts within sea turtle habitats, as well the potential for low prevalence and overdispersion. A high-throughput DNA extraction and polymerase chain reaction–based method was developed to detect the internal transcribed spacer 2 (ITS2) region of the ribosomal gene of 2 spirorchiid genera, Learedius and Hapalotrema, within pooled samples of gastropod tissues. A model system consisting of freshwater snail (Pomacea bridgesii) tissues and DNA extracts spiked with adult Learedius learedi and known quantities of spirorchiid DNA was used to develop and test the technique. Threshold of detection was found to be equivalent to an early prepatent infection within 1.5 g of gastropod tissue. This technique was used to screen approximately 25 species of marine gastropods at a captive facility where green turtles (Chelonia mydas) become infected by L. learedi. The parasite was detected in a sample of knobby keyhole limpet (Fissurella nodosa), thus providing the first evidence of an intermediate host for a marine spirorchiid trematode. This technique has many potential applications in trematode life cycle discovery studies.

Chagas' disease, induced by Trypanosoma cruzi, is a common cause of infectious myocarditis. Recent clinical treatment trials and vaccine studies indicate that chagasic immunopathology is directed against the parasite and not self-antigens. Therefore, vaccines may have the potential to protect against disease progression. Certain combinations of mouse and parasite strains produce significant histopathology and can be used for safety analyses of new vaccination strategies. The goals of this study were to determine (1) whether the development of chagasic cardiomyopathy in the murine model could be identified by electrocardiogram (ECG); and (2) whether these potential chagasic ECG changes would correlate with histopathologic findings. Groups of BALB/c, C57BL/6, and C3H mice were infected with different parasite strains (Tulahuén, Brazil, or Sylvio-X10/4) and evaluated weekly by ECG. Selected tissues from subsets of mice were harvested periodically for blinded histologic evaluation. Significantly increased proportions of BALB/c mice infected with Brazil and Tulahuén strain parasites displayed prolonged QT intervals. Prolonged mean QT intervals detected in infected BALB/c mice significantly correlated with chagasic histopathologic changes. These results indicate that ECG can be used as a non-invasive method to screen for immune-mediated damage resulting in chagasic cardiomyopathy in the murine model.

Macroscopic sarcocysts are often observed in ducks, but at present their taxonomic status remains uncertain because ducks serve as intermediate hosts for several such parasites in the genus Sarcocystis. One such species, Sarcocystis rileyi, was long ago established to involve the northern shoveler duck (Anas clypeata) and the striped skunk (Mephitis mephitis) as its intermediate and definitive hosts, respectively. Here, we employed light microscopy, electron microscopy, and DNA sequencing to more precisely describe diagnostic attributes of parasites presumed to represent S. rileyi occurring in a naturally-infected mallard duck (Anas platyrhynchos). By light and transmission electron microscopy, sarcocysts from the mallard duck resembled the S. rileyi described from A. clypeata. We document 18S, ITS-1, and 28S rDNA sequences from the mallard duck, the first for S. rileyi from any host. Sequences of conserved and variable portions of nuclear ribosomal DNA indicated that S. rileyi is related to, but distinct from, parasites employing opossums as their definitive host (including Sarcocystis neurona and Sarcocystis falcatula). Diagnostic ultrastructural features and nucleotide sequences should aid in future studies and communications regarding this parasitic taxon, which lends itself to experimentation because its sarcocysts are macroscopic and easily excised from infected birds.

A new nematode species, Capillaria acanthopagri n. sp. (Capillariidae), is described from the intestine of the marine fish (black porgy) Acanthopagrus schlegelii schlegelii (Bleeker) from coastal waters of the western north Pacific Ocean off Kochi, Shikoku Island, Japan. The new species, belonging to the subgenus Neocapillaria Moravec, 1987, differs from other congeneric species of this subgenus from marine fishes (with the exception of C. navonae Timi, Rossin and Lanfranchi, 2006) mainly in the length (204–285 µm), shape, and structure of the spicule; and except for C. cooperi Johnston and Mawson, 1945, in markedly small body measurements (males and females 3–4 and 6–10 mm long, respectively). It is characterized by the presence of 33–43 elongate stichocytes; a heavily sclerotized spicule with rough transverse grooves; a spinous spicular sheath; and by eggs measuring 27–30 × 57–60 µm, without protruding polar plugs. Capillaria acanthopagri n. sp. is the first known species of Neocapillaria parasitizing fishes of the perciform Sparidae and the second species of this subgenus recorded from fishes of the Pacific Ocean.

Herein, we describe Litomosoides salazari n. sp. collected from the body cavity of the yellow bat, Lasiurus ega, from Bolivia. This new species of filarioid nematode is most closely related to the carinii group and is characterized by its relatively small size with the vulva located slightly posterior to the esophago-intestinal junction; an arrow-shaped buccal capsule; and a short, rounded tail. New host and locality records for both Litomosoides hamletti and L. chandleri in phyllostomid bats, and L. brasiliensis occurring in both phyllostomid and vespertilionid bats, are provided. The morphological variability of the specimens is documented by providing comparative measurements of 3 known species. Litomosoides brasiliensis occurs in 6 species of bats from Bolivia and was the most common species of filarioid nematode encountered. All 4 species of nematodes, including the new species, were found in sympatry at Chijchijpa, a locality in the Yungas of Bolivia.

Haemoproteus (Haemoproteus) multipigmentatus n. sp. (Haemosporida, Haemoproteidae) was found in the endemic Galapagos dove Zenaida galapagoensis. It is described based on the morphology of its blood stages and segments of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis of this species. Haemoproteus multipigmentatus can be readily distinguished from all species of hemoproteids of the subgenus Haemoproteus, primarily due to numerous (approximately 40 on average) small pigment granules in its mature gametocytes. Illustrations of blood stages of the new species are given, and phylogenetic analysis identifies DNA lineages closely related to this parasite, which is prevalent in the Galapagos dove and also has been recorded in other species of Columbiformes in Mexico, Guatemala, and Peru, and so seems to be widespread in countries in the New World with warm climates. Cytochrome b lineages of H. multipigmentatus cluster with hippoboscid-transmitted lineages of Haemoproteus columbae. The same lineages of H. multipigmentatus were recorded in thoraxes of the hippoboscid fly Microlynchia galapagoensis, which likely is a natural vector of this parasite in Galapagos. Because different primers might amplify different parasites if they have a better match during a simultaneous infection, it is important that researchers standardize the genetic marker of choice for molecular typing of hemosporidian species. This study shows that more discussion among researchers is needed to clearly establish the sequence length and number of genes used for identification of hemosporidian parasites at different taxonomic levels. We point to the need of using both morphology and gene markers in studies of hemosporidian parasites, particularly in wildlife.

A single-tube multiprobe real-time PCR assay for simultaneous detection of Entamoeba histolytica and Entamoeba dispar was developed. One primer pair with 2 species-specific probes was designed based on new SSU RNA regions of the ribosomal DNA-containing episome. The sensitivity is 1 parasite per milliliter of feces and thus superior to the conventional nested PCR and comparable to other published real-time PCR protocols. The applicability for clinical diagnosis was validated with 218 stool specimens from patients. A total of 51 E. histolytica and 39 E. dispar positive samples was detected by the multiprobe real-time PCR compared to 39 and 22 by routine nested PCR diagnosis. The detection rate of Entamoeba species for the multiprobe real-time PCR assays was significantly higher than the nested PCR (40.8% vs. 28.0%, P < 0.01). The test did not show cross reactivity with DNA from Entamoeba moshkovskii, Giardia lamblia, Cryptosporidium sp., Escherichia coli, or other nonpathogenic enteric parasites. The multiprobe real-time PCR assay is simple and rapid and has high specificity and sensitivity. The assay could streamline the laboratory diagnosis procedure and facilitate epidemiological investigation.

In France, more than 80% of human congenital toxoplasmosis is attributable to Toxoplasma gondii strains belonging to the type-II lineage, whereas 3 main lineages have been described in Europe. Cell invasion, parasite replication, and cyst formation of type-II strains isolated from congenital infections were compared in a human cell model. The phenotype patterns of the 4 type-II strains studied differed from each other; the 2 strains responsible for asymptomatic infection formed significantly fewer cysts than the 2 strains isolated from symptomatic toxoplasmosis. The capacity to form cysts was different among the type-II strains studied and may be related to the clinical form.

Sarcocystis neurona is best known as the causative agent of equine protozoal myeloencephalitis of horses in the Americas. Domestic cats (Felis domesticus) were the first animals described as an intermediate host for S. neurona. However, S. neurona-associated encephalitis has also been reported in naturally infected cats in the United States. Thus, cats can be implicated in the life cycle of S. neurona as natural intermediate hosts. The present study examined the seroprevalence of IgG antibodies to merozoites of S. neurona in populations of domestic cats from Virginia and Pennsylvania. Overall, sera or plasma from 441 cats (Virginia  =  232, Pennsylvania  =  209) were tested by an indirect immunofluorescent assay at a 1∶50 dilution. Antibodies to S. neurona were found in 32 (7%) of 441 cats. Of these, 22 (9%) of the 232 cats from Virginia and 10 (5%) of the 209 cats from Pennsylvania were seropositive for S. neurona.

The most frequent causative agents of cercarial dermatitis in Europe are the avian schistosomes of the genus Trichobilharzia. They preferably parasitize birds of the Anatidae. Trichobilharzia spp. schistosomes are also able to penetrate mammalian skin, posing a health risk to mammals, including humans. Currently several loci from nuclear and mitochondrial genomes are determined for European species of Trichobilharzia. Among them there is 1 genome sequence, ToSau3A, which is suitable for detection of Trichobilharzia spp. infection in aquatic systems. In the present paper, we used a PCR assay to obtain novel genome sequences from cercariae isolates of 3 European bird schistosome species (Trichobilharzia franki, Trichobilharzia szidati, and Trichobilharzia regenti) collected from freshwater ponds in Belorussia and Russia. We applied RAPD-fingerprinting using 1 random primer to differentiate 3 trichobilharzian species and subsequently cloned and sequenced putative species-specific RAPD fragments. One of them (410 bp in length), which was obtained for T. franki, revealed 64% homology with the repeat region of Schistosoma mansoni (GenBank FN357352) and turned out to be suitable for designing a specific primer pair (TR98F and TR98R) to detect 7 novel DNA sequences in the genome of 3 European Trichobilharzia species. The newly designed primer pair was found to be potentially suitable for PCR-based detection of trichobilharzian infection in snails. PCR primers TR98F and TR98R amplified only the DNA isolated from cercariae and sporocysts of 3 trichobilharzian species, but neither the DNA of 3 other digenean species (Bilharziella polonica, Apatemon sp., and Diplostomum sp.) nor the DNA of uninfected host snails (Lymnaea stagnalis, Radix auricularia, and Radix ovata).

Little is known of the seroprevalence of Toxoplasma gondii in bred cynomolgus monkeys (Macaca fascicularis) in China. In the present survey, 240 serum samples of cynomolgus monkeys from 4 nonhuman primate centers in Guangxi Zhuang Nationality Autonomous Region (GX), and 120 serum samples from 2 nonhuman primate centers in Guangdong Province (GD) were obtained, and the modified agglutination test (MAT) was performed to assay for anti–T. gondii antibodies. Antibodies to T. gondii (MAT titer of 1∶16 or higher) were found in 0 of 120 (0/120) samples in GD, and 5 (2.1%) of 240 sera with titers of 1∶16 in 1, 1∶64 or higher in 4 in primate centers from GX. The total prevalence of T. gondii in bred cynomolgus monkeys was 1.4% (5/360, MAT titer ≥ 1∶16) in southern China according to our investigation. To our knowledge, this is the first seropositive report in China on the prevalence of anti–T. gondii antibodies in bred cynomolgus monkeys using MAT.

Ninety-five percent ethanol is the most widely used field and laboratory preservative for nematodes and other helminth specimens intended for use in molecular systematics. Preservation of nematodes in high-concentration alcohols results in structural dehydration artifacts, including shrinkage and body surface distortions sufficient to obscure features required for morphological identification and analysis, thereby compromising precise morphometrics. However, treating dehydrated nematodes using a solution of DMSO, disodium EDTA, and NaCl, followed by rehydration in water produces marked improvements in specimen shape and surface features, resulting from diffusion of water into the tissues and pseudocoelom as the internal salt concentration is reduced. Following rehydration, tissue samples can be obtained for molecular research and individuals can be fixed for morphological examination. This treatment method is demonstrated for species of 3 nematode genera that vary substantially in body size (Baylisascaris, Uncinaria, and Bidigiticauda). The method also works on nematodes that have been cut in half, provided the individuals are large enough to be folded and clamped during treatment. This method appears promising for other helminths, although for an acanthocephalan, the treatment restored the body surface but failed to reverse the retracted proboscis.

Toxoplasmosis is an important cause of abortion and stillbirth in sheep on a worldwide basis. In the present study, the role of Toxoplasma gondii in inducing abortion in sheep of the Mashhad area of Iran was addressed using serological and parasitological methods. In total, 325 aborted ovine fetuses were collected between 2006 and 2008 during lambing season. Thoracic and abdominal fluids of aborted fetus were serologically investigated with a T. gondii-IFAT. Antibody titers equal to or greater than 1∶20 were detected in 17 (5.2%) of ovine fetuses. Processed brain samples of seropositive ovine fetuses were intraperitoneally inoculated into mice for isolation of T. gondii. The process yielded a single T. gondii isolate that remained avirulant for mice after several passages. The results document that T. gondii is among the important causes of ovine abortion in Iran.

In many eukaryotes, the introduction of double-stranded RNA (dsRNA) into cells triggers the degradation of mRNAs through a post-transcriptional gene-silencing mechanism called RNA interference or RNAi. In the present study, we found that endogenous long-dsRNA was substantially more effective at producing interference than endogenous, or exogenous, short-dsRNA expression in Giardia lamblia. The effects of this interference were not evident in the highly expressed protein tubulin or the stage-specific cyst wall protein 2. However, long-dsRNA caused potent and specific interference in the medium subunits of adaptins, the RNA-dependent RNA polymerase, and the exogenous green fluorescence protein. Our results suggest that the ability of dsRNA antisense to inhibit the expression of these specific types of proteins is indicative of a gene-specific mechanism.

In the present study, we report the earliest record of Ixodes sigelos from the late Holocene in Argentina. The tick was recovered from an owl pellet collected within a small mammal sequence in Las Máscaras Cave, Catamarca, Argentina (27°01′12S″, 66°44′37″W) and dated at 990 ± 35 cal yr. Based on bones also present in the pellet, the tick most-likely parasitized a rodent, identified as an Eligmodontia sp., which had been ingested by the owl.

Ninety specimens of Rhinella fernandezae, collected in Imbé, State of Rio Grande do Sul, Brazil, from August 2006 to April 2007, were examined for presence of helminth parasites; all were infected by at least 1 species. Thirteen species of parasites were found: 4 digeneans, 2 cestodes, 2 acanthocephalans, and 5 nematodes. Rhinella fernandezae represents a new host record, as well as for Gorgoderina festoni, Cylindrotaenia americana, Acanthocephalus lutzi, Aplectana meridionalis, and Strongyloides carinii. The nematodes Cosmocerca parva and A. meridionalis occurred with a prevalence of 79.1%, and, as in other Rhinella species, the nematodes dominated the parasite community. Host gender had no influence on either abundance or prevalence of the helminths, and neither the length nor weight of the hosts influenced the richness of the parasitic helminths of these burrowing toads. Only A. meridionalis and Centrorhynchus sp. (both cystacanths) exhibited a significant correlation between host length and abundance of helminths; only A. meridionalis showed a relationship between host length and prevalence.

Very slight sequence differences in the mitochondrial cytochrome b gene, even single nucleotide substitutions, have been proposed as indicative of different species of avian malaria parasites. However, few studies have examined within-species variation in that gene for Plasmodium or related genera. We examined sequences for the entire cytochrome b gene from Plasmodium mexicanum, a parasite of lizards, for sites where microsatellite markers revealed substantial genetic diversity. For sites where the parasite is geographically genetically differentiated, and may have been isolated for thousands of years, there was no sequence variation (1,153 nucleotides) for >160 infections studied. The low degree of variation found in the cytochrome b gene for two human malaria parasites world-wide, as well as the lack of variation for P. mexicanum, contrast with the substantial variation found in surveys of bird malaria parasites, even in restricted geographic regions.

Variation in host susceptibility and parasite-induced mortality are preconditions for parasite-related selection on host populations. In terrestrial gastropods, variation in resistance against ectoparasite infection is poorly understood. We examined the within- and among-family variation in parasite load in full-siblings of the land snail Arianta arbustorum experimentally infected with Riccardoella limacum, a mite living in the mantle cavity of helicid land snails. We also quantified the influence of family origin and host size on parasite load and calculated its heritability (h²). Furthermore, we examined the influence of parasite load, snail size, and family origin on host winter mortality, an important life-history trait of A. arbustorum. Parasite load was heritable (h²  =  0.63). In infected snails, parasite load was affected by family origin and increased with increasing shell size. Host mortality during hibernation increased with increasing parasite load and differed among families, but was not affected by snail size. Our results show high among-family variation both in resistance against ectoparasite infection and in host winter mortality. Furthermore, we show that parasite load is linked to snail size, which suggests that the proliferation of R. limacum is limited by resources provided by A. arbustorum.

Strongyloides stercoralis infection is endemic in many tropical and subtropical areas. The parasite has the unusual ability to multiply inside the host due to the transformation of rhabditiform larvae into infective filariforms. Several studies have shown that chronic alcoholism is an important factor that predisposes to strongyloidiasis. The increased susceptibility to S. stercoralis infections seen in alcoholic individuals could be explained by their increased exposure to the parasite, malnutrition, breakdown of local immune responses, and/or alterations in intestinal barriers. Moreover, ethanol intoxication can elevate human endogenous corticosterone, which, in turn, suppresses T cell function and increases the fecundity and survival of the parasite, mimicking the effect of worm ecdysteroides. Although chronic alcoholism is a risk factor for nematode infection, most cases of hyperinfection or dissemination are associated with the presence of hepatic cirrhosis or strongyloidiasis-related symptoms. The present study describes a case of S. stercoralis hyperinfection in a 51-yr-old male patient without gastrointestinal or pulmonary symptoms and with previous anemia and chronic alcoholism. He was not receiving glucocorticoid therapy and tested negative for HTLV and human immunodeficiency virus (HIV), but he had a history of alcohol addiction for more than 20 yr. Laboratory test results showed increased eosinophilia and a high immunoglobulin E (IgE) level, which may have temporarily protected the patient from dissemination of infection, but not prevented proliferation of the parasite, as shown by the large number of S. stercoralis larvae recovered using the Baermann method. Evaluation for strongyloidiasis should occur in alcoholics, especially in endemic areas, to prevent occult asymptomatic infections from progressing to life-threatening cases.