3′,5′-Cyclic guanosine monophosphate (cGMP), a well-known intracellular second messenger, is released to the intestinal lumen by the tapeworm, Hymenolepis diminuta. Enzyme-linked immunosorbent assay analysis of tapeworm conditioned media shows that cGMP is released at a constant rate. Multidrug resistant (MDR) proteins are efflux transporters for cyclic nucleotides. Two MDR inhibitors, niflumic acid and zaprinast, inhibit cGMP secretion by tapeworms and change the cGMP localization within the tapeworm tegument, as assessed by immunochemistry. cGMP, normally present throughout the tapeworm tegumental cytoplasm, is absent from the outer cytoplasmic band upon treatment with inhibitors. Inhibition of cGMP secretion by colchicine indicates that cGMP secretion is cytoskeleton dependent. Binding studies of [³H]cGMP to ileal segments of intestine demonstrate 2 saturable, reversible, and high-affinity binding sites. These studies demonstrate that cGMP is secreted from the cestode via a cytoskeleton-dependent mechanism and MDR efflux transporters. In addition, cGMP reaching the intestinal lumen can bind to the mucosa via receptors for cGMP. These data, combined with earlier observations of cGMP altering intestinal motility and slowing lumenal transit, indicate that tapeworms alter the physiology of the host digestive process via the secretion and binding of extracellular cGMP to lumenal receptors in the host intestine.

Patterns of infracommunity structure and infra- and component community similarity were examined for helminths of 6 species of turtles, each collected from a single locality in Australia in 1993 and 1994. Elseya latisternum (N = 11) and Emydura kreffti (N = 16) were collected from northern Queensland, Emydura macquarii macquarii (N = 11) from southern Queensland, Emydura macquarii dhara (N = 11) and Chelodina longicollis (N = 11) from northern New South Wales, and Chelodina oblonga (N = 5) from Western Australia. Local parasite species richness was not correlated with host geographical range. Differences in parasite diversity among host species were related primarily to differences in evenness, a pattern attributed to local habitat characteristics, rather than species-specific differences in colonization potential. Ordination and analysis of similarity demonstrated the patterns of infracommunity structure of Chelodina spp. to be distinct from those of the other host species sampled, which showed considerable overlap among patterns of infracommunity structure. Despite overlap with the component communities of Em. kreffti and El. latisternum, the component communities of Em. m. dhara and Em. m. macquarii were more distinct from one another than either was to the component communities of Em. kreffti or El. latisternum.

Adults of 3 tick species (Acari: Argasidae) identified as Antricola guglielmonei, Antricola delacruzi, and Carios rondoniensis n. sp. were collected on bat guano in a cave in the state of Rondônia, western Amazon, Brazil. Adults of C. rondoniensis possess a unique combination of characters that distinguish them from all described adults in the Argasidae, i.e., a large spiracular plate densely filled with small goblets, a well-developed flap covering the female genital opening, and palpi containing several tufts of long setae on articles 2 and 3. Unlike Ornithodoros or other Carios species, adults of C. rondoniensis have a scooplike hypostome devoid of denticles, as in Antricola spp. Conversely, the presence of a pair of long posthypostomal setae, and a slitlike transverse fissure at the capsule opening of the Haller's organ, are characters of C. rondonensis that are also found in species of Carios and Ornithodoros, but not in Antricola species. Molecular analyses inferred from a portion of the 16S rRNA mitochondrial gene indicate that C. rondoniensis is phylogenetically closest to species of Carios, followed by species of Antricola, and then Ornithodoros. Because the highest bootstrap value linking C. rondoniensis to Carios spp. was 62%, further phylogenetic studies are needed to better evaluate the taxonomic status of the former species.

During an investigation of gill monogenoidean parasites from freshwater fishes in central Panama, 5 new species of Urocleidoides (sensu stricto) were found: Urocleidoides cultellus n. sp., Urocleidoides visiofortatus n. sp., and Urocleidoides advenai n. sp. from the gymnotiform Brachyhypopomus occidentalis (Hypopomidae); Urocleidoides neotropicalis n. sp. and Urocleidoides piriatiu n. sp. from the characiforms Saccodon dariensis (Parodontidae) and Ctenolucius beani (Ctenoluciidae), respectively. Our findings represent the first known species of Urocleidoides from these fishes in Central America and demonstrate that they are morphologically linked to their South American congeners.

For the first time, the ultrastructure of the armed cirrus of an echinophallid cestode, Paraechinophallus japonicus (Yamaguti, 1934), has been studied with the use of scanning and transmission electron microscopy. Two sets of eversible copulatory organs (≈300 μm in length and ≈130 μm in width) are present on the dorsal side of each segment near the lateral margin of the strobila. Except for the terminal portion, the cirrus is covered with large spines (up to 40 μm long, measured from SEM photomicrographs) composed of 2 parts. The basal portion contains a lobed electron-dense outer region that gives way to a reticular meshwork of electron-dense material. The apical region of the spines, composed of a homogeneous, moderately electron-dense matrix, is slightly curved distally. Spines are covered with a cortical zone. Between the spines, the distal cytoplasm is covered with microvilli of about 1.2 μm in length. The wall of the cirrus sac, which is ≈500 μm long and ≈250 μm wide, is composed of 2 layers of muscles, i.e., an internal layer of circular muscles and external longitudinal muscles. Microvilli on the cirrus of P. japonicus are reported for the first time in the Cestoda, whereas the spines on the cirrus may represent a synapomorphy of bothriocephalidean cestodes of the Echinophallidae.

There is scarce information concerning the epidemiology of Toxoplasma gondii infection in people of rural Mexico. Anti-T. gondii immunoglobulin (Ig)G and IgM antibodies were sought in 462 adult inhabitants from 3 rural communities of Durango, Mexico, using enzyme-linked immunoassays. In total, 110 (23.8%) of 463 persons had IgG anti-T. gondii antibodies. Ten (2.2%) of them also had IgM anti-T. gondii antibodies. Prevalences of T. gondii IgG antibodies in the 3 communities varied from 14.8 to 35.8%. The highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions. Toxoplasma gondii infection was significantly associated with consumption of squirrel (adjusted odds ratio [OR] = 4.22; 95% confidence interval [CI] = 1.11–16.05) and turkey meat (adjusted OR = 4.58; 95% CI = 1.14–18.44). This is the first epidemiological study of T. gondii prevalence in rural Mexico.

Blood samples from 99 cats from the Ankara province of Turkey were examined for the presence of anti–Toxoplasma gondii antibody with the use of both the Sabin–Feldman dye test (DT) and an indirect fluorescent antibody test (IFAT). Forty of the 99 sera (40.3%) were positive for antibodies against T. gondii with the DT, whereas the IFAT assay detected antibodies in 34 (34.3%). The study also evaluated 3 factors for their potential association with the presence of T. gondii antibody: age (<1 yr, 1–2 yr, and >2 yr), gender (female vs. male), and outdoor access (stray, owned with outdoor access, or indoor only). The DT detected antibodies in 3 cats under 1 yr of age, 22 cats between 1 and 2 yr, and 15 cats older than 2 yr, whereas the IFAT found 1, 18, and 15 cats positive for antibodies, respectively, in each of these categories. Of 61 female cats, 27 (44.2%) were positive by the DT; and of 38 male cats, 13 (34%) were positive by the DT. For the IFAT, 24 female cats (39.3%) and 10 male cats (26.3%) were positive. The percent seropositivity in indoor cats was 30.8% by the DT and 23.1% by the IFAT. In stray cats, the percent seropositivity was 52.8% by the DT and 41.7% by the IFAT. Antibody presence was significantly associated with age, but not with outdoor access.

Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. In previous serological surveys, >90% of bottlenose dolphins (Tursiops truncatus) from the coasts of Florida, South Carolina, and California had antibodies to T. gondii by the modified agglutination test (MAT). In the present study, attempts were made to isolate T. gondii from dead T. truncatus. During 2005, 2006, and 2007, serum or blood clot, and tissues (brain, heart, skeletal muscle) of 52 T. truncatus stranded on the coasts of South Carolina were tested for T. gondii. Antibodies to T. gondii (MAT 1:25 or higher) were found in 26 (53%) of 49 dolphins; serum was not available from 3 animals. Tissues (heart, muscle, and sometimes brain) of 32 dolphins (26 seropositive, 3 seronegative, and 3 without accompanying sera) were bioassayed for T. gondii in mice, or cats, or both. Tissues of the recipient mice were examined for T. gondii stages. Feces of recipient cats were examined for shedding of T. gondii oocysts, but none excreted oocysts. Toxoplasma gondii was isolated from hearts of the 3 dolphins (2 with MAT titers of 1:200, and 1 without accompanied serum) by bioassay in mice. Genotyping of these 3 T. gondii isolates (designated TgDoUs1-3) with the use of 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) revealed 2 genotypes. Two of the 3 isolates have Type II alleles at all loci and belong to the clonal Type II lineage. One isolate has a unique genotype. This is the first report of isolation of viable T. gondii from T. truncatus.

The 2 objectives of this study were: (1) to compare parasite detectability in blood smears obtained from toe-clips versus the heart from amphibian hosts; and (2) to test whether microfilariae density is correlated with adult filarial worm intensity. We examined blood parasites of 2 species of amphibians, Rana vaillanti (n = 45) and Eleutherodactylus fitzingeri (n = 36), from Costa Rica collected during the summer of 2003. Separate blood smears were obtained from toe-clips and the heart during necrospy. Eight species of blood parasites were identified from R. vaillanti and 1 from E. fitzingeri. Each parasite species was counted in a 2 × 2.2-cm² area on each blood smear, and the density of host red blood cells (RBCs) was estimated using a sub-sampling approach, allowing parasite infections to be expressed as individuals per RBC. The detection failure rate for toe-cut smears ranged from 71–100% (x̄ = 92.3%) and from 0–9% (x̄ = 2.4%) for heart smears, depending on parasite species. The density of RBCs was significantly higher in smears produced from heart samples and may explain the differences in detectability. Foleyellides striatus microfilariae densities (per RBC) were significantly correlated with adult female worm intensity (R² = 0.32, P = 0.011).

Antibodies to Toxoplasma gondii were assayed by ELISA in 22 experimentally inoculated domestic ducks. In addition, a serological assay was carried out at Obihiro, Hokkaido, Japan, in 2004 and 2005, on 221 wild ducks of 5 species: Anas platyrhynchus (n = 111); A. poecilorhyncha (n = 27); A. acuta (n = 58); A. penelope (n = 16); and A. crecca (n = 9). Assays were also conducted using sera from 197 wild geese of 2 species, i.e., Anser albifrons (n = 162) and Ans. fabalis (n = 35). Birds were collected between 2003 and 2005 from 3 different areas: Lake Miyajima-numa, Hokkaido, Japan, regions around Anadyr city of Chukotka autonomous okrug, and Lake Makobetukoe, Kamchatka oblast, Russia. The ELISA cutoff value (OD) was ≥0.395 based on results from uninfected ducks; the final dilution ratio recognized as positive was represented by the end titer. The end titer in the experimentally infected ducks ranged from 1:400 to 1:3,200. Antibodies to T. gondii were found in 49 of the 221 wild duck samples from Japan: A. platyrhynchus (22/74); A. poecilorhyncha (2/15); A. penelope (3/16); A. acuta (4/58); and A. crecca (0/9), all in 2004. In 2005, T. gondii was found in A. platyrhynchus (13/37); and A. poecilorhyncha (5/12). Thirty-two of 197 wild goose samples were seropositive, i.e., Ans. albifrons (7/51) in 2004 and (11/72) in 2005 in Miyajima-numa, Japan and 9/39 in Chukotka, Russia as well as in Ans. fabalis (5/35) in Kamchatka, for which the end titer ranged from 1:100 to 1:3,200. In immunoblotting, the A. platyrhynchus samples showed specific IgG antibody binding to several antigens in the T. gondii lane, i.e., at 30 and 43 kDa, but not in the Neospora caninum lane. No specific bands were noted in samples for which antibody activity was not detected. These results suggest that wild waterfowl inhabiting Hokkaido, Chukotka, and Kamchatka may be exposed to T. gondii.

To understand patterns of intestinal parasitism in healthy, undisturbed endangered mountain gorillas (Gorilla beringei), we regularly collected fecal samples from a group of 14 wild gorillas residing in Bwindi Impenetrable National Park (BINP), Uganda, for about 1 yr. The objectives of the study were to collect baseline data in order to document the helminth parasites infecting this group of gorillas and to examine the effects of season and host age-sex class on patterns of parasite infection. In addition to weekly surveys of feces from all group members, fecal samples from 4 identified individuals were examined almost daily. We identified the diagnostic stages of the following parasites: strongylids (Strongylida), Anoplocephala gorillae, Probstmayria sp., Strongyloides fuelleborni, and a trematode. Monthly and daily fluctuations in strongylid egg counts were observed. Infants had lower strongylid egg counts compared with other group members. Both of the silverbacks had higher mean egg counts in the wet season than in the dry season. Examination of fecal samples from identifiable gorillas revealed high day-to-day variation in strongylid egg counts. No evidence of anthropozoonotic transmission of intestinal helminths was found.

During a parasitological survey of Galaxias platei Steindachner, 1898, from Patagonian Andean Lakes, a new species of Cystidicolidae was found in the stomach of fish. The new species was described using light and scanning electron microscopy; the species has characteristics of Ascarophis and is distinguishable from other species by a combination of the following features: well-developed pseudolabia with T-shaped inner extensions, bifurcate deirids, small ratio GE:ME, small left spicule, small ratio LS:RS, and larvigerous eggs with thick and fine filaments in both poles. Intraspecific variation in the morphology of larvigerous eggs was studied. This is the first species of Ascarophis described from freshwater fishes.

A description is provided for Gracilioxyuris agilisis n. g., n. sp. found in the cecum of Gracilinanus agilis Burmeister, 1854 (Gardner, 2005) (Didelphidae) in Brazilian Pantanal. The new species can be distinguished from Didelphoxyuris thylamisis by a dome-shaped anterior end, a weakly developed cephalic vesicle, males with no postcloacal ornamentation, and operculate eggs with 3 longitudinal ridges. Gracilioxyuris n. g. is characterized by a small and apical oral opening and double-crested lateral alae. Males possess an area rugosa as a ventral, keellike elevation with transverse striations, 4 pairs of genital papillae, the first and second pairs of which are adanal, and a third minute pair just posterior to cloacal aperture; the last pair are at the caudal end with no tail tip. Females possess a thick muscular vagina, a didelphic genital tract, and operculated eggs with ridges.

The anisakid species Contracaecum chubutensis n. sp. was found parasitizing the imperial cormorant Phalacrocorax atriceps at 2 different localities, Bahía Bustamante (45°11′S, 66°30′W) and Puerto Madryn (42°47′S, 65°02′W) on the Patagonian coast. Morphometrical analysis and further studies of adult specimens of C. chubutensis n. sp. and fourth-stage larvae of Contracaecum sp. were done using light and scanning electron microscopy. The possession and disposition of 7 pairs of tail papillae differentiate this new species from C. osculatum, C. radiatum, C. plagiaticium, and C. mirounga. Double-sized spicules separate it from C. variegatum and C. pelagicum. Moreover, the paracloacal papillae disposition and tail shape differentiate this new species from C. travassosi. The presence of bifurcated interlabia separate it from C. ogmorhini and C. margolisi. Three well-marked lip notches, a sharp tail shape, and the of the transversal paracloacal papillae disposition distinguishes C. chubutensis n. sp. from C. magnipapillatum and C. septentrionale. The species here described can be differentiated from C. caballeroi by its bifurcated interlabia, longer spicules, and for possessing more precloacal papillae pairs. It can be separated from C. rudolphii by a thinner interlabia at the base, deeper lip notches, a sharper tail, the disposition of transversal paracloacal papillae, and greater distance between both papillae of the first subventral distal papillae pair. In addition, fourth-stage larvae recovered from the same host and localities were identified and described as Contracaecum sp. Prevalence of adult parasites was 66.7 %, mean intensity was 4.0, and mean abundance was 7.1.

Heteromyoxyuris otomii n. sp., which inhabits the intestinal caecum of Perognathus flavus (Heteromyidae), in Zaragoza, Hidalgo, Mexico, is described. This new species differs from the 2 other congeneric species in the morphology and length of lateral alae in males. Heteromyoxyuris deserti has simple lateral alae located at both sides of the body, whereas in the new species, these structures are double at both sides; in contrast, lateral alae of Heteromyoxyuris longejector begin at the posterior half of the body, whereas they arise in the first third in the new species. Heteromyoxyuris longejector was found in 2 new host species, i.e., Perognathus amplus and Chaetodipus hispidus. This record represents the first record for the species in Mexico, increasing its geographic distribution.

Hamulonema gen. nov. is proposed for Teladorsagia hamata and Ostertagia kenyensis in the ostertagiine nematode fauna found in artiodactyl hosts from Africa. Monomorphic species representing this genus are characterized by a bilaterally symmetrical and parallel synlophe in males and females, a 2-2-1 bursal formula, an accessory bursal membrane that is strongly cuticularized and reduced, a strongly reduced dorsal lobe and ray, and robust spicules with a simple, weakly pointed, ventral process, and curved, hooklike dorsal process. Species referred to Hamulonema nov. gen. are immediately distinguished from those of Camelostrongylus, Longistrongylus, Marshallagia, Orloffia, Ostertagia, and Pseudomarshallagia in which the bursal formula is 2-1-2 in males. Hamulonema nov. gen. is distinguished from those genera having a 2-2-1 bursa, including Africanastrongylus, Cervicaprastrongylus, Hyostrongylus, Mazamastrongylus, Sarwaria, Spiculopteragia, and Teladorsagia by the structure of the synlophe, bursa, genital cone, “0” and “7” papillae, dorsal lobe, and spicules in specific instances. In the global fauna, 4 of 14 ostertagiine genera are endemic to Africa. African genera may represent morphologically divergent and discrete or historically isolated lineages reflecting a pattern of geographic and host colonization as a driver for diversification since the Miocene.

Octomyomermis connellyi n. sp. (Nematoda: Mermithidae) is described from the hemocoel of male and female imagos of Cladopelma collator (Townes) eclosing from Lake Ozawindib and from Gulsvig Landing in the upper Mississippi River in northern Minnesota. The species is distinguished from the other species in the genus. Included is a list of the other 9 adequately described members of the genus Octomyomermis that have been reported from the United States (California and Minnesota), Argentina, Russia, and Zambia. Bionomics and anomalies of the new species are addressed.

Fecal samples (n = 636) from 10 species of shrews collected in Alaska (n = 540) and northeastern Siberia (n = 96) were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct oocyst morphotypes were observed. Three types were consistent with oocysts of previously recognized coccidia species from other shrew hosts. These were Eimeria inyoni, E. vagrantis, and Isospora brevicauda, originally described from the inyo shrew (Sorex tenellus), dusky shrew (S. monticolus), and northern short-tailed shrew (Blarina brevicauda), respectively. We found 5 new host records for E. inyoni, 3 for E. vagrantis, and 3 for I. brevicauda. The 2 additional oocyst morphotypes, both from the tundra shrew (Sorex tundrensis), are putative new species. Sporulated oocysts of Eimeria beringiacea n. sp. are subspheroidal, 17.7 × 15.6 μm (14–24 × 13–20 μm) with a length (L)/width (W) ratio of 1.1 (1.0–1.4); these lack a micropyle (M), an oocyst residuum (OR), and a polar granule (PG). Sporocysts are ellipsoidal, 10.3 × 6.1 μm (7–14 × 4–8 μm), with a L/W ratio of 1.7 (1.3–2.3) and have a Stieda body (SB), Substieda body (SSB), and sporocyst residuum (SR). Oocysts of Eimeria tundraensis n. sp. are spheroidal to subspheroidal, 24.8 × 23.5 μm (23–26 × 22–25 μm), with a L/W ratio of 1.1 (1.0–1.2); these lack a M and OR, but a single PG is present. Sporocysts are elongate ellipsoidal, 15.4 × 8.3 μm (13–17 × 7–9 μm), with a L/W ratio of 1.9 (1.4–2.1) and have a SB, SSB, and SR.

The cystidicolid nematode Cystidicoloides fischeri (Travassos, Artigas and Pereira, 1928) is redescribed from specimens collected from the stomach of the San Francisco piranha, Pygocentrus piraya (Cuvier), and the white piranha, Serrasalmus brandtii (Lütken) (both Characidae, Characiformes) (new host records), from the Três Marias Reservoir, Upper São Francisco River, Minas Gerais state, Brazil. The morphology of this type species of Cystidicoloides Skinker, 1931, studied with both light and scanning electron microscopy, is characterized by some taxonomically important, previously unreported features, such as the presence of a cephalic cuticular collarette, subdorsal and subventral cephalic spikes, cuticular tooth-like elevations inside the prostom, deirids, area rugosa, and details in the structure of the cephalic end. Heliconema izecksohni Fabio, 1982 is transferred to Cystidicoloides as C. izecksohni (Fabio, 1982) n. comb. Cystidicoloides uniseriata Valovaya and Valter, 1988 is considered a species inquirenda with uncertain generic appurtenance. The presence of subdorsal and subventral cephalic spikes and the collarette are characteristic of Cystidicoloides, comprising only species parasitizing Neotropical fishes. The species from salmonids in the Holarctic, hitherto reported mostly as Cystidicoloides ephemeridarum (Linstow, 1872), belongs to a different, newly erected genus, for which the name Salmonema n. gen. (type species S. ephemeridarum) is now proposed. Cystidicoloides prevosti (Choquette, 1951) is transferred to Salmonema as S. prevosti (Choquette, 1951) n. comb. Sterliadochona ssavini Skryabin, 1948 and Sterliadochona Skryabin, 1948 are considered as species inquirenda and a genus inquirendum, respectively. A key to species of Cystidicoloides is provided.

The tapeworm Archigetes sieboldi Leuckart, 1878 (Platyhelminthes: Cestoda: Caryophyllidea) has been cited as a likely representative of the “protocestode” condition, owing to its lack of segmentation and ability to attain sexual maturity in the invertebrate host (aquatic oligochaetes). The idea has been variously amplified or rejected in the literature, although the actual phylogenetic position of the species has not been investigated until now. New collections of Archigetes sp. from both its vertebrate and invertebrate hosts provided the opportunity to estimate its phylogenetic position with the use of molecular systematics, while prompting new analyses aimed at assessing the early diversification of the Cestoda. Additional collections representing the Amphilinidea, Caryophyllidea, and Gyrocotylidea were combined with published gene sequences to construct data sets of complete 18S (110 taxa) and partial (D1-D3) 28S (107 taxa) rDNA sequences, including 8 neodermatan outgroup taxa. Estimates resulting from Bayesian inference, maximum likelihood, and maximum parsimony analyses of the separate and combined data sets supported a derived position of the genus within the Caryophyllidea, and thus reject the idea that Archigetes sp. may exemplify a “primitive” condition. Topological constraint analyses rejected the hypothesis that Archigetes represents the most basal lineage of the Eucestoda, but did not rule out that it could represent the earliest branching taxon of the Caryophyllidea. In all analyses, the Eucestoda were monophyletic and supported basal positions of the nonsegmented Caryophyllidea and Spathebothriidea relative to other major lineages of the Eucestoda, implying that segmentation is a derived feature of the common ancestor of the di- and tetrafossate eucestodes. However, constraint analyses could not provide unequivocal evidence as to the precise branching patterns of the cestodarian, spathebothriidean, and caryophyllidean lineages. Phylogenetic analyses favor the interpretation that sexual maturity of Archigetes sp. in the invertebrate host, and similar examples in members of the Spathebothriidea, are the result of progenesis and have little if any bearing on understanding the protocestode condition.

Prodistomum lichtenfelsi n. sp. (Digenea: Lepocreadiidae) is described; it was obtained from the intestine of the longtail bass, Hemanthias leptus (Ginsburg), collected from the Bay of Campeche in the Gulf of Mexico. This is the first record of a parasite from this host. Prodistomum lichtenfelsi n. sp. is similar to P. hynnodi, P. menidiae, and P. waltairensis in that it possesses a prepharynx that is distinctly shorter (153 μm [110–210] long) than the combined length of the esophagus (163 μm [110–220] long) and the pseudoesophagus (137 μm [120–170] long), but it differs from them in having an excretory vesicle that extends into the forebody, a smooth ovary and testes, and vitellaria that extend to the posterior level of the esophagus. An updated key to the 12 nominal species within Prodistomum is given, and the diagnosis of the genus is emended to include species possessing a sinuous external seminal vesicle.

Liniscus diazae n. sp. (Nematoda: Trichuridae) is described from the urinary bladder of Oxymycterus rufus and Akodon azarae (Cricetidae: Sigmodontinae) from Buenos Aires Province, Argentina. Liniscus diazae can be differentiated from its congeners by having a much longer spicule and without an elevated vulva. In addition, L. diazae can be distinguished from L. incrassatus and L. himizu by having a longer body length. Males are similar in posterior width to L. papillosus and L. himizu, but thinner than L. incrassatus and L. maseri. This is the second record of a capillarid from mammals in Argentina. An updated list of capillarid species of rodents and insectivores from North America, with their synonyms, hosts, sites of infection, and geographic distribution, is provided.

Aptorchis glandularis n. sp. is described from the intestine of the northwestern red-faced turtle, Emydura australis (Pleurodira: Chelidae), in the Kimberley, Western Australia. This digenean is morphologically most similar to Aptorchis aequalis but can be differentiated readily from the latter species by the presence of ventral glands arranged in 3 rows. This feature is unique among plagiorhioidean digeneans and resembles the glands observed in some monostome digeneans in Notocotylidae and Microscaphidiidae. Comparison of approximately 2,600 bases of ribosomal DNA (partial 18S, complete ITS1 5.8S ITS2, partial 28S), obtained from all 5 known Aptorchis species, strongly supports the status of Aptorchis glandularis n. sp. as a new species. Phylogenetic analysis of these sequence data demonstrates 2 strongly supported clades (A. pearsoni A. megacetabulus) and (A. aequalis A. glandularis n. sp.), with A. megapharynx representing a separate lineage. This is the first report of an endoparasite from Emydura australis.

A coprological survey to analyze the presence of flock resistance to benzimidazoles (BZ) and macrocyclic lactones (ML) was performed in sheep under field conditions. Fecal samples were collected from 2,625 sheep in 72 commercial farms from Galicia (NW Spain). The in vitro (FECRT, fecal egg count reduction test) and in vivo (EHA, egg hatch assay, and LFIA, larval feeding inhibition assay) tests were used to assess the efficacy of these anthelmintics. Coprocultures were also developed to obtain knowledge on the main genera of trichostrongylid nematoda prior to, and after, the administration of the anthelmintics. By using the FECRT, BZ resistance was observed in 13 (18%) flocks, whereas ML resistance was only detected in 2 (3%) farms. The number of resistant flocks to BZ was 21 (29%) by using the EHA and 7 (10%) by means of the LFIA. None of the flocks used in this study showed simultaneous resistance to both employed anthelmintics. The results from the in vitro and in vivo tests revealed that 92% of the flocks FECRT resistant to BZ were also resistant with the EHA. The LFIA confirmed all the farms resistant to ML by using the in vivo test. After the administration of BZ, nematode larvae belonging to Teladorsagia circumcincta (32.2%), Trichostrongylus spp. (29%), Nematodirus spp. (6.5%), and Chabertia ovis (3.2%) were identified. In the flocks receiving ML, only T. circumcincta was identified (57%). We recommend the use of in vitro tests because they are more efficient. As the use of macrocyclic lactones is increasing in this region, further investigation is needed for detecting resistance to the anthelmintic family compounds by the LFIA.

Australasian marsupials, especially wallabies, are highly susceptible to clinical toxoplasmosis. This paper describes the use of atovaquone for effective treatment of toxoplasmosis in 4 Bennett's wallabies (Macropus rufogriseus), along with the serology, isolation of Toxoplasma gondii, and genotyping of 3 T. gondii isolates from 5 captive wallabies. This is the first report of success in treating acute toxoplasmosis in wallabies, the first report of serology followed over a significant period of time, and the first report of isolation and genetic typing of T. gondii from wallabies in the United States.

Sulfaquinoxaline played an important part in the demotion of roast chicken from vaunted Sunday-dinner status to an unrespected position on the everyday menu of the Western world. It had its origins in the chemical synthetic program that sprang from the introduction of sulfonamide drugs into human medicine in the 1930s. The program was sustained through the years of World War II despite declining clinical use of that chemical class. Several sulfa drugs were known to be active against the sporozoan parasite (Plasmodium spp.) that causes malaria, but were not satisfactory in clinical practice. A sulfonamide that had a long plasma half-life would ipso facto be considered promising as an antimalarial drug. Sulfaquinoxaline, synthesized during the war, was such a compound. It proved too toxic to be used in human malaria, but was found to be a superior agent against another sporozoan parasite, Eimeria spp., the causative agent of coccidiosis in domestic chickens. In 1948 sulfaquinoxaline was introduced commercially as a poultry coccidiostat. It was not the first sulfonamide found active against Eimeria spp. in poultry, but its practical success in disease control firmly established the routine incorporation of anticoccidial drugs in poultry feed. In this way, the drug exerted a major impact on the worldwide production of poultry meat. Although it has long been eclipsed by other drugs in poultry management, it continues to be used in other host species. This article describes the discovery of sulfaquinoxaline as a practical therapeutic agent, and examines the way in which the discovery arose from a partnership between industry and academia.

There is an increasing interest in parasites of marine mammals of Argentina. Here, we examined several poorly known cetaceans, i.e., 2 spectacled porpoises and 1 Burmeister's porpoise (Phocoenidae), and 1 Gray's beaked whale and 1 Cuvier's beaked whale (Ziphidae); we also updated the parasite information for 1 sperm whale (Physeteridae). These hosts strand only occasionally. We found Anisakis simplex s.l. in 2 spectacled porpoises and the Burmeister's porpoise, and recorded its distribution among the stomach chambers. Anisakis physeteris infected the sperm whale; Corynosoma cetaceum occurred in the duodenal ampulla of the Burmeister's porpoise; Corynosoma australe was found in the posterior-most region of the intestine of 1 spectacled porpoise, while another one had Tetrabothrius sp. in the anal crypts; Corynosoma bullosum and Corynosoma sp. were found in the sperm whale. The only digenean found was Pholeter gastrophilus in the Burmeister's porpoise. Merocercoids of Phyllobothrium delphini were present in the blubber of 1 spectacled porpoise, the sperm whale, and the Gray's beaked whale, while Scolex pleuronectis infected the Gray's beaked whale and 1 spectacled porpoise. No parasites were recovered from the Cuvier's beaked whale. Poor parasite-species assemblages are consistent in marine mammals of Patagonia. Given the conservation status of these hosts, the limited parasitological information gathered is valuable for conservation or management of these hosts in Patagonia.

We report myiasis by Lucilia silvarum with an overall prevalence of 0.9% in amphibian populations in boreal Alberta. In the period 1998–1999, we documented L. silvarum infestations in wild populations of wood frog (Rana sylvatica), boreal chorus frog (Pseudacris maculata), boreal toad (Bufo boreas boreas), and Canadian toad (B. hemiophrys). We believe this is the first record of this parasite from boreal and Canadian toads. Almost all previous records of L. silvarum parasitism in North America indicate that myiasis is fatal to an anuran host. Here, we provide the first record of adult individuals from 2 species (wood frog and boreal toad) surviving infestations. Although we actively captured and examined amphibians in Alberta from 1996 to 2006, we only found parasitism in 1998 and 1999. This is the most northerly record of anuran infestations by this parasite.

Ticks use bloodmeals as a source of nutrients and energy to molt and survive until the next meal and to oviposit, in the case of females. However, only the larvae of some tick species are known to feed upon bats; females are obligatorily autogenous, and nymphal stages are believed to not feed. We investigated the presence of blood in a natural population of nymphal Antricola delacruzi ticks collected from bat guano; their ability to feed upon laboratory hosts; and the microscopic structure of both salivary glands and gut. DNA amplification of gut contents of freshly collected material was positive for a mammal in 4 of 11 first instar nymphs, but we were unsuccesful in the amplification of host bloodmeal DNA from late instar nymphs. All early nymphal stages (n = 10) fed on rabbits, and host DNA was detected and sequenced from gut contents. However, all the large nymphs (n = 10) rejected feeding, and host DNA remained undetected in these ticks. All stages of A. delacruzi have salivary glands similar in morphology to the ixodid agranular Type I salivary gland acini and to granular Type II or Type B acini. All stages of A. delacruzi had a similar gut structure, consisting of digestive cells in the basal portion that contained hematin granules. Neither regenerative nor secretory cell traces were observed in the sections of gut.

Parasites are intimately connected to the host in which they live, and some may be affected by the polluted environment of their host. The present study describes the effect of a steroid hormone (11-ketotestosterone) on the sex ratio of the invasive hematophagous nematode Anguillicola crassus Kuwahara, Niimi & Itagaki, 1974, when experimentally injected to European eels, Anguilla anguilla. Our results showed that this steroid induced a significant male-biased ratio in the nematode A. crassus infrapopulations, suggesting that the presence of endocrine disruptors in the environment may lead to skewed sex ratios among parasites.

The systematic relationships of acanthocephalans, including Leptorhynchoides and Pseudoleptorhynchoides that occur in freshwater and marine fishes in Neartic and Neotropical regions, are enigmatic. Leptorhynchoides (3 species) and Pseudoleptorhynchoides (1 species) are presently classified in the Rhadinorhynchidae. However, recent molecular and morphological phylogenies have challenged the monophyly of this family. Sequences of nuclear ribosomal DNA (large subunit, small subunit regions) and the mitochondrial cytochrome c oxidase subunit I gene of Leptorhynchoides thecatus and Pseudoleptorhynchoides lamothei were used in phylogenetic analyses with available sequences of 26 other acanthocephalans. Maximum parsimony and maximum likelihood analyses were identical in placing both genera in the Illiosentidae. Bootstrap analyses also indicate that placement of these genera with members of Illiosentidae is reliably supported.

A total of 351 serum samples was examined for anti–T. gondii antibody titers; the overall seroprevalence was 3.7%. The Sabin– Feldman dye test (DT), latex agglutination test (LAT), and IgG enzyme-linked immunosorbent assay (IgG ELISA) indicated seroprevalences of 3.7%, 3.4%, and 4.0%, respectively. Compared with the DT, the sensitivities of the LAT and IgG ELISA were 84.6% and 100.0%, respectively, and the specificities of the LAT and IgG ELISA were both 99.7%. An increase in T. gondii seroprevalence with increasing age was detected, but the difference was not significant. The overall seroprevalence of T. gondii–antibody titers in pregnant Korean women was relatively low compared to those of Europeans and Americans. A multivariate analysis of risk factors showed that T. gondii infection was positively correlated with eating raw meat, but was not associated with the consumption of unwashed vegetables, drinking untreated water, a history of raising a cat, or blood transfusion. The consumption of raw or undercooked meat may, therefore, be the main route of T. gondii infection in Korea.

Trematode communities in populations of estuarine snails can reflect surrounding animal diversity, abundance, and trophic interactions. We know less about the potential for trematodes to serve as bioindicators in other habitats. Here, we reanalyze data from 2 published studies concerning trematodes, 1 in the Chilean rocky intertidal zone and the other from the East African rift lake, Lake Tanganyika. Our analyses indicate that trematodes are more common in protected areas and that in both habitats they are directly and positively related to surrounding host abundance. This further supports the notion that trematodes in first intermediate hosts can serve as bioindicators of the condition of free-living animal communities in diverse ecosystems.

Oocysts obtained from a guanaco and an alpaca with natural infections were identified as Eimeria macusaniensis and evaluated for host specificity and infectivity over time. In 3 separate trials conducted over 4 yr, 4 adult llamas were fed 500–5,000 sporulated oocysts obtained from guanaco feces stored under laboratory conditions for 41– 84 mo. Infections with prepatent periods of 36–41 days and patent periods of 38–55 days developed in 4/4 llamas. In a fourth trial, 3 adult llamas and 1 alpaca were each fed 1,000 sporulated E. macusaniensis oocysts obtained from alpaca feces stored in the laboratory for 3 mo. Infections with prepatent periods of 33–34 days and patent periods of 14–20 days developed in 3/3 llamas. Infection in the alpaca had a prepatent period of 58 days and a patent period of 1 day. Clinical signs associated with infection, if any, were minimal and included increased fecal mucus and occasional soft feces. These results provide evidence that E. macusaniensis is a single species transmissible amongst alpacas, llamas, and guanacos and that oocysts of this species can remain infective for many years.

The monogene Dactylogyrus eucalius Mizelle and Regensberger, 1945 and its ability to maintain a population from year to year on the annual fish Culaea inconstans Kirkland was examined in a small lake in central Ontario. Fish were sampled toward the end of their annual breeding season, at a time when the host population consisted of 2 cohorts, i.e., young-of-the-year (0 ) and mature adults (1 ). Prevalence of infection was 94%, with a mean intensity of 8.8 ± 9.6; neither measure varied significantly with host length or between cohorts (P > 0.05). At necropsy, parasites were characterized as juveniles that included postoncomiracidia (immature, with a ventrally directed haptor) as well as developing protandrous males (body with a near-complete haptor and with little or no pigmented vitellaria), or as adults (with testis, ovarium, darkened vitellaria, and occasionally bearing a tanned egg). The proportion of juvenile to adult parasites differed significantly between cohorts (P < 0.05), with 0 fish infected with a mixture of juveniles and adults, whereas 1 fish had almost exclusively adult parasites. Since adult (1 ) brook stickleback typically die after spawning, the increased frequency of juvenile parasites exploiting juvenile hosts may represent an evolutionary adaptation, maximizing the chances of parasites infecting hosts that will enter winter. It is suspected that 0 fish can be infected in the nest within 2 wk of hatching and persist by effectively infecting new host recruits when they are sympatric with their parents.

Fatal toxoplasmosis was diagnosed in a sand fox (Vulpes rueppelli) from United Arab Emirates. Toxoplasma gondii–like tachyzoites were found associated with necrosis in the intestine, spleen, liver, pancreas, lungs, mesenteric lymph nodes, and heart. Tachyzoites reacted positively with T. gondii–specific polyclonal antibodies. Antibodies to T. gondii were detected in 8 captive V. rueppelli assayed by the modified direct agglutination test in titers of 1:800 or higher.

Live attenuated coccidiosis vaccines could be used as powerful carriers, expressing exogenous viral and bacterial antigens, to induce protective immunity against pathogenic organisms. We investigated the ability of Eimeria tenella to express an exogenous gene in vitro. Eimeria tenella sporozoites were transfected with the plasmid pH4-2EYFP-Actin3 containing the yellow fluorescent protein gene (yfp) and inoculated into primary chicken kidney cells (PCKCs), followed by incubation at 41 C in a 5% CO₂ chamber. Fluorescent sporozoites were observed as early as 15–20 hr post-inoculation (PI). Fluorescence displayed by the expressed YFP protein was visible throughout the schizogony and gametogony stages of the tranfected E. tenella. Fluorescent oocysts were found between 200–327 hr PI. Higher fluorescence intensity was observed in the nucleus than in other compartments of the transfectants, while little or no fluorescence was seen in the refractile globule. The diversity of schizonts, particularly of the first generation, was presented by fluorescent nuclei arranged in different patterns. Our results demonstrated the ability of E. tenella to express an exogenous gene throughout the endogenous development in vitro. Completion of the endogenous development of transfected E. tenella in cell cultures will facilitate the study of foreign antigen expression in Eimeria spp., paving the way for the development of an Eimeria spp. vector vaccine that also carries and delivers other vaccines by oral administration.

One hundred fecal samples were collected during research on Eurasian lynx ecology and food habits in the Polish part of the Białowieża Primeval Forest (BPF) from 2001 to 2006. Seventy-three percent of samples contained eggs or larvae of helminths. A total of 10 species of helminths was identified, including 3 Cestoda (Diphyllobothrium latum, Spirometra janickii, and unidentified species of Taeniidae), 1 Trematoda (Alaria alata), and 6 Nematoda (Aelurostrongylus abstrusus, Ancylostoma tubaeforme, Eucoleus aerophilus, Metastrongylus sp., Nematodirus sp., and Toxocara cati). Alaria alata has not been reported previously in lynx. A statistical comparison of the 2 techniques used to isolate eggs, i.e., flotation and sedimentation, indicates that sedimentation was more effective.

Between March 2000 and February 2003, 63 specimens of Genidens barbus and 69 specimens of Aspistor luniscutis (Siluriformes: Ariidae), sympatric species from the coastal zone of Angra dos Reis (23°01′S, 44°19′W), RJ, Brazil, were necropsied to study their metazoan parasite communities. Parasite community descriptors were calculated and possible similarities statistically tested. Twenty-two species of metazoan parasites were identified, 15 species from G. barbus and 16 associated with A. luniscutis. Nine species were common to both host species; 4 of them exhibited significant differences in terms of abundance and prevalence. Mean total abundance, species richness, diversity, evenness, and Berger–Parker dominance values were not significantly different in the 2 species of fish. Similarity within parasite infracommunities showed highest homogeneity in A. luniscutis. The parasite infracommunities of A. luniscutis and G. barbus were characterized by ectoparasite dominance and scarcity of species with high prevalence. Nevertheless, low values of similarity were observed between infracommunities, and evidence for 2 distinct infracommunities groups was found.

The survival of all stages of Haemaphysalis longicornis was investigated at different densities and at 3 levels of relative humidity. Larvae survived longer when the density was higher, or the size of a cluster was larger, or both. However, in nymphs and adults, there was no significant relationship between the density and the survival period. Moreover, in nymphs and adults, there was no positive relationship between the size of the aggregation and tick longevity, except for 2 nymphs/vial in high humidity. These results suggest that the advantage gained from a higher density, or from taking part in a cluster, or both, differed between stages. Furthermore, the fact that the survival period of larvae and nymphs was influenced by cohort suggests that a maternal effect, as well as aggregation, influences the survival of immature ticks.

Schistosoma mansoni is 1 of the causative agents of schistosomiasis, an endemic disease in 76 countries of the world. The study of its genome, estimated to be 270 Mb, is very important to understanding schistosome biology, the mechanisms of drug resistance, and immune evasion. Repetitive elements constitute more than 40% of the S. mansoni genome and may play a role in the parasite evolution. The retrotransposons Boudicca, a long terminal repeat (LTR), and Perere 03, a non-LTR, are present in a high number in the S. mansoni genome and were localized with the use of fluorescence in situ hybridization (FISH) and primed in situ labeling (PRINS). Bacterial artificial chromosomes (BAC) clones containing the retrotransposons Boudicca and Perere 03 were selected by bioinformatic analysis and used as probes in FISH. Using metaphase chromosomes from sporocysts and the FISH and PRINS techniques, we were able to map these retrotransposons. Perere 03 was localized in the euchromatic regions of the short arm of chromosome 2 and Boudicca in the euchromatic regions of the short arm of chromosomes 2 and Z.