Polyamines are essential for proliferation of Trypanosoma brucei brucei, and feeding rats polyamine-deficient chow (PDC) decreases their blood polyamine concentrations. Proliferation of T. b. brucei (IL-tat 1.4 strain) (IL) is not restrained within PDC-fed rats. However, symptoms of IL-infected rats such as anemia decrease by PDC feeding. We reported cytokine and nitric oxide (NO) production of T. b. gambiense (Wellcome strain [WS])–infected rats were affected by PDC feeding, and WS proliferation was restrained. Therefore, we investigated whether the change in production of cytokines and NO by PDC feeding affects IL proliferation and decreases symptoms in vivo. In IL-infected PDC-fed rats, NO, interleukin (IL)-12, and tumor necrosis factor-α production increased while interferon-γ and IL-10 decreased compared to normal chow-fed rats. IL proliferation was restrained by NO production when it was co-cultured with spleen cells harvested from uninfected rats. In contrast, IL proliferation in infected rats was not changed by PDC feeding, although NO production was increased. The results suggest that changes in cytokines and NO production in IL-infected rats by PDC feeding have little influence on IL proliferation. However, they may serve to decrease symptoms.

High intensity infections of Echinostoma trivolvis metacercariae decrease survival and growth of young amphibian larvae. However, in nature, parasites are highly aggregated, which results in a large proportion of the amphibian population being only moderately infected. Survival and growth responses at these more-common, low-infection levels remain poorly studied. Thus, we investigated the effects of moderate Echinostoma trivolvis metacercariae infection (following exposure to 0, 10, 30, or 90 cercariae) on the growth and development of pickerel frog (Rana palustris) tadpoles. We measured metabolism to determine whether increased energy expenditure is a potential physiological mechanism underlying previously documented reduced growth. Furthermore, we quantified tadpole intestine size, which can exhibit plasticity in response to changing metabolic demands, and we characterized metacercariae distribution in tadpole kidneys. Metacercariae encysted in the pronephros significantly more than in the mesonephros, but tended to occur equally in right and left kidneys. Two mo post-infection (PI), there were no changes in tadpole survival, development, intestine size, or growth related to metacercariae infection. Similarly, metacercariae did not significantly increase metabolic rates during encystment or at 1 mo PI. Our study demonstrated that modest E. trivolvis infections, representative of a large proportion of the host population, had no detectable effects on fitness-related traits in laboratory isolation from other ecological variables.

Cystoisospora canis is a coccidial parasite of the intestinal tract that can cause severe disease in dogs. Clinical signs include watery diarrhea, vomiting, fever, and weight loss. Extraintestinal stages of Cystoisospora spp. have been demonstrated in the mesenteric lymph nodes of paratenic hosts. Information on the biology of extraintestinal stages of canine Cystoisospora species is limited. The current study examined the development of C. canis in 2 noncanine cell lines and the ultrastructure of the monozoic cysts that formed. Monolayers of bovine turbinate cells and African green monkey kidney cells were grown on coverslips and inoculated with excysted C. canis sporozoites. Coverslips were collected on various days and fixed and stained for light microscopy (LM) or transmission electron microscopy (TEM). A single, centrally located, slightly crescent-shaped sporozoite surrounded by a thick cyst wall within a parasitophorous vacuole was observed with the use of LM and TEM. No division and no multinucleated stages were observed with either LM or TEM. With TEM, typical organelles of sporozoites were observed, such as rhoptries, dense granules, a crystalloid body, polysaccharide granules, and a conoid. The structure and ultrastructure of C. canis monozoic cysts produced in vitro are similar to extraintestinal cysts of other Cystoisospora species in experimentally infected animals and those of Cystoisospora belli observed in immunocompromised humans. This is the first study that fully demonstrates in vitro the development of what structurally resemble extraintestinal cysts of a Cystoisospora spp.

The snail Ilyanassa obsoleta is native in estuaries along the eastern seaboard of North America. In Delaware, most studies on this snail and its larval trematode parasites have been done in snail populations where prevalence (percent infected) is high. Here, data were obtained from a lower-prevalence population in southeastern Rehoboth Bay, Delaware, to study how the resident trematodes exploit the snail resource among the salt marsh islands. Snails were sieved from 3 plots (1 m² each) at each of 21 locations in the ∼1.5-km² study area. Snails were counted and all, or a random selection, were measured for size and dissected to reveal sex and trematode infections. Snails in the area were distributed heterogeneously with respect to density, size, and parasite prevalence. Overall, utilization of the snail resource by trematodes was low. Prevalence of 6 trematode species (in 11 combinations) was 13.9% among 6,862 snails collected. Most snails in the area had remained uninfected for many years. All snail infections except 1 were at least twice as aggregated in their spatial distributions as uninfected snails. In a test for species associations, trematodes were independent in locations where they infected snails. Parasite assemblages at species-poor locations were nonrandom subsets in species-rich locations; i.e., they were nested, suggesting that snails at different locations are exposed to different, and somewhat ordered, sets of infective larvae (miracidia). Low utilization of the snail resource could result from limited visitation by infected definitive hosts and/or unsuccessful miracidia. I propose it is mainly the latter. Miracidia are microscopic, swimming, and short-lived larvae. Tidal currents in the narrow waterways would sweep them along and make it difficult to stop and infect snails.

The European eel, Anguilla anguilla, is considered an endangered species that is under pressure for many reasons. Among others, the introduced parasite Anguillicola crassus is thought to play an important role in the decline of eel populations. These nematodes have been shown to negatively affect many fitness-related traits in eels, e.g., growth, osmoregulation, and stress tolerance. Nevertheless, there has been little work on the way in which the host–parasite interaction influences the molecular regulation of these key physiological processes. We experimentally analyzed the effect of this nematode on the expression of genes involved in the physiology of European eels during their continental life. Included are genes that are implicated in the eel's somatic growth (insulin-like growth factor 1 and thyroid hormone receptor β), osmoregulation (Na /K -ATPase β1 and aquaporin 3), and hematopoiesis (hemoglobin α-chain). Our results showed the absence of an effect on genes involved in fish growth; the parasite may, however, have an effect on osmoregulation and hematopoiesis. We also noted a differential impact of male and female parasites on the expression of some genes, perhaps owing to the sexual dimorphism in body size of the parasite.

Sixty-five specimens of the frog Leptodactylus chaquensis were infected by 2 Glypthelmins species (Glypthelmins repandum: 41%, and Glypthelmins palmipedis: 38%) in the small intestine. This study was designed to determine the site specificity of both species along the length of the small intestine by analyzing the distribution, niche overlap, morphological characteristics, and population dynamics. The location of G. palmipedis is very restricted, with the core infection site in the anterior small intestine. In contrast, G. repandum can be characterized as having an expanded niche within the small intestine. In single infections and with different intensities, individuals of both parasitic species showed preference for the anterior small intestine. In concurrent infections and with different intensities, the distribution of G. palmipedis did not change when G. repandum was present; however, displacement of G. repandum toward the middle of the small intestine was observed. Glypthelmins species used the same microhabitat and presumably the same food resource and were generally found to overlap more than expected by chance. This finding suggests the possibility of different feeding mechanisms given by differences in their pharynx size by 37%. Also, the coexistence of these could be associated with the differentiation of realized niches.

Seasonal dynamics of 2 trematode species, Cyathocotyle bushiensis and Sphaeridiotrema globulus, were assessed in relation to life history traits of the parasites and their hosts, as well as abundance of host species and abundance of infective stages. Both of these trematodes are associated with recurrent mortality of migrating waterbirds on the Upper Mississippi River National Wildlife and Fish Refuge. An invasive snail species, Bithynia tentaculata, serves as intermediate host for both trematode species. In total, 2,970 snails were collected at 2 study sites. Prevalence and mean abundance of the 2 trematode species varied among dates and was attributed to several factors, including migration patterns of definitive hosts, snail population dynamics, and seasonal changes in temperature. The surge of new infections of both parasites seems to be due to avian hosts foraging at this site during spring migration. The high prevalence and abundance of metacercariae among the snail population promote mortality among molluscivorous birds by increasing the probability of ingestion of a lethal dose. Additionally, mortality of non-molluscivorous birds can be explained by accidental ingestion of a couple of highly infected snails resulting in a lethal dose.

Because of a lack of comprehensive surveys, the geographic distributions of the North American species of encapsulating Trichinella (T. nativa and its variant T6, T. murrelli, and T. spiralis) are poorly characterized in detail. These species are potentially zoonotic; therefore, biogeographic information is critical to monitoring their status and any distribution changes due to climatic and man-made environmental impacts. The maximum entropy (Maxent) program was used to model predicted ranges for these sylvatic Trichinella spp., using a limited number of available location records with confirmed species identifications collected over 55 yr throughout North America. The resulting prediction models were shown to be robust, and the species maps created are presented. The predicted range of T. nativa is primarily north of the 48°–52° latitudes, overlapping the Tundra, sub-Arctic, and Warm Continental eco-regions. Its sympatric genotypic variant, T6, has a predicted range covering primarily the sub-Arctic and mountainous Temperate Steppe eco-regions, the latter extending below 48°N latitude. In the east, the T6 range includes the Warm Continental and the mountainous Hot Continental eco-regions; the T6 range is also predicted to extend to the Sierra Madre Mountains of Mexico. The most probable range of T. murrelli is centered in the Midwest within the Hot Continental and Prairie eco-regions, with an extension southward to the Subtropical and Tropical/Subtropical Steppe and Desert eco-regions. In the west, it exists in a restricted range characterized as mountainous Mediterranean. The most probable distribution of sylvatic T. spiralis is along the humid east North American coast (Hot Continental south to Subtropical), and along the coast of northwest North America (Marine) to Alaska (sub-Arctic and Tundra). Its most southerly range extends into central Mexico (Tropical/Subtropical Desert). The difference in relative freeze resistance between T. nativa/T6 and T. murrelli undoubtedly accounts for much of this geographic separation. However, the factors responsible for the absence of a more southerly distribution of T. nativa are not obvious, given the overlap in host range with T. murrelli. The maximum July temperature appears to have a significant effect on this distribution pattern. The results of the model building highlight subjects for future research on the biotic and abiotic factors important in determining Trichinella spp. distributions and directions for model validation research.

This study describes the parasite communities of juvenile bluegill and examines the development of parasite communities in juvenile bluegill from 2 Michigan lakes. Parasitological examination of 510 juvenile bluegill from 2 Michigan lakes (Three Lakes II [TL] and Gull Lake [GL]) demonstrated that TL bluegill harbored 19 parasite species and GL bluegill harbored 16 parasite species. Parasite communities of juvenile bluegill from both lakes were dominated by larval parasites, particularly larval trematodes. A nonmetric multidimensional scaling analysis showed bluegill of similar lengths to have similar parasite communities. Relative influences of species richness on parasite infracommunities of juvenile bluegill suggest similar patterns of parasite community structure between TL and GL. Patterns in parasite colonization evident in both lakes suggest that the smallest juvenile bluegill are primarily vulnerable to colonization by parasites acquired through direct contact, particularly larval trematodes, while the majority of parasites acquired through ingestion are not acquired until juvenile bluegill are larger and less-gape limited.

Fundulotrema porterensis n. sp. (Monogenea: Gyrodactylidae) is described from the mummichog, Fundulus heteroclitus (L.; Cyprinodontidae), inhabiting Porters Lake, Nova Scotia, Canada. The new parasite species is characterized by having a ventral bar with small anterolateral processes and linguiform membrane, differentiating it from all other known species of Fundulotrema. The morphological description of F. porterensis is supplemented with 1,011 sequenced base pairs (bp) of ribosomal DNA (rDNA) spanning both internal transcribed spacers (ITS-1 and ITS-2) and 5.8S regions of the genome. A BLAST (basic local alignment search tool) search revealed that the 5.8S (157 bp) region varied by 1 bp from Gyrodactylus turnbulli Harris, 1986 and G. pictae Cable, Oosterhout, Barson and Harris, 2005, which also infect cyprinodontids. Morphometrically, F. porterensis most closely resembles Fundulotrema foxi (Rawson, 1973), but the 2 species are easily separated by length of hamuli (50.7 vs. 42.2 µm, respectively), length of anterolateral process of the ventral bar (4.9 vs. 8.9 µm), shape of marginal hooks, and shape of the ventral bar membrane. A morphological and molecular supplemental diagnosis of Gyrodactylus stephanus Mueller, 1937, from the mummichog, is also presented. This new material provides previously unrecorded information on the attributes of the ventral bar, marginal hooks, and also clarifies the structure of the male copulatory organ (MCO).

Polystomoides magdalenensis n. sp. is described from the buccal cavity of the Colombian slider Trachemys callirostris callirostris (Gray, 1856) in the middle of Magdalena River drainage, Colombia. The new species is characterized by a combination of traits, i.e., 29–35 genital spines, outer and inner hamuli length (123–150 and 54–63, respectively), testis size (261.4–554.5 × 388.2–768.4), marginal hook lengths (45–51), and pharynx length (150–333), as well as testis length/oral sucker length, testis length/pharynx length, and testis width/pharynx width ratios. This is the first species described from turtles in Colombia and the fifth reported in chelonians from South America.

Four species of Ligophorus (Monogenea: Dactylogyridae), i.e., L. tainhae n. sp., L. brasiliensis n. sp., L. guanduensis n. sp., and L. lizae n. sp., are described. The specimens were collected from the gills of Mugil liza (Mugilidae) from the Guandu River (22°48′32″S, 43°37′35″W), State of Rio de Janeiro, Brazil, between January 2008 and March 2008. The male copulatory organ of L. tainhae n. sp. differs from the all known species of this genus in having the largest accessory piece, the length of accessory piece exceeding the length of the copulatory organ tube, and the distal tip of the lower lobe crossing the upper lobe. Ligophorus brasiliensis n. sp. and L. guanduensis n. sp. have a similar shape of the accessory piece, but in L. guanduensis n. sp. the lower lobe is larger than the upper lobe (as opposed to L. brasiliensis n. sp.), the ratio between length of upper lobe and the length of the proximal part of the accessory piece before the bifurcation is shorter and the distal tip of the lower lobe extends to the level of the upper lobe (in L. brasiliensis n. sp. the distal tip of lower lobe crossing the upper lobe). In L. lizae n. sp., the terminal bifurcations of the accessory piece are equal in length and unequal in the other 3 new species. Species of Ligophorus are recorded for the first time from Brazil.

Three dactylogyrid (Monogenea) species are described from the gills of siluriform fishes from the rivers around Iquitos, tributaries of the Amazon River in Peru: Demidospermus centromochli n. sp. from Centromochlus heckelii (de Filippi) (Auchenipteridae) and Demidospermus macropteri n. sp. and Ameloblastella unapi n. sp. from Calophysus macropterus (Lichtenstein) (Pimelodidae). The new species of Demidospermus differ from their congeners in having 2 different hook shapes. Ameloblastella unapi n. sp. differs from the other 3 species of the genus in having anchors with an elongate, straight shaft and a short point that forms a 90° angle, a coiled (counterclockwise) male copulatory organ with 13–14 rings, and a coiled vaginal tube. Based on the present study, Pseudovancleaveus França, Issac, Pavanelli, and Takemoto, 2003, is regarded as a junior subjective synonym of Ameloblastella Kritsky, Mendoza-Franco, and Scholz, 2000. The finding of Demidospermus and Ameloblastella spp. on these siluriforms extends our host and geographic knowledge of species of these monogenean genera to Peru.

The impact of coccidiosis outbreaks on the productivity of broiler chicken farms can be substantial, depending on the severity of disease caused by particular species and strains of Eimeria. We examined the genetic diversity of Eimeria species present in commercial broiler farms in relation to their performance level. Four groups of broiler chicken farms in Arkansas (AR) and North Carolina (NC), having either high or low performance levels, were sampled for Eimeria spp. oocysts. We amplified gDNA from oocysts by using genus-specific primers targeting 18S ribosomal RNA, the first and second internal transcribed spacer regions, and cytochrome c oxidase subunit I as the established species-specific primers. Eimeria spp. diversity was not homogenous among the 4 farm groups, with less-pathogenic species (E. mitis and E. mivati-like) associated with AR and NC high-performance farms, respectively, and a pathogenic species (E. brunetti) associated with AR low-performance farms. Sequence analyses identified multiple E. maxima and E. mitis genetic variants, from which 2 E. maxima variants were unique to low-performance farms. Distinct populations of sequences at the NC high-performance farms were identified as E. mivati-like, based on homology searches. Our study demonstrated the utility of analyzing multiple genomic loci to assess composition and polymorphisms of Eimeria spp. populations.

Many parasite populations are difficult to sample because they are not uniformly distributed between several host species and are often not easily collected from the living host, thereby limiting sample size and possibly distorting the representation of the population. For the parasite Schistosoma mansoni, we investigated the use of eggs, in aggregate, from the stools of infected individuals as a simple and representative sample. Previously, we demonstrated that microsatellite allele frequencies can be accurately estimated from pooled DNA of cloned S. mansoni adults. Here, we show that genotyping of parasite populations from reproductively isolated laboratory strains can be used to identify these specific populations based on characteristic patterns of allele frequencies, as observed by polyacrylamide gel electrophoresis and automated sequencer analysis of fluorescently labeled PCR products. Microsatellites used to genotype aggregates of eggs collected from stools of infected individuals produced results consistent with the geographic distribution of the samples. Preferential amplification of smaller alleles, and stutter PCR products, had negligible effect on measurement of genetic differentiation. Direct analysis of total stool eggs can be an important approach to questions of population genetics for this parasite by increasing the sample size to thousands per infected individual and by reducing bias.

The levels of IFN-γ, TNF-α, IL-10, and TGF-β1 cytokines associated with Trypanosoma cruzi during pregnancy were determined by enzyme-linked immunosorbent assay (ELISA) in serum samples from peripheral, placental, and cord blood of chronic infected mothers with detectable and undetectable parasitemia, and in their uninfected newborns. Compared to uninfected pregnant women and mothers with undetectable parasitemia, the concentrations of IFN-γ were higher at the 3 sites in mothers with detectable parasitemia. In these mothers and their newborns, the TNF-α concentrations were higher in the periphery and cord in comparison to serum samples from non-chagasic pregnant women. TNF-α levels were higher in newborns of mothers with detectable parasitemia than in newborns of mothers with undetectable parasitemia. IL-10 and TGF-β1 levels at the 3 sites were unchanged and diminished, respectively, in samples from infected mothers with patent parasitemia in comparison with uninfected pregnant women. Cytokine concentrations did not change significantly in all samples from mothers with undetectable parasitemia; however, the concentration of TGF-β1 was significantly reduced in their peripheral samples but significantly higher in the placenta in comparison with uninfected mothers and mothers with detectable parasitemia, respectively. These results suggest that elevated numbers of circulating parasites in vivo elicit production of pro-inflammatory cytokines that control congenital T. cruzi infection.

A cDNA coding for δ-giardin was cloned from Giardia lamblia trophozoites to localize the protein and to study its function in mediating surface attachment. Recombinant δ-giardin antigen was expressed in Escherichia coli as a poly-histidine fusion protein and was purified by affinity chromatography for production of antisera to δ-giardin. By immunoblotting analysis, antisera to recombinant δ-giardin antigen recognized a 31-kDa protein on G. lamblia trophozoites. Anti-recombinant δ-giardin was used to localize the native protein to the trophozoite ventral disk in both immunofluorescence and immunoelectron microscopy assays. Pre-treatment of G. lamblia trophozoites with anti-δ-giardin sera caused morphological changes in the parasite and inhibited trophozoite binding to the surface of cell culture slides. Binding of antibodies to δ-giardin may provide a means of inhibiting attachment of G. lamblia trophozoites to the intestinal epithelium and thereby prevent clinical giardiasis.

Perkinsus marinus is a facultative intracellular parasite that causes “Dermo” disease in the eastern oyster Crassostrea virginica. Although hemocytes from healthy oysters rapidly phagocytize P. marinus trophozoites, they fail to efficiently kill them. Instead, trophozoites survive and proliferate, eventually overwhelming the host. Because Chesapeake Bay oyster populations have been reduced to unprecedented levels, the introduction of the Suminoe oyster, Crassostrea ariakensis (synonymous C. rivularis), has recently been proposed. Although this species is refractory to developing Dermo disease, it can be infected by Perkinsus spp. and, thus, the mechanistic basis of its disease resistance remains intriguing. To examine whether the resistance to develop Dermo is due to a high capacity of C. ariakensis hemocytes to kill internalized P. marinus, we developed an in vitro assay to compare intracellular survival and proliferation of P. marinus in C. virginica and C. ariakensis hemocytes. Our results revealed that P. marinus cultured trophozoites have a similar capacity for in vitro survival within hemocytes from both oyster species, suggesting that the resistance of C. ariakensis to develop Dermo disease is most likely due to reduced parasite pathogenicity for the latter oyster species, rather than to infectivity. Together with the currently available P. marinus genome, EST sequences, and the transfection methodology we recently developed, this assay should significantly contribute to a rigorous identification of the P. marinus genes responsible for its intrahemocytic survival.

Gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, Didelphis virginiana. Despite its wide distribution in the Americas, its natural life cycle is poorly understood. Recently, we found an endemic area for G. turgidum infection in Sinaloa, Mexico (Díaz-Camacho et al., 2009). Based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. To confirm that this is really a seasonal variance, we conducted a longitudinal survey on G. turgidum infection in opossums from November 2007 to November 2008. The results showed amazing seasonal changes in the prevalence, with synchronized migration and maturation of worms in opossums. Between February and March, many juvenile worms, with occasional AL3, were found in the liver, but no worms were found in the stomach. Mature adult worms began to appear in the stomach around April and rapidly increased in number toward July, when all worms resided in the stomach. Then, the worms disappeared almost completely by November. These results suggest that G. turgidum is an annual parasite of the opossum, D. virginiana, in Mexico.

In vitro cultivation of trematodes would aid studies on the basic biology of the parasites and the development of chemotherapies and vaccines. Our goal was to measure the in vitro survival and maturation of metacercariae of Microphallus turgidus under different culture conditions. Metacercariae of M. turgidus from grass shrimp (Palaemonetes pugio) were excysted and cultured in humidified air at 37 C in RPMI-1640 medium supplemented with 20% calf, chicken, or horse serum. Deposition of eggs was greatest in media containing horse or calf serum. Worms survived longest at 37 C, but did not produce greater numbers of eggs than worms cultured in RPMI-1640–supplemented horse serum at 42 C. Most eggs deposited in vitro (>80%) were normal in shape and, after incubation for 10 days at 30 C in brackish water, approximately 30% of them contained miracidia. Eighteen percent of hydrobiid snails (Spurwinkia salsa) fed these eggs shed cercariae 5–6 wk later. The cercariae were infective to grass shrimp (Palaemonetes vulgaris) and developed into metacercariae. This study is significant because it is the second instance in which a digenean, and the first time that a microphallid, has been demonstrated to develop in vitro from metacercariae into adult worms capable of producing infective eggs.

Pseudabbreviata novaeguineaensis n. sp. from the stomach of Hypsilurus modestus (Agamidae) from Papua New Guinea is described and illustrated. The new species was also found in the stomach of Hypsilurus papuensis from Papua New Guinea. Pseudabbreviata novaeguineaensis n. sp. represents the sixth species assigned to the genus and the first from the Australo-Papuan Region. The new species differs from other species assigned to Pseudabbreviata by the vulva position in the female and pedunculate papillae arrangement in the male tail morphology. In addition to the new species, H. modestus harbored Meteterakis crombiei, Strongyluris gonyocephali, and larvae of Abbreviata sp. (in cysts).

The onchobothriid Triloculatum n. gen. is erected to house species formerly considered members of Phoreiobothrium, but that bear 3, rather than 5 or more, bothridial subloculi. The species formerly known as Phoreiobothrium triloculatum is designated as its type. This species is redescribed based on 2 syntypes and on voucher material consistent with type material taken from the type host, Carcharhinus obscurus, from the type and 1 additional locality. Examination of the cestode fauna of a diversity of carcharhinid sharks resulted in the discovery of an additional 5 new tri-subloculate species belonging to the genus. These include: Triloculatum andersonorum n. sp. from Negaprion acutidens; Triloculatum bullardi n. sp. from Carcharhinus brevipinna; Triloculatum geeceearelensis n. sp. from Carcharhinus isodon; Triloculatum jodyi n. sp. from Carcharhinus acronotus; and Triloculatum oregontwoae n. sp. from Carcharhinus plumbeus. The new species differ from one another in the number of proglottids, scolex size, number of testes, number of lateral columns of vitelline follicles, and whether they possess craspedote or acraspedote proglottids. Histology and scanning electron microscopy suggest that the new genus differs further from Phoreiobothrium in that its species possess an anterior margin of the posterior loculus that is fused to the anterior loculus, rather than free. The diagnosis of Phoreiobothrium is emended to accommodate the removal of tri-subloculate species and the new information on the condition of the locular interface, and the symmetrical ovary and vitelline follicles arranged in 2 lateral bands; each band consisting of 2 to many columns of follicles. Existing host data indicate that the new genus is restricted to only a subset of the sharks parasitized by species of Phoreiobothrium. Results from the examination of a diversity of carcharhinid species suggest that species in the new genus may have an affinity for the larger, i.e., >200 cm in total length, species of Carcharhinus and Negaprion. One of the new Triloculatum species was found to attach in the crypts lying between the larger ridges found on the mucosal surface of the posterior inner region of the scroll-type spiral intestine of C. brevipinna.

Trichobilharzia is a genus of threadlike schistosomes with a cosmopolitan distribution in birds. Species of Trichobilharzia achieve notoriety as major etiological agents of cercarial dermatitis, or swimmer's itch. There are 40 species described in the literature, for which the majority lacks molecular sequence information. To better understand the phylogenetic relationships, diversity, species boundaries, host use, and geographic distribution of this genus better, we surveyed 378 birds and over 10,000 snails from North America. The phylogenetic analysis was based on nuclear 18S, 28S rDNA, internal transcribed spacer region and mitochondrial cytochrome oxidase I sequence data. Specimens were recovered that could be related to 6 of the 14 described species of Trichobilharzia from North America (Trichobilharzia physellae, Trichobilharzia querquedulae, Trichobilharzia szidati, Trichobilharzia stagnicolae, Trichobilharzia franki, and Trichobilharzia brantae). An additional 5 lineages were found that could not be related directly to previously described species. Trichobilharzia brantae, transmitted by Gyraulus parvus, grouped outside the clade containing the recognized species of Trichobilharzia. A subgroup of the Trichobilharzia clade designated Clade Q was comprised of closely related species whose adults and eggs are similar, yet the European species use lymnaeids whereas the North American species use physids as snail hosts. This molecular phylogeny provides a useful framework (1) to facilitate identification of worms, including those involved in dermatitis outbreaks; (2) to test hypotheses about the evolution, diversification, host–parasite interactions and character evolution of Trichobilharzia; and (3) to guide future taxonomic revision of Trichobilharzia.

Specimens of Dictyocaulus spp. were extracted from the respiratory tracts of 3 ruminant hosts including roe deer (Capreolus capreolus), red deer (Cervus elaphus), and chamois (Rupicapra rupicapra) from wild populations in the province of León, northwestern Spain. The near-complete nuclear small-subunit ribosomal RNA gene, and 2 regions of the large-subunit ribosomal RNA gene, were amplified by PCR and sequenced. The SSU rDNA gene sequences indicated a high level of similarity between the isolate from C. elaphus and the published sequences for Dictyocaulus eckerti. SSU rDNA gene sequences were identical in the isolates from C. capreolus and R. rupicapra, and both corresponded to published sequences for D. capreolus. The LSU rDNA gene sequences differed in isolates from the latter 2 hosts, indicating the possible presence of an undescribed Dictyocaulus sp. in R. rupicapra. These results showed that the LSU rDNA gene sequences are useful indicators of genetic and species diversity in species of Dictyocaulus.

A new species of dicyemid mesozoan is described from Opisthoteuthis depressa Iijima and Ikeda, 1895, collected from Suruga Bay in Japan. Dicyemennea umbraculum n. sp. is a medium species that reaches approximately 3,500 μm in length. This species attaches to the surface of the renal appendages. The vermiform stages are characterized as having 22 or 23 peripheral cells, a disc-shaped calotte, and an axial cell that extends to the propolar cells. An anterior abortive axial cell is absent in vermiform embryos. Infusoriform embryos consist of 37 cells; a single nucleus is present in each urn cell, and the refringent bodies are solid. This is the first description of a dicyemid from Opisthoteuthis.

We describe a new microsporidian species, Encephalitozoon romaleae n. sp., isolated from an invertebrate host, the grasshopper Romalea microptera, collected near Weeks Island, Louisiana, and Jacksonville, Florida. This microsporidian is characterized by specificity to the gastric caecae and midgut tissues of the host and a life cycle that is nearly identical to that of Encephalitozoon hellem and Encephalitozoon cuniculi. Mature spores are larger (3.97 × 1.95 µm) than those of other Encephalitozoon species. Polar filament coils number 7 to 8 in a single row. Analysis of the small subunit (SSU) rDNA shows that E. romaleae fits well into the Encephalitozoon group and is a sister taxon to E. hellem. This is the first Encephalitozoon species that has been shown to complete its life cycle in an invertebrate host.

A new species of capillariid nematode, Freitascapillaria laticauda n. sp. (Capillariidae), is described from the intestine of the blue ridge sculpin, Cottus caeruleomentum (Cottidae, Scorpaeniformes) from the Blue Lick Run, Maryland, United States. It differs from its congeners mainly in the body length (male 3.1–5.4 mm, female 7.0–11.1 mm), the length of the male esophagus (1.5–2.9 mm) and spicule (42–45 µm), and the size of eggs (60–66 × 27–33 µm). Previous records of Freitascapillaria spp. were from characid, poeciliid, and cyprinid fishes in Brazil, Neotropical Mexico, and China, respectively, so that F. laticauda n. sp. is the first species of this genus reported from Nearctic North America and from a scorpaeniform fish.

During August 2003 and August 2004, 11 adult eastern red bats, Lasiurus borealis, were collected and their feces examined for coccidian parasites. Bats were obtained in August 2003 from Garland, Montgomery, and Yell counties, Arkansas (n  =  6) and in August 2004 from Anson and Montgomery counties, North Carolina (n  =  5). Seven (63.6%) of the bats were passing oocysts of 2 undescribed species of Eimeria. Oocysts of Eimeria dowleri n. sp. were subspherical to ellipsoidal, 24.7 × 22.0 (23–26 × 20–23) µm, with a bilayered wall, externally moderately pitted, internally smooth, and with a shape index of 1.1. Micropyle and oocyst residuum were absent, but a polar granule was present. Sporocysts were ovoidal, 13.4 × 9.2 (12–14 × 8–9) µm; shape index was 1.5; Stieda and sub-Stieda bodies were present. A sporocyst residuum consisting of homogeneous granules was scattered among the sporozoites; sporozoites were elongate, with a subspherical anterior refractile body and an elongate posterior refractile body; a nucleus was not discernable. Oocysts of Eimeria sealanderi n. sp. were subspherical to ellipsoidal, 16.7 × 14.4 (15–18 × 13–16) µm, with a bilayered wall, externally lightly pitted, internally smooth, and with a shape index of 1.2. A micropyle was absent, but the oocyst residuum and polar granule were present. Oocyst residuum consisted of a single, membrane-bound homogenous granule. Sporocysts were ovoidal, 8.9 × 5.7 (8–10 × 5–6) µm, with a shape index of 1.6; Stieda and sub-Stieda bodies were present. The sporocyst residuum consisted of 10, to several dozen, homogeneous granules of various sizes loosely clustered among the sporozoites, which were elongate and without obvious refractile bodies and nucleus. This is the first time any coccidian has been reported from this host and the first instance of a bat coccidian reported from North Carolina.

Rhinebothrium paranaensis n. sp. (Tetraphyllidea: Cestoda) is described from the freshwater stingray Potamotrygon falkneri collected in the Colastiné River, a tributary to the Lower Paraná River in Argentina. The specimens were studied in detail using light and scanning electron microscopy and histology. Rhinebothrium paranaensis can be distinguished from all valid species in the genus using the following combination of characters: worm length, number of proglottids, diamond-shaped bothridia lacking constriction, number of loculi on the distal surface of bothridium, and the lack of vaginal sphincter and external seminal vesicle.

Two major genotypic assemblages of Giardia intestinalis infect humans; the nested real-time polymerase chain reaction (PCR) was used for targeting the triose phosphate isomerase (tpi) gene to detect and genotype G. intestinalis in human feces in Egypt. Among 97 fecal samples, 30 (31%) were diagnosed as giardiasis by saline wet mount microscopy after staining with Lugol's iodine. The tpi gene was amplified from 41 (42.3%) fecal samples, of which 11 were microscopy-negative specimens. Of the total samples, 24 (58.5%) contained assemblage A group I, and 7 (17.1%) were assemblage A group II from the group of patients complaining of intermittent diarrhea. Eight (19.5%) samples contained assemblage B from patients with persistent diarrhea. Two (5%) samples had a mixture of assemblage A group II and assemblage B. The technique was able to detect as few as 20 trophozoites per PCR on fecal DNA-isolated, microscopy-negative, and quantitative (q)PCR-positive specimens; there was a higher average cycle threshold value than microscopy-positive and qPCR-positive specimens, suggesting that they represented true, low-burden infections. In conclusion, we could genotype G. intestinalis from fresh stool samples in Egypt; in infections commonly presented with intermittent diarrhea, the most prevalent genotype was assemblage A group I. The most vulnerable age group included 10- to 20-yr-old individuals.

Toxoplasma gondii is a widely distributed obligatory intracellular parasite that causes severe disease to the fetus when transmitted during pregnancy. Drugs used to avoid congenital transmission have shown side effects, and their efficacy is controversial. The most widely used treatment for acute toxoplasmosis during pregnancy is pyrimethamine plus sulfadiazine, which has several side effects. In this work, we tested the efficacy of azithromycin in reducing congenital transmission of T. gondii in the large vesper mouse, Calomys callosus, a rodent. Females of C. callosus were inoculated perorally with 20 cysts of ME49 strain of T. gondii on the day of fertilization, and fetuses were collected from the 15th to the 19th day of gestation. Azithromycin (300 mg/kg), in association with pyrimethamine (100 or 50 mg/kg) plus sulfadiazine (100 or 75 mg/kg) and folinic acid (15 mg/kg) (SPAf), or vehicle, were administered orally on different days after infection. Brain and ocular tissues were removed and processed for immunohistochemistry using a polyclonal antibody against T. gondii, or were processed for parasite DNA quantification. Toxoplasma gondii was detected in the brains of all females and in fetuses' eyes of C. callosus treated with SPAf. On the other hand, in females treated with azithromycin, there was a reduction of T. gondii in the brains of mothers, and no parasites were detected in eyes of fetuses, indicating that azithromycin may represent an alternative treatment for toxoplasmosis during pregnancy.

Columbina picui (picui ground-dove) is a small, diurnal columbid bird that lives, in couples or flocks, in open areas in the countryside and urban centers. The species occurs in Brazil and other countries in South America. The aim of this study was to identify the helminths that parasitize C. picui in the state of Rio Grande do Sul, southern Brazil. Thirty-four specimens were necropsied; in each case, the organs were isolated and examined separately. The nematodes and their prevalences were: Ascaridia columbae (26.5%) and Ornithostrongylus iheringi (11.8%) in the small intestine; Dispharynx nasuta in the proventriculus (5.9%) and gizzard (2.9%); and a Dispharynx sp. (2.9%) in the proventriculus. This is the first report of D. nasuta parasitizing C. picui in Brazil and the first record of A. columbae and O. iheringi infecting C. picui in the state of Rio Grande do Sul, Brazil.

Geographic variations in the diversity and prevalence of helminth parasites of fish can provide important clues as to the relatedness of fish populations. In the present work, the stomachs of 64 conger eels, Conger conger, collected during 1999 and 2000, were examined for the presence of parasites. Four fish were infected with L3 stages of the nematode Anisakis simplex s.l. (Anisakidae), 1 with the nematode Cristitectus congeri (Cystidicolidae), 1 with the acanthocephalan Rhadinorhynchus pristis, 17 with postlarvae of Sphyriocephalus tergestinus (Eucestoda: Trypanorhyncha), and 55 with Lecithochirium spp. (Digenea: Hemiuridae). The hemiurids were the most abundant parasites, with a total of 385 individuals recovered. Strong aggregated distributions were found for both the digeneans, Lecithochirium musculus and Lecithochirium fusiforme, with variance-to-mean ratios (s²/x) and index of discrepancy (D) 13.98 and 0.672 (for L. musculus) and 8.08 and 0.90 for L. fusiforme, respectively. Intensity of L. musculus, L. fusiforme, and S. tergestinus showed significant relationships with depth of capture. Differences in number of species and prevalence were found between Madeira and the Atlantic coasts of the Iberian Peninsula.

Previous population dynamics data, generated for Amblyomma parvum Aragão and Amblyomma cajennense (Fabricius) in Argentina and southeastern Brazil, have indicated that these ticks complete 1 generation per year, with larvae predominating in autumn, nymphs in winter, and mostly adults during spring and summer. The present study reports population dynamics data for free-living Amblyomma spp. ticks in northern Brazil (Amazon forest, latitude 10°S, 63°W), and for Amblyomma spp. ticks collected on birds in southeastern Brazil (latitude 23°S, 45°W). In northern Brazil, adult ticks predominated from mid-spring to mid-autumn, larvae predominated in early winter, and nymphs from mid-winter to mid-spring. Seven Amblyomma spp. were identified, although A. cajennense predominated in 1 of the 2 sites sampled. In southeastern Brazil, larval infestations on birds peaked in autumn, followed by a nymphal infestation peak in late winter. At least 32% and 75% of these larvae and nymphs, respectively, were identified as Amblyomma longirostre (Koch). Similar to previous work, the present study showed that Amblyomma spp. larvae and nymphs predominated during autumn–winter months, and mostly adults during spring–summer months, a pattern compatible with 1 generation/yr, even at latitude 10°S in northern Brazil.

Toxoplasma gondii is now recognized as an important pathogen in costal marine mammals. Oocysts from cat feces are believed to be washed into seawater and serve as a source of infection via transport hosts. Experimentally, it has been demonstrated that T. gondii oocysts can sporulate in seawater and remain infectious for mice for up to 6 mo. The present study examined the long-term survival of T. gondii in seawater (15 ppt NaCl) kept at 4 C or at room temperature. Oocysts kept at 4 C for 24 mo were orally infectious for mice, while those kept at room temperature for 24 mo were not.

A host–parasite relationship was observed, for the first time, between a piscicolid leech and a species of amphibious goby (Scartelaos tenuis) from an intertidal mud flat in southern Iran. Morphological and molecular investigations assign the leech to Zeylanicobdella arugamensis. Of the 3 endemic and sympatric mudskipper species living in the Persian Gulf (S. tenuis, Boleophthalmus dussumieri, and Periophthalmus waltoni), leeches were only found on S. tenuis (prevalence and mean intensity  =  71.4% and 2.3 ± 2.5, respectively), which is also the most-aquatic mudskipper species. Scartelaos tenuis is not the largest species, but more leeches (≥4 leeches/host) were found on larger specimens (>12 cm standard length [SL]). Nonetheless, in aquaria, leeches also attached on P. waltoni. This suggests either an ecological partitioning of host–parasite complexes, determined by host habitat selection, or leech limited-resistance to air exposure, or both.

The present study reports the occurrence of helminths in the introduced species Tupinambis merianae (tegu lizard), and in two endemic species Trachylepis atlantica (small lizard) and Amphisbaena ridleyi (two-head-snake lizard ), from Fernando de Noronha Archipelago, State of Pernambuco, Brazil. Nine species of helminths were found, mainly in the digestive tract and accessory organs, with the following prevalence (P) and mean infection intensity (MII). Tupinambis merianae: Diaphanocephalus galeatus (P  =  96%, MII  =  20.5), Spinicauda spinicauda (P  =  100%, MII  =  197.8), and Oochoristica sp.1 (P  =  20%, MII  =  4.4). Trachylepis atlantica: Moaciria alvarengai (P  =  20%, MII  =  1.4), S. spinicauda (P  =  92%, MII  =  22.1), Mesocoelium monas (P  =  4%, MII  =  3.0), Platynosomum sp. (P  =  8%, MII  =  7.0), and Oochoristica sp.2 (P  =  16%, MII  =  1.25). Amphisbaena ridleyi: Aplectana albae (P  =  96%, MII  =  143.4), Thelandros alvarengai (P  =  4%, MII  =  1.0), Me. monas (P  =  44%, MII  =  2.8), Platynosomum sp. (P  =  36%; MII  =  13.8), and Oochoristica sp.2 (P  =  48%; MII  =  2.17). More than 80% of T. merianae were infected with 2, or more, helminth species. In Tr. atlantica, single-species infections were present in 50% of the specimens, but co-occurrence of 2 parasites was also high (41.7%). In A. ridleyi, multiple infections were more common, with up to 5 parasite species present. The helminth fauna observed allowed us to conclude that helminths can be carried together with their host when they colonize new geographic localities and that these introduced helminths can, in turn, colonize endemic, or native, hosts.

Peripheral blood from a ball python (Python reginus) imported from Ghana was cultured in Barbour-Stoenner-Kelly (BSK) medium for Borrelia spp. isolation, resulting in the prominent appearance of free, and clusters of, trypanosomes in a variety of morphological forms. The molecular phylogenetic characterization of these cultured trypanosomes, using the small subunit rDNA, indicated that this python was infected with a species closely related to Trypanosoma varani Wenyon, 1908, originally described in the Nile monitor lizard (Varanus niloticus) from Sudan. Furthermore, nucleotide sequences of glycosomal glyceraldehyde-3-phosphate dehydrogenase gene of both isolates showed few differences. Giemsa-stained blood smears, prepared from the infected python 8 mo after the initial observation of trypanosomes in hemoculture, contained trypomastigotes with a broad body and a short, free flagellum; these most closely resembled the original description of T. varani, or T. voltariae Macfie, 1919 recorded in a black-necked spitting cobra (Naja nigricollis) from Ghana. It is highly possible that lizards and snakes could naturally share an identical trypanosome species. Alternatively, lizards and snakes in the same region might have closely related, but distinct, Trypanosoma species as a result of sympatric speciation. From multiple viewpoints, including molecular phylogenetic analyses, reappraisal of trypanosome species from a wide range of reptiles in Africa is needed to clarify the relationship of recorded species, or to unmask unrecorded species.