Cellular details of early embryogenesis have been studied extensively among cyclophyllidean cestodes, but have been reported for only 2 species of the order Proteocephalidea, both belonging to the genus Proteocephalus. Thus, we performed a detailed ultrastructural analysis of early embryos of a second species, Corallobothrium fimbriatum, including early events in the formation of the embryonic envelopes. Adult worms were collected from the small intestine of brown bullhead catfish, Ameiurus nebulosus, from the St. Lawrence River in North America and processed by standard methods for transmission electron microscopy. The vitelline capsule consists of 2 closely apposed electron-dense membranous layers, separated by a more electron-lucent material. The 2 vitellocytes that accompany each oocyte contain numerous ribosomes, vesicles, and lipid droplets. These fuse to form a vitelline syncytium, which elongates and almost completely encircles the cleaving embryo by the 4-blastomere stage, forming a partial lipid-rich cellular envelope that undergoes apoptosis as cleavage continues. This envelope is later replaced by outer and inner embryonic envelopes. The outer envelope derives from the fusion of the vitelline syncytium with the cytoplasm of macromeres, whereas the inner envelope originates from 3 mesomeres. Simultaneous to the formation of the embryonic envelopes, other blastomeres multiply and differentiate, while some micromeres undergo degeneration or apoptosis. In most respects, ultrastructural features of early C. fimbriatum embryos closely resemble those of previously studied Proteocephalus longicollis, but differ somewhat from those of other orders. This demonstrates that, despite marked ultrastructural heterogeneity within some orders such as the Cyclophyllidea, some embryonic traits distinguish cestode orders from each other.

Water, sewage, and soil are potential sources of infection for Toxoplasma gondii. Therefore, we sought to determine the prevalence of T. gondii infection and associated characteristics in 61 plumbers, 203 construction workers, and 168 gardeners in Durango City, Mexico. Participants were tested for T. gondii IgG and IgM antibodies with the use of enzyme-linked immunoassays. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. IgG T. gondii antibodies were found in 4 (6.6%) plumbers, 17 (8.4%) construction workers, and 10 (6.0%) gardeners; T. gondii IgM antibodies were found in 3 (1.5%) construction workers and 4 (2.4%) gardeners, but in none of the plumbers. In the total population, the prevalence of T. gondii infection was significantly higher in workers living in suburban areas, without education, workers that consumed chorizo, and those who suffered from any disease (P < 0.05). In gardeners, prevalence of infection was significantly higher in those with blood transfusion, and memory impairment (P < 0.05). Multivariate analysis showed that T. gondii infection was positively associated with consumption of unwashed fruits (adjusted odds ratio [OR]  =  2.41; 95% confidence interval [CI]: 1.13–5.13), and with raising animals (adjusted OR  =  2.53; 95% CI: 1.00–6.37). This is the first report of contributing factors for T. gondii infection in workers occupationally exposed to water, sewage, and soil in a Mexican city, and results will contribute to the design of optimal preventive measures.

Echinostomes are receiving increased attention because of their emerging parasite status in landscapes associated with human development and their ability to infect and kill many North American larval amphibians. While laboratory experiments have shown that echinostomes can cause extensive mortality in their amphibian hosts, their effect on tadpoles in the field is less clear. I conducted a controlled-infection field-enclosure experiment in 4 ponds to compare the effects of echinostomes on green frog (Rana clamitans) and gray tree frog (Hyla versicolor) tadpoles in the field. I measured tadpole growth, development, mortality, and infection intensity. Echinostome infection resulted in high mortality in green frog tadpoles and less mortality in gray tree frogs. However, metacercariae encystment rates were higher in gray tree frog tadpoles than in green frog tadpoles. The effect of echinostomes on mortality varies across amphibian species, with the result that some species may experience more extensive echinostome-induced mortality than others. Mortality as a result of echinostome infection in green frog tadpoles was similar to mortality observed in predation experiments.

An important question in many parasitological studies is the assessment of differences in parasite numbers between samples of hosts. This is not always an easy problem with which to deal. While almost everyone will agree that the main task consists in deciding whether the values in one sample tend to be higher than the values of another sample, there is considerable disagreement about what higher (or lower) should mean. In most cases, dissimilarity measures are differences between mean values, medians, geometric means, prevalence rates, relative effects, and more. In general, different measures can lead to different conclusions. However, a debate as to which measure is superior is fruitless; it depends on goals and circumstances of the respective study. In our opinion, it is more important to identify situations in which most of the above measures coincide, and, hence, one can confidently claim that the values in one sample are higher than in another. This is the case when one sample is stochastically larger than a second. Roughly speaking, a random variable X is stochastically larger than a second random variable Y, when X assumes large values with a higher probability than Y. In this paper, we review this concept using distributional and data examples, and we propose the use of graphical tools for detecting stochastic dominance. Our method provides a relatively easy, visual way of fully justifying general statements that the number of parasites in one sample is larger than in another.

Patterns of host use by parasites throughout a guild community of intermediate hosts can depend on several biological and ecological factors, including physiology, morphology, immunology, and behavior. We looked at parasite transmission in the intertidal crustacean community of Lower Portobello Bay, Dunedin, New Zealand, with the intent of: (1) mapping the flow of parasites throughout the major crustacean species, (2) identifying hosts that play the most important transmission role for each parasite, and (3) assessing the impact of parasitism on host populations. The most prevalent parasites found in 14 species of crustaceans (635 specimens) examined were the trematodes Maritrema novaezealandensis and Microphallus sp., the acanthocephalans Profilicollis spp., the nematode Ascarophis sp., and an acuariid nematode. Decapods were compatible hosts for M. novaezealandensis, while other crustaceans demonstrated lower host suitability as shown by high levels of melanized and immature parasite stages. Carapace thickness, gill morphology, and breathing style may contribute to the differential infection success of M. novaezealandensis and Microphallus sp. in the decapod species. Parasite-induced host mortality appears likely with M. novaezealandensis in the crabs Austrohelice crassa, Halicarcinus varius, Hemigrapsus sexdentatus, and Macrophthalmus hirtipes, and also with Microphallus sp. in A. crassa. Overall, the different parasite species make different use of available crustacean intermediate hosts and possibly contribute to intertidal community structure.

Three new species of dactylogyrids (Monogenea) from the Araguaia River in Brazil are described herein. Specimens of Demidospermus ceccarellii n. sp., Demidospermus brachyplatystomae n. sp., and Demidospermus araguaiaensis n. sp. were collected from the gills of the siluriform fish, Brachyplatystoma filamentosum (Lichtenstein, 1819). The 3 new species can be easily distinguished from their congeners by the shape of the male copulatory organ (MCO) and accessory piece. Demidospermus ceccarellii n. sp. presents a J-shaped and robust MCO, a base with a short sclerotized margin, and a slightly curved and robust accessory piece with the base slightly dilated. In contrast, D. brachyplatystomae n. sp. has a thin MCO forming an incomplete ring, a base with an irregular sclerotized margin, and a long and curved accessory piece with a wider distal portion. Demidospermus araguaiaensis n. sp. has a thin MCO with a base directly coupled to the accessory piece and an articulated accessory piece that is sinuous in shape in the distal portion. In addition, the 3 species present haptoral hooks similar in shape and size and, thus, were compared in detail with the other Demidospermus species with this particular characteristic. This is the first record of monogeneans that are parasitic on B. filamentosum.

Sucking lice and ticks were collected from live-trapped eastern rufous mouse lemurs, Microcebus rufus Geoffroy, in and around the periphery of Ranomafana National Park, southeastern Madagascar, from 2007 to 2009. Samples of 53 sucking lice (Insecta: Phthiraptera: Anoplura) and 28 hard ticks (Acari: Ixodidae) were collected from 36 lemur captures representing 26 different host individuals. All of the lice were Lemurpediculus verruculosus (Ward) (6 males, 46 females, 1 third instar nymph). Only the holotype female was known previously for this louse and the host was stated to be a “mouse lemur.” Therefore, we describe the male and third instar nymph of L. verruculosus and confirm M. rufus as a host (possibly the only host) of this louse. All of the ticks were nymphs and consisted of 16 Haemaphysalis lemuris Hoogstraal, 11 Haemaphysalis sp., and 1 Ixodes sp. The last 2 ticks listed did not morphologically match any of the Madagascar Haemaphysalis or Ixodes ticks for which nymphal stages have been described.

Examination of the gill lamellae of 3 species of Centropomus spp. (Centropomidae) from 9 localities around the southern coast of Florida revealed 3 species of Rhabdosynochus (Monogenoidea, Diplectanidae). The common snook, Centropomus undecimalis, was infected with Rhabdosynochus rhabdosynochus (30 of 37 infected; prevalence 81%), Rhabdosynochus hargisi (9 of 37; 24%), and Rhabdosynochus hudsoni (20 of 37; 46%); the fat snook, Centropomus parallelus, with R. rhabdosynochus (12 of 22; 55%) and R. hudsoni (8 of 22; 36%) (new host records for both); and the tarpon snook, Centropomus pectinatus, with R. hudsoni (3 of 4; 75%) (new host record). Snooks infected with R. rhabdosynochus were collected only from tidal waters of salinity ≤10.4 ppt, where the parasite dominated the monogenoidean community. Rhabdosynochus hargisi and R. hudsoni showed greater salinity tolerance; the former dominated where salinity was ≥28.8 ppt. Thus, salinity appears to be a determinate factor in partitioning the monogenoidean community, while water depth and temperature and host population (as defined by collection locality) did not appear to affect occurrence of Rhabdosynochus spp. on snooks in Florida. With the exception of Tampa Bay for R. hargisi, each locality represented a new geographic record for the respective diplectanid. The type species, R. rhabdosynochus, is redescribed based on specimens collected from its type host, C. undecimalis.

The infection pattern of Kroeyerina elongata (Kroyeriidae, Copepoda) in the olfactory sacs of the blue shark, Prionace glauca, was investigated using 4,722 copepods from 54 olfactory sacs. Copepod prevalence and mean intensity of infection per olfactory sac were 94.0 and 91.1%, respectively, and the most intensely infected olfactory sac and shark hosted 218 and 409 copepods, respectively. There were significant linear relationships between the number of female and total copepods per left olfactory sac and shark fork length as well as between the numbers of female, male, and total copepods per shark and mean olfactory sac width and cumulative olfactory sac width. Female copepods typically outnumbered males within olfactory sacs (mean intensity  =  65.7 and 26.3, respectively), and no statistical differences were detected between the numbers of copepods inhabiting the left and right olfactory sacs. Copepods were not evenly distributed within olfactory sacs. Typically, female copepods occupied olfactory chambers located centrally along the length of the olfactory sac, while males infected lateral olfactory chambers nearest the naris. The orientation of most copepods (84.6%) suggested positive rheotaxis relative to the path of water through the olfactory sac. Within olfactory chambers, most mature females (68.2%) infected the first third of the peripheral excurrent channel and the adjacent fringe of olfactory lamellae, while most males (91.7%) infected the olfactory lamellae, and the 4 larval females collected were attached within the lamellar field and grasped by males. Based on the observed infection patterns and the pattern of water flow throughout the olfactory sac, a hypothesis regarding the life cycle of K. elongata is advanced wherein infective copepodids are swept into the olfactory sac from the surrounding sea and initially colonize the olfactory lamellae. Copepodids feed and mature among the olfactory lamellae, and adult males search for mates and copulate with young females among the olfactory lamellae. Inseminated females move to the peripheral excurrent channels to mature and produce ovisacs. Hatching ovisacs release free-swimming nauplii into the excurrent water flow to be swept into the milieu, where they can molt into infective copepodids that may infect new hosts.

Gyrodactylus granoei n. sp. (Monogenea: Gyrodactylidae) is described from the fins and body surface of the spine loach, Cobitis granoei (Rendahl) (Cobitidae), in central China. It resembles a suite of species from cyprinid and cobitid fishes that have short, compact hamuli, a ventral bar with no obvious anterolateral projections, a linguiform posterior membrane, a male copulatory organ with small hooks in multiple rows, a simple cylindrical dorsal bar, and short marginal hooks, with an expanded sickle heel. Of these, the new species resembles most closely Gyrodactylus micracanthus Hukuda, 1940 from Misgurnus anguillicaudatus (Cantor) (Cobitidae), but it is identified by the length of the hamuli and the morphology of dorsal and ventral bars. When searched using BLAST, sequence data (829 bp) spanning the ITS1, 5.8s, and ITS2 region did not return an identical match; close similarity (82–88%) was found with sequenced members of the subgenus Gyrodactylus. It is suggested that the new species is part of a freshwater lineage that has radiated successfully among cyprinid fishes in North America, Europe, and Asia, and some of their predator and amphibian neighbors.

Measures of genetic differentiation between populations are useful tools for understanding the long-term dynamics of parasite communities. We followed the allele frequencies of microsatellite markers in samples taken over a period of 16 yr from the Case Western Reserve University-Naval Medical Research Institute (CWRU-NMRI) laboratory strain of Schistosoma mansoni. DNA was isolated from pooled samples of adults, eggs, or cercariae collected at 46 time points and genotyped for 14 tri- or tetranucleotide microsatellite markers. For comparison, 2 S. mansoni reference strains (Biomedical Research Institute-NMRI, which has a common origin with the CWRU line, and PR-1) were analyzed over shorter periods of time. We observed that the long-term allele frequencies are generally stable in large laboratory populations of this parasite, and a high degree of similarity was observed between the allele frequencies of consecutive samples from different developmental stages. The CWRU strain, however, showed 2 periods of marked deviation from stability as demonstrated using genetic differentiation measures. The first period corresponds to an admixture event with the BRI strain in which a new equilibrium was established as the “migrants” became blended into the existing CWRU population, consistent with 23% admixture from BRI. The second corresponds to a period of genetic drift when the CWRU population size was greatly reduced with an accompanying loss in genetic diversity. Having demonstrated the utility of pooled samples for the genetic analysis of population dynamics in laboratory strains of schistosomes, this approach will be useful for analyzing field samples to determine the impact of schistosomiasis control programs on parasite population structure. Accounting only for the intensity or prevalence of parasite populations may fail to register significant changes in population structure that could have implications for resistance, morbidity, and the design of control measures.

Quantifying the relative proportion of coexisting genotypes (clones) of a malaria parasite within its vertebrate host's blood would provide insights into critical features of the biology of the parasite, including competition among clones, gametocyte sex ratio, and virulence. However, no technique has been available to extract such data for natural parasite-host systems when the number of clones cycling in the overall parasite population is likely to be large. Recent studies find that data from genetic analyzer instruments for microsatellite markers allow measuring clonal proportions. We conducted a validation study for Plasmodium mexicanum and Plasmodium falciparum by mixing DNA from single-clone infections to simulate mixed infections of each species with known proportions of clones. Results for any mixture of DNA gave highly reproducible results. The relationship between known and measured relative proportions of clones was linear, with high regression r² values. Known and measured clone proportions for simulated infections followed over time (mixtures) were compared with 3 methods: using uncorrected data, with uncorrected data and confidence intervals constructed from observed experimental error, and using a baseline mixture of equal proportions to calibrate all other results. All 3 methods demonstrated value in studies of mixed-genotype infections sampled a single time or followed over time. Thus, the method should open new windows into the biology of malaria parasites.

Cyclospora cayetanensis, a protozoan of emerging concern, causes self-limiting gastroenteritis in immune-competent hosts. It has been established that sequence variability exists in the first internal transcribed spacer region (ITS-1) of the ribosomal DNA operon from collections of oocysts obtained from individual or pooled fecal samples. To determine if single oocysts also exhibited ITS-1 sequence variability, DNA was extracted from individually flow-cytometry–counted oocysts. We determined that ITS-1 sequence variability exists at an individual-genome level for C. cayetanensis and approached or exceeded the variability exhibited among oocyst collections. ITS-1 variability, at the genome level, reduces this region's utility for inferring relationships between strains.

Balb/cJ mice infected in the peritoneal cavity with larval Taenia crassiceps fail to mount a protective immune response. In mice, inflammatory immune responses are believed to control larval reproduction, whereas antibody-mediated responses are believed to be permissive. In the present study, mice were treated with CpG-oligodeoxynucleotides (CpG) to determine whether stimulation of the innate inflammatory response would confer increased resistance to larval growth. Female mice treated with CpG displayed a decrease in mean parasite burden by 54%, while male mice displayed a 73% reduction. Moreover, 5 of 12 CpG-treated male mice completely eliminated all larvae by 9 wk post-infection. In contrast, no female animals were found to be infection free. CpG treatment induced an increase in the transcript levels of tumor necrosis factor-α and inducible nitric oxide synthase (iNOS) from splenocytes and resulted in elevated levels of the proinflammatory molecules monocyte chemotactic protein (MCP)-1, MCP-3, and interleukin-6 at the site of infection. Additionally, CpG administration induced the enhanced recruitment of neutrophils and macrophages to the site of infection. The finding that both neutrophils and macrophages were recruited in significantly higher numbers in the male host as compared to the female host may explain the increased level of protection realized in male animals in response to CpG treatment.

Visceral leishmaniasis presents a serious health threat in many parts of the world. There is, therefore, an urgent need for an approved vaccine for clinical use to protect against infection. In this study, the ability of recombinant Leishmania donovani gamma-glutamyl cysteine synthetase protein (LdγGCS) alone or incorporated into a non-ionic surfactant vesicle (NIV) delivery system to protect against L. donovani infection was evaluated in a BALB/c mouse model. Immunization with LdγGCS alone or LdγGCS-NIV induced specific IgG1 and IgG2a antibodies compared to controls, with LdγGCS-NIV inducing significantly higher titers of both antibody classes (P < 0.05). Both formulations induced similar increases in splenocyte IFN-γ production following ex vivo antigen stimulation with LdγGCS compared with cells from control mice (P < 0.05). Similar levels of protection against infection were induced by LdγGCS alone and LdγGCS-NIV, based on their ability to suppress liver parasite burdens compared to control values (P < 0.01), indicating that using a carrier system did not enhance the protective responses induced by the recombinant protein. The results of this study indicate that LdγGCS may be a useful component in a vaccine against L. donovani.

Ground-feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of T. gondii prevalence in rodents and other small mammals. Cats excrete environmentally resistant oocysts after consuming tissues of T. gondii–infected birds. In the present study, sera and tissues from 382 wild birds from Colorado were tested for T. gondii infection. Antibodies to T. gondii were found in 38 birds with the use of the modified agglutination test (MAT, 1∶25 titer). Tissues (brains, hearts) of 84 birds were bioassayed in mice. Viable T. gondii was isolated from 1 of 1 barn owl (Tyto alba), 1 of 5 American kestrels (Falco sparverius), 1 of 7 ferruginous hawks (Buteo regalis), 1 of 4 rough-legged hawks (Buteo lagopus), 2 of 13 Swainson's hawks (Buteo swainsoni), and 1 of 25 red-tailed hawks (Buteo jamaicensis). This is the first time T. gondii has been isolated from the barn owl, ferruginous hawk, rough-legged hawk, and Swainson's hawk.

There is a lack of information concerning the epidemiology of Toxoplasma gondii infection in Mennonites (an ethnic group of Mexican citizens of German descent living in rural communities). The prevalence of anti–T. gondii immunoglobulin (Ig) G and IgM antibodies was examined in 152 Mennonites in Durango State, Mexico, using enzyme-linked immunoassays. In total, 46 (30.3%) of 152 participants (mean age 38.4 ± 15.5 yr) had IgG T. gondii antibodies; 5 (3.3%) also had IgM T. gondii antibodies. Toxoplasma gondii infection was significantly associated with the presence of cats at home (adjusted OR  =  3.93; 95% CI: 1.40–11.05), raising cattle (adjusted OR  =  3.88; 95% CI: 1.24–12.11), consumption of pigeon meat (adjusted OR  =  3.0; 95% CI: 1.36–6.63), and consumption of untreated water (adjusted OR  =  2.42; 95% CI: 1.09–5.40). This is the first report of seroprevalence and contributing factors for T. gondii infection in Mennonites and of an association of the consumption of pigeon meat with T. gondii infection. Results of this study should be useful in the design of optimal preventive measures against T. gondii infection.

Complete gastrointestinal tracts from 257 ringed seals (Pusa hispida) from Svalbard, Norway, were examined for helminth parasites. Three different helminth groups were recorded (acanthocephalans 61.1%; nematodes 38%; cestodes 0.9%). Acanthocephalans (Polymorphidae) and cestodes (Anophryocephalus and Diphyllobothrium sp(p)., as well as unidentified species, were confined to the intestines. The anisakid nematodes Phocascaris phocae, Pseudoterranova sp(p)., Anisakis sp(p)., and Phocascaris/Contracaecum sp(p). were recorded in both stomachs and the anterior part of the small intestines. The abundance of nematodes and acanthocephalans varied significantly with sampling location of the seal hosts. This is likely due to the relative prevalence of Arctic versus Atlantic water in the different fjord systems, which strongly influences the age class and species of fish available as prey for the seals. Adult male ringed seals had significantly higher abundances of nematodes than did adult females or juveniles. Adult males also had significantly higher abundances of acanthocephalans than did adult females, but were not significantly different from juveniles in this regard. Nematode abundance increased significantly with age of male hosts, but this trend was lacking in female seals. Infection parameters appeared to be related to differences in the age of polar cod (Boreogadus saida) exploited by male, female, and juvenile seals.

In order to obtain basic data on parasitic infections of Bornean orangutans, Pongo pygmaeus morio (Owen, 1837), in Danum Valley, Sabah, Malaysia, fecal examinations were conducted. Based on a total of 73 fecal samples from 25 individuals, cysts of Entamoeba coli, Entamoeba spp., and Chilomastix mesnili, cysts and trophozoites of Balantidium coli, and eggs of Trichuris sp. or spp., unknown strongylid(s), Strongyloides fuelleborni, and an unknown oxyurid, plus a rhabditoid larva of Strongyloides sp., were found. Mature and immature worms of Pongobius hugoti Baruš et al., 2007 and Pongobius foitovae n. sp. (Oxyuridae: Enterobiinae) were recovered from fecal debris and described. Pongobius foitovae is readily distinguished from P. hugoti by having a much longer esophageal corpus, a longer and distally hooked spicule in males, and a more posteriorly positioned vulva in female. Presence of plural species of non-Enterobius pinworms is a remarkable feature of the orangutan–pinworm relationship, which may reflect speciation process of the orangutans, host switching, and coevolution by pinworms.

Coenurus gaigeri is the larval stage of Taenia multiceps gaigeri, which infects the muscles of goats and, to a lesser extent, sheep. Metacestodes of the goat such as Coenurus cerebralis, Cysticercus tenuicollis, Cysticercus ovis, and hydatid cysts have been extensively studied. However, because of the uncommon occurrence of C. gaigeri, very few records exist of its biology, pathogenesis, and pathology. Therefore, an investigation was conducted in the summer of 2008 at Shiraz Slaughterhouse, where 2.6% of the goats were infected with intramuscular cysts. Scolices from coenuri were collected for morphologic analysis, and the cysts were identified as C. gaigeri, the intermediate stage of T. multiceps gaigeri. In addition, molecular genetic markers of mitochondrial DNA were applied phylogenetically to resolve the questionable relationship between C. gaigeri and C. cerebralis. All coenuri fluids were aspirated and centrifuged separately; the supernatants were analyzed for biochemical features that included glucose, total protein, urea nitrogen, uric acid, triglycerides, cholesterol, creatinine, calcium, sodium, potassium, alanine aminotransferase, and aspartate aminotransferase. The pathologic changes around the coenuri included mechanical destruction of the affected tissues, associated with degenerative and necrotic changes, infiltration by polymorphonuclear and mononuclear cells, proliferation of fibroblasts, and development of adventitious tissue. Results based on phylogenetic analysis of the mitochondrial DNA (CO1 and ND1) suggest that the larval stages of T. multiceps gaigeri and C. cerebralis, which showed similar morphological criteria, are monophyletic species. However, C. gaigeri interestingly were situated in the biceps femoris, triceps, and abdominal muscles without localization in the nervous system.

Falcaustra tannaensis n. sp. (Ascaridida: Kathlaniidae) from the large intestine of Nactus pelagicus (Squamata: Gekkonidae) is described and illustrated. Falcaustra tannaensis represents the first species from Oceanica to be assigned to the genus and is distinguished from other species of Falcaustra by the distribution pattern of caudal papillae (8 precloacal, 2 adcloacal, 10 postcloacal, and 1 median), length of spicules (2.43–2.68 mm), and presence of a pseudosucker.

Infection with Sarcocystis species is common in many species of animals, but it has not yet been reported in wolverines (Gulo gulo). Histological sections of tongues from 41 wolverines in the Kitikmeot Region, Nunavut, Canada, were examined for sarcocysts. Sarcocysts were found in 33 (80.4%) wolverines. Two structurally distinct types of sarcocysts were found. Type A sarcocysts were thin (<1 µm thick) walled. Ultrastructurally, the parasitophorous vacuolar membrane (Pvm) had minute undulations, but it lacked villar protrusions and was not invaginated into the granular layer. The bradyzoites were slender, about 5 × 1 µm in size. Structurally, these sarcocysts were distinct from known species of Sarcocystis and possessed a novel 18S and ITS-1 sequence, sharing 98% and 78% sequence similarity with Sarcocystis canis. A new species name, Sarcocystis kalvikus, is proposed for type A sarcocysts. In contrast, type B sarcocysts had relatively thicker (about 2 µm) cyst walls and larger bradyzoites, each about 10 × 2–3 µm. Ultrastructurally, the Pvm on the sarcocyst wall had villar protrusions that were either mushroom-like or sloping. Molecular analysis identified a unique 18S and ITS-1 sequence that placed them in a clade within the Sarcocystidae. Based on histology, TEM, and genetic data, the new name, Sarcocystis kitikmeotensis, is proposed. Sarcocystis kalvikus was found in 14 (34.1%), S. kitikmeotensis was found in 7 (17%), and both species were found in 12 (29.2%) of 41 wolverines.

The present study presents the description of Oochoristica beveridgei n. sp. (Linstowiinae Fuhrmann, 1907). The species was found in the small intestine of Tarentola parvicarinata Joger (Gekkonidae) in East Senegal (West Africa). Among known species of Oochoristica Lühe, 1898, O. beveridgei is most similar to Oochoristica junkea (Johri, 1950) Schmidt, 1986, found in Gekko gecko (Linnaeus) from India. A common feature of both species is the location of the cirrus sac, which lies anterior to the poral part of the ovary. The new species differs from O. junkea in having a higher number of testes, different testes arrangement, wider cirrus sac, and a different shape of ovary. The position of the cirrus sac in O. beveridgei is also similar to that found in Oochoristica gallica Dollfus, 1954, whose host is Psammodromus hispanicus Fitzinger (Lacertidae) from Morocco. The new species differs from O. gallica in that it possesses fewer testes and that these testes have a different arrangement. The location of the cirrus sac in O. beveridgei is also similar to that seen in Oochoristica bivitellolobata Loewen, 1940, whose host is Cnemidophorus sexlineatus (Linnaeus) (Teiidae) from the United States. The latter species has a higher number of testes, with only half of the cirrus sac located anterior to the poral part of the ovary, and possesses a divided vitellarium.

In order to determine the evolutionary relationships among Eimeria species that parasitize birds of the Galliformes, the 18s rDNA gene and a portion of the cytochrome oxidase subunit 1 (cox-1) were amplified from Eimeria species isolated from turkeys, chukars, and pheasants. The phylogenetic analysis of these sequences suggests that species infecting chickens are polyphyletic and, therefore, do not all share a direct common ancestor. Both the 18s rDNA and the cox-1 sequences indicate that Eimeria tenella and Eimeria necatrix are more closely related to Eimeria of turkeys and pheasants than to other species that infect the chicken. It is, therefore, likely that the chicken Eimeria spp. represent 2 separate ancestral colonizations of the gut, one of which comprises E. tenella and E. necatrix that infect the ceca, while the other includes Eimeria acervulina, Eimeria brunetti, Eimeria maxima, and Eimeria mitis, which infect the upper regions of the intestine.

A new nematode species, Philometra diplectri n. sp. (Philometridae), is described from male and female specimens found in unidentified tissues of head and anterior trunk (males) and subcutaneously in the mouth and under the operculum (females) of sand perch, Diplectrum formosum (Linnaeus) (Serranidae, Perciformes), from the northern Gulf of Mexico off Florida (Florida Middle Grounds). Based on light and scanning electron microscopy examination, the new species differs from other congeners parasitizing the subcutaneous tissues, fins, tissues of the buccal cavity, and gill covers or gill arches of marine and brackish-water fishes, mainly in having 8 conspicuously large cephalic papillae of the external circle, the absence of caudal projections, and the shape and small size of the anterior inflation of the esophagus in gravid females, and in possessing 5 pairs of caudal papillae and spicules 66–78 µm long in males. Philometra diplectri is the first known species of this genus whose gravid females are parasitic in the head tissues of serranid fishes.

Two nematode species are redescribed from the type host species Holochilus chacarius Thomas (Rodentia, Cricetidae, Sigmodontinae) and from the type locality of 1 of them, i.e., Ingenio San Martín de Tabacal, Salta Province, Argentina. Rodents were deposited at the Colección Mamíferos Lillo, Tucumán, Argentina. Litomosoides patersoni (Mazza, 1928) (Onchocercidae) possesses a buccal capsule with irregular external walls, a buccal cavity smooth, becoming thinner near the oral opening, a complete set of head papillae, 3–6 pairs of cloacal papillae, and the “sigmodontis” type of spicules. Filarioids were found in 3 of 17 examined hosts. Stilestrongylus stilesi Freitas, Lent, and Almeida, 1937 (Heligmonellidae), whose description was based on male specimens, was found in all 17 of the examined hosts. Here, we describe the female and the synlophe of both sexes. Females are characterized by a short uterus with less than 25 eggs, short ovejector, short and conical tail, and the posterior extremity strongly invaginated in a cuticular expansion usually harboring 1 to several eggs. The synlophe is characterized by 29–31 sub-equal cuticular ridges at the mid-body, with single (in males) or double (in females) axis of orientation of the ridges. The present work validates and enlarges the original descriptions of both species and assigns the specimens from L. patersoni, recovered from the type locality and the type host species, as neotypes.

Paramacroderoides kinsellai n. sp. is described based on specimens collected from the spotted gar (Lepisosteus oculatus) from the Pascagoula River, Jackson County, Mississippi, and the Florida gar (Lepisosteus platyrhincus) from Cross Creek, Alachua County, Florida. The new species is the third recognized species of Paramacroderoides. Two Indian species of Paramacroderoides, originally described within Pseudoparamacroderoides, are transferred into Macroderoides. Paramacroderoides kinsellai n. sp. differs from Paramacroderoides echinus in having a much longer body, greater body width/length ratio, ovary situated at a significant distance from the cirrus sac rather than immediately posterior to it, and anterior margin of vitellaria at a significant distance posterior to ventral sucker. The new species differs from Paramacroderoides pseudoechinus in having a much longer body, greater body width/length ratio, ovary situated at a significant distance from the cirrus sac rather than immediately posterior to it, anterior margin of vitellaria at a significant distance anterior to ovary, vitellaria extending further posteriorly, and relative position of the intestinal bifurcation. The generic diagnosis of Paramacroderoides is amended to incorporate features found in the new species. This is the first record of a species of Paramacroderoides from the spotted gar and the first record from any host in Mississippi. Comparison of more than 2,300 base-pair sequences of nuclear rDNA (partial 18S, complete ITS region, and partial 28S) of 3 specimens from Florida and 2 specimens from Mississippi revealed only 1 base-pair difference between specimens collected in the 2 areas from the 2 host species. Sequence comparison between P. kinsellai n. sp. and previously published sequences of 3 Macroderoides species revealed that the levels of divergence between members of Paramacroderoides and Macroderoides are not much higher than levels of divergence among some species of Macroderoides.

This study was designed to detect antibodies to Toxoplasma gondii and Neospora caninum in wild captive carnivores maintained in Brazilian zoos. Blood samples were collected from 142 Brazilian wild felids and 19 exotic felids in zoos, and 3 European wolves (Canis lupus) and 94 Brazilian wild canids maintained in captivity in Brazilian zoos of São Paulo, Mato Grosso states and Federal District. One hundred and two (63.4%) and 70 (50.3%) of the 161 wild felids tested were seropositive for T. gondii and N. caninum by indirect immunofluorescent assay test (IFAT), respectively. Among sampled wild canids, 49 (50.5%) and 40 (41.2%) animals were seropositive for T. gondii and N. caninum antigens by IFAT, respectively. To our knowledge, this is the first serological detection of antibodies to N. caninum in Brazilian wild captive felids and bush dogs (Speothos venaticus (Lund)).

The study of 4 dasyatid stingrays—Dasyatis centroura (Mitchill, 1815), D. americana Hildebrand and Schroeder, 1928, D. say (Lesueur, 1817), and D. sabina (Lesueur, 1824)—from the northwestern Atlantic and the Gulf of Mexico showed the presence of monocotylid monogeneans Thaumatocotyle Scott, 1904 in their nasal fossae. Specimens collected from D. centroura from the northern Atlantic were identified as T. dasybatis (MacCallum, 1916). This confirmed the incorrect type host attribution of D. pastinaca (Linnaeus, 1758), which does not occur in the geographic area where T. dasybatis was described. Monogeneans collected from D. americana and D. say in the western Atlantic and the Gulf of Mexico were identified as T. longicirrus Hargis, 1955 and T. retorta Hargis, 1955, respectively, which corresponds to the opposite hosts attributed for each parasite species compared with their original description in the Gulf of Mexico. The species T. roumillati de Buron and Euzet, 2005 described from D. sabina in the northwestern Atlantic is reported for the first time in D. sabina from the Gulf of Mexico. Results clarify confusion in the literature regarding the hosts and habitats of Thaumatocotyle from dasyatids of the western Atlantic and Gulf of Mexico and support the oioxenous specificity of these monogeneans as well as their specificity for the nasal fossae of their hosts.

Ciliated protists were isolated from the ovarian fluid of apparently healthy adult rainbow trout (Oncorhynchus mykiss) maintained in freshwater. The organism was identified as Pseudocohnilembus persalinus based on morphometric and morphological analysis of silver-stained specimens obtained from culture and on analysis of ribosomal RNA gene sequences. The cytochrome c oxidase subunit 1 gene sequence of this organism also was characterized. This ciliate has been reported previously as free living only in saline environments and as an endosymbiont in a marine teleost, the olive flounder (Paralichthys olivaceus). A cyst-like stage may have facilitated the novel occurrence of this organism as an endosymbiont in rainbow trout.

Neospora caninum is one of the more-efficient transplacentally-transmitted organisms. The goal of the present study was to investigate the pathologic and immunologic changes that occur at the materno-fetal interphase in pregnant BALB/c mice infected with N. caninum at mid-gestation. Parasite DNA was detected in feto-placentary units 3 days post-infection (PI). On day 7 PI, the DNA detection level and parasite burden were significantly higher in the placentas than in the fetuses, which may indicate that the parasite is mainly multiplying in the placenta during the initial infection. In the spleens of infected dams, we observed an increase in IFN-γ, IL-10, and IL-4. However, only IL-4 was upregulated in placentas from the infected dams; this may enhance susceptibility to N. caninum at the materno-fetal interphase and favor transmission to the progeny. Finally, an increase in TNF-α expression in nested–PCR-positive placentas combined with necrosis may compromise the viability of the fetuses.

One hundred and seven reptiles (11 families, 32 species) from the Northern and Western Cape Provinces of South Africa were examined for helminths. Twenty-three (22%) individual reptiles were found to harbor at least 1 species of nematode; 3 (7%) reptiles harbored multiple infections of 2 nematode species. Eight species within 5 families of Nematoda were found in the reptiles surveyed including 1 atractid, 1 diaphanocephalid, 1 heterakid, 3 pharyngodonids, and 2 physalopterans. Ten new host records are reported. A summary of the nematode parasites identified from South African reptiles is provided.

Toxoplasma gondii genetic diversity varies in different geographical regions. In South America, T. gondii isolates are highly diverse, whereas in North America and Europe, the parasite is highly clonal, with 3 distinct lineage types (I, II, III). However, little is known of the T. gondii genotypes in the People's Republic of China. Because pork is considered the principal meat source for T. gondii infection in China, we conducted a survey to determine the prevalence and genetic diversity of this parasite in pigs from central China. In total, 434 DNA samples were extracted from the hilar lymph nodes of sick pigs in Hubei and Henan provinces in central China, and 34 were T. gondii B1 gene-positive. These T. gondii-positive DNA samples were typed at 10 genetic markers, including 9 nuclear loci, i.e., SAG1, SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico. Of these, 16 isolates could be genotyped with complete data for all loci. Two genotypes were present; one was the clonal type I lineage and the other was previously identified as a widespread lineage from many hosts in China. These results indicate that these 2 genotypes may be the major lineages in China. This is the first report of genetic typing of T. gondii isolates from pigs in central China. The results have implications for the prevention and control of T. gondii infections in humans and other animals.