Trans-host effects can alter the ecological and evolutionary dynamics of parasite and host populations. Here, we examine whether resource limitation within a parasite's natal host affects propagule size and influences parasite fitness in a new host. To alter resource competition, we infected caterpillars with 3 doses of the nematode Steinernema carpocapsae and harvested transmission-stage juveniles either early or late in the infection. We measured the size of these juveniles, and then we examined their ability to colonize and their sex ratio upon maturity in a new host. We found a trade-off between the cumulative number and size of nematodes emerging from a host. Emerging nematode size declined significantly over the time course of the infection, but dose had no significant effects. Larger, early emerging nematodes had greater success in colonizing a new host than smaller, later emerging nematodes, independently of whether they needed to locate the host. Furthermore, although early emerging nematodes resulted in an equal sex ratio in the new host, late emerging nematodes resulted in female-biased populations. These transmission and sex-ratio effects demonstrate that conditions in the natal host can affect parasite fitness, and they suggest that trans-host effects need to be more fully integrated into our studies of parasite populations.

This paper describes morphological characteristics and the occurrence of Demodex corniculatus n. sp., which was found on Apodemus flavicollis in Poland. The yellow-necked murid mouse is a common European rodent; until now, it was parasitized by a single demodectic mite species, Demodex rosus, which occurs in the oral cavity and esophagus. The new species was found in hair follicles, particularly within hairy regions of the head and genital–anal area. Demodex corniculatus occurred in 33% of the yellow-necked mice examined. The new species is small (adult stages 140 μm in length); characteristic features of these mites are massive supracoxal spines (ca. 5–6 μm long) on the dorsal side of the gnathosoma and palps with thick-set, bifurcated terminal spines. This paper also contains a checklist of demodecids in European and cosmopolitan murids.

Gyrodactylid population growth may depend on abiotic variables such as temperature. We tested the survival and reproductive rate of Gyrodactylus mexicanus, a parasite infecting fins of Girardinichthys multiradiatus, at 3 different water temperatures, 10–13, 19–22, and 24 C. The temporal sequence of birth and age at death of each parasite isolated from the hosts was recorded through at least 8 generations. Our results showed that the average number of offspring per parasite was 2.0 when averaged across all temperatures. However, the generation time was negatively correlated with temperature. The innate capacity for increase (r_m) was positively correlated with water temperature: from 0.29 parasite/day at 13 C to 0.48 parasite/day at 24 C. These data confirm that water temperature has a direct influence on parasite population dynamics. The current study represents the first contribution to understanding the population ecology of the monogenean G. mexicanus in central Mexico.

Previous works demonstrated that various species of Leishmania promastigotes exhibit differential sensitivity to complement-mediated lysis (CML) during development. Upon exposure to normal human serum (NHS), cultures of Leishmania chagasi promastigotes recently isolated from infected hamsters (fewer than 5 in vitro passages) are CML-sensitive when in the logarithmic growth phase but become CML-resistant upon transition to the stationary culture phase. Visualization by light and electron microscopy revealed dramatic morphological differences between promastigotes from the 2 culture phases following exposure to NHS. Flow cytometric analysis demonstrated that surface deposition of the complement components C3, C5, and C9 correlated inversely with promastigote CML-resistance. The highest levels of complement protein surface accumulation were observed for logarithmic phase promastigotes, while stationary phase promastigotes adsorbed the least amount of complement proteins. Additionally, fluorescence microscopy revealed that C3 and C5 localized in a fairly uniform pattern to the plasma membrane of promastigotes from logarithmic phase cultures, while the staining of promastigotes from stationary phase cultures was indistinguishable from background. By Western blot analysis, high levels of the complement proteins C3, C5, and C9 were detected in the total lysates of NHS-exposed logarithmic phase L. chagasi promastigotes, relative to NHS-exposed stationary phase promastigotes; this finding indicates that the low levels of C3 and C5 seen on the surface of stationary phase promastigotes were not due to protein uptake/internalization. Together, these data demonstrate the differential deposition of complement proteins on the surfaces of logarithmic and stationary phase L. chagasi promastigotes. The data support a model wherein stationary phase L. chagasi promastigotes resist CML by limiting the deposition of C3 and its derivatives, which, in turn, limit surface levels of complement proteins (including C5 and C9) that form the lytic membrane attack complex.

Human babesiosis in the United States is caused most commonly by the intraerythrocytic protozoan parasite, Babesia microti. Although a few reports have described evidence of Babesia species in animals in Florida, to date Babesia microti specifically has not been reported from Florida or most other southern states. To determine if the organism is present in vertebrates in the region, small mammals were trapped and sampled at 2 sites in northeastern Florida, and DNA extracts from blood samples were screened for B. microti DNA via PCR assays targeting portions of the nuclear small subunit rRNA (18S rDNA) and beta-tubulin genes. Amplified fragments from representative samples of PCR-positive hosts were sequenced and compared phylogenetically to reference strains of Babesia species. The B. microti strains found in cotton rats (Sigmodon hispidus) most closely resembles B. microti sensu stricto strains that are pathogenic to humans, and strains found in raccoons (Procyon lotor) most closely resembles previously described raccoon-related strains of B. microti sensu lato. The results of this study suggest that B. microti is prevalent among cotton rats and raccoons at some sites in northeast Florida and may pose a risk to humans in the region.

Metacercariae of an unidentified species of Apophallus Lühe, 1909 are associated with overwinter mortality in coho salmon, Oncorhynchus kisutch (Walbaum, 1792), in the West Fork Smith River, Oregon. We infected chicks with these metacercariae in order to identify the species. The average size of adult worms was 197 × 57 μm, which was 2 to 11 times smaller than other described Apophallus species. Eggs were also smaller, but larger in proportion to body size, than in other species of Apophallus. Based on these morphological differences, we describe Apophallus microsoma n. sp. In addition, sequences from the cytochrome c oxidase 1 gene from Apophallus sp. cercariae collected in the study area, which are likely conspecific with experimentally cultivated A. microsoma, differ by >12% from those we obtained from Apophallus donicus (Skrjabin and Lindtrop, 1919) and from Apophallus brevis Ransom, 1920. The taxonomy and pathology of Apophallus species is reviewed.

Angiostrongylus is a metastrongylid nematode genus that includes species found in carnivores, rodents, and occasionally primates (including humans). About 100 species of wild sigmodontine rodents occur in Argentina, 16 of which are species of Akodon. The lungs of Akodon azarae and Akodon dolores from Sierra de la Ventana, Buenos Aires, Argentina, were examined, and 2 of 10 A. dolores specimens were positive for angiostrongylosis, showing macroscopic lesions of verminous pneumonia. Adults found were identified as Angiostrongylus morerai. Histopathology of the lungs revealed multiple nodules in the interstitium, alveoli, and vessels, resulting in interstitial fibrosis and the destruction of small capillaries and arterioles. Since extensive pathology in the lung was noted here from only 2 adults, it is probable that heavier infections may cause mortality in their hosts. This is the first record of this nematode species from A. dolores, expanding its geographic distribution to the southwest of Buenos Aires Province, and the first description of the histopathology of larval angiostrongylosis in a wild rodent from South America.

Primisanguis caribbeanensis n. gen., n. sp. (Digenea: Aporocotylidae) infects the stoplight parrotfish, Sparisoma viride (Bonnaterre, 1788), (Labridae: Scarinae) in the Caribbean Sea off La Parguera (17°58′26″N, 67°02′47″W), Puerto Rico. It is most easily distinguished from other nominal aporocotylids by the combination of having an adult body that is approximately 5–10 times longer than wide, a sinistral posterolateral body protuberance, tegumental body spines that are straight (lacking recurved tip) and wrap dorsoventrally around the body margin, posterior ceca that are 2–5 times the anterior ceca length, a single testis that extends lateral to both the ceca and nerve cords, an ovary abutting the posterior margin of the testis, a symmetrical vitellarium and medial primary vitelline duct, a post-cecal and post-gonadal ootype, and a proximal uterus that is extensively convoluted posterior to the ootype and which functions as a uterine seminal receptacle. The new genus lacks a spinous anterior sucker, pharynx, auxiliary external seminal vesicle, cirrus stylet, oviducal seminal receptacle, and Laurer's canal. The new species is morphologically most similar to the other aporocotylids that have a posterolateral body protuberance, including species of Psettarium Goto and Ozaki, 1930, Aporocotyle Odhner, 1900, Ankistromeces Nolan and Cribb, 2004, Phthinomita Nolan and Cribb, 2006, and Littorellicola Bullard, 2010, but it can be differentiated from them, at the least, by lack of a spinous anterior sucker in the adult and by the combination of having dorsoventral rows of tegumental spines, a testis dorsal to the posterior ceca, and a uterine seminal receptacle posterior to the ootype. The new species is the first aporocotylid reported from the Caribbean Sea or from a parrotfish of Sparisoma.

A new species of digenean, Caudotestis patagonensis n. sp. (Digenea: Opecoelidae), is described and illustrated based on specimens collected from the intestine of the horsefish, Congiopodus peruvianus (Cuvier, 1829) (Scorpaeniformes: Congiopodidae) from the Patagonian Shelf, Argentina (45–48°S, 60–64°W). This opecelid differs from the 4 previously known species of Caudotestis mainly in the extent of its seminal vesicle within the hindbody and the distribution of vitelline follicles. Moreover, the new species can also be distinguished by possessing the following combination of features: oral and ventral suckers nearly equal in size, ventral sucker at boundary of anterior third of body, intestinal bifurcation in posterior third of forebody and anterior to genital pore, genital pore submedial sinistral, anteriormost extent of the excretory vesicle reaching ovarian region, ovary nearly equidistant from both ventral sucker and anterior testis, posteriormost extent of the uterine loops just reaching ovarian region, testes oval and in tandem, ceca ending in front of the anterior testis, and size and number of eggs. This is the fifth recognized species of Caudotestis, the first report of a species of this genus in the southern Atlantic Ocean, and the second from a congiopodid fish.

Many trematode groups have a long history of systematic revision, which can make parasite identification a difficult task. The trematode parasites of muskrats are no exception. Here, we highlight the systematic issues associated with trematodes of muskrats (Ondatra zibethicus). Then, we demonstrate the utility of using both morphological and molecular tools to identify these parasites. Morphological examinations of specimens from muskrats (n = 63) first suggested that at least 4 genera were present including Echinostoma, Wardius, Quinqueserialis, and Notocotylus. For the latter 3 groups, the 28S region verified this assessment. For echinostomes, ND1 sequences revealed at least 5 genetic lineages. A particular lineage, Echinostoma trivolvis lineage b, predominated in both prevalence and intensity of infection. Molecular sequences provided a more accurate estimate of echinostome diversity in the muskrats and further support the idea that E. trivolvis is a species complex. Future studies will focus on whether there are differences in host specificity among the E. trivolvis lineages. In addition, this study has provided initial sequences that will help verify the life cycles of Wardius, Quinqueserialis, and especially, Notocotylus. By linking molecular, morphological, and life history information, we can better understand parasite diversity.

Delicata abbai n. sp. collected from the small intestine of the southern long-nosed armadillo, Dasypus hybridus, from Argentina is herein described. This new species is characterized by vulvar opening within second half of body length, female tail conical, ending bluntly with a terminal spine, complex spicules, presence of a bursal membrane supported by 2 small rays, and a synlophe with bilateral symmetry and 26 cuticular ridges. By the morphology of the caudal bursa, caudal end of female, and shape of spicules, the new species resembles Delicata cameroni Travassos, 1935 and Delicata variabilis Travassos, 1935. However, it differs from D. cameroni by having rays 5 and 6 diverging more proximally, rays 8 shorter than the dorsal ray, and spicules with a different shape. Delicata abbai n. sp. is distinguished from D. variabilis mainly by the spicules, which have a different shape and proportion of their constitutive parts. This is the first report of a species of Delicata in Argentina.

Skrjabinema kamosika sp. n. (Nematoda: Oxyuridae) is described based on both sexes collected from endemic Japanese serows, Capricornis crispus (Mammalia: Bovidae), of Wakayama Prefecture, western Honshu Island, and Kochi Prefecture, Shikoku Island, Japan. It is readily distinguished from the congeners by having tricuspid sub-interlabial projections in males, large triangular lateral lobes of the lips that do not reach the mouth rim, and a large length ratio of alate/nonalate portions of the tail in females. Close identity in the nucleotide arrangement of ITS2 region between the present material and that from C. crispus of Iwate Prefecture, northern Honshu Island, suggests wide distribution of S. kamosika in Japan. In partial 18S rDNA nucleotide sequence, 0.77% differed from that of Skrjabinema sp. from Capra hircus in the United States.

The Great American Interchange resulted in the mixing of faunistic groups with different origins and evolutionary trajectories that underwent rapid diversification in North and South America. As a result, groups of animals of recent arrival converged into similar habits and formed ecological guilds with some of the endemics. We present a reconstruction of the evolutionary events in Aspidoderidae, a family of nematodes that infect mammals that are part of this interchange, i.e., dasypodids, opossums, and sigmodontine, geomyid, and hystricognath rodents. By treating hosts as discrete states of character and using parsimony and Bayesian inferences to optimize these traits into the phylogeny of Aspidoderidae, we reconstructed Dasypodidae (armadillos) as the synapomorphic host for the family. In addition, 4 events of host switching were detected. One consisted of the switch from dasypodids to hystricognath rodents, and subsequently to geomyid rodents. The remaining set of events consisted of a switch from dasypodids to didelphid marsupials and then to sigmodontine rodents. The reconstruction of the ancestral distribution suggests 3 events of dispersal into the Nearctic. Two of these invasions would suggest that 2 different lineages of dasypodid parasites entered the Northern Hemisphere at different times, which is consistent with the presence of 2 lineages of armadillos in Mexico.

Three acanthocephalan species, Sphaerirostris turdi from the island thrush (Turdus poliocephalus), and Porrorchis centropusi and Porrorchis kinsellai n. sp., both from Philippine scops owls (Otus megalotis), are reported from Aurora Province, Luzon Island, Philippines. Porrorchis kinsellai n. sp. can be readily differentiated from previously known members of the genus by an almost perfectly spherical proboscis and presence of a characteristic finger-like process at the female posterior end, among other features. Porrorchis centropusi and Porrorchis hylae are regarded as synonyms by some authors, but based on several morphological features, they are considered separate species here. A key to the identification of all known species of Porrorchis (other than insufficiently described Porrorchis brevicanthus) is provided.

A new species of Grillotia was found from teleosts and elasmobranchs along the Patagonian shelf off Argentina. Grillotia patagonica n. sp. is described from plerocerci recovered from gadiform (Moridae) and perciform fish (Cheilodactylidae, Bovichtidae, and Nototheniidae) and adults from the smallthorn sand skate Psammobatis rudis (Rajiformes, Rajidae). Grillotia patagonica most closely resembles species in the Grillotia erinaceus species complex (viz., Grillotia borealis, Grillotia brayi, Grillotia dollfusi, G. erinaceus, and Grillotia musculara) in having 4 hooks per principal row and 2 or more intercalary rows in the metabasal region, a band of hooks on the external surface of the tentacle, numerous proglottids, a hermaphroditic sac, internal and external seminal vesicles, uterine pore, and attachment of the retractor muscle in the mid region of the tentacular bulb. Grillotia patagonica n. sp. is unique among all valid species in the genus by having the hooks on the first row reduced and of a different shape from the rest of the metabasal rows. Despite the diversity of elasmobranchs that are available as definitive hosts for species in Grillotia, most species (10/14) are oioxenous or mesostenoxenous. The specificity for the last intermediate host is variable among species of Grillotia, with most plerocerci being oioxenous (5/15) or euryxenous (8/15). Host specificity is higher for the adult stage in the definitive host (mean HS_S = 4.07) than for the plerocerci (mean HS_S = 7.30). All the species with oioxenous specificity (either larvae or adults) have limited geographic distributions. Some previous records of species of Grillotia from fishes caught off Argentina require reconsideration, i.e., G. erinaceus, Grillotia minuta (reported as Grillotia bothridiopunctata) and G. borealis. An updated host–parasite checklist for the valid species of Grillotia is also presented along with new host records for Grillotia carvajalregorum.

We report the distribution of 2 species of filarioid nematodes occurring in different hosts in the central region of South America. Molinema boliviensis n. sp. was recorded as a parasite of sigmodontine and echymyid rodents in Bolivia, and Litomosoides esslingeri was recorded in sigmodontine and ctenomyid rodents from Bolivia and Argentina. Molinema boliviensis n. sp. shares several similarities with other species reported in spiny rats; however, it can be easily differentiated by the presence of a flat anterior end, gradually tapering lappets and a tubercle present in posterior end, a short, uniform buccal capsule, an oval-shaped vagina vera, and a ratio of spicules of 1:1.44. An account for the morphological variability of L. esslingeri is presented that allows the identification of the buccal capsule, the tail tip in females, and the shape of spicules as reliable diagnostic traits. A complete set of head papillae is also described. The finding of these parasites in phylogenetically unrelated hosts suggests that host capture may be a frequent phenomenon in these filarioids. Researchers should focus efforts in surveying mammals within the same ecological guild to understand the distribution and host specificity of these nematodes.

A new species of Biacantha Wolfgang, 1954 (Nematoda: Molineidae), is described from the common vampire bat, Desmodus rotundus Geoffroy and St. Hilaire, 1810, from northwest Argentina. Biacantha normaliae n. sp. Oviedo, Ramallo, and Claps, is characterized by the disposition and number of ridges of the synlophe, the excretory pore located on a knob, 2 lateral processes on the tail of females, the male caudal bursa morphology, and lack of gubernaculum. This is the first species of nematode described in a vampire bat from Argentina.

Yorkeria chonburiensis n. sp. (Tetraphyllidea: Onchobothriidae) is described from the spiral intestine of a specimen of the brownbanded bamboo shark, Chiloscyllium punctatum, collected from the Gulf of Thailand, Chon Buri Province, Thailand. Yorkeria chonburiensis n. sp. is distinguished from all other species of Yorkeria by the pattern of proglottids (craspedote as opposed to acraspedote) and the proglottid number (more than 168). The new species is larger than all other members of Yorkeria, and the medial hooks are slightly larger than the lateral hooks with a ratio of 1:1.87–1:1.96. The position of the genital pore is 29–34% from the anterior margin of proglottid, greater than all other members of Yorkeria.

Between April and June 2009, 1,075 feral rainbow trout from 10 different lakes involved with aquaculture activities in Los Lagos Region, Chile, were inspected for Diphyllobothrium species. All viscera and muscles of the fish were examined using stereomicroscopy; pyloric cecae and stomachs infected with plerocercoids were checked by histology and scanning electron microscopy. Plerocercoids of Diphyllobothrium dendriticum were confirmed by PCR and sequencing of COI and 18S rRNA ITS1 5.8S rRNA ITS2 genes for the first time in Chile. Overall prevalence of plerocercoids of D. dendriticum was 9.2% (99/1,075) in Los Lagos Region and 17.4% (99/570) for Chiloe Island. Plerocercoids were not detected in the continental lakes of the Los Lagos Region (Chapo, Rupanco, and Llanquihue). Tarahuín Lake exhibited a prevalence of 50.9% (81/159), Cucao Lake 5.1% (4/79), Natri Lake 4.7% (5/107), Huillinco Lake 3.6% (5/138), and San Antonio Lake 66.7% (4/6). Abundance was 1.1 plerocercoid larvae per fish (1,169 larvae/1,075 fish). All the plerocercoids were found encysted in the viscera of the fish. Plerocercoids were 10.9 ± 3 (7–16) mm long by 0.4 ± 0.2 (0.2–0.6) mm wide. The scolex was enlarged, with 2 bothria and a frontal pit. The body was covered with short capilliform filitriches, 4–6 mm long. The Chilean COI and 18SrRNA ITS1 5.8SrRNA ITS2 gene sequences indicated 96.34–96.52% and 99% similarity with D. dendriticum sequences, respectively. Diphyllobothrium dendriticum is reported for the first time in freshwater ecosystems as far as 43°S on Chiloe Island. These findings and previous reports of plerocercoids of Diphyllobothrium spp. in farmed rainbow trout at Tarahuín Lake support the putative life cycle of this parasite in lakes of southern Chile where there are aquaculture activities.

Physaloptera tupinambae n. sp. (Nematoda: Physalopteridae) collected from the stomach of 1 Tupinambis merianae (Squamata: Teiidae) male lizard is described. Physaloptera tupinambae, which belongs to the didelphys group, is the only species in the genus that exhibits a bipartite internal tooth and in which the excretory pore is anterior to the deirids. The new species can be differentiated from the other congeners mainly based on the number and pattern of caudal papillae and the length and shape of spicules. Physaloptera murisbrasiliensis and Physaloptera clausa orientalis are the only physalopterids with the same number of caudal papillae as for P. tupinambae, but they differ from the new species mainly in length and shape of spicules. Based on morphological analysis, the speciation process among Physaloptera probably occurred via host capture, and P. tupinambae occupies an intermediate phylogenetic position in the genus. Most likely, the new parasite was acquired by the lizard through ingestion of an intermediate host. Finally, Physaloptera calotisi, Physaloptera funambuli, Physaloptera guptae, Physaloptera indica, Physaloptera johnsoni, Physaloptera kherai, and Physaloptera thaparus are moved to Abbreviata.

During investigations of young-of-the year smallmouth bass (Micropterus dolomieu) mortalities in the Susquehanna River, Pennsylvania, U.S.A. and affected tributaries, raised areas were noted in the muscle in the vicinity of the caudal peduncle. The raised areas were caused by plasmodia of a myxozoan parasite. Spores found within plasmodia were similar to those of Myxobolus inornatus previously described from the caudal peduncle of fingerling largemouth bass (Micropterus salmoides) in Montana. Here, M. inornatus is redescribed based on histologic comparisons and spore measurements. The addition of spore photographs, line drawings, a voucher specimen, and partial small-subunit ribosomal (rSSU) DNA gene sequence are new in this study. This is also the first description of M. inornatus from smallmouth bass. The plasmodia of M. inornatus were grossly observed at the base of the caudal and dorsal fins and were 280.3 ± 33.5 (range 77.1–920.3) μm long and 320.6 ± 41.0 (range 74.85–898.4) μm wide. In some instances, plasmodia of M. inornatus were large enough to rupture the epidermis or were associated with misaligned vertebrae. The slightly pyriform spores were 11.3 ± 0.2 (range 8.6-17.4) μm in length and 8.6 ± 0.2 (range 7.1–13.7) μm wide with an iodinophilous vacuole and a sutural ridge with 8 to 10 sutural folds. The SSU rDNA gene sequence places M. inornatus in a sister group with Myxobolus osburni.

The bear tapeworm Diphyllobothrium ursi is described based upon the morphology of adult tapeworms recovered from the brown bear (Ursus arctos middendorffi) and larval plerocercoids found in sockeye salmon (Oncorhynchus nerka) from Kodiak Island in Alaska in 1952. However, in 1987 D. ursi was synonymized with Diphyllobothrium dendriticum, and the taxonomic relationship between both species has not subsequently been revised. In this study mitochondrial cytochrome c oxidase subunit 1 gene (cox1) sequences of holotype and paratype D. ursi specimens that had been preserved in a formalin-acetic acid-alcohol solution since the time the species was initially described approximately 60 yr ago were analyzed. Molecular and phylogenetic analysis of the cox1 sequences revealed that D. ursi is more closely related to D. dendriticum than it is to Diphyllobothrium nihonkaiense and Diphyllobothrium latum. In addition to molecular evidence, differences in the life cycle and ecology of the larval plerocercoids between D. ursi and D. dendriticum also suggest that D. ursi is a distinct species, separate from D. dendriticum and D. nihonkaiense, and also possibly from D. latum.

Pigs are important in the epidemiology of toxoplasmosis in North America. Seroprevalence of Toxoplasma gondii infection in 525 domestic pigs (337 backyard raised, 188 farm raised) in Oaxaca State, Mexico was determined using the modified agglutination test (MAT, cutoff 1:25). Antibodies to T. gondii were found in 58 (17.2%) of the 337 backyard pigs with MAT titers of 1:25 in 10, 1:50 in 12, 1:100 in 18, 1:200 in 6, 1:400 in 6, 1:800 in 3, and 1:1,600 in 3. Seropositive pigs were found in 39 (37.9%) of 103 homes in all 7 municipalities surveyed. Seroprevalence of T. gondii infection in backyard pigs varied with age, gender, geographic region, climate, and altitude. High seroprevalence was found in pigs ≥9-mo-old (40%), in females (40%), in pigs from the Istmo region (33.3%), and in those raised in a tropical climate (65%). Seroprevalence was higher (24.5%) in pigs raised at 100–660 m above sea level than in those at 20–60 m of altitude (14.2%). With respect to farm pigs, only 1 (0.5%, MAT titer 1:100) of 188 pigs from 5 farms was positive for anti-T. gondii antibodies. The results affirm that the management system (outdoor vs. indoor system with biosecurity) is a key factor in the epidemiology of porcine toxoplasmosis. Because there is no national system of determining the T. gondii infection status at the time of slaughter, precautions should be taken while handling pig carcasses, and all pork should be cooked thoroughly before human consumption.

Cutaneous leishmaniasis (CL), an endemic disease in the littoral zones of the Mediterranean area, the Middle East, East Africa, and especially in Libya, has not been fully documented. The present study clarifies the clinico-epidemiologic profile of CL and the molecular genotyping of the Leishmania spp. in the Nalut district, Libya. Two hundred and twenty-three CL patients were examined at the out-patient clinics of Nalut Hospital from March 2006 to February 2007. CL was diagnosed by clinical, microscopic, culture, polymerase chain reaction (PCR), and PCR-restriction fragment length polymorphism (RFLP) analyses. The disease was observed year-round, with the highest prevalence between November and February. Fifty-nine percent of patients were younger than 20 yr. Nodulo-ulcerative lesions, indurated ulcers, papulo-ulcerative lesions, and subcutaneous nodular lesions were observed in 170, 25, 15, and 13 patients, respectively. Two hundred patients (89.7%) had dry type of lesions, whereas 23 patients (10.3%) presented a wet type of lesion. One hundred and fifty-nine (71.3%) of 223 patients were confirmed positive for CL by the presence of the amastigote form of Leishmania by stained Giemsa smear, and 170 (76.2%) were positive according to the presence of the promastigote form of Leishmania by culture in RPMI 1640 medium supplemented with 10% fetal bovine serum (FBS). PCR confirmed 203 (91.0%) positive cases. Genotyping of Leishmania spp. by RFLP analysis revealed that L. tropica was the most common species at all ages, and L. infantum was second under 20 yr of age. In summary, CL is endemic in the Nalut district, Libya; PCR was the most sensitive parasite diagnostic test, and L. tropica was the most common species.

Schistosomula, the larval stage of schistosomes in vertebrate hosts, are highly vulnerable and considered an ideal target for vaccine and drug development. Although the schistosomule stage is essential for biological studies, collecting sufficient numbers of schistosomula from their definitive hosts in vivo is difficult to accomplish. However, in vitro collection via cercariae transformation can effectively yield high numbers of schistosomula. We compared a current and widely used double-ended–needle mechanical transformation method to a culture medium based on a nonmechanical method. We found the rates of transformed cercariae, i.e., separated cercariae heads from tails, differed by only 2–7% at 0.5, 1, and 2 days in culture and that there was no significant difference in the number of transformed cercariae between the transformation methods at 3 and 4 days in culture. Notably, the mechanical and nonmechanical cercariae transformation methods both yielded significantly large and similar quantities of viable schistosomula. Given that the nonmechanical method is simpler and less damaging to the parasites, we recommend the use of it as an alternative way for in vitro cercariae transformation. In addition, we also observed morphological changes of the detached cercariae tails in culture medium. Interestingly, the tails are able to regenerate head-like organs/tissues and survive for at least 4 days. This intriguing change suggests unique biological features of the cells in the tails.

Nine opossums, Didelphis aurita, were captured in the city of Seropédica, State of Rio de Janeiro, Brazil and examined for species of Sarcocystis. Sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. Five budgerigars, Melopsittacus undulatus, were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. Of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums developed tissue parasites. Meronts in the vascular endothelium of the lung venous capillaries and cysts in the skeletal and cardiac muscle cells were observed in histological sections stained with hematoxylin and eosin. The microscopic cysts, which were predominantly in the tongue and leg muscles, ranged from 65.3 to 118.1 μm in length and 14.0 to 29.4 μm in width and from 0.9 to 1.9 μm in thickness of the cystic wall. Sections examined by transmission electron microscopy revealed that the cyst wall contained numerous slender and jagged-shaped protrusions, each with a finger-like formation at the end. The morphology, especially of the cyst wall, and the morphometry of the tissue cysts indicate that the parasite is Sarcocystis lindsayi and, therefore, the opossum, D. aurita, is now considered a definitive host for this species in Brazil.

The present study analyzed giardin transcription in trophozoites and cysts during encystation of Giardia lamblia. Encystment was induced using standard methods, and the numbers of trophozoites and cysts were counted at various time points during the process. At all time points, RNA from both stages were assayed for levels of alpha2-, beta-, and delta-giardin mRNA as well as for cyst wall protein 3 (CWP3) mRNA using quantitative RT-PCR. In encystation medium, the number of G. lamblia trophozoites decreased, while the number of cysts increased between 0 and 72 hr. In trophozoites, alpha2- and beta-giardin transcription decreased over time, while delta-giardin transcription remained unchanged during the same time period. CWP3 transcription exhibited a slight increase in trophozoites at 8 hr, followed by a decrease at subsequent time points. Expression of alpha2-giardin increased at 48 hr in cysts followed by decreased expression at 72 hr, while beta- and delta-giardin expression was unchanged during encystation. CWP3 transcription gradually decreased from 24–72 hr in cysts. Consistent with previous studies, giardin proteins appeared to be disassembled into amorphous structures inside cysts during encystation. These findings represent the first analysis of giardin transcription in separate populations of trophozoites and cysts during encystation and indicate differential regulation of giardin mRNA expression by these developmental stages.

Gynandromorphism is a rare, abnormal phenomenon in which both female and male characteristics are simultaneously displayed in an organism. It has been described in many arthropods, including ticks. This unique occurrence is known within several species of Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes, and Rhipicephalus. Bipartite protogynander is the most common form of gynandromorphism, whereas gynander intriqué is the rarest type among the ticks. Here, we report the first case of a gynandromorph of Hyalomma marginatum Koch, 1844 collected from a naturally infested human during a tick survey in the Tokat Province of Turkey in 2006. It is an interesting gynander intriqué, with features of a protogynander. The tick described here displays abnormal characters such as an alloscutum with a male consucutum in dorsal view, male and female spiracular plates, female genital aperture under the male genital flap, and adanal plates located on the both side of the anus, whereas accessory plates are on the left side only in ventral view.

For the first time in the study of ancient parasites, analyses were carried out on samples taken from a First World War settlement in France (Geispolsheim, region of Alsace). Microscopic examination of sediment samples revealed the presence of 3 common human parasites, i.e., Trichuris trichiura, Ascaris lumbricoides, and Taenia sp. A review of paleoparasitological studies in Europe shows that these 3 parasites have infected humanity for centuries. Despite this recurrence, literature shows that knowledge regarding many helminths was limited, and their life cycles were only relatively recently elucidated. Finally, the present study provides additional information about the health of the German soldiers and the sanitary conditions in the trenches during the first modern world conflict.

Prevalence of Toxoplasma gondii and Neospora caninum antibodies in sera of 325 dogs in 11 villages inhabited by the Tapirapé and Karajá ethnic groups in the south of the Brazilian Amazon was determined by the use of an indirect fluorescence antibody test. Antibodies (cutoff 1:16) to T. gondii were found in 169 (52%) and to N. caninum (cut-off 1:50) in 32 (9.8%) of 325 dogs. Seropositivity for both parasitic infections was widely prevalent in dogs from these villages and was higher in older dogs, indicating post-natal transmission.

Baylisascaris procyonis is a zoonotic nematode commonly found in raccoons (Procyon lotor). Human-altered landscapes can support dense populations of raccoons, increasing the potential for interaction between humans and these animals. We used raccoon feces provided by licensed fur trappers to investigate environmental variables that influence prevalence of B. procyonis at 2 sites in Wisconsin. Trappers submitted raccoon feces to us, along with information on sex, age (juvenile and adult), and approximate trap location for each animal. We used zinc sulfate (1.18 specific gravity) flotation to detect B. procyonis eggs in approximately 1 g of fecal matter from each host. We used ArcView software to determine the distance of each trap location to an urban area as determined by the U.S. Census Bureau in 2000. We compared the habitat components in buffered home ranges (0.805 km around trap locations) of infected animals with those from uninfected animals using Mann-Whitney U-tests (P < 0.05). Variables investigated were human population, road density, housing units per census block, and land cover, including area of agriculture, forest, developed, shrubland, water, and grassland. We positively identified eggs in 64.9% of the animals sampled. Raccoons infected with B. procyonis had significantly larger area of agricultural habitats and significantly smaller areas of forested habitats in buffered home ranges than uninfected individuals. We found that raccoons near Madison and Milwaukee, Wisconsin, are commonly infected with B. procyonis, indicating that public education regarding protection from disease is warranted.

Gymnophalloides seoi is a trematode species discovered as recently as 1993. Interestingly, ancient G. seoi eggs were identified in our earlier study on a 17th Century female mummy unearthed in a Korean county (HD-1) where G. seoi infection, according to a nationwide survey of 2001, was considered not to have been endemic. Although we suspected that the geographical distribution of G. seoi might have contracted over the past several hundred years from wider coastal areas on the Korean peninsula to the much more restricted region delineated by the survey, there has been only the single, above-noted report of an ancient G. seoi infection in a currently non-endemic area. As such, more evidence is needed before our contraction theory of G. seoi infection prevalence can be confirmed as fact. Our current report in this regard will perhaps help to end the controversy. In a newly discovered 17th Century male mummy found in another Korean county considered non-endemic by the 2001 survey, we identified a large number of ancient G. seoi eggs. We believe that this additional evidence for a wider distribution of G. seoi infection prior to the 20th Century is invaluable support for our earlier hypothesis.

Paramphistomiasis is a parasitic disease caused by various species of the Paramphistomidae. These species mainly affect domestic and wild ruminants; the economic impact of these diseases is often underestimated. Traditionally, the identification of paramphistomes has been difficult and has been based on morphological aspects such as the body shape, the position of the esophagus and cecae, or the tegumental papillae. Despite the many investigations regarding the tegumental papillae for other paramphistomes, very few efforts have been made using Zygocotyle lunata, partly because many authors differ with respect to the importance of papillae in the classification of paramphistomids. Herein, we characterize by scanning electron microscopy new tegumental papillae not previously described on the tegument of 3-wk-old Z. lunata adults obtained from mice. Three morphologically different papillae (rosette, ciliated, and conical papillae) were observed and are described. Based on these results, we assert that the newly recognized morphological features should be used for species differentiation in the future in addition to the new molecular techniques.

Populations of Biomphalaria straminea, Biomphalaria peregrina, Biomphalaria tenagophila, Biomphalaria orbignyi, and Biomphalaria oligoza from different Argentine localities were exposed to miracidia of Schistosoma mansoni EC strain, and Biomphalaria tenagophila, in addition to the SJ2 strain. Biomphalaria straminea and B. tenagophila displayed different susceptibility and compatibility (Frandsen's total cercariae production index class 0–II), whereas B. orbigny and B. oligoza were incompatible. Although B. peregrina and B. tenagophila were found naturally infected with the amphistome Zygocotyle lunata, all 5 species could be experimentally infected with Z. lunata. Exposure to Z. lunata infections with S. mansoni were obtained in natural populations of B. straminea and B. tenagophila with the EC strain (13.5–17.1% and 1.2%), respectively, and in B. tenagophila with the SJ2 strain (2.6%), 60 days postexposure [PE]), and in B. orbignyi and B. oligoza (31.1% and 26.7% 60 days PE, respectively, including single infections with S. mansoni and double infections with Z. lunata). The high susceptibility of B. orbignyi and B. oligoza is noteworthy, as these 2 species are considered resistant to S. mansoni.

Toxoplasma gondii is an obligate intracellular parasite often found in the brain of humans. Research has shown a correlation between prevalence of antibody titers to T. gondii and psychological illness in humans. Recent studies indicate that individuals seropositive for T. gondii antibodies are more likely to develop psychotic disorders including schizophrenia, which is associated with changes in the dopamine neurotransmitter system. Dopamine in the brain may play a role in proliferation, chemoattraction, infection efficiency, or stage conversion of T. gondii. Because tachyzoites are the first developmental stage to reach the brain, the present study was conducted to determine the effects of dopamine on their development in vitro. In human fibroblast host cells, dopamine was added at either 100 nM or 250 nM to cell culture media, and the numbers of tachyzoites produced at 48 hr were determined and compared to vehicle-treated controls. An increase of tachyzoite numbers and increased destruction in cell monolayer were observed at both concentrations of dopamine. Dopamine used at 250 nM caused a significant (P < 0.05) increase in tachyzoites counts compared to controls. Dopamine antagonists (10 μM) did not significantly alter dopamine-stimulated tachyzoite production in human fibroblasts. In primary neonatal rat astrocyte cell cultures, dopamine (200 μM) significantly (P < 0.05) increased numbers of intracellular tachyzoites after 24 hr. The role that this increase plays in tachyzoite production under the stimulus of dopamine in the modulation of neural infection in humans awaits further studies.

There is a lack of epidemiological data on Toxoplasma gondii infection in chickens in China. In the present study, serum samples from 160 free-range chickens and 450 caged chickens collected from Jinzhou, northeastern China were examined for T. gondii antibodies using a modified agglutination test (MAT). Antibodies to T. gondii were found in 30 of 160 free-range chickens (18.8%) and in 25 of 450 caged chickens (5.6%), with a significantly higher prevalence in free-range chickens (P < 0.01). In caged chickens, 8 of 100 breeders (8.0%), 15 of 190 layers (7.9%), and 2 of 160 broilers (1.3%) were positive, with the highest prevalence in breeders and layers (P < 0.05). No significant difference was found in comparing free-range chickens and caged chickens from different regions. The results of the present study indicated that infection with T. gondii in chickens, particularly in free-range chickens, is common in Jinzhou and that the meat from the poultry may be an important source for human infection by T. gondii.