The infrapopulation size, or crowding, is an important measure in parasitology because of its impact on many facets of parasite biology. However, crowding values are difficult to handle statistically because of dependencies. Therefore, a bootstrap procedure was proposed in order to compare crowding between 2 groups or samples of hosts. Here, we propose Lepage's location-scale test based on intensities as an alternative to test whether there is a difference in mean crowding. Simulation results indicate that Lepage's test is superior to the bootstrap, even when sample sizes are large as needed for the bootstrap procedure. Lepage's test, however, can also be applied with moderate or small sample sizes.

We describe the distribution and abundance of the brain-encysting trematode Euhaplorchis californiensis and its second intermediate host, the California killifish (Fundulus parvipinnis), in 3 estuaries in southern California and Baja California. We quantified the density of fish and metacercariae at 13–14 sites per estuary and dissected 375 killifish. Density (numbers and biomass) was examined at 3 spatial scales, i.e., small replicate sites, habitats, and entire estuaries. At those same scales, factors that might influence metacercaria prevalence, abundance, and aggregation in host individuals and populations were also examined. Metacercaria prevalence was 94–100% among the estuaries. Most fish were infected with 100s to 1,000s of E. californiensis metacercariae, with mean abundance generally increasing with host size. Although body condition of fish did not vary among sites or estuaries, the abundance of metacercariae varied significantly among sites, habitats, estuaries, and substantially with host size and gender. Metacercariae were modestly aggregated in killifish (k > 1), with aggregation decreasing in larger hosts. Across the 3 estuaries, the total populations of killifish ranged from 9,000–12,000 individuals/ha and from 7–43 kg/ha. The component populations of E. californiensis metacercariae ranged from 78–200 million individuals/ha and from 0.1–0.3 kg/ha. Biomass of E. californiensis metacercariae constituted 0.5–1.7% of the killifish biomass in the estuaries. Our findings, in conjunction with previously documented effects of E. californiensis, suggest a strong influence of this parasite on the size, distribution, biomass, and abundance of its killifish host.

During parasitological research on cichlid fish from the tributaries of the Amazon River around Iquitos, Peru, the following gill monogenoidean species were found: Tucunarella cichlae n. gen. and n. sp. from Cichla monoculus Spix and Agassiz; Gussevia alioides Kritsky, Thatcher, and Boeger, 1986 from Heros severus Heckel; Gussevia asota Kritsky, Thatcher, and Boeger, 1989 from Astronotus ocellatus (Agassiz); Gussevia disparoides Kritsky, Thatcher, and Boeger, 1986 from H. severus (all new geographical records) and Cichlasoma amazonarum Kullander (new host record); Gussevia longihaptor (Mizelle and Kritsky, 1969) Kritsky, Thatcher, and Boeger, 1986 and Gussevia undulata Kritsky, Thatcher, and Boeger, 1986 from C. monoculus; Sciadicleithrum satanopercae Yamada, Takemoto, Bellay, and Pavanelli, 2008 from Satanoperca jurupari Heckel; and Sciadicleithrum variabilum (Mizelle and Kritsky, 1969) Kritsky, Thatcher, and Boeger, 1989 from C. amazonarum (new host and geographical records). Tucunarella n. gen. is proposed to accommodate a new species, Tucunarella cichlae, which is its type and only known species in the genus. The new genus is characterized by, besides a very large body size (about 1.5 mm vs. much less than 1 mm in other ancyrocephaline genera in Amazonia), a thickened tegument, 1 pair of eyes, overlapping gonads (testis dorsal to the germarium), nonarticulated male copulatory organ (MCO) and accessory piece, a coiled (counterclockwise) MCO, a dextral vaginal aperture, a haptor armed with 2 pairs of anchors (each with broad base and subequal roots, which are marginally folded), and dorsal and ventral bars and 14 hooks with protruding blunt thumbs and 2 different shapes (slender vs. slightly expanded shanks). Illustrations and data on morphological and biometric variability of individual species from different hosts are provided. The present data provide evidence of a relatively wide host specificity of gill monogenoideans parasitic in South American cichlids.

Morphological descriptions of Dirofilaria immitis are scarce. For this reason, we carried out morphological studies using both light and scanning electron microscopy for this filaroid species. Morphometric and morphological data were compatible with previous descriptions of D. immitis, but several anatomical structures are described by scanning electron microscopy for the first time, such as details of the cuticular striations, positioning of amphids, visualization of anal and vulvar opening, descriptions of deirids, lateral line, the pair of phasmids in the posterior end in females, and visualization of a small pair of latero-terminal papillae in the posterior end in males.

Toxoplasma gondii infection may cause a variety of symptoms involving virtually all organs. Little is known of the epidemiology of T. gondii infection in different patient groups in Mexico. We sought to determine the prevalence of T. gondii infection and associated epidemiological characteristics in 472 patients in Durango, Mexico. Participants were tested for T. gondii IgG and IgM antibodies. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. Seroprevalences of T. gondii IgG antibodies were found in 7 (8.2%) of 85 patients with hearing impairment, 5 (10.0%) of 50 patients with hemodialysis, 28 (12.0%) of 234 patients with visual impairment, and 7 (6.8%) of 103 at risk of immunosuppression. In total, 47 (10%) of 472 subjects had IgG T. gondii antibodies; 6 (1.3%) of them also had IgM anti–T. gondii antibodies. Patients born in Durango State had a significantly lower prevalence of T. gondii infection than patients born in other Mexican states (9.0% vs. 21.4%, respectively; P < 0.05). Multivariate analysis showed that T. gondii infection was significantly associated with consumption of undercooked meat (adjusted odds ratio [OR]  =  2.95; 95% confidence interval [CI]: 1.18–7.35) or raw cow's milk (adjusted OR  =  2.52; 95% CI: 1.28–4.96), presence of cats at home (adjusted OR  =  2.01; 95% CI: 1.06–3.78), raising animals (adjusted OR  =  2.44; 95% CI: 1.06–5.63), or eating away from home (adjusted OR  =  2.70; 95% CI: 1.03–7.11). In the group of patients with visual impairment, those with reflex impairment had a significantly higher frequency of T. gondii infection than those with normal reflexes (19% vs. 9.4%, respectively: P  =  0.04). Results of the present study are the first step in the design of prevention programs to avoid the sequelae of toxoplasmosis.

The antigenic profile and infectivity were compared between 3 recent Leishmania (Viannia) isolates from the Amazonian region (Instituto Nacional de Pesquisas da Amazonia [INPA] strains) and 3 World Health Organization (WHO) reference species (Leishmania guyanensis, Leishmania braziliensis, and Leishmania naiffi). Differences were observed in the peak and extent of promastigote growth. The WHO reference strains exhibited significantly higher exponential growth as promastigotes than INPA strains. In the immunoblot analyses, the INPA strains revealed several specific peptide fragments, as well as the greatest recognition frequencies by sera from Leishmania sp.–infected patients; among the latter, antigens derived from L. naiffi were the most frequently recognized. In vitro infection was carried out using mice peritoneal macrophages; all strains were able to enter the macrophages, but only L. amazonensis was able to reproduce. A striking observation was that L. naiffi exhibited the longest survival time inside the macrophages. Our data strongly suggest the application of recently isolated parasites as sources of antigen for diagnosis procedures. Moreover, L. naiffi species possesses several characteristics relevant for its use as a source of novel antigens to be explored in the design of diagnostic tools and vaccines.

To investigate how different routes of Toxoplasma gondii transmission influence the antibody response and infection status of deer mice (Peromyscus maniculatus), 80 mice were orally infected with 1, 5, 10, or 100 T. gondii oocysts. Ten weeks postinfection, 15 T. gondii–seropositive female mice were bred and allowed to produce 2 litters. Evidence of persistent T .gondii infection in orally infected mice was detected by serology and DNA amplification in mice from all 4 oocyst treatment groups, including those that received only a single T. gondii oocyst. Congenital transmission of T. gondii was detected by polymerase chain reaction (PCR) in 7/8 first and 4/7 second litters. Toxoplasma gondii was also detected by PCR in 9/30 congenitally infected offspring 16 wk after birth, despite the fact that detectable serological titers had waned. These findings raise questions about the applicability of serological testing to assess the prevalence of T. gondii infection in deer mice and other rodents in the wild. Additionally, the detection of frequent congenital transmission suggests that deer mice could help maintain T. gondii in the environment even in the absence of definitive feline hosts.

Little is known about the importance of capybara, Hydrochoerus hydrochaeris, as reservoirs for parasites of zoonotic or veterinary importance. Sera from 63 capybaras, from 6 counties in the state of São Paulo, Brazil, were examined for antibodies to Trypanosoma cruzi, Leishmania infantum, Encephalitozoon cuniculi, Sarcocystis neurona, and Neospora caninum using an indirect immunofluorescent antibody test. Five (8%) of the 63 capybaras had antibodies to T. cruzi epimastigotes. None of the samples from capybara reacted positively with L. infantum promastigotes or with spores of E. cuniculi. Two (3%) of the serum samples were positive for antibodies to S. neurona merozoites, and 2 (3%) of the serum samples were positive for antibodies to N. caninum tachyzoites. A serum sample from 1 capybara was positive for antibodies to both T. cruzi and N. caninum. None of the remaining 62 samples reacted with more than 1 parasite.

Pristionchus spp. nematodes exhibit several traits that might serve as pre-adaptations to parasitism. Under harsh environmental conditions, these nematodes can arrest development and form dauer larvae. In addition, they have been shown to live in necromenic association with a range of beetles, including dung beetles (Geotrupes stercorosus) on which, for example, Pristionchus entomophagus is commonly found. It has been argued that the formation of dauer larvae and the association with invertebrates represent intermediate steps towards parasitism. To better understand necromenic associations, and to gain information on Pristionchus spp. abundance and the general species composition on dung beetles, we extracted all the nematode fauna present on 114 individuals of G. stercorosus. By direct sequencing using the 18S SSU, we provide a barcode for all nematodes isolated from the beetle samples. In total, 5,002 dauer-stage nematodes were sequenced, which included Pristionchus spp., Koerneria spp. (Diplogastridae), Pelodera spp. (Rhabditidae), and Strongyloidea as well as Spirurida. Intensities of infection varied from over 1,000 nematodes isolated from a single G. stercorosus to none, with Pelodera spp. being the most abundant group isolated. This study presents the first quantitative data on the Pristionchus spp. infection of beetles.

A fourth known species of Entovalva (Mollusca: Galeommatoidea), found in the esophagus of Holothuria spinifera and Holothuria leucospilota from Nha Trang Bay, Viet Nam, is described. Morphologic comparisons with the 3 previously described species are presented and the first DNA sequences for Entovalva are provided. Entovalva nhatrangensis, n. sp., differs from Entovalva mirabilis Voeltzkow, 1890 in its body shape, folded outer body epithelium, and lack of ovary in the foot. It differs from Entovalva (Cycladoconcha) amboinensis (Spärk, 1931) in its body shape and folded outer body epithelium. It differs from Entovalva lessonothuriae Kato, 1998, in shape of its foot. Two partial cytochrome oxidase I sequences for species diagnostic use have been submitted to GenBank.

Red-shouldered hawks (Buteo lineatus) are threatened in Wisconsin and long-term data suggest that nest productivity is low in the state for unknown reasons. Our objective was to determine whether red-shouldered hawks in northeast Wisconsin were infected with parasites that could contribute to low nest productivity. We examined nestlings for the presence of Trichomonas gallinae, Protocalliphora avium, and blood parasites in June 2006 and 2007. We did not detect T. gallinae in throat swabs taken from 24 nestlings in 2007. Ear canals of nestlings were parasitized by P. avium larvae in 10 of 11 (91%) nests and in 22 of 24 (92%) nestlings. Larvae were found in higher intensity in 1 ear relative to the other. Leucocytozoon toddi was present in 90.5% (38/42) of the nestlings. At least 1 bird in each nest was infected. Intensity of L. toddi averaged 48.6 ± 58.3 infected cells per 2,000 erythrocytes (2.4 ± 2.9%). No other blood parasites were identified.

In this article, we examined the influences of the polycultured potential hosts on monogenean seasonality and the possible linkage between the infestations on different species of hosts and host phylogeny. The seasonality of Diplectanum grouperi, the dominant species, on wild versus cultured groupers, Epinephelus spp., was analyzed in Daya Bay, South China Sea, between April 2008 and January 2009. The prevalence, mean intensity, abundance, and variance/mean ratio were calculated for each species of host under polycultured and wild conditions. Except for the overall prevalence, which was slightly higher in autumn than that in summer under wild conditions, the mean intensity and variance were highest in summer, decreasing slightly in autumn to lowest levels in winter or spring. The infection level (prevalence, mean intensity, and abundance) was correlated with changes in water temperature during the sampling period, with a peak in summer, with the exception of E. awoara in autumn under wild conditions. The prevalence, intensity, and mean intensity of D. grouperi on Epinephelus spp. in the wild were much lower than those in experimental (mixed species) culture ponds. The correlation between the molecular phylogeny of 5 species of Epinephelus and the dendrogram based on the susceptibility to D. grouperi was not significant, which infers that variable susceptibilities of these Epinephelus species cannot be revealed by phylogenetic relationships determined from mitochondrial 16S rDNA and Cyt b gene sequences.

Trypanosoma cruzi, the etiologic agent of Chagas' disease, is enzootic in animal populations of the southeastern United States. In the United States, T. cruzi prevalence has been reported for over 20 different wildlife species, and 7 autochthonous human cases have been documented since 1955. Previous canine (Canis familiaris) serosurveys have been limited either by small sample size or confined geographic reporting areas. In this study, we report a seroprevalence of 6.4% among 860 canines from 31 counties and 5 ecoregions throughout Tennessee, using an indirect immunofluorescent assay (IFA). Statistically significant associations between seropositivity and age, weight, and outdoor living were noted. Differences in seropositivity were not seen based on American Kennel Club (AKC) group, sex, habitat, land cover, and ecoregion. Greater attention should be given to possible T. cruzi transmission in Tennessee and veterinarians should consider Chagas' disease as a differential diagnosis with compatible signs.

Pathogens can alter host life-history traits by affecting host feeding activities. In anuran tadpoles, keratinized mouthparts (teeth and jaw sheaths) are essential for feeding. Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus of amphibians that can infect these mouthparts and reduce tadpole survival. However, the precise way that Bd-induced changes in tadpole mouthparts impact tadpole feeding is unknown. We use high-speed (500 frames/sec) videography to study how Bd-induced mouthpart deformities affect the feeding kinematics of Fowler's toad (Anaxyrus [ =  Bufo] fowleri) and grey tree frog (Hyla chrysoscelis) tadpoles. We tested for species-specific patterns of Bd-induced mouthpart deformities to assess how deformations to specific areas of tadpole mouthparts alter feeding kinematics. The teeth of tadpoles from the Bd-exposed treatment slipped off of surfaces on which tadpoles graze and were in contact with an algal-covered substratum for a shorter duration in each gape cycle compared to teeth of control tadpoles. We also found that the jaw sheaths had significantly more deformations than labial teeth; however, how this relates to feeding kinematics is unclear. Our data show explicitly how Bd infection reduces foraging efficiency of anuran tadpoles by altering feeding kinematics and elucidate a mechanistic link between the pathogen infection and reduced host fitness.

Cosmocercoides sauria n. sp., an intestinal parasite of the gymnophthalmid lizard Iphisa elegans from western Brazil, is described. Of the 18 species previously described, C. sauria represents the 19th species, and is the third to be reported in the Neotropical region. Moreover, C. sauria is the second species reported from a reptilian host and is distinguished by a smaller number of rosette papillae (4 pairs). Additionally, the new species can be distinguished from the other Neotropical species (Cosmocercoides lilloi Ramallo, Bursey and Goldberg, 2007 and C. variabilis (Harwood, 1930)) by possessing smaller spicule size and presence of both gubernaculum and lateral alae in Cosmocercoides lilloi.

Adults of Sphaerirostris picae (Rudolphi, 1819) Golvan, 1956 are described from European magpie, Pica pica Linnaeus (Corvidae), collected in 2008 from wooded areas near the northern Iranian town of Tonekabon by the southern shores of the Caspian Sea. Other specimens also were collected from Corvus cornix Linnaeus, Corvus corone Linnaeus, and Corvus frugilegus Linnaeus (Corvidae) in the same location, as well as from some of these hosts in other locations. Our specimens had 31–38 proboscis hook rows on the ovoid anterior proboscis and 27–36 spine rows on the cylindrical- to cone-shaped posterior proboscis, each with 8–10 hooks and 2–5 spines per row, respectively. They are distinguished from those of all other species of the genus by having a unique prominent expansion of the dorsal inner receptacle wall, called the receptacle process (RP), anteriorly into the anterior proboscis and by the presence of longitudinal alveolar lobes throughout the receptacle and proboscis. The RP is described using histological sections. Sphaerirostris picae is further distinguished from 2 closely related species, namely, Sphaerirostris lancea (Westrumb, 1821) Golvan, 1956 and Sphaerirostris pinguis (Van Cleave, 1918) Golvan, 1956, by characteristics of proboscis armature, position of female gonopore, and other reproductive system and receptacle features. Histological sections revealed damage to host intestinal tissue.

Three new species of Ohbayashinema (Nematoda, Heligmosomoidea) are described from localities in western North America and central Asia. Two of these species, Ohbayashinema nearctica n. sp. and Ohbayashinema aspeira n. sp., are parasitic in American pika, Ochotona princeps. Ohbayashinema nearctica is differentiated from the 5 known species of the genus parasitic in Ochotonidae from the Old World by very long spicules and an oblique axis of orientation for the ridges composing the synlophe. Ohbayashinema aspeira, described only from females, is similar to Oh. nearctica based on the number of cuticular ridges at the mid-body. It is mainly differentiated by an uncoiled anterior extremity and by near equal dimensions of the vestibule and the uterus. The third species, Ohbayashinema patriciae n. sp., is parasitic in Gansu pika, Ochotona cansus, from China. It is similar to Ohbayashinema erbaevae parasitic in Ochotona dauurica from Buriatia and Ohbayashinema ochotoni in Ochotona macrotis from Nepal, based on the length of the spicules and the ratio of spicule length to body length. It differs from the former species by possessing a smaller number of cuticular ridges and in the comparative length of the vestibule and infundibulum. Related to Oh. ochotoni by an identical number of cuticular ridges at the mid-body, it differs from this species in having smaller ridges in the dorsal rather than ventral field and in the dimensions of the dorsal ray where rays 9 are less than rays 10. Species of Ohbayashinema appear to be host-specific among the Ochotonidae but had not been previously reported in pikas from the Nearctic. Although much remains to be demonstrated about the diversity for helminths in pikas, it is apparent that factors associated with the assembly and structure of parasite faunas have been complex, involving episodic processes for geographic and host colonization along with coevolutionary mechanisms. Understanding the historical factors, particularly climate-driven fluctuations in geographic range, that have structured these faunas suggests that the current regime for global warming and habitat modification has considerable implications for the continuity of already localized assemblages of hosts and parasites.

Anoplocephalid cestodes have a worldwide distribution, but relatively few species are known from South American rodents. By examining the collections of the Harold W. Manter Laboratory of Parasitology and the United States National Parasite Collection, 6 new species of Monoecocestus Beddard, 1914, are described, along with a redescription of Monoecocestus mackiewiczi Schmidt and Martin, 1978, based on the type specimens. The discussion includes commentary about uterine development, an important taxonomic character of the family, the vaginal dilation in immature segments (a character of potential taxonomic importance), and the implication of host usage to the evolutionary history and biogeography of species in this genus.

In a survey of the brown dorcopsis, Dorcopsis muelleri, on Salawati Island, Papua, Indonesia, 2 new species were found in the stomach. Dorcopsistrongylus ewini n. sp. can be differentiated from its congeners in having the proximal end of the spicule twisted and from Dorcopsistrongylus labiacarinatus in having shorter intestinal diverticula and in the proportions of the elements of the ovejector. Dorcopsistrongylus salawatiensis n. sp. can be differentiated from its congeners in having bilobed lateral lip-like elements and an elongated terminal bulb of the esophagus. A survey of other Dorcopsis and Dorcopsulus spp. may reveal more species of Dorcopsistrongylus.

Helminths, 3 cestode and 8 nematode species, including 2 new genera, 5 new species, and 1 putative new species, of nematode were collected from the digestive tracts of 23 Lorentzimys nouhuysi (Murinae; Hydromyini) from Papua New Guinea. Odilia wauensis n. sp. (Heligmonellidae) most closely resembles Odilia mallomyos Hasegawa and Syafruddin, 1994, but differs from this species in the detail of the synlophe ridges, the length and tip shape of the spicules, the absence of a gubernaculum, and the size of the eggs. Papuastrongylus kishinamiae n. gen., n. sp. differs from all other genera in the Herpetostrongylidae in the form of the synlophe and spicules, the lack of a gubernaculum, and in being monodelphic. Syphacia lorentzimyos n. sp. and Syphacia mamelonitenuis n. sp. (Oxyuridae) differ from all other species in having a circular cephalic plate and from each other in that S. mamelonitenuis lacks lateral alae. Lorentzicola woolleyae n. gen., n. sp. differs from all other genera in the Oxyuridae (Syphaciini) in having the peribuccal wall with denticles, a simple esophagus, and males with 3 mamelons of the Syphacia type. The helminth assemblage of L. nouhuysi did not resemble that of any other hydromyin rodent from the region studied thus far.

Dicyemid mesozoans are endoparasites, or endosymbionts, found only in the renal sac of benthic cephalopod molluscs. The body organization of dicyemids is very simple, consisting of usually 10 to 40 cells, with neither body cavities nor differentiated organs. Dicyemids were considered as primitive animals, and the out-group of all metazoans, or as occupying a basal position of lophotrochozoans close to flatworms. We cloned cDNAs encoding for the gap junction component proteins, innexin, from the dicyemids. Its expression pattern was observed by whole-mount in situ hybridization. In adult individuals, the innexin was expressed in calottes, infusorigens, and infusoriform embryos. The unique temporal pattern was observed in the developing infusoriform embryos. Innexin amino acid sequences had taxon-specific indels which enabled identification of the 3 major protostome lineages, i.e., 2 ecdysozoans (arthropods and nematodes) and the lophotrochozoans. The dicyemids show typical, lophotrochozoan-type indels. In addition, the Bayesian and maximum likelihood trees based on the innexin amino acid sequences suggested dicyemids to be more closely related to the higher lophotrochozoans than to the flatworms. Flatworms were the sister group, or consistently basal, to the other lophotrochozoan clade that included dicyemids, annelids, molluscs, and brachiopods.

A cross-sectional study was conducted to assess the seroprevalence of fascioliasis by immunoenzymatic probes in an endemic area (northwestern Spain). Blood samples were collected from 1,034 cattle (crossbred, Rubia Gallega, and Friesian breeds), and the diagnosis of fascioliasis was carried out by determining both the occurrence of antigenemia and the presence of specific IgG antibodies against a Fasciola hepatica recombinant protein (FhrAPS). The IgG seroprevalence was 65% (95% CI, 62–68) by the FhrAPS-ELISA, and 32% (29–35) exhibited antigenemia; the lowest percentages occurred in the Friesians, and the highest percentages were found in the crossbreds. These results confirm an elevated seroprevalence of fascioliasis that is unexpected considering that most of the cattle livestock (Friesian and Rubia Gallega) receive fasciolicide treatment. The lack of adequate measures on the environment and erratic chemotherapy seem to be responsible for the fact that control of fascioliasis has not improved in the last 10 yr in the area of study.

Metam sodium (MS, sodium N-methyldithiocarbamate) is a widely used soil pesticide. Fumigation or chemical sterilization of poultry litter containing infectious oocysts could be an effective strategy to block the transmission of avian coccidia. In the current study, the effect of MS on the viability and infectivity of ocysts was investigated. The development of isolated, unsporulated oocysts of both Eimeria tenella and Eimeria maxima was inhibited, in a dose-related manner (IC₅₀ 8 to 14 µg/ml), by exposure to aqueous MS. Most treated oocysts failed to develop beyond early stages of sporulation. To determine the effect of MS on infectivity, isolated oocysts of E. tenella, Eimeria acervulina, and E. maxima were exposed for 24 hr to aqueous concentrations of MS ranging from 0 to 1,000 µg/ml. Treated oocysts were inoculated into chickens, and parameters of coccidiosis infection were compared to chickens inoculated with equal numbers of untreated oocysts. In a dose-related manner, MS significantly reduced the infectivity of oocysts with maximum effect observed at a dose of 300 µg/ml. When a mixture of oocysts containing 3 coccidian species was exposed to 300 µg/ml MS, from 0 to 24 hr, infectivity of oocysts was significantly reduced after a minimum of 12 hr of exposure. Treatment of aqueous slurries of litter samples obtained from commercial poultry houses, with 300 µg/ml MS for 24 hr, prevented the sporulation of eimerian oocysts in the litter samples relative to untreated control samples. The results indicate that MS could be used to reduce coccidial contamination of poultry litter.

Cationic steroid antibiotics (CSAs), or ceragenins, are amphiphilic compounds consisting of a cholic acid backbone that is attached to several cationic amines. In this study, we tested the hypothesis that CSAs possess antiparasitic activities with minimal to no effects on mammalian cells, and thus could be used as potential therapeutic agents against pathogenic trypanosomatids. To investigate this notion, we synthesized CSAs and determined their trypanocidal and leishmanicidal activities in vitro. The 3 ceragenins assayed, i.e., CSA-8, CSA-13, and CSA-54, showed several degrees of parasiticidal activity. CSA-13 was the most effective compound against Leishmania major promastigotes and Trypanosoma cruzi trypomastigotes, at LD₅₀ 4.9 and 9 µM, respectively. The trypanocidal activities of these ceragenins were also assessed by infectivity experiments. We found CSA-8 was more effective on T. cruzi intracellular amastigotes when the infected host cells were treated for 24 hr (LD₅₀, 6.7 µM). Macrophages and LLC-MK₂ (treated for 72 hr) showed relative low susceptibility to these compounds. Our results suggest that ceragenins are indeed promising chemotherapeutic agents against trypanosomatids, but they require further investigation.

Control of Strongyloides stercoralis infection is based on antihelminthic treatment. However, the development of an efficient vaccine is an important goal for more effectively managing this disease. Different Strongyloides spp. antigen preparations have been previously tested but without satisfactory results. In the present study, we evaluated whether the doxycholic acid extract of Strongyloides venezuelensis stage 3 larvae was able to protect CD1 mice against a homologue infection. Moreover, we included saponins from Quillaja saponaria (Qs) and immunomodulatory substances, i.e., Phlebodium pseudoaureum hydroalcoholic extract (PAL) or the amino alcohol AA0029, which has an aliphatic chain of 14 carbon atoms with a hydrophilic amino alcohol head, where the amino group is protected with a butoxycarbonyl group. The DOCSv antigen, together with the adjuvant components, was emulsified in a non-mineral water/oil emulsion. We performed duplicate experiments with each of the 2 immunomodulators. The DOCSv antigen used with Qs PAL induced high levels of protection in terms of fecal egg count reduction (93.2–99.4%), 86–88% in adult worm recovery, and reduction in swelling of the small intestine. Mice vaccinated with the DOCSv antigen, together with Qs AA0029, showed a 73.7–97.0% reduction in fecal egg count, with reduction in inflammation of the small intestine. High levels of IgG and IgG2a were observed in mice vaccinated with Qs AA0029 DOCSv, indicating a Th1 immune response. Also, vaccinated mice recognized bands of 34, 39, 43, 95, and 170 kDa in a Western blot.

These are the first paleoparasitological results from the Late Holocene in Patagonian coprolites. Coprolites collected from layers dated at 3,480 and 2,740 yr before present (B.P.), from the archaeological site Cerro Casa de Piedra, were examined. The site is a hill located in a forest steppe ecotone in Perito Moreno National Park. The coprolites could belong to humans or to other carnivores such as canids. After rehydration and spontaneous sedimentation of the samples, the parasite contents were examined. Results obtained showed the common presence of eggs of a Calodium sp., eggs of other capillariids and trichostrongylids, oocysts of Eimeria macusaniensis (Apicomplexa), and eggs of taeniids (Cestoda). Although the generic identification of some parasites could not be provided, the presence of tapeworm eggs represents the first record for the Late Holocene in Patagonia and shows that parasitism by cestodes existed in the region in pre-Columbian times. Results indicate that in the Late Patagonic Holocene, zoonotic helminths may have been commonly present in the inhabitants of Patagonia. The parasites found in the coprolites allow us to deduce what these people were eating and, thus, indicate what other pathogens, such as viruses, bacteria, and parasitic protozoans, may have infected them via the same sources.

Knowledge of population dynamics of parasites in freshwater snails from South America is scarce. The objective of the present study was to describe the infection dynamics of larval digeneans in the planorbid snail, Biomphalaria peregrina, during 2 sampling periods in a Patagonian temporary pond. In total, 1,003 snails were examined. Rediae of Notocotylus biomphalariae and Echinoparyphium sp., sporocysts of Cotylurus sp., and metacercariae of the 2 latter species were found. The overall prevalence was significantly higher in the second sampling period, always as single-species infections in the hepatopancreas. The presence of larvae in the first sampled snails of the second hydroperiod indicated that parasitized snails survive drought. Both species exhibited different seasonal prevalence patterns, with Echinoparyphium sp. present in all sampling months. Metacercariae of Echinoparyphium sp. occurred in the heart and kidney, and those of Cotylurus sp. between organs. No significant differences in overall prevalence of metacercariae were found, and a progressive rise in prevalence from spring to summer for both species was observed. Almost all size classes of B. peregrina were infected with metacercariae of both species, but rediae and sporocysts were present only in snails larger than 3.1 mm. The predictability of the hydroperiod year after year, the tolerance of B. peregrina to drought, and the survival of infected specimens allows the parasite community to show a similar pattern of infection over time. This is the first study in Argentina analyzing the infection dynamics of digeneans of a pulmonate snail from a temporary pond.

This study was designed to investigate serum glucose, lipid, and lipoprotein in sheep naturally infected with Fasciola hepatica. Ten healthy sheep and 15 infected with F. hepatica were used in study. Serum concentrations of total protein (TP), albumin, glucose, cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoproteins (VLDL), and serum activities of AST, ALT, GGT, and LDH were measured using a Roche-Cobas Integra 800 auto-analyzer. At day 0 (prior to treatment) and on the 28th day (after treatment) the serum concentrations of TP, albumin, glucose, cholesterol, triglyceride, HDL, LDL, and VLDL values in sheep with F. hepatica were significantly lower than those of the control group, while serum activities of AST, ALT, GGT, and LDH of lambs with F. hepatica were significantly higher than those of the control group. At day 56 (after treatment), none of the variables was significantly different between control sheep and those that received treatment for fascioliasis (P > 0.05). Nutritional management may be used to reduce the impact of fascioliasis.

The gut protozoan parasite, Giardia lamblia (Assemblage A), has 5 major chromosomes, 1 of which is 2 Mb, as determined from gel separations of whole chromosomes. We originally published a physical map of this chromosome and, now, using the sequence data from 46 chromosome-specific probes, have produced a sequence map of the 2 Mb chromosome. Comparison of the probe sequences with the Giardia genome database ( http://GiardiaDB.org) has identified 4 scaffolds (CH991771, CH991780, CH991782, and CH991767) belonging to the 2 Mb, Assemblage A, chromosome. Because of the density of probe sequences, we have been able to predict the orientation of the scaffolds and have identified erroneous inclusions in scaffold CH991767. Exclusion of erroneously included sequences resulted in a 1.96 Mb chromosome sequence. This study brings together experimental data and the GiardiaDB data to compile the sequence of a whole chromosome.

Infectivity, development, and growth of Zygocotyle lunata in 18 male Balb/c mice, each exposed to 20 metacercariae cysts, were examined 1 to 6 wk post-infection (PI). Metacercariae cysts were obtained from naturally infected Helisoma trivolvis snails. At necropsy, 11 of 18 mice were found infected with a total of 32 worms. The range of recovery was 1 to 6 worms per host. The mean body area of worms, fixed in 10% neutral-buffered formalin and mounted in glycerin jelly, was found to be 4.0 mm² at 2 wk PI, increased to 6.8 mm² at 4 wk, and reached 11.4 mm² by 6 wk PI, at which time the study was terminated. Worms were ovigerous by 3 wk PI. Eggs were collected from 4-wk-old worms and incubated at 28 C in artificial spring water (ASW). Eggs were fully developed by 3 wk post-incubation and miracidia hatched in the ASW. Laboratory-reared H. trivolvis snails were not available to attempt miracidia infections with Z. lunata.

Light and scanning electron microscopical examination of gravid females of the philometrid nematode Buckleyella buckleyi Rasheed, 1963 from the original material, collected by Rasheed from the mesentery of the type host (marine fish) Scomberoides tala off Pakistan in 1961, revealed the presence of a mound, surrounding the oral aperture and separated from the more-posterior part of body by a deep cephalic groove, and the absence of lateral cordons extending along the body. Microscopic examination also showed the presence of 3 large esophageal teeth, 8 large cephalic papillae, and a pair of amphids and transverse rod-like structures situated on irregularly scattered elevations of the body cuticle. Based on some of these features, Buckleyella Rasheed, 1963 distinctly differs from the recently established, related genus Caranginema Moravec, Montoya-Mendoza and Salgado-Maldonado, 2008.

A total of 228 salmonids (90 Oncorhynchus mykiss, 48 Oncorhynchus kisutch, and 90 Salmo salar) from 8 intensive aquaculture centers in the south of Chile were examined for endohelminths parasites between December 2008 and May 2009. The body cavities of 2 O. mykiss were infected by Diphyllobothrium sp. plerocercoids (prevalence: 6.7%, mean intensity: 1.0, mean abundance: 0.07) from the Lake Tarahuin hatchery on the south of Chiloé Island. Also, tetraphyllidean plerocercoids (prevalence: 3.3%, mean intensity: 1, mean abundance: 0.03) and fourth-stage larvae of Hysterothylacium aduncum (prevalence: 6.7%, mean intensity: 1, mean abundance 0.07) were observed in O. kisutch from a marine hatchery in Chiloé. The occurrences of Diphyllobothrium sp. in a lake and a tetraphyllidean plerocercoid from marine cultured salmonid in Chiloé are reported for first time. No muscular infection by helminths was recorded in the fish examined.

The frequency of Toxoplasma gondii antibodies in stray and household dogs in Guangzhou, China was examined by ELISA on serum samples from 150 animals (36 strays and 114 from households) and the overall prevalence was 21.3%. The extent of infection in stray dogs (33.3%) was significantly higher (P < 0.05) than in household dogs (17.5%). Infection in male and female dogs of both groups was not significantly different (P ≥ 0.05), i.e., 31.8% versus 35.7% for male and female in stray dogs, and 14.5% versus 22.2% in household dogs. The results of the present investigation indicate that the seroprevalence of T. gondii infection in dogs was high in Guangzhou, especially in strays. Therefore, it is essential to implement integrated strategies to prevent and control T. gondii infection in both stray and household dogs.

The seroprevalence of toxoplasmosis in pigs was examined in China's southern Guangdong Province from March 2008 through May 2009. A total of 1,022 serum samples was collected from 12 administrative cities and assayed for Toxoplasma gondii antibodies by enzyme-linked immunosorbent assay test. The seroprevalence ranged from 0 to 58.1% and the average T. gondii antibody-positive prevalence was 27.0% (276/1,022), with breeding boars having the highest level at 39.6% (38/96) followed by breeding sows at 36.9% (52/141). The results of the present survey indicate that T. gondii infection is a significant health problem in pigs and represents a public health concern in southern China.