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Purpose: Cosmocercids are common nematodes that parasitize the digestive tract and lungs of amphibians and reptiles around the world. They are commonly found in leptodactylid and bufonid anurans in South America, primarily in Brazil and Argentina. This paper describes a new species of genus Cosmocerca based on specimens collected in a microhylid from the Dry Chaco ecoregion., Methods: A total of 18 specimens of Elachistocleis haroi were collected in October 2011 in Chaco province and in December 2021 and March 2022 in Formosa province, Argentina, both areas of the Dry Chaco ecoregion. The morphology of the nematodes was studied in detail using light microscopy and scanning electron microscopy., Results: One hundred and fifty-one nematodes were collected from the large intestines of E. haroi. Based on the morphology of the caudal papillae (rosette papillae and plectanes), the presence of two spicules and the absence of caudal alae in males, and the presence of two prodelphic ovaries in females, these specimens were allocated to the genus Cosmocerca. However, they presented unique characteristics that differentiate them from all known species. Cosmocerca wichiorum sp. nov. is similar to C. archeyi, C. australis, C. sardiniae, C. zugi, and C. leytensis by having four pairs of plectanes, but can be easily distinguished from all of them by the type, number, and arrangement of the precloacal (non-plectanes), adcloacal and postcloacal papillae, by the length of the spicules and by its different zoogeographical distribution., Conclusion: This is the 14th species of the genus Cosmocerca described in South America and the first one for the microhylid E. haroi from the Dry Chaco ecoregion., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Essentially all grazing horses are infected with cyathostomin parasites. Adult cyathostomins reside in the large intestine of the horse and larval stages encyst within intestinal mucosa. Manual worm collection from aliquots of intestinal content is the current gold standard for retrieval and enumeration of luminal parasites, however, no research has been conducted to standardize specific parameters for processing and storage of samples. The aims of this study were (1) to evaluate the precision of current standard operating procedures for enumeration of luminal adult cyathostomin populations, (2) investigate the influence of chosen fixative, either 70 % ethanol or 10 % buffered formalin, as well as storage duration, immediately post necropsy vs. stored for eight weeks, on the magnitude and precision of worm counts, and (3) compare the luminal count magnitude between the three intestinal segments (cecum, ventral colon, dorsal colon). Ten miniature horses were enrolled in this study for euthanasia and necropsy over a four-week period. Luminal worm counts were conducted for 2 % aliquots of the cecum, ventral colon, and dorsal colon and samples were allocated to the two fixatives and the two storage durations. Precision was evaluated by coefficient of variation (CV) and was 13.04 % for total cyathostomin counts. Mean CV for large intestinal segments ranged from 15.31 % to 52.50 % irrespective of fixative used or storage duration. cecum worm counts were significantly lower compared to the ventral colon (p = 0.008) and dorsal colon (p = 0.01). Fixative and storage duration were not statistically associated with count precision or magnitude. This study demonstrated moderate to high precision estimates for luminal cyathostomin worm counts but did not identify any effects of fixative and storage duration within the framework of the study. This is the first study to determine cyathostomin worm count precision, and results will be useful for power analyses in the future., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Spinicauda ciremaiensis sp. nov. (Nematoda: Heterakidae) from the large intestine of Gonocephalus kuhlii (Reptilia: Agamidae) collected in Gunung Ciremai National Park, West Java, Indonesia is described and illustrated. Of the five described species of Spinicauda from the Oriental region, Spinicauda ciremaiensis sp. nov. comes closest to S. sumatrana in having 14 pairs of caudal papillae and the presence of a tail filament. However, the new species differs from S. sumatrana in the longer spicula, smaller eggs, and weak sclerotization of the gubernaculum. S. ciremaiensis sp. nov. is also the only species belonging to the genus Spinicauda which has a sclerotized accessories piece of gubernaculum. A key to the species of Spinicauda is also provided. [http://zoobank.org/urn:lsid:zoobank.org:act:785F2D63-E5EB-4E4C-A7E1-7F7E7AD7C392].

Increasing evidence suggests that intestinal helminth infection can alter intestinal microbial communities with important impacts on the mammalian host. However, all of the studies to date utilize different techniques to study the microbiome and access different sites of the intestine with little consistency noted between studies. In the present study, we set out to perform a comprehensive analysis of the impact of intestinal helminth infection on the mammalian intestinal bacterial microbiome. For this purpose, we investigated the impact of experimental infection using the natural murine small intestinal helminth, Heligmosomoides polygyrus bakeri and examined possible alterations in both the mucous and luminal bacterial communities along the entire small and large intestine. We also explored the impact of common experimental variables including the parasite batch and pre-infection microbiome, on the outcome of helminth-bacterial interactions. This work provides evidence that helminth infection reproducibly alters intestinal microbial communities, with an impact of infection noted along the entire length of the intestine. Although the exact nature of helminth-induced alterations to the intestinal microbiome differed depending on the microbiome community structure present prior to infection, changes extended well beyond the introduction of new bacterial species by the infecting larvae. Moreover, striking similarities between different experiments were noted, including the consistent outgrowth of a bacterium belonging to the Peptostreptococcaceae family throughout the intestine., (Copyright © 2019 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

We have validated ITS-2 rDNA nemabiome next-generation amplicon sequencing to determine relative species abundance of gastrointestinal nematode species in ovine fecal samples. In order to determine species representation biases, ITS-2 rDNA amplicon sequencing was applied to mock communities or field populations with known proportions of L3 for eight of the major ovine gastrointestinal nematode species: Teladorsagia circumcincta, Trichostrongylus vitrinus, Haemonchus contortus, Cooperia curticei, Trichostrongylus axei, Trichostrongylus colubriformis, Chabertia ovina and Oesophagostumum venulosum. Correction factors, calculated from this data, were shown to reduce species representation biases when applied to an independent set of field samples of known composition. We compared ITS-2 rDNA amplicon sequencing data that was generated from harvested eggs, freshly hatched L1 or L3 larvae following fecal culture and no statistically significant differences were found for the more abundant parasite species. We then applied the validated ITS-2 rDNA nemabiome amplicon sequencing assay to a set of archived L1 gastrointestinal nematode populations, collected in 2008 from fecal samples from 93 groups of 20 ewes and 61 groups of 20 lambs derived from 99 UK sheep farms. The presence of the major gastrointestinal nematode species had previously been determined on this large sample set by species-specific PCR. We show how the ITS-2rDNA amplicon sequencing data provided much more detailed information on species abundance than the previous species-specific PCR. This new data represents the most comprehensive overview of the relative abundance of the major gastrointestinal nematode species across UK sheep farms to date. Substantial variance in the relative abundance of both T. circumcincta and T. vitrinus between farms was revealed with the former species being of statistically significantly higher abundance in all three regions sampled (England, Scotland and Wales). The data also revealed that the relative abundance of T. circumcinta was statistically significantly higher in ewes than in lambs with the opposite pattern being the case for T. vitrinus. The nemabiome sequencing data also clearly illustrated the sporadic nature and skewed distribution of H. controtus across UK sheep farms as well as a higher relative abundance on farms from England compared to Wales and Scotland. The nemabiome survey also provides the first widescale data on the relative abundance of the two major large intestinal nematodes C. ovina and O. venulosum. This work validates ITS-2 rDNA nemabiome sequencing for use in sheep and illustrates the power of the approach for large scale surveillance of ovine gastrointestinal nematodes., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The gastrointestinal (GI) tract of vertebrates is inhabited by a vast array of organisms, i.e., the microbiota and macrobiota. The former is composed largely of commensal microorganisms, which play vital roles in host nutrition and maintenance of energy balance, in addition to supporting the development and function of the vertebrate immune system. By contrast, the macrobiota includes parasitic helminths, which are mostly considered detrimental to host health via a range of pathogenic effects that depend on parasite size, location in the GI tract, burden of infection, metabolic activity, and interactions with the host immune system. Sharing the same environment within the vertebrate host, the GI microbiota and parasitic helminths interact with each other, and the results of such interactions may impact, directly or indirectly, on host health and homeostasis. The complex relationships occurring between parasitic helminths and microbiota have long been neglected; however, recent studies point towards a role for these interactions in the overall pathophysiology of helminth disease, as well as in parasite-mediated suppression of inflammation. Whilst several discrepancies in qualitative and quantitative modifications in gut microbiota composition have been described based on host and helminth species under investigation, we argue that attention should be paid to the systems biology of the gut compartment under consideration, as variations in the abundances of the same population of bacteria inhabiting different niches of the GI tract may result in varying functional consequences for host physiology., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Cyathostomins are pervasive equine parasites in horses across the world, and larval stages are known to cause the deadly disease larval cyathostominosis. The mucosal digestion technique is widely used for enumeration of encysted larval stages. Previous studies have investigated the spatial variation of encysted larvae, however current protocols lack a description of a standardized area from which to take the tissue sample. This study sought to evaluate spatial variation in encysted cyathostomin larval counts among the large intestinal organs and their subsections. Following humane euthanasia, ceca, ventral, and dorsal colons were harvested from 8 foals (aged 4-8 months) raised in an anthelmintic naïve parasitology research herd. Each organ was weighed and separated into 3 equal sections by length: the orad, intermediate, and aborad portions. From each of those sections, two 5% weight tissue samples were collected and digested to quantify the early third stage larvae (EL3) and late third stage larvae/fourth stage larvae (LL3/L4). A mixed model statistical analysis was carried out to evaluate for differences of larval counts among the different organs, sections, and the interaction term between the organs and sections. There were significant differences among organs (P < 0.0001), with the ceca having higher counts than the ventral and dorsal colons. However, there were no significant differences among the three defined organ sections (P = 0.1076). Coefficients of variation (CV) were all calculated to be greater than 1, suggesting a high level of variability among the samples; the least amount of variation can be found in the cecal data with a CV of 1.4024 compared with the ventral colon's 1.529845 and dorsal colon's 3.339135 within the respective organ. The following sections had the highest mean counts of encysted larvae: intermediate cecum, orad ventral colon, and aborad dorsal colon. Though only a portion of the results were significant, trends were observed and these should be investigated further in future studies and potentially employed in larvicidal efficacy evaluations., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Protozoa of the genus Cryptosporidium are common parasites of domestic and wild animals-mammals, birds, reptiles, and fishes. The invasive forms are thick-walled oocysts, which can be present in water supplies, on fruits, vegetables, or in the soil contaminated with feces. In this work, we describe three cases of middle-aged persons with massive Cryptosporidium hominis infection and chronic diarrhea with no immunological abnormalities and no history of previous travels to tropical countries. The lesions discovered during colonoscopy within the large intestine-cryptitis and the histopathological changes were related to massive cryptosporidiosis. All these statements indicate necessity of parasitological stool examination in cases with chronic diarrhea in which no etiological agents are detected, but not only in HIV positive individuals. Parasite's eradication leads to symptom disappearance as well as improvement of histopathological mucosa alterations.

Parapharyngodon politoedi n. sp. is described here, based on specimens found in the large intestines of Osteocephalus taurinus from the Caxiuanã National Forest, State of Pará, Brazil. The new species is assigned to Parapharyngodon based on the presence of non-embryonated eggs with sub-terminal opercula, when in the ovijector. Parapharyngodon politoedi belongs to a group of species with three pairs of cloacal papillae and differs from its congeners by morphometric aspects, such as the length of the spicule, and the combination of the following morphological characters: ovaries never encircling the oesophagus, tail shape in females, cloacal lips, sharply pointed spicule and presence of genital cone. This is the second species of nematode reported to parasitize O. taurinus and the eleventh species of Parapharyngodon from hylids in the Neotropical region.

Rhabdias garhwalensis sp. nov. from the lungs of Duttaphrynus himalayanus (Günther, 1864) collected in Kimoi Tehsil, district Tehri Garhwal (Uttarakhand), India is described and illustrated. Rhabdias garhwalensis sp. nov. represents the 15th species described from the Oriental zoogeographical zone and the 9th species from India. The new species is differentiated from the closely related Oriental species in having 6 lips, cup-shaped buccal cavity with muscular striations in the posterior region and smaller esophagus to body length ratio. In addition to the new species, a second species, Cosmocercoides bufonis Karve, 1944, was found in the large intestine of D. himalayanus.

Falcaustra tintlwini sp. nov. (Ascaridida, Kathlaniidae) from the large intestine of Batagur trivittata (Testudines, Geoemydidae) is described and illustrated. Falcaustra tintlwini represents the 20th Oriental species assigned to the genus and is distinguished from other Oriental species by the distribution pattern of the caudal papillae (6 precloacal, 12 postcloacal, and 1 median), length of spicules (0.43-0.50 mm) and absence of a pseudosucker.

Amebiasis, a global intestinal parasitic disease, is due to Entamoeba histolytica. This parasite, which feeds on bacteria in the large intestine of its human host, can trigger a strong inflammatory response upon invasion of the colonic mucosa. Whereas information about the mechanisms which are used by the parasite to cope with oxidative and nitrosative stresses during infection is available, knowledge about the contribution of bacteria to these mechanisms is lacking. In a recent study, we demonstrated that enteropathogenic Escherichia coli O55 protects E. histolytica against oxidative stress. Resin-assisted capture (RAC) of oxidized (OX) proteins coupled to mass spectrometry (OX-RAC) was used to investigate the oxidation status of cysteine residues in proteins present in E. histolytica trophozoites incubated with live or heat-killed E. coli O55 and then exposed to H2O2-mediated oxidative stress. We found that the redox proteome of E. histolytica exposed to heat-killed E. coli O55 is enriched with proteins involved in redox homeostasis, lipid metabolism, small molecule metabolism, carbohydrate derivative metabolism, and organonitrogen compound biosynthesis. In contrast, we found that proteins associated with redox homeostasis were the only OX-proteins that were enriched in E. histolytica trophozoites which were incubated with live E. coli O55. These data indicate that E. coli has a profound impact on the redox proteome of E. histolytica. Unexpectedly, some E. coli proteins were also co-identified with E. histolytica proteins by OX-RAC. We demonstrated that one of these proteins, E. coli malate dehydrogenase (EcMDH) and its product, oxaloacetate, are key elements of E. coli-mediated resistance of E. histolytica to oxidative stress and that oxaloacetate helps the parasite survive in the large intestine. We also provide evidence that the protective effect of oxaloacetate against oxidative stress extends to Caenorhabditis elegans., Competing Interests: The authors have declared that no competing interests exist.

Neocosmocercella fisherae n. sp. is the first nematode species found parasitising Phyllomedusa bicolor from the Brazilian Amazon Region. The new species has a triangular oral opening, with bi-lobed lips, and is distinguished from N. bakeri (triangular oral opening with simple lips), and from N. paraguayensis (hexagonal oral opening with bi-lobed lips). Additionally, the new species has ciliated cephalic papillae, which are absent in the other species of the genus. The reduced uterine sac and the presence of a single egg in the uterus in females are the main morphological characters that differentiate the new species from its congeners N. bakeri (8-10 eggs) and N. paraguayensis (10 eggs, based on the allotype). Additionally, the new species differs from the other two species of the genus by morphometric characters such as the size of spicules and gubernaculum in males and the vagina in females. Until now, phyllomedusid anurans are the only known hosts for the nematodes of this genus. The present work describes the third species of the genus and the first species of nematode parasitising P. bicolor.

Mammalakis zambiensis n. sp. is described from the large intestine and caecum of Fukomys anselli (Burda, Zima, Scharff, Macholán & Kawalika), a bathyergid rodent endemic to Zambia. Morphological data for comparison with its three congeners, M. macrospiculum (Ortlepp, 1939), M. spalacis (Marcu, 1930) and M. spalaxi (Kozlov & Jangolenko, 1962) are provided. Based on studies of the type-material, observations of hitherto undescribed morphological characters of M. macrospiculum, a parasite of Bathyergus suillus (Schreber) (Hystricomorpha: Bathyergidae) in South Africa, are presented. To date, the generic diagnosis of Mammalakis Inglis, 1991 is based largely on characters of its type-species, M. macrospiculum. In having three rounded lips, not set-off from the body, a stout oesophagus with a flask-shaped posterior bulb, lateral alae that broaden on the level of the precloacal sucker and cloaca, and mature eggs with a smooth shell, M. zambienis n. sp. corresponds to the characters of the genus. However, the presence of lips with anterior flanges that were observed in M. zambiensis n. sp., and also for the first time in M. macrospiculum, are in contrast with the current diagnosis of Mammalakis. Further studies will be needed to determine if an amendment of the generic diagnosis is indicated.

Adult schistosomes were detected in the veins or capillaries of the large intestine, mesentery, liver, and adrenal glands in eight of 13 whooper swans (Cygnus cygnus) examined in Iwate Prefecture, Japan. However, neither eggs nor severe tissue injuries were observed in any of the swans. The schistosomes were definitively identified as Allobilharzia visceralis based on the nucleotide sequences of the ribosomal internal transcribed spacer (ITS) region. Allobilharzia visceralis infections have been reported in whooper swan in Iceland and tundra swan (Cygnus columbianus) in North America. These detections suggest that A. visceralis is distributed extensively along the swan flyways because the swans are migratory birds. To the best of our knowledge, this is the first report of A. visceralis infection in Asia., (Copyright © 2016. Published by Elsevier Ireland Ltd.)

Parapharyngodon sanjuanensis sp. nov. (Nematoda: Pharyngodonidae) from the large intestines of Phymaturus punae and Phymaturus williamsi (Squamata: Liolaemidae) from province of San Juan, Argentina, is described and illustrated. Parapharyngodon sanjuanensis sp. nov. is the 54th species assigned to the genus and the 8th from the Neotropical region. It differs from other species in the genus in that males possess 8 caudal papillae, 6 of which are large and pedunculate, 2 are small, almost inconspicuous; anterior lip echinate, posterior lip bilobate; females possess prominent vulva and short stiff tail spike.

Cacajao calvus ucayalii (Thomas, 1928) (Primates: Pitheciidae), a subspecies endemic to the Peruvian Amazon, occurs in patchy and sometimes isolated populations in north-eastern Peru and is in a vulnerable situation, mainly due to habitat loss and hunting. This rareness and remote distribution means that, until now, parasitical studies have been limited. Based on optical and scanning electron microscopy of specimens of both sexes, we report two new species of Trypanoxyuris pinworms occurring in the large intestine of the Peruvian red uakari, namely Trypanoxyuris (Trypanoxyuris) cacajao and Trypanoxyuris (Trypanoxyuris) ucayalii. Both species showed a distinct morphology of the lips and cephalic structure. Sexual dimorphism in the lateral alae was observed in both male and the female worms, with ventral ornamentation being shown in the oesophageal teeth. The finding of these new pinworm species highlights the possibility of discovering other species.

Strongyluris calotis is a heterakid nematode in the large intestine of agamid lizards (Reptilia: Sauria: Agamidae) from the Oriental Region. The standard light microscopic definition of the species counts the "caudal papillae" as 10 pairs on male worms. However, previous work from our group using scanning electron microscopy (SEM) on the heterakid from agamid lizards in Japan, Taiwan, and Singapore revealed that this counting contained a pair of phasmids and that two pairs of postcloacal papillae were completely fused to form a pair of united papillae, thus resulting in "10 pairs." In the present study, we examined S. calotis specimens from the Emma Gray's forest lizard, Calotes emma (Agamidae), living in the plain forest at low altitude, and the Vietnam false bloodsucker, Pseudocalotes brevipes (Agamidae), living in the mountainous forest at high altitude in the northern part of Vietnam. Using SEM, the arrangement of caudal papillae in male worms from an Emma Gray's forest lizard was found to be comparable to classical S. calotis specimens from agamid lizards collected in Japan, Taiwan, and Singapore. However, male worms from Vietnam false bloodsuckers did not have a pair of united papillae but had 10 pairs of independent caudal papillae with a pair of phasmids. Molecular genetic analyses of the ribosomal RNA gene (rDNA) of worms of the classical S. calotis morphotype from Japan and Singapore and two S. calotis morphotypes from Vietnam demonstrated absolutely identical nucleotide sequences of partial 18S rDNA (at least 1764 base pairs (bp)) and 5.8S rDNA (158 bp). However, intraspecific differences were detected in other regions of the rDNA, related to the geographical distribution of hosts regardless of morphotype: 97.8-98.5 % identity (443-446 bp/453 bp) in the internal transcribed spacer (ITS)-1 region, 96.6-98.0 % identity (425-431 bp/440 bp) in the ITS-2 region, and 99.6-99.7 % identity (1149-1151 bp/1154 bp) in the 28S rDNA. Thus, in the future, taxonomic relationships of S. calotis distributed widely in the Oriental Region as well as other nominal Oriental Strongyluris spp., currently six in number, need to be extensively explored based on molecular genetic analyses in addition to intensive morphological characterization.

Blastocystis spp., one of the most common parasites colonizing the human intestine, is an extracellular, luminal protozoan with controversial pathogenesis. The host's immune response against Blastocystis spp. infection has also not been defined yet. Therefore, this research aimed to assess the potential pathogenicity of this parasite and its ability to modulate the immune response in experimental infected immunocompetent and immunosuppresed mice. These results demonstrated that the infected immunosuppressed mice were more affected than infected immunocompetent mice. Histopathological examination of the small intestine in the infected immunosuppressed mice showed that Blastocystis spp. infiltrated all the layers. Moreover, the epithelia showed exfoliation and inflammatory cell infiltration in submucosa compared to that of the infected immunocompetent mice. As well, examination of the large intestine of the infected immunosuppressed group showed severe goblet cell hyperplasia. Blastocystis spp. infiltrated all the large intestine layers compared to that of the infected immunocompetent group. Furthermore, there was a significant upregulation of the expression of proinflammatory cytokines: interleukin 12 (IL-12) and tumor necrosis factor alpha (TNF-α) in the infected immunosuppressed mice compared to that of the infected immunocompetent ones (p ≤ 0.004 and p ≤ 0.002, respectively). However, the expression of anti-inflammatory cytokines (IL-4 and IL-10) was significantly downregulated in the infected immunosuppressed group compared to that of the infected immunocompetent group one at 10 days postinfection (p ≤ 0.002 and p ≤ 0.001, respectively). The results of this study revealed that Blastocystis spp. affected the production of pro- and anti-inflammatory cytokines in both groups of mice compared to healthy normal (naive) group. Additionally, these data showed that there was a significant upregulation (p ≤ 0.005) of the locally synthesized antibody: secretary IgA (sIgA) in the gut of the infected immunocompetent mice when compared to that of the infected immunosuppressed ones.

Surveillance was conducted for the occurrence of protozoan parasites of the genus Cryptosporidium in European hedgehogs (Erinaceus europaeus) in Great Britain. In total, 108 voided faecal samples were collected from hedgehogs newly admitted to eight wildlife casualty treatment and rehabilitation centres. Terminal large intestinal (LI) contents from three hedgehog carcasses were also analysed. Information on host and location variables, including faecal appearance, body weight, and apparent health status, was compiled. Polymerase Chain Reaction (PCR) targeting the 18S ribosomal RNA gene, confirmed by sequencing, revealed an 8% (9/111) occurrence of Cryptosporidium parvum in faeces or LI contents, with no significant association between the host or location variables and infection. Archived small intestinal (SI) tissue from a hedgehog with histological evidence of cryptosporidiosis was also positive for C. parvum by PCR and sequence analysis of the 18S rRNA gene. No other Cryptosporidium species were detected. PCR and sequencing of the glycoprotein 60 gene identified three known zoonotic C. parvum subtypes not previously found in hedgehogs: IIdA17G1 (n=4), IIdA19G1 (n=1) and IIdA24G1 (n=1). These subtypes are also known to infect livestock. Another faecal sample contained C. parvum IIcA5G3j which has been found previously in hedgehogs, and for which there is one published report in a human, but is not known to affect livestock. The presence of zoonotic subtypes of C. parvum in British hedgehogs highlights a potential public health concern. Further research is needed to better understand the epidemiology and potential impacts of Cryptosporidium infection in hedgehogs., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This paper describes cultivation methods for ciliates from the digestive tract of horses. Members of three different genera were successfully grown in vitro for short periods of time. However, only cells belonging to the genus Blepharocorys, which resides in the horse's large intestine, were maintained for longer periods. This Blepharocorys culture was successfully grown in vitro after inoculation of freshly excreted horse faeces in culture medium containing a population of bacteria. The ciliates survived for over six months, and the density of their population varied between 1.7 × 10(3) and 2.4 × 10(3) cells mL(-1). Favourable conditions for the prolonged cultivation of this ciliate were observed when the medium was prepared by mixing horse faeces and 'caudatum' salt solution in a 1:1 V/V ratio together with food (60% powdered meadow hay, 16% wheat gluten, 12% barley flour and 12% microcrystalline cellulose) supplied as 0.20 mg mL(-1) culture per day., (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Chabaudus dehradunensis sp. nov. (Nematoda: Seuratoidea) from the large intestine of the water skipper, Euphlyctis cyanophlyctis (Anura, Dicroglossidae), from Dehrandun, India is described and illustrated. Chabaudus dehradunensis sp. nov. is the 6th species assigned to the genus and 1st species reported from India. It is separated from its congeners based upon the number and arrangement of caudal papillae and the length of spicule. Euphlyctis cyanophlyctis is the new host record for the genus Chabaudus.

The pathogenic potential of Blastocystis sp. in experimental models requires further investigation. In this work, the pathogenicity of this parasite in the gastrointestinal tract of male Swiss mice was evaluated according to the inoculum size and period of infection. Animals were infected intragastrically, with 100, 500, 1,000, 5,000 and 10,000 Blastocystis sp. vacuolar forms obtained from a mixture of eight human isolates cultured axenically in Jones' medium. After seven, 14, 21, 28 and 60 days of infection, the animals were sacrificed and fragments of the small intestine (duodenum), large intestine, and cecum were subjected to histopathological analysis. Blastocystis sp. triggered an inflammatory response in the different tissues analyzed, with a predominance of mononuclear cells. The parasite was found in the muscular layer of the cecum, showing its invasive character. Larger inocula triggered inflammatory processes earlier (seven days) than smaller ones (from 21 days). We conclude that, in the proposed model, the pathogenicity of Blastocystis sp. isolates that were studied is related to inoculum size and period of infection.

Cosmocercoides malayensis sp. nov. (Nematoda, Cosmocercidae) from the large intestine of Gonocephalus liogaster (Squamata, Agamidae) from Peninsular Malaysia is described and illustrated. Cosmocercoides malayensis sp. nov. represents the 23rd species assigned to the genus and the 10th species from the Oriental biogeographical region. Cosmocercoides malayensis sp. nov. differs from the previously described Oriental species in number and position of rosette papillae; however, it is most similar to C. bufonis and C. rickae in that these 3 species have 6 post cloacal rosette papillae. Cosmocercoides bufonis possesses a prebulbar copular swelling, which is absent in C. malayensis; C. rickae posssesess somatic papillae, which are absent in C. malayensis. Three addtional nematode species were found, adult specimens of Meteterakis singaporensis and Orneoascaris sandoshami and larva of Physocephalus sp.

The roundworms of genus Strongylus are the common parasitic nematodes in the large intestine of equine, causing significant economic losses to the livestock industries. In spite of its importance, the genetic data and epidemiology of this parasite are not entirely understood. In the present study, the complete S. equinus mitochondrial (mt) genome was determined. The length of S. equinus mt genome DNA sequence is 14,545 bp, containing 36 genes, of which 12 code for protein, 22 for transfer RNA, and two for ribosomal RNA, but lacks atp8 gene. All 36 genes are encoded in the same direction which is consistent with all other Chromadorea nematode mtDNAs published to date. Phylogenetic analysis based on concatenated amino acid sequence data of all 12 protein-coding genes showed that there were two large branches in the Strongyloidea nematodes, and S. equinus is genetically closer to S. vulgaris than to Cylicocyclus insignis in Strongylidae. This new mt genome provides a source of genetic markers for the molecular phylogeny and population genetics of equine strongyles., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Unlabelled: Prion diseases are infectious neurodegenerative disorders characterized by accumulations of abnormally folded cellular prion protein in affected tissues. Many natural prion diseases are acquired orally, and following exposure, the early replication of some prion isolates upon follicular dendritic cells (FDC) within gut-associated lymphoid tissues (GALT) is important for the efficient spread of disease to the brain (neuroinvasion). Prion detection within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, the relative contributions of the small and large intestinal GALT to oral prion pathogenesis were unknown. To address this issue, we created mice that specifically lacked FDC-containing GALT only in the small intestine. Our data show that oral prion disease susceptibility was dramatically reduced in mice lacking small intestinal GALT. Although these mice had FDC-containing GALT throughout their large intestines, these tissues were not early sites of prion accumulation or neuroinvasion. We also determined whether pathology specifically within the large intestine might influence prion pathogenesis. Congruent infection with the nematode parasite Trichuris muris in the large intestine around the time of oral prion exposure did not affect disease pathogenesis. Together, these data demonstrate that the small intestinal GALT are the major early sites of prion accumulation and neuroinvasion after oral exposure. This has important implications for our understanding of the factors that influence the risk of infection and the preclinical diagnosis of disease., Importance: Many natural prion diseases are acquired orally. After exposure, the accumulation of some prion diseases in the gut-associated lymphoid tissues (GALT) is important for efficient spread of disease to the brain. However, the relative contributions of GALT in the small and large intestines to oral prion pathogenesis were unknown. We show that the small intestinal GALT are the essential early sites of prion accumulation. Furthermore, congruent infection with a large intestinal helminth (worm) around the time of oral prion exposure did not affect disease pathogenesis. This is important for our understanding of the factors that influence the risk of prion infection and the preclinical diagnosis of disease. The detection of prions within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, our data suggest that using these biopsy specimens may miss individuals in the early stages of oral prion infection and significantly underestimate the disease prevalence., (Copyright © 2015 Donaldson et al.)

Eggs of the pig whipworm, Trichuris suis ova (TSO), are currently tested in human clinical trials for their potential immunomodulatory capacity. The biological potency of TSO (egg viability and infectivity) is traditionally assessed in Göttingen minipigs as the establishment of intestinal larvae after inoculation with a known number of eggs. To minimize testing in animal models, development of an in vitro egg hatching assay is proposed as a reliable, cost-effective, and a faster alternative to test the egg viability. The present study aimed to investigate the influence of different chemical, physical, and biological factors on egg hatching. Thus, in a series of experiments and in different combinations, the eggs were stimulated with glass beads, artificial gastric juice, bile salt and trypsin solution, fermentation gut medium, or stimulated with mucosal scrapings from the ileum and the large intestine of the infected and uninfected Göttingen minipig. Mechanical stimulation with glass beads presented a simple and reproducible method for egg hatching. However, incubation of eggs with mucosal scrapings from the ileum, caecum, and colon for 24 h at 38 °C significantly increased hatching.

Gross and histological lesions caused by an intestinal parasite were described in three capybaras. The parasites presented a mean length of 14 mm and width of 7 mm, were round to oval or piriform, reddish and pedunculated, and adhered strongly to the mucosa of the large intestine. The intestinal mucosa at the parasite attachment site presented loss of surface epithelium and most glands, with replacement by fibrovascular proliferation that protruded from the mucosa and was involuted by the ventral sucker of the parasite. The lamina propria presented cellular debris, eosinophils, macrophages and plasma cells. The morphological characteristics, observed using serial histological sections, made it possible to classify the parasite as a trematode (Paramphistomatidae), compatible with Taxorchis schistocotyle. One capybara also harbored many ciliated protozoa in the large intestine (at the site of attachment of the parasite) and inside the caeca of the trematodes. In conclusion, this study described a multifocal necrotizing colitis associated with T. schistocotyle parasitism in capybaras.

Parapharyngodon guerreroensis n. sp. (Nematoda: Pharyngodonidae) from the large intestine of Lepidophyma smithii from Mexico is described and illustrated. A list of nominal species and a key to species from the Panamanian region are provided. Parapharyngodon guerreroensis n. sp. is the 57th species assigned to the genus and the 10th from the Panamanian region. It differs from other species in the genus in that males possess 3 pairs of caudal papillae, an anterior cloacal lip supporting 4 digitiform processes, and a blunt spicule 67-104 μm in length, while females possess long flexible caudal appendages.

Macrophages (Mφs) accumulate at sites of inflammation, and, because they can assume several functionally distinct states of activation, they can either drive or restrain inflammatory responses. Once believed to depend on the recruitment of blood monocytes, it is now clear that the accumulation of Mφs in some tissues can result from the proliferation of resident Mφs in situ. However, little is known about the proliferation and activation state of Mφ subsets in the gut during the development and resolution of intestinal inflammation. We show that inflammatory Mφs accumulate in the large intestine of mice during the local inflammatory response to infection with the gastrointestinal nematode parasite Trichuris muris. Classically activated Mφs predominate initially (as the inflammation develops) and then, following worm expulsion (as the inflammation resolves), both the resident and inflammatory populations of Mφs become alternatively activated. A small but significant increase in the proliferation of inflammatory Mφs is seen but only during the resolution phase of the inflammatory response following both worm expulsion and the peak in Mφ accumulation. In contrast to recent studies in the pleural and peritoneal cavities, the proliferation of resident and alternatively activated Mφs does not increase during the inflammatory response. Furthermore, in CCR2(-/-) mice, monocyte recruitment to the gut is impeded, and the accumulation of alternatively activated Mφs is greatly reduced. In conclusion, the recruitment of blood monocytes is the principle mechanism of Mφ accumulation in the large intestine. This study provides a novel insight into the phenotype and behavior of intestinal Mφ during infection-driven inflammation., (Copyright © 2014 The Authors.)

Toll-like receptors (TLRs) play a fundamental role in the rapid activation of innate immune responses to a variety of pathogen-associated molecular patterns (PAMPs). In a previous study we observed an increase in the level of expression of TLR2 and TLR4 mRNA in the jejunum and colon during experimental hymenolepidosis in rats. In this study, we performed a quantitative real-time polymerase chain reaction (qRT-PCR), Western blot analysis and immunohistochemical staining of TLR3 and TLR9 receptors during experimental hymenolepidosis in rats. The levels of mRNA and protein expression of TLR3 and TLR9 in the jejunum had increased at 16 days post Hymenolepis diminuta infection (dpi) in the case of TLR3 and at 16 and 25 dpi in the case of TLR9. In the colon the expression of TLR3 and TLR9 had increased at 16, 25 and 40 dpi. The results of the immunohistochemical reactions showed that H. diminuta infected rats (16, 25, 40 and 60 dpi) exhibited changes in TLR3 and TLR9 localization and intensity in the epithelial cells of the jejunum and colon. The changes in the level of TLR3 and TLR9 expression may confirm involvement of the innate immune system in the pathomechanism of hymenolepidosis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Strongylid infections are ubiquitous in grazing horse populations. Infections with cyathostomin (small strongyle) and strongylin (large strongyle) nematodes have long been associated with clinical disease in horses, but little is known about their subclinical impact. A masked, randomized, controlled study was conducted to evaluate the effects of daily administration of pyrantel tartrate on body condition scores, weight gain, fecal egg counts, and total worm counts of young horses repeatedly inoculated with strongylid larvae. Twenty eight immature horses were treated with larvicidal anthelmintic regimens and randomly allocated to two groups. Group 1 horses were given a pelleted placebo product once daily, and those in Group 2 received pyrantel tartrate once daily at ∼ 2.64 mg/kg body weight. On five days during each week, ∼ 5000 infective cyathostomin larvae were administered to each horse. In addition, horses received ∼ 25 infective Strongylus vulgaris larvae once weekly. Horses were maintained on pasture for 154 days and had ad libitum access to grass hay throughout. At approximate, 14-day intervals, body weights were measured, body condition scores were assigned, fecal samples were collected for egg counts, and blood samples were collected for measurement of S. vulgaris antibodies and various physiologic parameters. After 22 weeks at pasture and 14-17 days in confinement, horses were euthanatized and necropsied. Nematodes were recovered and counted from aliquots of organ contents, representative samples of large intestinal mucosa, and the root of the cranial mesenteric artery. Daily treatment with pyrantel tartrate at the recommended dosage significantly reduced numbers of adult cyathostomins in the gut lumen and early third-stage larvae in the cecal mucosa, increased the proportions of fourth-stage larvae in the gut contents, and was accompanied by significant improvements in body condition scores. Fecal egg counts of horses receiving daily pyrantel tartrate were significantly reduced, with percentages of efficacy ranging from 84.4% to 98.9%, but egg counts of both groups increased significantly over the course of the study. Treatment also significantly reduced the numbers of S. vulgaris larvae in the cranial mesenteric artery by 99.2%. Serum antibodies to S. vulgaris apparently persisted from pre-enrollment infections, but ELISA values gradually declined over the course of the study. This study has provided useful insights into the effects of daily pyrantel tartrate on the dynamics of cyathostomin infection, and into some subclinical effects of strongylid parasitism in horses., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Protozoan parasites of the genus Entamoeba infect many classes of vertebrates and are primarily classified based on morphological criteria. To date, only a few species have been proven to cause disease. Here, we examined the pathology of infected pigs with hemorrhage and detected Entamoeba parasites. Isolates were characterized genetically and ultrastructurally to identify the species. Histopathologically, bleeding and thrombus formation were seen only in the large intestine mucosa, where a large number of trophozoites or some Entamoeba cysts were observed around breakdowns in the lamina propria. No screw-shaped bacteria were detected in the lesions, and no pathogenic bacteria such as Brachyspira spp. were detected in fecal cultures. Interestingly, electron microscopy revealed that the parasites possessed mitochondrial organelles, unlike other Entamoeba spp. The isolates were identified as Entamoeba suis by PCR analysis and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene. In phylogenetic analyses based on the actin gene, the E. suis isolate formed a cluster with Entamoeba histolytica and Entamoeba invadens, as well as with other parasites of the Amoebidae. Whether the pathogenicity of the E. suis isolate is affected by the severity of infection or host health status remains unclear; however, our results suggest that E. suis could cause or exacerbate clinical symptoms such as hemorrhagic colitis or diarrhea.

Spauligodon bintangensis n. sp. from the intestines of Cyrtodactylus bintangrendah (Gekkonidae) from Peninsular Malaysia is described and illustrated. Spauligodon bintangensis n. sp. represents the 51st species assigned to the genus and the first species from the Oriental Region. The new species is most similar to Spauligodon atlanticus, Spauligodon eremiasi, and Spauligodon occidentalis, but is easily separated by position of vulva, prebulbar in S. atlanticus and S. occidentalis , postbulbar in the new species, and location of lateral alae; in S. eremiasi, the lateral alae occur only in the fourth quarter of the body, whereas in the new species the lateral alae begin just posterior to lips.

Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Skrjabin and Schikobalova, 1947, are widely distributed in the Americas. The family Aspidoderidae includes the subfamilies Aspidoderinae Skrjabin and Schikobalova, 1947, and Lauroiinae Skrjabin and Schikobalova, 1951. These two subfamilies are delineated by the presence or absence of cephalic cordons at the anterior region. The nematodes in the subfamily Aspidoderinae, which includes the genus AspidoderaRailliet and Henry, 1912, are represented by nematodes with anterior cephalic cordons at the anterior end. The nematodes of the genus AspidoderaRailliet and Henry, 1912, are found in the cecum and large intestine of mammals of the orders Edentata, Marsupialia and Rodentia. Species within this genus have many morphological similarities. The use of scanning electron microscopy allows the specific characterization of the species within this genus. In the present work, we describe a new species of Aspidodera parasite of the large intestine of Didelphis aurita (Mammalia: Didelphidae) Wied-Neuwied, 1826, collected from Cachoeiras de Macacu, Rio de Janeiro. The combination of light and scanning electron microscopy allowed us a detailed analysis of this nematode., (Copyright © 2013. Published by Elsevier B.V.)

Blastocystis hominis (B. hominis) is a cosmopolitan pro- tozoa which parasitizes the human large intestine. This parasite had been considered to be commensal of the large intestine for a long time, because even an intense invasion may be asymptomatic. However, this species is now being regarded as a parasitic organism. In this paper the latest data concerning the epidemiology, diagnostics and treatment of B. hominis invasion have been cited and discussed.

Strongyluris dracocola n. sp. from the intestine of Lophognathus temporalis collected in Papua New Guinea is described and illustrated. Strongyluris dracocola n. sp. represents the 32nd species assigned to the genus and the sixth from the Australo-Papuan region. It can be easily separated from the other Australo-Papuan species because it is the only species to have an unpaired median papilla adjacent to the sucker.

Toll-like receptors in the gastrointestinal tract can influence intestinal homeostasis and play a role in the repair and restitution of intestinal epithelium following tissue damage. In our previous study a statistically significant increase in the level of TLR4 and TLR2 gene expression was observed in rats in early stages of hymenolepidosis. Moreover, the immunopositive cell number and the intensity of immunohistochemical staining (indicating the presence of TLRs within intestinal epithelial cells) increased over the infection period. In this paper, we determined changes in the expression of TLR2 and TLR4 and the number of anaerobic intestinal commensal bacteria in Hymenolepis diminuta infected rats. In the isolated jejunum of infected rats at 16 days post infection (dpi), the expression of TLR4 and TLR2 was significantly higher than uninfected rats. In the colon, a statistically significantly increased expression of TLR2 was observed from 16 to 40 dpi, and TLR4 from 16 to 60 dpi. The jejunum and colon of infected rats contained Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Enterococcus, Streptococcus, Staphylococcus, Bacillus, Lactobacillus) and Candida. The total number of intestinal bacteria was higher in H. diminuta infected rats, but the observed microbiota had only minor effects on the expression of TLR2 and TLR4. Toll-like receptors play a role in maintaining epithelial barrier function in response to enteric pathogens and parasites. In our study, the alteration of TLR2 and TLR4 expression in the infected rats indicates the potential role of the innate immune system in the pathomechanism of this infection., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Tropidurus oreadicus Rodrigues 1987 is a recently described species, thus there are no reports of helminthes parasites for this species. In this study, a morphological characterisation was performed of a nematode species parasite of the large intestine of T. oreadicus captured in an urban area. This urban area is similar to the estuarine dale from Guamá river and the "igarapés" of Belém, Pará State, Brazil. Morphological analysis suggested that the parasite is a new species of nematode, based mainly on the number and distribution pattern of the caudal papillae in males, which is unique for this species. In the present work, we describe for the first time the structure, number, and disposition of the cervical papillae. The morphological data were supported by scanning electron microscopy, which served as an important tool for distinguishing these nematodes from other species of the genus., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The aim of this study was to evaluate differences between the small and large intestines (SI and LI) with regard to colonization and immunity during infection with Trichinella spiralis. In orally infected C57BL/6 mice, the gender ratios of worms differed among the SI, cecum, and LI. Mucosal mastocytosis developed in the SI but not in the LI, consistent with reduced IL-9 and IL-13 production by explants from the LI. Despite these differences, worms were cleared at the same rate from both sites. Furthermore, IL-10 production was reduced in the LI, yet it was instrumental in limiting local inflammation. Finally, passive immunization of rat pups with tyvelose-specific antibodies effectively cleared fist-stage larvae from all intestinal regions. We conclude that despite regional differences in immune responsiveness and colonization, immune mechanisms that clear T. spiralis operate effectively throughout the intestinal tract., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The migration of lymphocytes to the small intestine is controlled by expression of the integrin α4β7 and the chemokine receptor CCR9. However, the molecules that specifically regulate migration to the large intestine remain unclear. Immunity to infection with the large intestinal helminth parasite Trichuris muris is dependent upon CD4(+) T cells that migrate to the large intestine. We examine the role of specific chemokine receptors, adhesion molecules and glycosyltransferases in the development of protective immunity to Trichuris. Mice deficient in expression of the chemokine receptors CCR2 or CCR6 were resistant to infection with Trichuris. Similarly, loss of CD34, CD43, CD44 or PSGL-1 had no effect on resistance to infection. In contrast, simultaneous deletion of the Core2 β1,6-N-acetylglucosaminyltransferase (C2GnT) enzymes C2GnT1 and C2Gnt2 resulted in delayed expulsion of worms. These results suggest that C2GnT-dependent modifications may play a role in migration of protective immune cells to the large intestine.

Postmortem parasitic examinations of the large intestines of 725 slaughtered horses from individual farmers in southeastern Poland were carried out. The examinations were carried out monthly since February 2006 until January 2007 (except for August 2007 because of a technological stoppage in the slaughterhouse). The examinations included the intensiveness and extensiveness of the infestation of the Strongylidae belonging to the Strongylus genus. The Strongylidae were found in 26.5% of the examined horses. Strongylus vulgaris was the most dominant nematode and had a 22.8% prevalence, Strongylus edentatus was carried by 18.3% of the horses. Strongylus equinus was identified only in 1.7% of the examined horses. Our findings revealed that combined infestation of S. vulgaris and S. edentatus occurred in 100 (52.1%) of the 725 horses infected by the Strongylidae. The present results indicate that the lowest prevalence of strongyle species except for S. equinus was found in January, February, and March. However, it is difficult to draw a conclusion because of an extremely low extensiveness of infestation. The results indicate that the prevalence of the Strongylidae in horses from southeastern Poland is limited.

Spauligodon bonairensis n. sp. from the large intestines of the Antilles gecko, Gonatodes antillensis (Lacertidae), from Bonaire, Lesser Antilles, is described and illustrated. The new species is the 48th assigned to the genus and the 10th from the Neotropical region. Spauligodon bonairensis n. sp. is most similar to S. giganticus, S. hemidactylus, S. lamonthei, and S. oxkutzcabiensis in that only these 5 species possess lanceolate eggs. For males of these species, only S. lamothei possess a spicule, and only S. oxktzcabiensis has an aspinose tail. The egg of S. hemidactylus has 2 knobs; in S. giganticus, the more rounded end supports the single knob. In S. bonairensis n. sp., the more pointed end supports the single knob.

Objective: The aim of this study was to determine the cytological features of 2 endocommensal ciliates, P. colpoidea and P. minuta belonging to genus Paraisotricha found in the hindgut of 15 Turk rahvan and 15 English and Arabic horses from Izmir, compare the morphological characters of species with their original descriptions and previous reports and discuss the similarities and differences., Methods: The cytological features of two endocommensal ciliates were investigated with the pyridinated silver carbonate impregnation and silver nitrate impregnation techniques at the level of light microscopy., Results: Specimens from our horses were found to be similar to the original descriptions on the basis of cytological features, morphological characters and biometric data., Conclusion: We have concluded that the geographical variation and feeding habits of the host animals are important for evaluating the biometric data of species.

The present study was conducted on 31 males and females of the European bison, eliminated during the winter seasons 2007-2011 in the Białowieza Primeval Forest, Poland. The caeca of 14 free-ranging bison, aged from 3 months up to 16 years, the most favorable infection site for the large intestine nematodes, were investigated during the winter of 2007/2008. The parasitological autopsies of the large intestines of 9 free-ranging bison aged from 5 months up to 10 years as well as 9 bison kept in the close reserves aged from one up to 20 years were done during the winter seasons of 2008-2011 to determine localization of nematodes in large intestine and the total intensity of parasite infection. Five species of nematodes (i.e., Trichuris ovis, Oesophagostomum venulosum, O. radiatum, Ashworthius sidemi, Nematodirus helvetianus) were found in dissected caecum of bison culled during the winter of 2007/2008. During the seasons of 2008-2010, 6 species of nematodes were found in the large intestine of bison (i.e., T. ovis, O. venulosum, O. radiatum, A. sidemi, N. roscidus and Bunostomum trigonocephalum). We did not find any nematodes in the lumen of the large intestine of captive bison culled during the seasons of 2010/2011. The results of the present study indicate that the intensity of infection by the large intestine nematodes of the European bison in the Białowieza Primeval Forest has stayed at the comparable level throughout the last 20 years; however the number of nematode species has increased. The observed level of parasitic infection is typical of subclinical parasitoses.

Background: Mouse angiogenin 4 (Ang4) has previously been described as a Paneth cell-derived antimicrobial peptide important in epithelial host defence in the small intestine. However, a source for Ang4 in the large intestine, which is devoid of Paneth cells, has not been defined., Methodology/principal Findings: Analysis was performed on Ang4 expression in colonic tissue by qPCR and immunohistochemistry following infection with the large intestine dwelling helminth parasite Trichuris muris. This demonstrated an increase in expression of the peptide following infection of resistant BALB/c mice. Further, histological analysis of colonic tissue revealed the cellular source of this Ang4 to be goblet cells. To elucidate the mechanism of Ang4 expression immunohistochemistry and qPCR for Ang4 was performed on colonic tissue from T. muris infected mouse mutants. Experiments comparing C3H/HeN and C3H/HeJ mice, which have a natural inactivating mutation of TLR4, revealed that Ang4 expression is TLR4 independent. Subsequent experiments with IL-13 and IL-4 receptor alpha deficient mice demonstrated that goblet cell expression of Ang4 is controlled either directly or indirectly by IL-13., Conclusions: The cellular source of mouse Ang4 in the colon following T. muris infection is the goblet cell and expression is under the control of IL-13.

Aplectana novaeguineae n. sp. (Ascaridida, Cosmocercidae) from the intestines of Sphenomorphus pratti (Squamata: Scincidae) is described and illustrated. Aplectana novaeguineae n. sp. represents the 48th species assigned to the genus and the 5th species of the genus reported from the Australo-Papuan region. It is most similar to Aplectana leesi, Aplectana linstowi , and Aplectana krausi in that females of only these 4 species exhibit a swollen anterior vulvar lip. These 4 species may be separated by spicule length and caudal papillae arrangement. Spicules of A. linstowi and A. krausi are less than 200 µm in length, A. leesi between 200 and 250 µm, and A novaeguineae greater than 400 µm. Aplectana linstowi possesses 18 post cloacal papillae, A. leesi and A. krausi each possess 10, and A. novaeguineae possesses 8. In addition, Paraleptonema ranae has been assigned to Aplectana as Aplectana fujianae nom. nov.

Entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. Understanding the genome and evolution of the parasite will help explain how, when and why it causes disease. Here we review current knowledge about the evolutionary genomics of Entamoeba: how differences between the genomes of different species may help explain different phenotypes, and how variation among E. histolytica parasites reveals patterns of population structure. The imminent expansion of the amount genome data will greatly improve our knowledge of the genus and of pathogenic species within it., (Copyright © 2011 Institut Pasteur. Published by Elsevier SAS. All rights reserved.)

Three species of cyathostomes--Cylicocyclus ashworthi, Cylicostephanus bidentatus, and Cylicostephanus hybridus were identified recently in horses in Kentucky. General characteristics and distinguishing description of these species are presented. Distribution of these species and their role in the horse strongylid community are discussed. The importance of examining the entire contents of the large intestine or alternatively a high number of specimens in order to recover and identify species residing in low numbers is stressed.

Parapharyngodon bainae n. sp. (Nematoda:Pharyngodonidae) collected from the small intestine of Tropidurus torquatus (Squamata:Tropiduridae) is described. The new species is the 47 th species in the genus and the 14 th in the Neotropical region. The morphology of male posterior end, ovary position in females, and egg size can be used to differentiate P. bainae from the other congeneric species. Parapharyngodon rotundatus , Parapharyngodon sanisfaciecaudus , and Parapharyngodon riojensis are most closely related to P. bainae. In males of P. sanisfaciecaudus and P. rotundatus , the cloacal lip has a smooth appearance, whereas in P. bainae , males have an echinate cloacal lip. Parapharyngodon riojensis differs from P. bainae because its females have postbulbar ovaries, the eggs are larger, and the esophagi are larger in both sexes. Parapharyngodon spp. nematodes occupy an intermediate phylogenetic position among pharyngodonid parasite lineages in carnivorous and herbivorous reptiles. The average low intensity of infection for P. bainae (4.8 ± 4.6) is typically found in carnivorous reptiles. This fact and the high prevalence value (60%) can be explained by the ingestion of environmental substrata material containing parasite eggs while foraging.