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The endoparasite fauna of the eastern rock sengi ( Elephantulus myurus Thomas and Schwann) was studied for the first time for any sengi species from September 2007 until August 2008 in the Limpopo Province of South Africa. From the 121 sengis examined, we recovered 11 endoparasite taxa, including 9 nematodes, 1 cestode family (Hymenolepididae), and 1 pentastomid species (Armillifer armillatus (Wyman, 1834)). The overall endoparasite prevalence was high, at 100%, and largely attributable to the nematode Maupasina weissi Seurat, 1913 , with only a single individual being parasite free. Despite the high diversity, species richness was low (1.58 ± 0.06) and only M. weissi and spiruroid larvae occurred at a prevalence exceeding 8%. The abundance of M. weissi varied significantly between seasons and was lowest in summer and autumn. In contrast, the abundance of spiruroid larvae remained relatively constant across seasons in males, but was significantly higher in spring and summer compared to winter in females. These patterns may be generated by an accumulation of M. weissi with age as well as sex-specific seasonal shifts in diet. An updated list on the hosts and geographic range of parasites of sengis is provided.

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

The present study used experimental infections to compare the life cycles and life histories of 6 Rhabdias spp. infecting snakes and anurans. Free-living development of anuran lungworms was primarily limited to heterogonic reproduction, and females utilized matricidal endotoky exclusively, whereas snake lungworms primarily reproduced homogonically and, when heterogonic reproduction occurred, females used a combination of releasing eggs and matricidal endotoky. Infective snake lungworms survived for longer periods in fresh water compared to anuran worms. Infective anuran lungworms penetrated into the skin of frogs and toads; few infections resulted from per os infections. In contrast, snake lungworms were unable to penetrate skin; instead, infective juveniles penetrated into snake esophageal tissue during per os infections. Despite separate points of entry, anuran and snake lungworms both migrated and developed in the fascia, eventually penetrating into the body cavity of the host. Worms molted to adulthood inside the body cavity and subsequently penetrated into the host's lungs, where they fed on blood while becoming gravid. Adult lungworm survival varied among lungworm species, but, in general, snake lungworms were longer lived than anuran worms. Anuran lungworms were poorly suited for transmission via transport hosts, whereas snake lungworms were consistently capable of establishing infections using transport hosts. Overall, these observations suggest that snake and anuran lungworms have discrepant life cycles and life history strategies.

Cryptosporidium parvum is a leading pathogen in children in developing countries. To investigate whether early postnatal malnutrition leads to heavier C. parvum infections, we assessed intestinal adaptation and parasite load in suckling mice during the first 2 wk of life, analogous to the first postnatal yr in humans. Undernutrition was induced by daily C57BL6J pup separation from lactating dams. Half of the pups were separated daily, for 4 hr on day 4, 8 hr on day 5, and for 12 hr from day 6 until day 14. On day 6, each pup received an oral inoculum of 10(5) to 10(7) parasites in 10-25 microl of PBS. Littermate controls received PBS alone. Stools were assessed from days 8, 11, and 14 for oocyst counts. Mice were killed on day 14, 8 days postinoculation, at the peak of the infection. Ileal and colon segments were obtained for histology, real-time and reverse transcriptase PCR, and immunoassays. Villus and crypt lengths and cross-sectional areas were also measured. Undernourished and nourished mice infected with excysted 10(6) or 10(7) oocysts exhibited the poorest growth outcomes compared with their uninfected controls. Nourished 10(6)-infected mice had comparable weight decrements to uninfected undernourished mice. Body weight and villi were additively affected by malnutrition and cryptosporidiosis. Hyperplastic crypts and heavier inflammatory responses were found in the ilea of infected malnourished mice. Undernourished infected mice exhibited greater oocyst shedding, TNF-alpha and IFN-gamma intestinal levels, and mRNA expression compared to nourished mice infected with either 10(5) or 10(6) oocysts. Taken together, these findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.

Tetraphyllidean plerocercoids have occasionally been reported in marine mammals, but they have rarely been described in detail, and the ecological significance of these infections is unclear. We described plerocercoids collected from the mucosa of the terminal colon and rectum, the anal crypts, and the hepatopancreatic ducts of 7 striped dolphins Stenella coeruleoalba, 1 Cuvier's beaked whale Ziphius cavirostris, and 3 Risso's dolphins Grampus griseus from the Spanish Mediterranean. We also examined undescribed plerocercoids from 3 cetacean species from the Atlantic and the Pacific. All plerocercoids had a lanceolate body, and a scolex with an apical sucker and 4 sessile monolocular bothridia. The bothridia had free posterior edges and an accessory sucker at their anterior end. Under light microscopy, the bothridia of some Mediterranean specimens looked bilocular without accessory suckers, but a true accessory sucker was observed in histological sections. A principal component analysis revealed 2 stable clusters of specimens along the first principal component regardless of host species. These "large" and "small" morphotypes are thought to represent early migratory stages of Phyllobothrium delphini and Monorygma grimaldii. The similarity in scolex morphology, the observation of plerocercoids buried in intestinal regions close to the sites where M. grimaldii and P. delphini occur, and the coexistence of all larval forms in the same individual hosts would support this hypothesis. Future molecular analysis may confirm it.

Between January and March 2001, eight 4- to 8-wk-old camels (Camelus dromedarius) from 2 farms from Dubai area of the United Arab Emirates were submitted for necropsy examination. The camels had diarrhea of 2-5 days duration. Grossly, a severe diphtheroid-to-hemorrhagic colitis was seen in all animals. Gamonts, unsporulated oocysts, sporulating oocysts, and fully sporulated oocysts were present in the intestinal epithelium and the lamina propria. Fully sporulated oocysts contained 2 sporocysts and 4 sporozoites in each sporocyst. Oocysts from fecal samples resembled oocysts of Isospora orlovi. This is the first report of an isosporan parasite associated with hemorrhagic enteritis in the large intestine of any animal.

Atractis marquezi n. sp. from the large intestine of the tortoise Geochelone nigrita is described and illustrated. Atractis Dujardin, 1845, sensu Baker, 1987, is revised to contain only those atractids having a lagonoid spicule. The remaining species of Atractis sensu Baker, 1987, are assigned to Cyrtosomum, Pseudatractis, and Klossinemella. A. marquezi represents the 12th species to be assigned to this genus and is distinguished from other Neotropical species by the distribution pattern of caudal papillae of the male: 2 pairs precloacal, 2 pairs adcloacal, and 6 pairs postcloacal.

The mechanisms of epithelial injury in giardiasis remain unknown. The effects of live Giardia lamblia on cellular G-actin, F-actin, alpha-actinin, and electrical resistance of human intestinal epithelial monolayers were investigated using SCBN and Caco2 cell lines grown on chamber slides or Transwell filter membranes. In separate experiments, some monolayers were also exposed to sonicated trophozoites, some to supernatant from live G. lamblia cultures, and some with or without the Ca2+ channel blocker verapamil. After 2, 24, or 48 hr of coincubation with G. lamblia, monolayers were assessed for cytoskeletal arrangement under fluorescence and confocal laser microscopy, and transepithelial electrical resistance was measured. Exposure to live G. lamblia trophozoites induced localized condensation of F-actin and loss of perijunctional alpha-actinin while G-actin remained unchanged. Confocal laser microscopy indicated that F-actin rearrangement was not affected by verapamil and was localized within the terminal web area. Coincubation of monolayers with G. lamblia lysates or with spent medium alone similarly rearranged F-actin. Verapamil alone did not alter F-actin. Electrical resistance of SCBN and Caco2 monolayers exposed to G. lamblia was significantly decreased versus controls regardless of whether live or lysed trophozoite samples were used. The results indicate that G. lamblia-induced epithelial injury is associated with F-actin and alpha-actinin rearrangements in the terminal web area via mechanisms independent of extracellular Ca2+. These alterations are associated with reduced transepithelial electrical resistance and are due at least in part to trophozoite products.

Seven donkeys (Equus asinus) from North-West and Mpumalanga Provinces in South Africa were examined at necropsy. Quantitative samples were collected from the gastrointestinal tract for recovery of helminth parasites from the stomach, small intestine, cecum, ventral colon, dorsal colon, descending colon, and cranial mesenteric artery. Fifteen genera and 29 species of helminths were identified comprising 27 species of nematodes in the Ascarididae, Atractidae, Habronematidae, Onchocercidae, Oxyuridae, and Strongylidae; 1 species of cestode in the Anoplocephalidae; and 1 species of trematode in the Paramphistomatidae. In addition, 2 species of oestrid fly larvae in the Gastrophiliidae were identified. The most abundant group in number of species was the cyathostomes (small strongyles) and, of these, Cyathostomum montgomeryi, Cylicocyclus sp. (a), and Cylicostephanus minutus were the most numerous. The most prevalent cyathostomes were C. montgomeryi and Cylicocyclus sp. n. (a). Strongylus vulgaris was the most abundant and prevalent large strongyle species. The occurrence of small strongyle species and their prevalences in this study are compared with 3 other studies on donkeys in Africa.

Tritrichomonas foetus is an obligate parasite of the bovine urogenital tract producing infection associated with inflammatory changes, abortion, and infertility, Tritrichomonas mobilensis was isolated from squirrel monkey colon, and symptoms involve diarrheal complications. Both tritrichomonads produced hemagglutinins with the properties of sialic acid-specific lectins. Assays on the adherence of these protozoans to Chinese hamster ovary (CHO) cells and to bovine cervical and monkey colon mucus were performed to assess the function of the lectins in adhesion. Sialic acid at concentration as low as 2 mM inhibited the adhesion to CHO cells, less effectively to the mucus. Predigestion with Clostridium perfringens sialidase prevented the adhesion to both epithelial cells and the mucus. Inhibition of endogenous sialidases with 2,3-dehydro-2-deoxy-NeuAc increased the adhesion of T. mobilensis to CHO cells. Specific anti-T. foetus lectin (TFL) and anti-T. mobilensis lectin (TML) antibodies inhibited adhesion of the trichomonads to the epithelial cells and to the mucus. TFL histochemistry disclosed the presence of lectin ligands on keratinized vaginal epithelia, cervical mucosa, and mucin and on endometrial glands and their secretions. TML histochemistry showed reactivity with the luminal membranes of colonic glandular epithelium and less with the colonic mucin. Both lectins bound to the surface membrane of CHO cells. Anti-lectin antibodies showed granular cytoplasmic and strong membrane localization of the lectins in both tritrichomonads. Although the 2 tritrichomonads have different habitats, the results indicate that both these protozoa use lectins with sialic acid specificity for adhesion to mucosal surfaces.

In the present study, we investigated the site in the host where protective gut immunity to Fasciola hepatica is induced and expressed, following the infection route of the parasite. Expression of protection was studied in ex vivo gut segments with intact blood and lymph supply that were prepared at different locations along the entire length of the small and large intestine. Four weeks after oral infection, significant protection was detected in the duodenum, upper jejunum, midjejunum, and ileum. Protection at the gut level was expressed as early as 2 wk after oral priming and waned after 27 wk. The possibility that the gut wall plays a role in age-related protection was excluded. The effect of newly excysted juveniles (NEJ) penetrating the gut on the induction of protection was studied by recovering or killing the NEJs of the primary infection immediately after gut migration. Results showed that protection was low (13.9-19.8%). However, when gut migration was by-passed and NEJs of the primary infection were injected into the peritoneal cavity or between the liver lobes, high levels of protection at the gut level were detected (76.5-87.4%). The results indicate that protection expressed at the gut level is induced by the parasite at a young stage, during migration through the peritoneal cavity, or liver, or both and not during penetration of the gut.

Fatal intestinal cryptosporidiosis of unknown source and unexplained epizootiology is reported in a neonatal captive African hedgehog (Ateletrinx albiventris) and for the first time in a hedgehog species. The infection, confined to ileum, jejunum, and colon, was extremely severe in the lower jejunum where over 75% of the epithelial cells harbored the pathogen. The ileum and the jejunum displayed moderate and severe villus atrophy and mucosal hyperplasia. Lamina propria and mucosa were infiltrated by eosinophils, lymphocytes, and macrophages. Developmental stages of Cryptosporidium sp. produced a positive reaction with immunofluorescent antibody for detection of the human pathogen, Cryptosporidium parvum. Personnel of captive centers with hedgehogs should be alerted and undertake appropriate precautions to prevent zoonotic transmission. Commercially offered hedgehog-pets may pose a risk for Cryptosporidium infection for human immunodeficiency virus-infected people.

The endogenous development and prepatent and patent periods of Eimeria ninakohlyakimovae were studied in 43 1-3-wk-old coccidia-free kids inoculated with 5.0 x 10(4), 1.5 x 10(5), 2.0 x 10(5), or 9.0 x 10(5) sporulated oocysts/kg. Twenty-five kids were killed at 24- or 48-hr intervals, 2-18 days after inoculation (DAI). Two generations of meronts, gamonts, gametes, and oocysts were found in sections stained with hematoxylin and eosin and examined using under light microscopy. The first generation of meronts developed in the endothelium of the lacteals, in the lamina propria, and in the lymphatic vessels of the ileum submucosa. Mature, first-generation meronts, 165.5 x 123.6 microm, were first found 10 DAI. Second-generation merogony developed in the crypt epithelial cells of the cecum and colon; mature meronts, 16.8 x 11.6 microm, were first seen 12 DAI. Gametogenesis occurred in the cecum and colon epithelium; mature microgamonts (16.1 x 13.0 microm), microgametes, macrogametes (14.7 x 12.5 microm), and oocysts (18.3 x 13.3 microm) were seen at 13 DAI. The course of the infection was followed in 18 kids examined every day until 24 DAI. The prepatent period was 14.7 (13-17) days and the patent period 6.8 (4-10) days. The sporulation time at 30 C, with constant aeration, was 2-3 days.

During the course of carrying out studies on the role of intestinal immunity in blocking the migration of larval Ascaris suum in the pig, it was discovered that the prevailing understanding of larval penetration sites was at variance with our observations. Therefore, a detailed investigation of the migration of A. suum 1.2 larvae through the intestine was initiated. The results demonstrate that the 1.2 larvae invade almost exclusively the wall of the pig cecum and colon and not the small intestine as is generally believed. The larvae were recovered from the mucosa of the cecum and colon as early as 3 hr postinoculation (PI) with infective eggs and were recovered from the liver by 6 hr PI. The maximal recovery of larvae (total larvae and larval/g of mucosa) from the intestinal mucosa occurred between 6 and 12 hr PI; by 24 hr PI, virtually all of the larvae had disappeared from the mucosa. These observations correct a common misunderstanding of this aspect of the life cycle of A. suum in the pig, and they raise 2 issues related to the biology and pathogenesis of Ascaris in humans. What is the actual migratory and development behavior of Ascaris lumbricoides and A. suum in humans and the potential risk for liver lesions? Most authors, in describing the life cycle of A. lumbricoides, either ignore or discount a possible obligatory liver stage of development, and, consequently, the potential for lesion formation similar to that which occurs in pigs infected with A. suum. This issue takes on added importance with the growing evidence that A. suum is an important zoonoses.

In the course of a comprehensive study on the population biology of Ascaris suum, it became necessary to determine quantitatively the migration of the larvae (L2) through the pig intestine. Because no satisfactory methods for recovering these larvae from the intestinal mucosa were apparently available in the literature, we undertook the development of such a procedure. Direct Baermannization of the intestine proved inadequate, so a series of studies was undertaken to find a method to solubilize the mucosa and free the larvae. Both pepsin digestion and mucus reduction with N-acetyl cysteine were evaluated. The highest recovery rates were obtained with short-term pepsin digestion (45-90 min), followed by a specific settling and washing procedure. A third alternative, migration of larvae out of agar-gel, was also tested. Although the recovery efficiency was low (10% of pepsin digestion), the larvae recovered were clean, with good motility. The agar-gel procedure could be useful when L2 larvae are needed for other purposes, such as antigen preparation or cultivation.

Experimental primary and challenge Schistosoma bovis infections were studied in West African Dwarf goats, using clinicopathological and parasitological parameters. The experiment included 44 goats divided into 4 groups of which group A received primary infection, group B received primary and challenge infection, group C received a challenge control infection, and group D included noninfected controls. Primary infection (wk 0) and challenge infection (wk 16) both comprised exposure to 1,000 cercariae per goat, and necropsies took place 16, 22 and 32 wk following primary infection. Clinicopathological effects were moderate in all infected groups. Egg excretion became gradually reduced following peak levels during early primary infection, and egg excretion increased only marginally following challenge infection in the primary- and challenge-infection group. Similarly, challenge infection of primary-infected goats did not result in an increase in tissue egg counts. Worm recovery and tissue egg counts in primary-infected goats remained comparable throughout the experiment, and although evidence was obtained for a delay in maturation, challenge worm establishment was comparable with challenge-control worm establishment. An anti-fecundity effect is thus an essential component of the regulatory response to both primary and challenge S. bovis infection in the goats. However, it was also shown that the intrauterine egg count is an unreliable parameter for fecundity assessments.

The nematode Heterakis spumosa lives and develops in the upper colon of mice. The colon mucosa contains soluble factors that significantly increase release of eggs by female H. spumosa in vitro. Egg release is stimulated more when colon factors are prepared from mice harboring adult H. spumosa. Also, soluble factors stimulating egg release can be prepared from homogenates of H. spumosa but are not contained in H. spumosa-conditioned medium. Moreover, soluble factors from the small intestine of mice infected with Heligmosomoides polygyrus also stimulate egg release by H. spumosa females in vitro to about the same extent as soluble factors from the colon of H. spumosa-infected mice. Our data suggest that colon factors are involved in the regulation of egg deposition of H. spumosa, the efficiency of these factors is increased by intestinal inflammation, and that these factors are accumulated by H. spumosa worms.

Lasiorhinus krefftii, the northern hairy-nosed wombat, is a rare and endangered marsupial existing as a single population in the Epping Forest National Park, Queensland, Australia. Dissection of a juvenile wombat that had died from natural causes revealed the presence in the colon of a new species of Oesophagostomoides Schwartz, 1928, a genus found only in wombats (Vombatidae, Marsupialia). Oesophagostomoides eppingensis n. sp. differs from the other species in the genus in the length of spicule, form of the dorsal ray, length of the vagina, and proportions of the female's posterior end. Morphological similarities between species suggest that there may have been switching of the species of Oesophagostomoides between L. krefftii and Vombatus ursinus (the common wombat). The potential contribution of colon parasites to the energy budget of wombats may be of importance when determining conservation management strategies for L. krefftii.

The distribution of Giardia lamblia (WB strain) trophozoites, encysting trophozoites (i.e., trophozoites bearing encystation-specific vesicles [ESV]) and cysts in the intestines of gerbils was examined over a period of 30 days. Trophozoites and encysting trophozoites were found in 3 equal length sections of the small intestine and in much lower numbers in the colon. Cysts were consistently found only in the second and third sections of the small intestine and in the colon. In a comparative encystation study in vitro, 4 populations of WB strain trophozoites were used: WB (uncloned), D1 (a recent clone of WB), WB-C6 (a 1983 clone of WB), and V1 (a recent subclone of WB-C6). The WB-C6 and V1 populations produced significantly higher numbers of encysting trophozoites and cysts in vitro than did the WB and D1 populations. In addition, WB-C6 and V1 produced significantly more water-resistant cysts in vitro than WB and D1. However, there was no difference in fecal cyst excretion in gerbils infected with the 4 populations of WB-derived trophozoites. One cycle of encystation/excystation in gerbils increased the in vitro encystation of WB and D1 populations but decreased in vitro encystation of C6 and V1. We could detect no difference in protein profiles or isoenzyme patterns between these 4 populations of cells before or after passage in gerbils.(ABSTRACT TRUNCATED AT 250 WORDS)

Oocysts of Eimeria stigmosa isolated from a wild juvenile lesser snow goose (Anser caerulescens caerulescens) were used in experimental infections of laboratory-reared geese. The structure of oocysts is described; a peculiar bumpy surface and a calyx-like thickening around the micropyle are illustrated by scanning electron microscopy. Experimentally infected geese had reduced feed intake and passed blood in their feces. Six days post-inoculation (p.i.) oocysts were passed for about 24 hr. Oocyst production was not increased in dexamethasone-treated geese. Complete sporulation of oocysts occurred after about 3.5 days. Developmental stages in lesser snow geese were occasionally present throughout the intestine, but were concentrated at Meckel's diverticulum, and at foci in the ileum and colon. Meronts were found 2, 3 and 4 days p.i. and gamonts and developing oocysts were observed 4, 5 and 5.5 days p.i. All endogenous stages of E. stigmosa were present in the nucleoplasm of enterocytes, primarily at the apical half of villi. Nuclear hypertrophy occurred in infected cells and nuclei containing gamonts were enlarged up to 4 times their normal size. Mild lesions were observed in the intestine of infected geese. Patent infections were established in lesser snow, Canada (Branta canadensis) and domestic (Anser anser domesticus) geese, but oocysts were not passed by inoculated ducks.

The endogenous development of Isospora suis Biester 1934 is described in piglets inoculated with 150,000 or 200,000 sporulated oocysts. Endogenous stages developed within villous epithelial cells throughout the small intestine. Two distinct types of meronts were seen in tissue sections. Type I meronts, which were seen at 3 days postinoculation, were binucleate, elongate, and 10.5 by 4.7 micron. They produced two to 14 Type I merozoites per parasitophorous vacuole. Type I merozoites were 10.0 by 3.6 micron. They produced two to 14 Type I merozoites per parasitophorous vacuole. Type I merozoites were 10.0 by 3.6 micron. Type II meronts, which were seen at 4 days postinoculation, were elongate and contained three to 12 nuclei. Type II meronts were 11.4 by 5.3 micron, and one to four were found per parasitophorous vacuole. Type II merozoites were 6.3 by 2.1 micron, and three to 16 were found per parasitophorous vacuole. The peak of asexual development occurred 4 days postinoculation. Fully developed microgamonts, macrogamonts, and oocysts were seen 5 days postinoculation. The prepatent period was 5 days, and the patent period was 5 to 8 days. No extraintestinal stages were seen.