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 10⁵ to 10⁷ parasites in 10–25 μl 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 10⁶ or 10⁷ oocysts exhibited the poorest growth outcomes compared with their uninfected controls. Nourished 10⁶-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-α and IFN-γ intestinal levels, and mRNA expression compared to nourished mice infected with either 10⁵ or 10⁶ oocysts. Taken together, these findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.

The distribution of cercariae was studied in 18-cm-sized cuvettes under different lighting conditions, in Plexiglas cylinders (80 cm high) vertically placed in a pond, and when swimming freely in a pond. The vertical distribution and the effect of light intensity on it were relatively similar in the cuvettes, in the cylinders, and in the pond. Each of the species (Schistosoma mansoni, Diplostomum spathaceum, Echinostoma caproni, and Pseudechinoparyphium echinatum) showed its individual distribution within the water column, with distinct changes during the time after shedding. We hypothesize that the species-specific distributions in the water reflect behavioral adaptations to increase the chances of encountering the host spectra.

The cyamids collected from a True's beaked whale (Mesoplodon mirus), a common dolphin (Delphinus delphis), and a harbour porpoise (Phocoena phocoena) stranded in Galicia (NW Spain) were identified as Isocyamus deltobranchium, extending the range of this species to the Atlantic Ocean. The 3 cetacean species examined are new hosts for this parasite. The microscopic examination of female specimens reveals that certain important taxonomic characters may be present or absent depending on the maturation stage, a taxonomic feature that should be considered in future studies describing cyamid species.

A new feather mite species, Ingrassia eudyptula n. sp. (Xolalgidae: Ingrassiinae), is described from the blue penguin Eudyptula minor (J. B. Forster, 1781) in Australia. This is the first description of a feather mite species from representatives of the avian order Sphenisciformes, which had previously been considered free from feather mites due to their strongly modified plumage and highly aquatic lifestyle. We suggest that, most probably, this mite species or its ancestor moved onto penguins from a shearwater species (Procellariiformes: Procellariidae) via shared nesting burrows in seabird colonies. In support of this argument, we illustrate similarities between I. eudyptula n. sp. and the closely related I. dubinini Černy, 1967 from shearwaters (Puffinus spp.).

To determine effects of the sera on cell proliferation, schistosomula of Schistosoma mansoni (20-days-old) were incubated in medium containing fetal calf serum plus hamster (highly susceptible host) portal or peripheral venous serum, or rat (poorly susceptible host) portal or peripheral venous serum in the presence of bromodeoxyuridine (BrdU). Compared with schistosomula cultured in presence of control medium containing fetal calf serum alone, BrdU labeling indices (BLIs) were increased by 39% in the presence of portal, but not in peripheral, serum of hamsters. In contrast, no significant differences were observed in the BLIs in rat portal, or peripheral, sera or in control media. In vivo BrdU labeling results revealed that there was no detectable cell proliferation in S. mansoni schistosomula (6 days old) in the lungs. However, cell proliferation was detected in schistosomula beginning at 17 days. The results indicated that portal venous serum from a highly susceptible host, but not from a poorly susceptible host, stimulated schistosome cell proliferation in vitro. The timing of the increase in cell proliferation in terms of development corresponded to liver portal-mesenteric localization of schistosomula. Together, the data support the conclusion that in susceptible hosts, portal serum may play a role in schistosome cell proliferation, possibly resulting in termination of schistosome migration. This may explain the colocalization of adults, and the known organ selectivity of disease.

Neurocysticercosis, caused by the cestode Taenia solium, is the most common parasitic infection of the human central nervous system that leads to seizures. Taenia crassiceps cysticercosis in mice is an experimental model for Taenia solium cysticercosis. Similar to the human infection, live parasites cause little or no granulomatous inflammation. Dying parasites initiate a granulomatous reaction. The neuropeptide substance P (SP) stimulates T-helper (Th) 1 cytokine production. In the current study, we determined whether absence of SP/SP receptor circuitry in the SP-precursor, preprotachykinin, knockout or SP-receptor, neurokinin (NK)1, knockout mice affected granuloma cytokine production. We hence compared the levels of Th1 cytokines interleukin (IL)-2 and interferon (IFN)-γ and levels of Th2/immunoregulatory cytokines IL-4 and IL-10 by enzyme-linked immunosorbent assay in T. crassiceps-induced granulomas derived from infected C57BL/6 wild-type (WT) versus SP-precursor knockout and NK1 knockout mice. We found that mean levels of IL-2, IFN-γ, IL-4, and IL-10 in infected WT-derived granulomas were significantly higher than those of granulomas derived from infected SP-precursor knockout or the NK1 receptor (NK1R) knockout mice. Levels of Th2/immunoregulatory cytokines IL-4 and IL-10 were higher in early stage granulomas (histologically staged on basis of evidence of parasite remnants) versus late stage granulomas (no parasite remnants) of both knockouts, whereas the reverse was noted in WT-derived granulomas. This study established that the absence of an SP/SP receptor circuitry in the SP-precursor knockout mice or NK1 receptor knockout mice led to an inhibited cytokine response.

Sheep are important in the epidemiology of Toxoplasma gondii infection, but little is known of ovine toxoplasmosis in Brazil. Antibodies to T. gondii were assayed in sera of 495 sheep from 36 counties of São Paulo state, Brazil, using the modified agglutination test (MAT titer ≥1:25); 120 (24.2%) sheep tested positive. Samples of brain, heart, and diaphragm of 82 seropositive sheep were pooled, digested in pepsin, and bioassayed in mice. Toxoplasma gondii was isolated from tissue homogenates of 16 sheep, and the isolates were designated TgShBr 1–16. Six of the 16 T. gondii isolates killed 100% of infected mice. Results indicate that asymptomatic sheep can harbor mouse-virulent T. gondii; hence, they can serve as a source of infection for humans.

Feces of harbor seals (Phoca vitulina richardsi) and hybrid Glaucous-winged/Western gulls (Larus glaucescens/ occidentalis) from Washington State's inland marine waters were examined for Giardia spp. and Cryptosporidium spp. to determine whether genotypes carried by these wildlife species were the same as those that commonly infect humans and domestic animals. Using immunomagnetic separation followed by direct fluorescent antibody detection, Giardia spp. cysts were detected in 42% (41/97) of seal fecal samples. Giardia spp.–positive samples came from 90% (9/10) of the sites, and the prevalence of positive seal fecal samples differed significantly among study sites. Fecal samples collected from seal haulout sites with >400 animals were 4.7 times more likely to have Giardia spp. cysts than were samples collected at smaller haulout sites. In gulls, a single Giardia sp. cyst was detected in 4% (3/78) of fecal samples. Cryptosporidium spp. oocysts were not detected in any of the seals or gulls tested. Sequence analysis of a 398 base pair (bp) segment of Giardia duodenalis DNA at the glutamate dehydrogenase (GDH) locus suggested that 11 isolates originating from seals throughout the region were a novel genotype and 3 isolates obtained from a single site in south Puget Sound were the G. duodenalis canine genotype D. Real-time TaqMan polymerase chain reaction (PCR) amplification and subsequent sequencing of a 52 bp small subunit ribosomal DNA region from novel harbor seal genotype isolates showed sequence homology to canine genotypes C and D. Sequence analysis of the 52 bp small subunit ribosomal DNA products from the 3 canine genotype isolates from seals produced mixed sequences that could not be evaluated.

Serpins are serine protease inhibitors that are widely distributed in metazoans, but they have not been characterized previously in Eimeria spp. A serpin from Eimeria acervulina was cloned, expressed, and characterized. Random screening of an E. acervulina sporozoite cDNA library identified a single clone (D14) whose coding region shared high similarity to consensus structure of serpins. Clone D14 contained an entire open reading frame consisting of 1,245 nucleotides that encode a peptide of 413 amino acids, with a predicted molecular weight of 45.5 kDa and containing a signal peptide 28 residues. By Western blot analysis, polyclonal antiserum to the recombinant serpin (rbSp) recognized a major 55-kDa protein band in unsporulated oocysts and in oocysts sporulated up to 24 hr (fully sporulated). The anti-rbSp detected bands of 55 and 48 kDa in sporozoites (SZ) and merozoites (MZ), respectively. Analysis of MZ secretion products revealed a single protein of 48 kDa that may correspond to secreted serpin. By immunostaining, the serpin was located in granules distributed throughout both the SZ and MZ, but granules seemed to be concentrated in the parasites' anterior. Analysis of the structure predicts that the E. acervulina serpin should be an active inhibitor. However, rbSp was without inhibitory activity against common serine proteases. By Western blot analysis, the endogenous serpin in MZ extracts did not form the expected high-molecular-weight complex when coincubated with either trypsin or subtilisin. The results demonstrate that E. acervulina contains a serpin gene and expresses a protein with structural properties similar to an active serine protease inhibitor. Although the function of the E. acervulina serpin remains unknown, the results further suggest that serpin is secreted by the parasite where it may be involved in cell invasion and other basic developmental processes.

Human head lice (Pediculus humanus capitis) are subdivided into 3 deeply divergent mitochondrial clades (Clades A, B, and C), each having unique geographical distributions. Determining the evolutionary history and geographic distribution of these mitochondrial clades can elucidate the evolutionary history of the lice as well as their human hosts. Previous data suggest that lice belonging to mitochondrial Clade B may have originated in North America or Asia; however, geographic sampling and sample sizes have been limited. With newly collected lice, we calculate the relative frequency, geographic distribution, and genetic diversity of louse mitochondrial clades to determine the geographic origin of lice belonging to Clade B. In agreement with previous studies, genetic diversity data support a North American origin of Clade B lice. It is likely that lice belonging to this mitochondrial clade recently migrated to other geographic localities, e.g., Europe and Australia, and, if not already present, may disperse further to occupy all geographic regions.

Toxoplasma gondii often migrates to the central nervous system in immunocompromised patients, where it induces a severe inflammation referred to as Toxoplasma encephalitis. The mechanisms involved in control of parasite multiplication and prevention of Toxoplasma encephalitis remain unclear. The objective of the present study was to characterize the inflammatory response in the brains of mice during acute T. gondii infection, with emphasis on the expression of chemokine receptors. Susceptible C57BL/6 mice were orally infected with 10 cysts of the low-virulent ME49 strain of T. gondii. Levels of cytokines (TNF-α, IFN-γ, IL-10, IL-6, and IL-12p70) and chemokines (CCL/2MCP-1) were measured in plasma at 5, 10, 15, 20, and 30 days after infection. In addition, the mRNA expression of chemokines (CCL5/RANTES, CCL2/MCP-1, CCL4/MIP-1β) and chemokine receptors (CCR1, CCR2, CCR5, CCR7, CCR8, CXCR4, and CXR5) were measured in brain tissues at the same time points. Plasma levels of IFN-γ and CCL2/MCP-1 were highly expressed at day 5, whereas TNF-α had a moderate increase at day 5, peaked at day 10, and returned to normal levels by day 30. Plasma levels of IL-10, IL-6, and IL-12p70 were not detected throughout the study. Analyses of mRNA expression of chemokines and chemokine receptors in the brain showed that CCL5/ RANTES, CCR7, CXCR4, and CXCR5 were upregulated, peaking after 10 days of T. gondii infection. IgM-specific antibody levels increased at day 5 and peaked at days 10 and 30, whereas IgG levels increased at day 10 and continued to increase thereafter, reaching maximum levels at day 30 postinfection (PI). Our results suggest that T. gondii infection is controlled at local and systemic levels, and that proinflammatory proteins and their receptors may be acting coordinately to induce stage conversion and prevent parasite multiplication and development of Toxoplasma encephalitis. The early production of IFN-γ and the delayed expression of CXCR4 and CXCR5 indicate that T. gondii induces an early robust cellular immune response, followed by a strong and sustained antibody-mediated immunity.

The water buffalo (Bubalus bubalus) is important to the economy of several countries, especially in Asia and South America. Little is known regarding the impact of coccidiosis in buffaloes. Cattle and buffaloes are considered to have common species of Eimeria, but critical cross-transmissions have not been made because it is difficult to raise these hosts coccidian free. Clinical coccidiosis was confirmed post mortem in a 22-day-old buffalo calf that died after a 3- to 4-day illness. Oocysts morphologically identical to Eimeria bareillyi were found in the feces and in sections of small intestine. Oocysts were often pyriform, sometimes with asymmetrical sides. The shorter end was flattened and approximately 5–6 μm wide. Unsporulated oocysts in feces were 23.2–29.5 × 16.5–22 μm, with an average of 27.2 × 19.3 μm. Schizonts, gamonts, and oocysts were identified in sections of small intestine where they were located in enterocytes of the jejunum and ileum. No coccidian stages were seen in sections of colon. This is one of the first confirmed cases of clinical coccidiosis in water buffalo.

A 13-yr-old boy was admitted because of persistent fever, abdominal pain, and diarrhea for 3 mo. Abdominal computerized tomography revealed hepatomegaly and multiple nodular low-density pathological changes. At laparotomy, considerable yellow and turbid ascites were seen in the abdominal cavity, and miliary nodules were noted on the surface of the omentum majus, liver, and small intestine wall. Histological examination revealed parenchymal tubercles containing several worms. Pathological diagnosis was parasitic granuloma. These parasites were identified as Porocephalus taiwana sp. nov. (Pentastomida). The patient made an uneventful recovery after therapy and was discharged. Another 17 cases of human pentastomiasis reported from China are reviewed. Human pentastomiasis is an extremely rare disease, and this is only the second case of human P. taiwana sp. nov. infection. Pentastomiasis should be considered in differential diagnosis of patients with a history of abdominal symptoms and eating of poorly cooked snakes.

Acanthocephalus rhinensis n. sp. is described from the European eel, Anguilla anguilla (Linnaeus, 1758), collected in the Rhine River near the city of Karlsruhe, Germany. It is the sixth species of Acanthocephalus Koelreuther, 1771 described from European fish. Four other species are known from amphibians. The new species is distinguished from the other 5 species infecting fish by having a 1.2-mm-long proboscis armed with 15–21 rows of 13–16 hooks each, lemnisci about as long as receptacle, oblong and slightly pre-equatorial testes, and thin fusiform eggs measuring 85–95 × 15–18 μ. Testes in the other European species are usually round to ovate, except in Ac. anguillae (Müller, 1780) Lühe, 1911 where they are also elongated but postequatorial. It also has an orange-brown belt encircling the anterior end of the trunk. The comparative distribution of Acanthocephalus in Europe and North America, and the validity of 2 presumably questionable species are discussed, Acanthocephalus falcatus (Froelich, 1789) Lühe, 1911 and Ac. paronai (Cendorelli, 1897) Meyer, 1932. A dichotomus key distinguishing Ac. rhinensis from the other 9 European species is also included. The new species was only found in 3 of 390 eels examined during 11 yr; this may be related to the changing benthos community in the Rhine River.

During November 2000, a collection of acanthocephalans from birds in Quang Ninh Province, Vietnam, included a new genus and species in a new family and order. Pyrirhynchus heterospinus n. gen., n. sp. (Pyrirhynchidae n. fam.: Heteramorphida: new order) is described from Actitis hypoleucos (Linnaeus, 1758) (common sandpiper). The new family combines characters from Polymorphidae and Heteracanthocephalidae, and it includes new features. Specimens of the new species are distinguished from those of Heteracanthocephalidae and/or Polymorphidae by their long cylindrical trunk with anterior swelling, pyriform proboscis with hooks much larger ventrally, brain at the anterior end of the receptacle, specialized tubular cement glands, and elliptoid eggs with concentric shells. A detailed analysis of proboscis and trunk armature is included, and specimens of several species of Arhythmorhynchus Lühe, 1911 (Polymorphidae) were studied for comparative purposes. The proboscis of P. heterospinus is armed with 17 to 20 rows of 17 to 19 hooks each, with anterior 9–11 hooks rooted and posterior 6–10 spines rootless.

We redescribe Orchispirium heterovitellatum based on the holotype and 3 original voucher specimens collected from the mesenteric blood vessels of scaly whiprays Himantura imbricata (Bloch and Schneider, 1801) (as Dasyatis imbricatus) captured in the western Bay of Bengal off Waltair, India. We emend the diagnosis of Orchispirium to include anterior sucker present, testis looping, cirrus sac enveloping large internal seminal vesicle, oviducal seminal receptacle present, and metraterm short and thin-walled. We describe Myliobaticola richardheardi n. gen., n. sp. based on live observations, light microscopy, and scanning electron microscopy of adult specimens collected from between the cardiac trabeculae of Atlantic stingrays Dasyatis sabina (Lesueur, 1824) captured in Mississippi Sound (type locality), Mississippi, and Apalachicola Bay, Florida. The new species has a minute, aspinous body lacking lateral tubercles; an aspinous and eversible anterior sucker lacking a peduncle; a posterior esophageal swelling; an inverse U-shaped intestine; smooth ceca terminating in the anterior body half; a looping testis lacking lobes; a cirrus sac enveloping a large internal seminal vesicle; a medial and primarily post-testicular ovary; an oviducal seminal receptacle; a postgonadal uterus flanking the internal seminal vesicle; a short and thin-walled metraterm; and a common genital pore. It lacks a pharynx and Laurer's canal. No other named aporocotylids infect a member of cohort Batoidea or have the combination of an aspinous body, an aspinous anterior sucker, a posterior esophageal swelling, an inverse U-shaped intestine, a looping testis, a cirrus sac enveloping a large internal seminal vesicle, and a common genital pore; these observations indicate that O. heterovitellatum and M. richardheardi are closely related. The discovery of a second species representing a second genus of Aporocotylidae in diamond stingrays (Dasyatidae) suggests that Batoidea is an undersampled host group for aporocotylid infections.

While investigating the parasite fauna of wild coho salmon. Oncorhynchus kisutch (Walbaum, 1792), histological examination provided evidence of a new species of Myxobolus (Myxozoa: Myxosporea) infecting nerves of skeletal muscle. Spores were morphologically similar to those of the intramuscular Myxobolus insidiosus Wyatt and Pratt, 1963, both having pyriform spores with clavate polar capsules. However, the former developed exclusively in the nerves of skeletal muscle rather than in myocytes. We examined both species of Myxobolus derived from coho salmon; Chinook salmon, Oncorhynchus tshawytscha (Walbaum, 1792); cutthroat trout, Oncorhynchus clarkii (Richardson, 1836); and rainbow trout Oncorhynchus mykiss (Walbaum, 1792) from freshwater in Oregon. Spore morphology, small subunit ribosomal RNA gene (rDNA) sequences, and site of infection were compared. Myxobolus arcticus Pugachev and Khokhlov, 1979 has pyriform spores, infects the central nervous system of many salmonids, and is found in the Pacific Northwest. It was therefore included in the analyses to rule out conspecificity with the new species. Together, these data show that the Myxobolus sp. from peripheral nerves in the skeletal musculature of coho salmon, rainbow trout, and cutthroat trout is a new species, described herein as Myxobolus fryeri n. sp.

Forty-two Trichomonas gallinae isolates were molecularly characterized to determine whether isolates differed in genetic sequence of multiple gene targets depending on host species or geographical location. The 5.8S ribosomal RNA (rRNA) and flanking internal transcribed spacer (ITS) gene regions were amplified by polymerase chain reaction, and the sequences were analyzed phylogenetically. The results of the sequence analysis strongly suggest at least 2 species may exist within the T. gallinae morphologic complex. Based on ITS sequences, one group demonstrated high nucleotide identity to the 3 T. gallinae sequences available in GenBank, whereas the second group was more closely related to T. vaginalis (98%) than to T. gallinae (92%). Two common ground-dove (Columbina passerina) isolates shared a 95% identity with T. vaginalis and a 92% identity with T. gallinae and T. tenax. Sequence analysis of both the 18S rRNA and α-tubulin genes from a subset of the isolates supports the 5.8S-ITS sequence results. All of the T. vaginalis-like isolates originated from Arizona, California, or Texas, whereas T. gallinae isolates were found in all sampled states. Both T. vaginalis-like and T. gallinae isolates were involved in trichomoniasis outbreaks in California and Arizona.

Hydromermis haggardi n. sp. (Nematoda: Mermithidae) is described from the hemocoel of chironomid imagos eclosing from Lake Alice Bog in northern Minnesota in June and July 2007. The species is distinguished from the other 27 described members of the genus by the subventral mouth, tulip shape to anterior end of esophagus, colorless vesicular trophosome, single nonbifurcated spicule, short body lengths of both males and females, structure of the S-shaped vagina, decrease in body width at vulva, brevity of postparasitic stage, and the greater development of a posterior ventral protractor muscle in the males. An anomalous adult male bearing large oval structures in the posterior testis is reported. Evidence is presented for the developmental interaction of the new species with Lanceimermis palustris Johnson and Kleve, 2004.

A new genus and species of nematode, Caranginema americanum n. gen., n. sp. (Philometridae), are described from gravid, subgravid, and nongravid female specimens collected from the subcutaneous tissue of the fish (crevalle jack) Caranx hippos (Carangidae, Perciformes) from the coral reef El Cabezo, southern Gulf of Mexico, Mexico. Caranginema, assigned to the Philometrinae, differs from other genera of this subfamily mainly in the presence of 2 conspicuous parallel cordons on either side, extending along nearly the entire body length and demarcating narrow smooth lateral fields and in having the remaining body surface with numerous ornamentations forming irregularly scattered, transversely elongated narrow cuticular molds. The new species is characterized mainly by the presence of 3 large, sclerotized esophageal teeth protruded out of the mouth, the number and arrangement of cephalic papillae (8 papillae in 4 pairs of external circle and 4 single papillae of internal circle), the length and structure of the esophagus, and by the body length of gravid and subgravid females (267 and 258 mm, respectively). Caranginema americanum is the seventh philometrid species reported from marine and brackish water fishes in Mexico.

Thirty-five strains of the Lyme disease spirochete Borrelia burgdorferi sensu lato (B. burgdorferi s. l.) were isolated from the blacklegged tick vector Ixodes scapularis in South Carolina, Georgia, Florida, and Rhode Island. They were characterized by PCR-restriction fragment length polymorphism (RFLP) analysis of rrf (5S)-rrl (23S) intergenic spacer amplicons. PCR-RFLP analysis indicated that the strains represented at least 3 genospecies (including a possible novel genospecies) and 4 different restriction patterns. Thirty strains belonged to the genospecies B. burgdorferi sensu stricto (B. burgdorferi s. s.), 4 southern strains were identified as B. bissettii, and strain SCCH-5 from South Carolina exhibited MseI and DraI restriction patterns different from those of previously reported genospecies. Complete sequences of rrf-rrl intergenic spacers from 14 southeastern and northeastern strains were determined and the phylogenetic relationships of these strains were compared. The 14 strains clustered into 3 separate lineages on the basis of sequence analysis. These results were confirmed by phylogenetic analysis based on 16S rDNA sequence analysis.

Aplectana adaechevarriae n. sp., from the large intestine of Rhinella granulosa and Rhinella schneideri, is described and illustrated. Of the 43 nominal species of Aplectana, A. adaechevarriae n. sp. represents the 23rd Neotropical species and the third species reported from Argentina. Of the Neotropical species, only 4, Aplectana elenae, Aplectana hylambatis, Aplectana raillieti, and A. adaechevarriae n. sp., have 8 pairs of preanal papillae. Aplectana adaechevarriae lacks a median preanal papilla; the other 3 species possess a median preanal papilla.

Aplectana tucumanensis n. sp., from the large intestine of Amphisbaena bolivica, is described and illustrated. Of the 43 nominal species of Aplectana, A. tucumanensis n. sp. represents the fourth species reported in Amphisbaena spp. These 4 species are separated on the basis of male characters: spicules of Aplectana alba approximately 60 μ in length, Aplectana pusilla and A. tucumanensis approximately 100 μ, Aplectana raillieti greater than 230 μ; papillae pattern of A. pusilla with 3 preanal pairs, 2 adanal pairs, 6 postanal pairs, and 1 median papilla compared to 9 preanal pairs, 1 adanal pair, 6 postanal, and no median papilla for A. tucumanensis.

We describe 2 new species of Camallanus (Nematoda: Camallanidae) from freshwater turtles collected in Queensland, Australia: Camallanus nithoggi n. sp. from Elseya latisternum (Gray) and Camallanus waelhreow n. sp. from Emydura krefftii (Gray), Emydura macquarrii (Gray), and Em. macquarrii dharra Cann. The only Camallanus sp. previously reported from turtles is C. chelonius Baker, 1983 (all other species in the family have been transferred to Serpinema). The 2 new species described here differ from C. chelonius in the number of male preanal papillae (7 vs. 6 in C. chelonius), the number of male postanal papillae (5 vs. 4 in C. chelonius), and the number of buccal capsule ridges. Additionally, we removed the tissues overlying the buccal capsule and used scanning electron micrographs (SEM) to show that the peribuccal shields extend laterally from the buccal capsule, the basal ring is separated from the buccal capsule by a narrow isthmus, and there is a buttress along the lateral margin of the buccal capsule that has not previously been observed in species of Camallanus.

Oligogonotylus mayae n. sp. is described from the intestine of the Mayan cichlid Cichlasoma urophthalmus (Günther) in Ría Lagartos, Ría Celestún, and Estero Progreso, Yucatán State. This is the second species described for Oligogonotylus Watson, 1976, the other being O. manteri Watson, 1976. The new species is readily distinguished from O. manteri by the anterior extension of the vitelline follicles. In O. manteri, vitelline follicles are found entirely in the hindbody, extending posteriorly to mid-testicular level. Vitelline follicles in the new species extend from the anterior margin of posterior testis to the region between the ventral sucker and the pharynx. Comparison of approximately 1,850 bases of ribosomal DNA (ITS1, ITS2, 5.8S, and 28S), and 400 bases of cytochrome c oxidase subunit I (cox1) strongly supports the status of O. mayae as a new species, as compared to O. manteri collected from cichlids in other localities of Mexico, Belize, and Guatemala.

Three species of neodiplostomula are known to inhabit the European grass snake, Rhabdophis tigrina, in the Republic of Korea: Pharyngostomum cordatum (large-sized neodiplostomula), an intestinal trematode of cats; Neodiplostomum seoulense (small-sized neodiplostomula), an intestinal trematode of humans and rodents; and Neodiplostomum leei (small-sized neodiplostomula), which migrates to the livers of rodents and is an intestinal trematode of birds. The present study describes a fourth species, Neodiplostomum (Conodiplostomum) boryongense n. sp. (Digenea: Neodiplostomidae), based on adult flukes recovered from the small intestines of chicks experimentally infected with small-sized neodiplostomula from the grass snake. The new species differs from 13 previously known species. It also differs from N. seoulense in its larger body size, severely bilobed testes, and smaller genital atrium, and from N. leei in its larger body size, smaller ventral sucker, presence of a genital cone, and vitelline follicles distributed chiefly in the forebody. The new species does not migrate to the livers of rodents nor does it develop to adulthood in the rodent intestines. However, the neodiplostomula of the new species are indistinguishable from those of the other 2 species. Results show that at least 4 species of neodiplostomula inhabit the grass snake in the Republic of Korea.

In spite of their potential as model organisms and their medical importance, parasite speciation processes have been insufficiently discussed in the general literature. Scarcity of experimental data regarding reproductive isolation of parasites is a serious obstacle. Toward this end we developed a method for the investigation of hybridization of hemosporidian parasites in vitro. Five species of Haemoproteus (Haemosporida, Haemoproteidae) were isolated from naturally infected passerine birds. They were identified to species based on morphology of their gametocytes and PCR amplification of a segment of the parasite's mitochondrial cytochrome b gene. Hybridization of Haemoproteus spp. was initiated in vitro by mixing blood containing mature gametocytes of different species with a 3.7% solution of sodium citrate and exposure of the mixture to air. The following hybridization experiments were performed: (1) Haemoproteus minutus × Haemoproteus pallidus, (2) Haemoproteus balmorali × Haemoproteus tartakovskyi, and (3) Haemoproteus fringillae × H. tartakovskyi. The development of ookinetes of both species was blocked in the first experiment. Ookinetes of all species developed in other experiments, but presumed hybrids were distinguished only in the third experiment. Illustrations of ookinetes of all species are given. The present communication indicates that controlled experiments for direct hybridization of hemosporidians can be carried out in vitro. Such experimental research can be used to reconcile molecular and morphological data and to define biological species for this group of parasites.

We compared information obtained by both microscopy and nested mitochondrial cytochrome b PCR in determining prevalence of haemosporidian infections in naturally infected birds. Blood samples from 472 birds of 11 species belonging to 7 families and 4 orders were collected in Europe, Africa, and North America. Skilled investigators investigated them using the PCR-based screening and microscopic examination of stained blood films. The overall prevalence of haemosporidian infections, which was determined by combining results of both these methods, was 60%. Both methods slightly underestimated the overall prevalence of infection, which was 54.2% after the PCR diagnostics and 53.6% after microscopic examination. Importantly, both these tools showed similar prevalence for Haemoproteus spp. (21% by PCR and 22% by microscopy), Plasmodium spp. (17% and 22%), and Leucocytozoon spp. (30% and 25%), verifying that microscopy is a reliable tool in determining patterns of distribution of blood haemosporidian parasites in naturally infected birds. We encourage using optical microscopy in studies of blood parasites in parallel to the now widely employed molecular methods. Microscopy is unlikely to result in false positives, which is a major concern in large-scale PCR studies. Moreover, it is relatively inexpensive and provides valuable information regarding the ways in which molecular methods can be further improved and most effectively applied, especially in the field studies of parasites. Importantly, blood films, which are used for microscopic examination, should be of good quality; they should be examined properly by skilled investigators. In spite of the substantial time investments associated with microscopy, such examination provides opportunities for simultaneous determination and verification of taxonomically different parasites. Presently, different PCR protocols must be used for the detection of parasites belonging to different genera; this is expensive and time consuming.

Newly developed serological tests for diagnosing parelaphostrongylosis in cervids, using the excretory-secretory products (ES) of the infective larvae of Parelaphostrongylus tenuis in enzyme-linked immunosorbent assays (ELISAs), have demonstrable superiority over the traditional method of larval recovery and microscopic identification. To generate a source of ELISA antigen by genetic engineering, we created a complementary DNA (cDNA) expression library by the reverse transcription of mRNA of P. tenuis adult worms and by ligation with the vector λ-ZAP II. The library was screened using antisera produced in mice by immunization with a somatic antigen preparation of adult worms. Seventeen clones were isolated, sequenced, and checked for similarity to other DNA sequences in GenBank. A previously identified parasite gene encoding an aspartyl protease inhibitor (API) was isolated from the cDNA library, subcloned, and expressed using the pET expression vector to produce a glutathione S transferase (GST)–His-S-tag-P. tenuis API fusion protein (molecular weight = 63 kDa). An ELISA utilizing the API fusion protein as the coating antigen was used to serologically diagnose all white-tailed deer (WTD, Odocoileus virginianus; 10 out of 10) that had been inoculated with a range of 6–150 L3 P. tenuis, indicating that the antigen may be a useful serodiagnostic antigen for P. tenuis infection in this cervid species.

The antibody levels against the C-terminal region of the merozoite surface protein 1 of Plasmodium vivax (PvMSP1c) were measured in 276 patients with P. vivax malaria (patient group), 320 malaria-naïve healthy individuals (control group 1), and 70 malaria-naïve individuals with various disorders (control group 2) using the immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA) and the direct sandwich ELISA. To evaluate the antibody response during relapse, 5 relapsed patients were tested using the IgM capture ELISA. The IgM antibodies were negative in 99.7% of control group 1 and in 100% of control group 2; they were positive in 90.6% of the patient group. The total antibody levels were positive in 88.4% of the patient group with the direct sandwich ELISA. The sera from the second malaria episode, i.e., relapsed patients, were 100% positive on the IgM capture ELISA. The results of this study suggest that the IgM capture ELISA may be a useful diagnostic method for P. vivax malaria for both primary infection and relapse.

Recently, our group demonstrated that mouse lesions infected with Leishmania amazonensis are hypoxic. Evidence indicates the negative impact of hypoxia on the efficacy of a variety of chemotherapeutic agents against tumors, fungi, bacteria, and malaria parasites. In the present study, comparison of the effect of antileishmanial drugs on L. amazonensis-infected macrophages under normoxic and hypoxic conditions was performed. We compared the effect of 5% oxygen tension with a tension of 21% oxygen on peritoneal murine macrophage cultures infected with the parasite and treated with glucantime, amphotericin B, or miltefosine. Analysis of the infection index (percentage of infected macrophages × number of amastigotes per macrophage), dose-dependent efficacy of drugs, and IC₅₀ values demonstrated that hypoxia conferred a small, but significant, resistance to all 3 antileishmanial drugs. The present finding suggests that in vitro assays under hypoxia should not be neglected in drug studies.

Oocysts attributable to Eimeria macusaniensis Guerrero et al. 1971, were found in coprolites and in archaeological sediments dating to the Holocene of Patagonia, Argentina. By means of a nonparametric regression using a generalized additive model, a significant relationship was found between the size of the oocysts and their antiquity. Specifically, a reduction in oocyst size over time was discovered, probably due to a parasite response to host replacement, to an extinct eimeriid species common during the Pliestocene–Holocene transition, or to environmental changes known for the Holocene. Explanations regarding coevolution between parasites, hosts, and paleoenvironmental conditions are discussed herein.

Human subcutaneous dirofilariasis is an increasingly reported zoonosis caused by several filarial species, in particular by Dirofilaria (Nochtiella) repens. Like many filarial worms, D. repens harbors the bacterial endosymbiont Wolbachia that has been implicated in the inflammatory features of filarial infection. Immunohistochemical staining against the Wolbachia surface protein (WSP) was carried out on 14 skin nodules and showed numerous bacteria within the intact worms and occasional positive staining within the surrounding inflammatory infiltrate. Serum samples from 11 of these patients resulted positive for total immunoglobulin G titers against WSP as examined in enzyme-linked immunosorbent assay. This is the first description of Wolbachia distribution in D. repens and the first report of specific immune response to Wolbachia in patients with subcutaneous dirofilariasis.

A small outbreak of fatal toxoplasmosis is described in 6 kakariki (Cyanoramphus spp.) in an aviary in Australia. Toxoplasma gondii-like tachyzoites were found associated with necrosis in intestine, spleen, liver, and lungs. Tachyzoites reacted positively with T. gondii-specific polyclonal antibodies. This is the first report of toxoplasmosis in kakariki.

Previous studies on long-term gyrodactylid infections on isolated fish have shown that for the majority of Gyrodactylus–fish interactions, infection intensity peaks and then declines as the host mounts an effective immune response. In the current study, juvenile chub collected from the wild still harbored Gyrodactylus lomi infections after 6–10 mo in the laboratory despite being individually maintained at 12 C.

Trypanosomosis (surra) caused by Trypanosoma evansi is quite common among horses where the parasite is endemic. In the present study, T. evansi was isolated from an infected horse and maintained by subinoculation in Swiss albino mice. At the peak of parasitemia (5 × 10⁶ parasites per ml of blood), 0.25 ml of the tail blood from infected mice was inoculated intraperitoneally and subcutaneously to 2 groups of adult pigeons and 2 groups of pigeon nestlings. Four days after inoculation, the trypanosomes occurred in the peripheral circulation of pigeon nestlings, but no parasitemia was observed in adult pigeons. The body temperatures of infected nestlings increased to 104 F, whereas uninfected controls remained steady at 102 F; thus, elevated temperatures coincided with parasite presence in the peripheral circulation. A decrease in hemoglobin concentration of blood also was observed in infected nestlings. On microscopic examination, increases in length and breadth of trypomastigotes and vigorous flagellar movement of the parasites were observed. The virulence and pathogenicity of the parasites after adaptation to nestlings remained unchanged for albino mice as proved by the death of all subinoculated mice. Furthermore, polymerase chain reaction studies confirmed that the genomic DNA of trypanosomes in pigeon blood was the same as that of T. evansi. This is the first report of the establishment of T. evansi infection in pigeon nestlings.

Nematodes similar to Oxyspirura sp. were recovered from the cornea and nictitating membrane of a fulvous owl (Strix fulvescens). The bird had been captive for several months, but died suddenly. It had no clinical history of prior diseases, including ocular lesions.

The apicomplexan pathogens of Eimeria tenella cause coccidiosis, an intestinal disease of chickens that has a major economic impact on the poultry industry. Members of Apicomplexa share an assortment of unique secretory organelles (rhoptries, micronemes, and dense granules) that mediate invasion of host cells and the formation and modification of the parasitophorous vacuole. Among these, microneme protein 2 from E. tenella (EtMIC2) has a putative function in parasite adhesion to the host cell to initiate the invasion process. To investigate the role of EtMIC2 in host parasite interactions, the production and characterization of 12 monoclonal antibodies (mabs) produced against recombinant EtMIC2 proteins is described. In an immunofluorescence assay, all mabs reacted with molecules belonging to the apical complex of sporozoites and merozoites of E. tenella, E. acervulina, and E. maxima. By Western blot analysis, the mabs identified a developmentally regulated protein of 42 kDa corresponding to EtMIC 2 and cross-reacted with proteins in developmental stages of E. acervulina. Collectively, these mabs are useful tools for the detailed investigation of the characterization of EtMIC2-related proteins in Eimeria species.

Soboliphyme baturini, a stomach-dwelling nematode of American martens (Martes americana), reaches high levels of infection; however, its effects on the nutritional condition of the host are unknown. To understand the effects of this parasite on American martens, we collected S. baturini and measured abdominal fat deposits from 155 marten carcasses on Prince of Wales Island, southeastern Alaska, in the winter 2006–2007. We analyzed how the dried mass of abdominal fat varied as a function of S. baturini intensity. Parasite intensity and nutritional condition were not correlated; these results suggest that American martens were able to withstand even very high levels of S. baturini infection (up to 178 parasites per host).

From October 2005 through September 2006, blood samples collected from 1,412 (768 male, 644 female) 1-yr-old and older stray dogs in Taipei City, Taiwan, were tested for antibodies to Toxoplasma gondii using the latex agglutination test (LAT). Antibodies (LAT titers >1:32) to T. gondii were found in 284 (20.1%) of the animals. Seroprevalences were not affected by the sex or density of dogs. The prevalence was highest in dogs from the eastern part of the city.

Barn swallows Hirundo rustica often have characteristic feather holes on wing and tail feathers. During the past 15 yr, several influential papers have been based on the assumption that these holes were chewed by the louse Machaerilaemus malleus. We gathered feather-hole data from barn swallows and other passerines at 2 sites in Hungary and correlated the presence of holes with louse infestations and, more specifically, with the occurrence of M. malleus versus other species of avian lice. The shape of frequency distribution of holes was left-biased, and this bias was more pronounced in large swallow colonies that in a random sample, in accordance with the view that the causative agent of the ‘feather hole symptom’ is a contagious macroparasite. However, both intra- and interspecific comparisons suggest that the causative agent of the symptom had probably been misidentified. The occurrence of Brueelia spp. ‘wing lice’ provides the best fit to the distribution and abundance of feather holes, both in barn swallows and across some other small passerines. This identification error does not challenge the results of the former evolutionary–ecological studies based on this model system, although it has important implications from the viewpoint of louse biology.