Showing papers in "Journal of Parasitology in 2008"
TL;DR: In this article, the authors compared information obtained by both microscopy and nested mitochondrial cytochrome b PCR in determining prevalence of haemosporidian infections in naturally infected birds.
Abstract: 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 542% after the PCR diagnostics and 536% 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 pa
279 citations
TL;DR: In this article, a new species of Myxobolus (Myxozoa: Myxosporea) infecting the central nervous system of coho salmon was identified.
Abstract: 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.
132 citations
TL;DR: The prevalence of T. gondii in free-range chickens from Ghana, Indonesia, Italy, Poland, and Vietnam was determined using the modified agglutination test (MAT) and 7 genotypes were identified; the 3 isolates from chickens from Italy were clonal type II, and the others were nonclonal.
Abstract: The prevalence of Toxoplasma gondii in free-ranging chickens (Gallus domesticus) is a good indicator of the prevalence of the parasite's oocysts in soil because chicken feed from the ground. The prevalence of T. gondii in free-range chickens from Ghana, Indonesia, Italy, Poland, and Vietnam was determined using the modified agglutination test (MAT). Antibodies to T. gondii were found in 41 (64%) of 64 chickens from Ghana, 24 (24.4%) of 98 chickens from Indonesia, 10 (12.5%) of 80 chickens from Italy, 6 (30%) of 20 chickens from Poland, and 81 (24.2%) of 330 chickens from Vietnam. Hearts and brains of chickens were bioassayed for T. gondii. Viable T. gondii was isolated from 2 chickens from Ghana, 1 chicken from Indonesia, 3 chickens from Italy, 2 chickens from Poland, and 1 chicken from Vietnam. Toxoplasma gondii isolates from 9 chickens were genotyped using 10 PCR-RFLP markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. A total of 7 genotypes was identified; the 3 isolates from chickens from Italy were clonal type II, and the others were nonclonal. This is the first report of genetic characterization of T. gondii isolates from animals from these countries.
94 citations
TL;DR: The results of the sequence analysis strongly suggest at least 2 species may exist within the T. gallinae morphologic complex, and both T. vaginalis-like and T.Gallinae isolates involved in trichomoniasis outbreaks in California and Arizona are suggested.
Abstract: 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 resu...
91 citations
TL;DR: Three Plasmodium strains that had already been found in Passeriformes were also detected in the birds of prey and owls examined here, supporting previous findings indicating a broad and nonspecific host spectrum bridging different bird orders.
Abstract: Avian blood parasites have been intensively studied using morphological methods with limited information on their host specificity and species taxonomic status. Now the analysis of gene sequences, especially the mitochondrial cytochrome b gene of the avian haemosporidian species of Haemoproteus, Plasmodium, and Leucocytozoon, offers a new tool to review the parasite specificity and status. By comparing morphological and genetic techniques, we observed nearly the same overall prevalence of haemosporidian parasites by microscopy (19.8%) and polymerase chain reaction (PCR) (21.8%) analyses. However, in contrast to the single valid Leucocytozoon species (L. toddi) in the Falconiformes we detected 4 clearly distinctive strains by PCR screening. In the Strigiformes, where the only valid Leucocytozoon species is L. danilewskyi, we detected 3 genetically different strains of Leucocytozoon spp. Two strains of Haemoproteus spp. were detected in the birds of prey and owls examined, whereas the strain found in the tawny owl belonged to the morphospecies Haemoproteus noctuae. Three Plasmodium spp. strains that had already been found in Passeriformes were also detected in the birds of prey and owls examined here, supporting previous findings indicating a broad and nonspecific host spectrum bridging different bird orders.
83 citations
TL;DR: It is demonstrated that intestinal flukes are common in farmed fish in this area, suggesting that reservoir hosts such as dogs, cats, and pigs are more important in sustaining the life cycles of these flukes in fish farms than human hosts, which has implications for the effectiveness of control programs focused mainly on treatment of humans.
Abstract: The prevalence of fish-borne zoonotic trematode (FZT) metacercariae was investigated in fish farmed by rural households in Nghe An Province, located in northern Vietnam. In total, 716 fish, including tilapia (Oreochromis niloticus) and 6 carp species, i.e., grass carp (Ctenopharyngodon idellus), bighead carp (Aristichthys nobilis), mrigal (Cirrhinus mrigala), common carp (Cyprinus carpio), silver carp (Hypophthalmychthys molitrix), and roha (Labeo rohita), collected from 53 fish farms were examined. The overall prevalence of FZT metacercariae was 44.6%, ranging from 12.5% to 61.0% in fish species collected from grow-out ponds, which are the production system for growing fish from fingerling size to market size. The overall prevalence was 43.6% in fingerlings cultured in nurseries, ranging from 7.4% to 62.8% for different fish species. The FZT species recovered were heterophyids and echinostomatids and included Haplorchis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus, Stellantchasmus falcatus,...
73 citations
TL;DR: Short (<500 bp) variable regions suitable for broader biogeographical studies of giant liver fluke were designed and determined to allow molecular differentiation of F. magna and F. hepatica.
Abstract: Complete sequences of ribosomal and mitochondrial genes of the giant liver fluke Fascioloides magna are presented. In particular, small subunit (18S) and internal transcribed spacers (ITS1 and ITS2) of the ribosomal gene (rDNA), as well as cytochrome c oxidase subunit I (cox1) and nicotinamide dehydrogenase subunit I (nad1) of the mitochondrial DNA (mtDNA), were analyzed. The 18S and ITS sequences were compared with previously published sequences of the liver fluke Fasciola hepatica. Fixed interspecific genetic differences were determined that allow molecular differentiation of F. magna and F. hepatica using either the PCR-RFLP method or PCR amplification of species-specific DNA regions. Additionally, intraspecific sequence polymorphism of the complete cox1 and nad1 mitochondrial genes in geographically distinct F. magna populations was determined. Based on the sequence divergences, short (<500 bp) variable regions suitable for broader biogeographical studies of giant liver fluke were designed.
70 citations
TL;DR: Seroprevalence of T. gondii antibodies in wild zoo felids, highly susceptible zoo species, and feral cats from 8 zoos of the midwestern United States was determined by using the modified agglutination test (MAT).
Abstract: Toxoplasma gondii infections in zoo animals are of interest because many captive animals die of clinical toxoplasmosis and because of the potential risk of exposure of children and elderly to T. gondii oocysts excreted by cats in the zoos. Seroprevalence of T. gondii antibodies in wild zoo felids, highly susceptible zoo species, and feral cats from 8 zoos of the midwestern United States was determined by using the modified agglutination test (MAT). A titer of 1:25 was considered indicative of T. gondii exposure. Among wild felids, antibodies to T. gondii were found in 6 (27.3%) of 22 cheetahs (Acynonyx jubatus jubatus), 2 of 4 African lynx (Caracal caracal), 1 of 7 clouded leopards (Neofelis nebulosa), 1 of 5 Pallas cats (Otocolobus manul), 12 (54.5%) of 22 African lions (Panthera leo), 1 of 1 jaguar (Panthera onca), 1 of 1 Amur leopard (Panthera pardus orientalis), 1 of 1 Persian leopard (Panthera pardus saxicolor), 5 (27.8%) of 18 Amur tigers (Panthera tigris altaica), 1 of 4 fishing cats (Prionailurus ...
70 citations
TL;DR: Results indicate that asymptomatic sheep can harbor mouse-virulent T. gondii; hence, they can serve as a source of infection for humans.
Abstract: 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 Sao 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.
65 citations
TL;DR: Findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.
Abstract: 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 infect...
65 citations
TL;DR: The high prevalence of G. duodenalis in ringed seals, and the presence of Assemblage B in these animals, highlights the potential for zoonotic transmission to the Inuit people, who consume dried seal intestines and uncooked seal meat.
Abstract: The prevalence of Giardia duodenalis and Cryptosporidium spp. was determined for ringed and bearded seals harvested for food in the Nunavik region in northern Quebec, Canada. Flow cytometric results demonstrated that G. duodenalis was present in the intestinal contents of 80% of the ringed seals and 75% of the bearded seals tested, while Cryptosporidium spp. were present in 9% of the ringed seals and none of the bearded seals. Prevalence of both parasites was highest in animals less than 1 yr of age. Giardia sp. isolates from ringed seals were identified as G. duodenalis Assemblage B, which is commonly identified in human infections. The high prevalence of G. duodenalis in ringed seals, and the presence of Assemblage B in these animals, highlights the potential for zoonotic transmission to the Inuit people, who consume dried seal intestines and uncooked seal meat.
TL;DR: Sera from 523 wild rodents were tested for Toxoplasma gondii antibodies using either an indirect fluorescent antibody test (IFAT) or a latex agglutination test (LAT) (voles, squirrels, and pocket mice, with titer ≥32 considered positive).
Abstract: Sera from 523 wild rodents were tested for Toxoplasma gondii antibodies using either an indirect fluorescent antibody test (IFAT) (rats and mice, with titer ≥80 considered positive) or a latex agglutination test (LAT) (voles, squirrels, and pocket mice, with titer ≥32 considered positive). Seventeen percent (88/523) of the rodents, including 26% (85/328) of the Peromyscus sp. and 8% (3/37) of Spermophilus beecheyi, were seropositive. Fourteen percent (23/161) of rodents captured in trap sites next to Morro Bay (California) and 15% (16/109) of rodents from sites adjacent to riparian habitats had antibodies to T. gondii, compared to 19% (49/253) of rodents captured in habitats not associated with water; this difference was not statistically significant (P = 0.32). Significantly fewer rodents were captured <200 m from residential housing compared to locations further away (11% vs. 30%, respectively). Factors associated with an increased risk for T. gondii seropositivity in rodents were capture location ≥200 ...
TL;DR: Phylogenetic analyses favor the interpretation that sexual maturity of Archigetes sp.
Abstract: The tapeworm Archigetes sieboldi Leuckart, 1878 (Platyhelminthes: Cestoda: Caryophyllidea) has been cited as a likely representative of the “protocestode” condition, owing to its lack of segmentation and ability to attain sexual maturity in the invertebrate host (aquatic oligochaetes). The idea has been variously amplified or rejected in the literature, although the actual phylogenetic position of the species has not been investigated until now. New collections of Archigetes sp. from both its vertebrate and invertebrate hosts provided the opportunity to estimate its phylogenetic position with the use of molecular systematics, while prompting new analyses aimed at assessing the early diversification of the Cestoda. Additional collections representing the Amphilinidea, Caryophyllidea, and Gyrocotylidea were combined with published gene sequences to construct data sets of complete 18S (110 taxa) and partial (D1-D3) 28S (107 taxa) rDNA sequences, including 8 neodermatan outgroup taxa. Estimates resulting from...
TL;DR: Results document high prevalence of T. gondii in pigs on a poorly managed pig farm in Maryland and 4 genotypes; 10 isolates belonged to type II lineage (genotypes 1 and 2), 3 belonged to genotype 3, and 1 belonged to Genotype 4.
Abstract: The prevalence of Toxoplasma gondii was investigated on a poorly managed pig farm in Maryland. Serum and tissue samples from 48 of the 100 pigs on the farm were available for T. gondii evaluation. Serological testing was performed using both ELISA and the modified agglutination test (MAT). Antibodies to T. gondii were detected by ELISA in 12 of 48 animals, while antibodies were detected in 34 of 48 pigs by MAT with titers of 1:10 in 1, 1:20 in 4, 1:40 in 7, 1:80 in 3, 1:160 in 8, 1:320 in 3, 1:640 in 4, and 1:1,280 in 4. Hearts of 16 pigs with MAT titers of 1:10 or higher were bioassayed for T. gondii in cats; 11 cats shed T. gondii oocysts. Hearts of 22 pigs were autolyzed and bioassayed only in mice; T. gondii was isolated from 3 of these 22 pigs. Genetic typing of the 14 T. gondii isolates using the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico loci revealed 4 genotypes; 10 isolates belonged to type II lineage (genotypes 1 and 2), 3 belonged to genotype 3, and 1 belonged to genotype 4. Genotype 1 and 2 have type II alleles at all genetic loci, except the former has type II allele and the latter has a type I allele at locus Apico. Both genotypes 1 and 2 are considered to belong to the clonal type II lineages. Genotype 3 and 4 are nonclonal isolates. Results document high prevalence of T. gondii in pigs on a farm in Maryland.
TL;DR: Phylogenetic analyses of the 18S ribosomal RNA, actin, and heat shock protein 70 (HSP70) loci demonstrate that C. macropodum is genetically distinct from all described Cryptosporidium species, including others found in marsupials.
Abstract: Cryptosporidium macropodum n. sp is described. Oocysts of C. macropodum from the feces of kangaroos (Macropus spp.) are morphologically indistinguishable from other mammalian Cryptosporidium species, including C. parvum, C. hominis, C. suis, and C. canis. The oocysts are fully sporulated on excretion, lack sporocysts, and have an average width of 4.9 μm (4.5– 6.0), a length of 5.4 μm (5.0–6.0), and a length:width ratio of 1.1. Phylogenetic analyses of the 18S ribosomal RNA, actin, and heat shock protein 70 (HSP70) loci demonstrate that C. macropodum is genetically distinct from all described Cryptosporidium species, including others found in marsupials. The parasite seems to be highly host-specific, because it has been found only in marsupials to date. Therefore, based on biological and molecular data, we consider C. macropodum a new species.
TL;DR: Genetic diversity data support a North American origin of Clade B lice and 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.
Abstract: 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, ma...
TL;DR: The presence of trematode eggs, including Clonorchis sinensis, Metagonimus yokogawai, and Gymnophalloides seoi (a human parasite known in Korea since 1993) in the feces of a recently excavated female mummy in Hadong, Republic of Korea is reported, the first report of the discovery of a G. seoi infection in a human mummy.
Abstract: It was previously reported that paleoparasitological clues for parasites infecting humans could be found in the feces of mummies of the Joseon Dynasty (1392-1910) in the Republic of Korea. Here, we report the presence of trematode eggs, including Clonorchis sinensis, Metagonimus yokogawai, and Gymnophalloides seoi (a human parasite known in Korea since 1993) in the feces of a recently excavated female mummy in Hadong, Republic of Korea. This is the first report of the discovery of a G. seoi infection in a human mummy. Since Hadong is currently not an endemic area for G. seoi, we speculate that the parasite might have occurred frequently along coastal areas of the Korean peninsula several hundred years ago and that the endemic areas contracted to, more or less, restricted regions since that time.
TL;DR: This is the first genotyping of T. gondii isolates from this part of North America and none of the isolates was clonal archetypal Types I, II, and III found in the United States.
Abstract: Viable Toxoplasma gondii was isolated by bioassay in mice from tissues of 2 feral cats (Felis domesticus), 2 raccoons (Procyon lotor), a skunk (Mephitis mephitis) trapped in remote locations in Manitoba, Canada, and a black bear (Ursus americanus) from Kuujjuaq, northern Quebec, Canada. Genotyping of these T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico revealed 4 genotypes. None of the isolates was clonal archetypal Types I, II, and III found in the United States. These results are in contrast with the Type II genotype that is widespread in domestic animals and humans throughout the United States and Europe. This is the first genotyping of T. gondii isolates from this part of North America.
TL;DR: The results provide support for the idea that Hexaglandula represents an independent lineage, whereas, in the case of Profilicollis, there is no conclusive evidence that they are not members of Polymorphus.
Abstract: Members of the Polymorphidae (Acanthocephala) are distributed worldwide as endoparasites of marine mammals, fish-eating birds, and waterfowl. The family contains 10 genera, with approximately 127 species. Polymorphids are characterized by having a spinose trunk with a bulbous proboscis, double-walled proboscis receptacle, long lemnisci, and 4 tubular cement glands. The taxonomic position of several genera within Polymorphidae has been controversial when considering morphological and ecological characters. The mitochondrial coding gene cytochrome-c oxidase representing species of 5 genera of polymorphids (Corynosoma, Luhe, 1904, Hexaglandula Petrochenko, 1950, Southwellina Witenberg 1932, Polymorphus Luhe, 1911, and Profilicollis Meyer, 1931) were sequenced to determine the sister-group relationships among 2 particular genera, i.e., Hexaglandula, and Profilicollis. Maximum likelihood and Bayesian analyses showed that Polymorphidae is a monophyletic assemblage, and that 3 major clades are present. Our resul...
TL;DR: The discovery of sulfaquinoxaline is described as a practical therapeutic agent, and the way in which the discovery arose from a partnership between industry and academia is examined.
Abstract: Sulfaquinoxaline played an important part in the demotion of roast chicken from vaunted Sunday-dinner status to an unrespected position on the everyday menu of the Western world. It had its origins in the chemical synthetic program that sprang from the introduction of sulfonamide drugs into human medicine in the 1930s. The program was sustained through the years of World War II despite declining clinical use of that chemical class. Several sulfa drugs were known to be active against the sporozoan parasite (Plasmodium spp.) that causes malaria, but were not satisfactory in clinical practice. A sulfonamide that had a long plasma half-life would ipso facto be considered promising as an antimalarial drug. Sulfaquinoxaline, synthesized during the war, was such a compound. It proved too toxic to be used in human malaria, but was found to be a superior agent against another sporozoan parasite, Eimeria spp., the causative agent of coccidiosis in domestic chickens. In 1948 sulfaquinoxaline was introduced commercially as a poultry coccidiostat. It was not the first sulfonamide found active against Eimeria spp. in poultry, but its practical success in disease control firmly established the routine incorporation of anticoccidial drugs in poultry feed. In this way, the drug exerted a major impact on the worldwide production of poultry meat. Although it has long been eclipsed by other drugs in poultry management, it continues to be used in other host species. This article describes the discovery of sulfaquinoxaline as a practical therapeutic agent, and examines the way in which the discovery arose from a partnership between industry and academia.
TL;DR: The first epidemiological study of T. gondii prevalence in rural Mexico found the highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions.
Abstract: There is scarce information concerning the epidemiology of Toxoplasma gondii infection in people of rural Mexico. Anti-T. gondii immunoglobulin (Ig)G and IgM antibodies were sought in 462 adult inhabitants from 3 rural communities of Durango, Mexico, using enzyme-linked immunoassays. In total, 110 (23.8%) of 463 persons had IgG anti-T. gondii antibodies. Ten (2.2%) of them also had IgM anti-T. gondii antibodies. Prevalences of T. gondii IgG antibodies in the 3 communities varied from 14.8 to 35.8%. The highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions. Toxoplasma gondii infection was significantly associated with consumption of squirrel (adjusted odds ratio [OR] = 4.22; 95% confidence interval [CI] = 1.11–16.05) and turkey meat (adjusted OR = 4.58; 95% CI = 1.14–18.44). This is the first epidemiological study of T. gondii prevalence in rural Mexico.
TL;DR: The results show that the in vitro T. gondii model and SkMC are potential tools for both the study of cystogenesis using molecular approaches and the drug screening action on tissue cysts and bradyzoites.
Abstract: Toxoplasma gondii is a protozoan pathogen of birds and mammals, including humans. The infective stage, the bradyzoite, lives within cysts, which occur predominantly in cells of the central nervous system and skeletal and cardiac muscles, characterizing the chronic phase of toxoplasmosis. In the present study, we employed for the first time primary mouse culture of skeletal muscle cells (SkMC) infected with bradyzoites, as a cellular model for cystogenesis. The interconversion of bradyzoite and tachyzoite was analyzed by immunofluorescence using 2 stage-specific antibodies, i.e., anti-bradyzoite (anti-BAG1) and anti-tachyzoite (anti-SAG1). After 24 hr of interaction only bradyzoites were multiplying, as revealed by anti-BAG1 incubation; interconversion to tachyzoites was not observed. After 48 hr of infection, 2 types of vacuoles were seen, i.e., BAG1+ and SAG1+, indicating the presence of bradyzoites as well as their interconversion to tachyzoites. After 96 hr of infection, BAG1+ vacuoles presented a high...
TL;DR: This is the first report of isolation of viable T. gondii from dead T. truncatus and two of the 3 isolates have Type II alleles at all loci and belong to the clonal Type II lineage.
Abstract: Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. In previous serological surveys, >90% of bottlenose dolphins (Tursiops truncatus) from the coasts of Florida, South Carolina, and California had antibodies to T. gondii by the modified agglutination test (MAT). In the present study, attempts were made to isolate T. gondii from dead T. truncatus. During 2005, 2006, and 2007, serum or blood clot, and tissues (brain, heart, skeletal muscle) of 52 T. truncatus stranded on the coasts of South Carolina were tested for T. gondii. Antibodies to T. gondii (MAT 1:25 or higher) were found in 26 (53%) of 49 dolphins; serum was not available from 3 animals. Tissues (heart, muscle, and sometimes brain) of 32 dolphins (26 seropositive, 3 seronegative, and 3 without accompanying sera) were bioassayed for T. gondii in mice, or cats, or both. Tissues of the recipient mice were examined for T. gondii stages. Feces of recipient cats were examined for shedding of T. gondii oocysts, but none excreted oocysts. Toxoplasma gondii was isolated from hearts of the 3 dolphins (2 with MAT titers of 1:200, and 1 without accompanied serum) by bioassay in mice. Genotyping of these 3 T. gondii isolates (designated TgDoUs1-3) with the use of 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) revealed 2 genotypes. Two of the 3 isolates have Type II alleles at all loci and belong to the clonal Type II lineage. One isolate has a unique genotype. This is the first report of isolation of viable T. gondii from T. truncatus.
TL;DR: A multivariate analysis of risk factors showed that T. gondii infection was positively correlated with eating raw meat, but was not associated with the consumption of unwashed vegetables, drinking untreated water, a history of raising a cat, or blood transfusion.
Abstract: A total of 351 serum samples was examined for anti–T. gondii antibody titers; the overall seroprevalence was 3.7%. The Sabin– Feldman dye test (DT), latex agglutination test (LAT), and IgG enzyme-linked immunosorbent assay (IgG ELISA) indicated seroprevalences of 3.7%, 3.4%, and 4.0%, respectively. Compared with the DT, the sensitivities of the LAT and IgG ELISA were 84.6% and 100.0%, respectively, and the specificities of the LAT and IgG ELISA were both 99.7%. An increase in T. gondii seroprevalence with increasing age was detected, but the difference was not significant. The overall seroprevalence of T. gondii–antibody titers in pregnant Korean women was relatively low compared to those of Europeans and Americans. A multivariate analysis of risk factors showed that T. gondii infection was positively correlated with eating raw meat, but was not associated with the consumption of unwashed vegetables, drinking untreated water, a history of raising a cat, or blood transfusion. The consumption of raw or unde...
TL;DR: Pentastomiasis should be considered in differential diagnosis of patients with a history of abdominal symptoms and eating of poorly cooked snakes, and this is only the second case of human P. taiwana sp.
Abstract: 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 poor...
TL;DR: 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.
Abstract: 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.
TL;DR: In this paper, the effects of seasonal and agricultural activity on the parasite communities of newly metamorphosed northern leopard frogs (Rana pipiens) were investigated in 5 wetlands, 3 of which were exposed to pesticide runoff from surrounding agriculture.
Abstract: Parasite community structure can change seasonally with shifts in host habitat and in diet. However, anthropogenic activity may influence the natural changes in transmission dynamics of different parasite species. Effects of seasonal and agricultural activity on the parasite communities of newly metamorphosed northern leopard frogs (Rana pipiens) were investigated in July and September 2001 in 5 wetlands, 3 of which were exposed to pesticide runoff from surrounding agriculture. Nineteen parasite taxa were found. Component community richness was consistently high at the pristine reference wetland, whereas the communities at a managed reference wetland remained depauperate. Infracommunity richness increased throughout the season, but more so in frogs resident in agricultural wetlands. Digeneans using frogs as intermediate hosts dominated the communities, although many species were much lower in abundance in September, suggesting mortality of heavily infected frogs. Mean abundance of Haematoloechus spp. was positively related to that of odonate naiads in the frog diet, which appeared to reflect differential second intermediate host availability between reference and agricultural wetlands. Although virtually absent from wetlands in July just after frog metamorphosis, monoxenous nematodes were more prevalent and abundant at agricultural wetlands as the season progressed. Our results suggest that agricultural activity may further facilitate the transmission of monoxenous nematodes as frogs become more terrestrial.
TL;DR: Results indicate a low prevalence of T. gondii in ruminants tested, and selection of owners and animals in the second step of the 2-stage random sampling procedure and sampling software ‘survey toolbox.’
Abstract: Sera from 186 sheep, 83 cattle, and 103 water buffaloes from Punjab, India, were evaluated for antibodies to Toxoplasma gondii using a commercial ELISA kit. This study was planned using a 2-stage random sampling procedure and sampling software ‘survey toolbox.’ In the first step, villages were selected randomly from a sampling frame of all the villages of Punjab, followed by selection of owners and animals in the second step. Antibodies to T. gondii were found in 7 of 186 sheep, 2 of 83 cattle, and 3 of 103 buffaloes. Results indicate a low prevalence of T. gondii in ruminants tested.
TL;DR: It is indicated that trematodes are more common in protected areas and that in both habitats they are directly and positively related to surrounding host abundance, which supports the notion that treMatodes in first intermediate hosts can serve as bioindicators of the condition of free-living animal communities in diverse ecosystems.
Abstract: Trematode communities in populations of estuarine snails can reflect surrounding animal diversity, abundance, and trophic interactions. We know less about the potential for trematodes to serve as bioindicators in other habitats. Here, we reanalyze data from 2 published studies concerning trematodes, 1 in the Chilean rocky intertidal zone and the other from the East African rift lake, Lake Tanganyika. Our analyses indicate that trematodes are more common in protected areas and that in both habitats they are directly and positively related to surrounding host abundance. This further supports the notion that trematodes in first intermediate hosts can serve as bioindicators of the condition of free-living animal communities in diverse ecosystems.
TL;DR: The occurrence of Brueelia spp.
Abstract: 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 i...