Showing papers in "Journal of Parasitology in 2010"
TL;DR: An extensive literature review on studies that have used DNA sequences to detect cryptic species of parasites during the last decade found a lack of methodological and theoretical uniformity in the discipline for finding and delimiting cryptic species and recommended that parasitologists describe (and formally name) cryptic species following standard taxonomic practice.
Abstract: We conducted an extensive literature review on studies that have used DNA sequences to detect cryptic species of parasites during the last decade Each literature citation that included the term "cryptic" or "sibling" species was analyzed to determine the approach used by the author(s) Reports were carefully filtered to retain only those that recognized the existence of cryptic species centered on the use of DNA sequences Based on analysis of these papers, we comment on the different ways that parasite cryptic species are discovered in studies focusing on different aspects of the host-parasite relationship, or disciplines, within parasitology We found a lack of methodological and theoretical uniformity in the discipline for finding and delimiting cryptic species, and we draw attention to the need for standardizing these approaches We suggest that cryptic species, in the strict sense, are always provisionally cryptic, in that the possibility does exist that new morphological studies or techniques will reveal previously unknown diagnostic structural differences which will permit rapid and practical morphological diagnosis To avoid future taxonomic confusion, we recommend that parasitologists describe (and formally name) cryptic species following standard taxonomic practice
180 citations
TL;DR: The hypothesis that avian malaria currently restricts the altitudinal distribution of Hawaiian honeycreeper populations and provide an ecological explanation for the absence of disease at high elevation is supported.
Abstract: More than half of the Hawaiian honeycreepers (Drepanidinae) known from historical records are now extinct. Introduced mosquito-borne disease, in particular the avian malaria Plasmodium relictum, has been incriminated as a leading cause of extinction during the 20th century and a major limiting factor in the recovery of remaining species populations. Today, most native Hawaiian bird species reach their highest densities and diversity in high elevation (>1,800 m above sea level) forests. We determined the thermal requirements for sporogonic development of P. relictum in the natural vector, Culex quinquefasciatus, and assessed the current distribution of native bird species in light of this information. Sporogonic development was completed at constant laboratory and mean field temperatures between 30 and 17 C, but development, prevalence, and intensity decreased significantly below 21 C. Using a degree-day (DD) model, we estimated a minimum threshold temperature of 12.97 C and a thermal requirement ...
153 citations
TL;DR: The association of both Culex species with most Plasmodium clades, and the presence of a single parasite lineage in 3 mosquito species representing 2 genera, suggests that avian Plas modium species are not tightly coevolved with vector species.
Abstract: Assessing parasite specificity to vector is crucial to understanding the emergence of vector-borne diseases and the evolution of parasite diversity. Avian malaria parasites have a cosmopolitan distribution and broad avian host range, which together predict they are vector generalists, but little is known about parasite-vector associations in the wild. We tested this prediction by asking if 5 different mosquito species, known to feed on birds and abundant in the northeastern United States, were naturally infected in the field with identical avian Plasmodium spp. lineages. Mosquitoes were not pooled but rather analyzed individually, and, possibly as a result, lineage diversity was higher than reported in previous avian malaria vector studies. Plasmodium spp. lineages were rare in Aedes canadensis and absent in Aedes aurifer and Culiseta melanura. We sequenced a standard Plasmodium cytochrome b marker from Culex pipiens pipiens, Culex restuans, and Ae. canadensis. Most Plasmodium clades were shared by Cx. pipiens and Cx. restuans. In addition, 4 individual lineages were shared by both mosquito species, including the most common lineage. One Plasmodium clade, however, was only found in Cx. restuans. We therefore found limited support for our prediction that avian Plasmodium spp. vector breadth accompanies host breadth. The association of both Culex species with most Plasmodium clades, and the presence of a single parasite lineage in 3 mosquito species representing 2 genera, suggests that avian Plasmodium species are not tightly coevolved with vector species.
115 citations
TL;DR: In this paper, the variation of parasitemia intensity and co-infections of avian haemosporidian parasites (Plasmodium and Haemoproteus species) in two common African birds species, the yellow-whiskered greenbul (Andropadus latirostris) and the olive sunbird (Cyanomitra olivacea), at 3 sites with distinct habitat characteristics in Ghana.
Abstract: Spatial heterogeneity influences the distribution, prevalence, and diversity of haemosporidian parasites. Previous studies have found complex patterns of prevalence with respect to habitat characteristics and parasite genotype, and their interactions, but there is little information regarding how parasitemia intensity and the prevalence of co-infections may vary in space. Here, using both molecular methods and microscopy, we report an analysis of the variation of parasitemia intensity and co-infections of avian haemosporidian parasites (Plasmodium and Haemoproteus species) in 2 common African birds species, the yellow-whiskered greenbul (Andropadus latirostris) and the olive sunbird (Cyanomitra olivacea), at 3 sites with distinct habitat characteristics in Ghana. First, we found an interaction between the site and host species for the prevalence of Plasmodium spp. and Haemoproteus spp. For the olive sunbird, the prevalence of Plasmodium spp., as well as the number of individuals with co-infections, varied significantly among the sites, but these measures remained constant for the yellow-whiskered greenbul. In addition, yellow-whiskered greenbuls infected with Haemoproteus spp. were found only at 1 site. Furthermore, for both bird species, the parasitemia intensity of Plasmodium spp. varied significantly among the 3 sites, but with opposing trends. These results suggest that spatial heterogeneity differently affects haemosporidian infection parameters in these vertebrate-hosts. Environmental conditions here can either favor or reduce parasite infection. We discuss the implications of these discrepancies for conservation and ecological studies of infectious diseases in natural populations. Spatial heterogeneity affects community structure and ecological processes, including host-parasite interactions. Transmission of infectious disease is a result of complex interactions between abiotic factors and biotic components. First, environmental conditions can strongly impact parasite species diversity and abundance, either favoring or limiting parasite numbers and, thereby, affecting the prevalence of host infection. Several studies have shown correlated
94 citations
TL;DR: The morphology of its blood stages and segments of the mitochondrial cytochrome b gene can be used for molecular identification and diagnosis of this species, which is prevalent in the Galapagos dove and also has been recorded in other species of Columbiformes in Mexico, Guatemala, and Peru, and so seems to be widespread in countries with warm climates.
Abstract: Haemoproteus (Haemoproteus) multipigmentatus n. sp. (Haemosporida, Haemoproteidae) was found in the endemic Galapagos dove Zenaida galapagoensis. It is described based on the morphology of its blood stages and segments of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis of this species. Haemoproteus multipigmentatus can be readily distinguished from all species of hemoproteids of the subgenus Haemoproteus, primarily due to numerous (approximately 40 on average) small pigment granules in its mature gametocytes. Illustrations of blood stages of the new species are given, and phylogenetic analysis identifies DNA lineages closely related to this parasite, which is prevalent in the Galapagos dove and also has been recorded in other species of Columbiformes in Mexico, Guatemala, and Peru, and so seems to be widespread in countries in the New World with warm climates. Cytochrome b lineages of H. multipigmentatus cluster with hippoboscid-transmitted lineages of Haemoproteus columbae. The same lineages of H. multipigmentatus were recorded in thoraxes of the hippoboscid fly Microlynchia galapagoensis, which likely is a natural vector of this parasite in Galapagos. Because different primers might amplify different parasites if they have a better match during a simultaneous infection, it is important that researchers standardize the genetic marker of choice for molecular typing of hemosporidian species. This study shows that more discussion among researchers is needed to clearly establish the sequence length and number of genes used for identification of hemosporidian parasites at different taxonomic levels. We point to the need of using both morphology and gene markers in studies of hemosporidian parasites, particularly in wildlife.
78 citations
TL;DR: The results indicate that these 2 genotypes may be the major lineages in China, and have implications for the prevention and control of T. gondii infections in humans and other animals.
Abstract: Toxoplasma gondii genetic diversity varies in different geographical regions. In South America, T. gondii isolates are highly diverse, whereas in North America and Europe, the parasite is highly clonal, with 3 distinct lineage types (I, II, III). However, little is known of the T. gondii genotypes in the People's Republic of China. Because pork is considered the principal meat source for T. gondii infection in China, we conducted a survey to determine the prevalence and genetic diversity of this parasite in pigs from central China. In total, 434 DNA samples were extracted from the hilar lymph nodes of sick pigs in Hubei and Henan provinces in central China, and 34 were T. gondii B1 gene-positive. These T. gondii-positive DNA samples were typed at 10 genetic markers, including 9 nuclear loci, i.e., SAG1, SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico. Of these, 16 isolates could be genotyped with complete data for all loci. Two genotypes were present; one was the cl...
76 citations
TL;DR: Results in this study indicate that T. gondii on this island consists of unique genotypes as well as clonal genotypes that are dominant in Europe and North America.
Abstract: Worldwide comparison of Toxoplasma gondii isolates from free-range chickens (Gallus domesticus) has indicated that T. gondii isolates from Brazil are phenotypically and genetically different from isolates from other countries; most strains from Brazil are pathogenic to mice, there is great genetic variability, most isolates are nonclonal, and Type II is absent or rare. The prevalence of T. gondii in 50 free-range chickens from the island of Fernando de Noronha, Brazil (this island is 350 km from the mainland) was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT); 42 (84%) chickens had titers of 1∶5 in 2, 1∶10 in 4, 1∶20 in 3, 1∶40 in 6, 1∶80 in 6, 1∶160 in 5, 1∶320 in 3, and 1∶640 or higher in 13 chickens. Hearts of 40 seropositive chickens were bioassayed individually in mice. Toxoplasma gondii was isolated from 24 chickens with MAT titers of 1∶5 or higher; the isolates were designated TgCKBr210-233. None of the isolates was pathogenic for mice. The restri...
69 citations
TL;DR: An Expressed Sequence Tag (EST) library-based analysis of the salivary transcriptome of the North American medicinal leech, Macrobdella decora, reveals a complex cocktail of anticoagulants and other bioactive secreted proteins not previously known to exist in a single leech.
Abstract: A variety of bioactive proteins from medicinal leeches, like species of Hirudo, have been characterized and evaluated for their potential therapeutic biomedical properties. However, there has not previously been a comprehensive attempt to fully characterize the salivary transcriptome of a medicinal leech that would allow a clearer understanding of the suite of polypeptides employed by these sanguivorous annelids and provide insights regarding their evolutionary origins. An Expressed Sequence Tag (EST) library-based analysis of the salivary transcriptome of the North American medicinal leech, Macrobdella decora, reveals a complex cocktail of anticoagulants and other bioactive secreted proteins not previously known to exist in a single leech. Transcripts were identified that correspond to each of saratin, bdellin, destabilase, hirudin, decorsin, endoglucoronidase, antistatin, and eglin, as well as to other previously uncharacterized predicted serine protease inhibitors, lectoxin-like c-type lectins...
63 citations
TL;DR: The authors may not be able to make you love reading, but toxoplasmosis of animals and humans second edition will lead you to love reading starting from now.
Abstract: We may not be able to make you love reading, but toxoplasmosis of animals and humans second edition will lead you to love reading starting from now. Book is the window to open the new world. The world that you want is in the better stage and level. World will always guide you to even the prestige stage of the life. You know, this is some of how reading will give you the kindness. In this case, more books you read more knowledge you know, but it can mean also the bore is full.
62 citations
TL;DR: Comparisons across parasite genera and/or host species from different sources need to consider several types of bias originating from variation in method sensitivity, indicating that differences between studies can affect detected estimates.
Abstract: Inferences about the evolution of host-parasitic relationships are often made based on the prevalence of avian malaria, which is usually estimated in a large sample of birds using either microscopic or molecular screening of blood samples. However, different techniques often have variable accuracy; thus, screening methodology can raise issues about statistical bias if method sensitivity varies systematically across parasites or hosts. To examine this possibility, published information was collected on the prevalence of species in 4 genera of avian blood parasites ( Plasmodium, Haemoproteus, Leucocytozoon, and Trypanosoma) from various sources that used different tools. The data were tested to determine if the application of different methods provided different estimates for the same hosts. In these comparisons between the main methodologies, the PCR-based molecular methods were generally found to provide higher estimates for Plasmodium spp. prevalence than microscopic tools, while there was no significant tendency for such a trend in species of Haemoproteus and Leucocytozoon. When analyzing intraspecific variance of prevalence within molecular studies, some studies provided consistently higher estimates for Haemoproteus spp. prevalence than others, indicating that differences between studies can affect detected estimates. Within microscopic studies, surveys that examined more microscopic fields were more likely to report higher prevalence for Plasmodium spp. than those relying on fewer microscopic fields. Consequently, studies making comparisons across parasite genera and/or host species from different sources need to consider several types of bias originating from variation in method sensitivity.
62 citations
TL;DR: It is suggested that future survey work aimed at enhancing the biodiversity inventory should be strategic, i.e., it should combine the need to target missing components of the host spectrum with the choice of appropriate drainages based on biogeographic, faunistic, and hydrologic data.
Abstract: Freshwater fish helminth parasites are undoubtedly the most well-known group among vertebrate parasites in Mexico; these parasites include 37 adult and 43 larval (metacercariae) species of trematodes, 62 monogeneans, 15 adult and 18 larval (metacestode) cestodes, 6 adult and 4 larval (cystacanth) acanthocephalans, and 54 adult and 15 larval nematodes (L3). Here, we evaluate the extent of the freshwater fish helminth inventory of Mexico using species accumulation curves and discuss the implications of DNA-based taxonomic methods in our understanding of the helminth biodiversity in freshwater fishes. Future directions for the study of the helminth parasites of freshwater fishes are proposed, particularly the role of DNA-based species delimitation criteria in recognizing parasite species, but also in discovering cryptic species. Species accumulation curves indicate that even though the asymptote has not been reached, a tendency toward stabilization is observed in all taxonomic groups except monogeneans. We suggest, therefore, that the inventory, as conventionally understood, is nearing completion for most groups. We suggest that future survey work aimed at enhancing the biodiversity inventory should be strategic, i.e., it should combine the need to target missing components of the host spectrum with the choice of appropriate drainages based on biogeographic, faunistic, and hydrologic data. We also posit that the future belongs to DNA-based taxonomic approaches that aim to uncover previously unrecognized biodiversity.
TL;DR: The high prevalence of T. gondii in feral cats in Egypt reported here indicates a high environmental contamination with oocysts.
Abstract: Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 158 feral cats from Giza, Egypt, were examined for T. gondii infection. Antibodies to T. gondii were found in 97.4% with the modified agglutination test. Viable T. gondii was isolated from tissues (brain, heart, tongue) of 115 of 137 cats by bioassay in mice. These isolates were designated TgCatEg 1-115; none of these isolates was virulent to out-bred Swiss Webster mice. Of the 112 seropositive cats whose tissues were bioassayed individually, T. gondii was isolated from the hearts of 83 (74.1%), tongues of 53 (47.3%), and brains of 36 (32.1%). Toxoplasma gondii oocysts were not detected in rectal contents of any of the 158 cats, probably related to high seropositivity (chronic infection) of cats surveyed. The high prevalence of T. gondii in feral cats in Egypt reported here indicates a high environmental contamination with oocysts.
TL;DR: The new species appears to have a life cycle with a larva that feeds on bats, a non-feeding nymphal stage (nymph I), a feeding nymphAL stage (NYmph II), and adults that probably represent non- feeding stages.
Abstract: Nothoaspis amazoniensis n. sp. (Acari: Ixodida: Argasidae) is described from adult and immature ticks (nymph II, nymph I, larva) collected from bat caves in the Brazilian Amazon. Also, 16S rDNA sequences are provided. The diagnostic characters for adults are the presence of false shield or nothoaspis, an anteriorly projecting hood covering the capitulum, a medial extension of palpal article I (flaps), genital plate extending from coxa I to IV, absence of 2 setae on the internal margin of the flaps, a minute hypostome without denticles, presence of a central pore in the base of hypostome, and a reticulate surface pattern on the posterior half of the nothoaspis in males. The nymph II stage is characterized by a hood that is small in relation to the capitulum, short coxal setae, palpal flaps lacking setae on the internal margin, long hypostome, pointed with dentition 4/4 apically, and the anterior half of the body is covered by a cell-like configuration. Nymph I stage is characterized by a hood, sma...
TL;DR: A strong clonal population structure with the dominance of clonal Type II and III lineages of T. gondii in feral cats from Egypt is revealed.
Abstract: Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 115 viable T. gondii isolates from tissues of cats from Egypt were genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and DNA from tachyzoites. Seven genotypes were recognized including the clonal Type II, Type III (2 genotypes), and 4 atypical genotypes. Ninety percent (103 of 115) of isolates were clonal, i.e., Type II (n = 61) and Type III (n = 42) strains. Of the 61 Type II strains, all had the Type II alleles at all loci, except for 2 strains that had allele I at Apico. Eight isolates were divided into 4 atypical genotypes. One of these genotypes (with 4 isolates) was previously reported in dogs from Sri Lanka and in sand cats from the United Arab Emirates. Four isolates had mixed infections. These results revealed a strong clonal po...
TL;DR: The findings indicate that E. bieneusi from horses can be a potential source of infection for humans, and three genotypes appear to be unique to horses.
Abstract: This is the first report of Enterocytozoon bieneusi in an equid species. Feces from 195 horses from 4 locations in Colombia were examined for E. bieneusi by polymerase chain reaction. Of these, 21 horses (10.8%) were found positive for E. bieneusi. The prevalence of E. bieneusi in horses ,1 yr of age was significantly higher (23.7%) than in horses .1 yr of age (2.5%). No significant differences in prevalence were observed between male (13.7%) and female horses (9%). Sequencing of the internal transcribed spacer region of the SSUrRNA locus identified 3 genotypes. Two genotypes appear to be unique to horses and were named Horse 1 and Horse 2. A third genotype, identified as genotype D, was detected in 4 horses. This genotype, previously reported to infect humans, beaver, cattle, dogs, falcons, foxes, macaques, muskrats, pigs, and raccoons, is the most ubiquitous of the E. bieneusi zoonotic genotypes. Our findings indicate that E. bieneusi from horses can be a potential source of infection for humans. Microsporidia are obligate, intracellular parasites consisting of more than 1,200 species in 143 genera. They infect a wide range of invertebrate and vertebrate hosts. Of 14 species in 6 genera reported to infect humans, Enterocytozoon bieneusi is recognized as the most common microsporidian species (Didier and Weiss, 2006). Enterocytozoon bieneusi has been also detected in a broad range of animals, raising the concern that animals could be a potential source of infection for humans. Considerable genetic diversity within E. bieneusi has been observed, with more than 80 genotypes of the parasite differentiated based on polymorphisms of the internal transcribed spacer (ITS) sequence of the rRNA gene; some genotypes appear to be host specific, while others have a broad host range, supporting the likelihood of zoonotic transmission (Santin and Fayer, 2009). The only published reports of testing for microsporidia in equids were of horses and donkeys in Switzerland and Spain, which were found to be negative for the parasite (Breitenmoser et al., 1999; Lores et al., 2002). The present study was conducted to examine horses from a different geographic location, Colombia, South America, for the presence of E. bieneusi in their feces.
TL;DR: The prevalence of T. gondii infection and associated epidemiological characteristics in 472 patients in Durango, Mexico is determined, the first step in the design of prevention programs to avoid the sequelae of toxoplasmosis.
Abstract: Toxoplasma gondii infection may cause a variety of symptoms involving virtually all organs. Little is known of the epidemiology of T. gondii infection in different patient groups in Mexico. We sought to determine the prevalence of T. gondii infection and associated epidemiological characteristics in 472 patients in Durango, Mexico. Participants were tested for T. gondii IgG and IgM antibodies. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. Seroprevalences of T. gondii IgG antibodies were found in 7 (8.2%) of 85 patients with hearing impairment, 5 (10.0%) of 50 patients with hemodialysis, 28 (12.0%) of 234 patients with visual impairment, and 7 (6.8%) of 103 at risk of immunosuppression. In total, 47 (10%) of 472 subjects had IgG T. gondii antibodies; 6 (1.3%) of them also had IgM anti–T. gondii antibodies. Patients born in Durango State had a significantly lower prevalence of T. gondii infection than patients born in other Mexican stat...
TL;DR: Mapping the flow of parasites throughout the major crustacean species, identifying hosts that play the most important transmission role for each parasite, and assessing the impact of parasitism on host populations find the different parasite species make different use of available crustACEan intermediate hosts and possibly contribute to intertidal community structure.
Abstract: Patterns of host use by parasites throughout a guild community of intermediate hosts can depend on several biological and ecological factors, including physiology, morphology, immunology, and behavior. We looked at parasite transmission in the intertidal crustacean community of Lower Portobello Bay, Dunedin, New Zealand, with the intent of: (1) mapping the flow of parasites throughout the major crustacean species, (2) identifying hosts that play the most important transmission role for each parasite, and (3) assessing the impact of parasitism on host populations. The most prevalent parasites found in 14 species of crustaceans (635 specimens) examined were the trematodes Maritrema novaezealandensis and Microphallus sp., the acanthocephalans Profilicollis spp., the nematode Ascarophis sp., and an acuariid nematode. Decapods were compatible hosts for M. novaezealandensis, while other crustaceans demonstrated lower host suitability as shown by high levels of melanized and immature parasite stages. Carapace thickness, gill morphology, and breathing style may contribute to the differential infection success of M. novaezealandensis and Microphallus sp. in the decapod species. Parasite-induced host mortality appears likely with M. novaezealandensis in the crabs Austrohelice crassa, Halicarcinus varius, Hemigrapsus sexdentatus, and Macrophthalmus hirtipes, and also with Microphallus sp. in A. crassa. Overall, the different parasite species make different use of available crustacean intermediate hosts and possibly contribute to intertidal community structure. At any stage of their life cycle, parasites can potentially use several sympatric host species belonging to either the same taxonomic group or ecological guild (sensu Root, 1967). Thus, trophically transmitted helminths can employ, as intermediate hosts, any species used as prey by the definitive host, provided they are able to survive and develop in those species. In natural communities, several co-existing parasite species with the same definitive hosts can potentially use the same intermediate host species. Alternatively, they may flow through the community in different ways, i.e., they may differ in how they utilize the variety of intermediate hosts available. Patterns of host use can play important roles in determining the structure of host communities, since they will determine how parasites affect relative host population abundances (Minchella and Scott, 1991; Hudson
TL;DR: To the authors' knowledge, this is the first serological detection of antibodies to N. caninum in Brazilian wild captive felids and bush dogs (Speothos venaticus (Lund)).
Abstract: This study was designed to detect antibodies to Toxoplasma gondii and Neospora caninum in wild captive carnivores maintained in Brazilian zoos. Blood samples were collected from 142 Brazilian wild felids and 19 exotic felids in zoos, and 3 European wolves (Canis lupus) and 94 Brazilian wild canids maintained in captivity in Brazilian zoos of Sao Paulo, Mato Grosso states and Federal District. One hundred and two (63.4%) and 70 (50.3%) of the 161 wild felids tested were seropositive for T. gondii and N. caninum by indirect immunofluorescent assay test (IFAT), respectively. Among sampled wild canids, 49 (50.5%) and 40 (41.2%) animals were seropositive for T. gondii and N. caninum antigens by IFAT, respectively. To our knowledge, this is the first serological detection of antibodies to N. caninum in Brazilian wild captive felids and bush dogs (Speothos venaticus (Lund)).
TL;DR: This study presents the first quantitative data on the Pristionchus spp.
Abstract: Pristionchus spp. nematodes exhibit several traits that might serve as pre-adaptations to parasitism. Under harsh environmental conditions, these nematodes can arrest development and form dauer larvae. In addition, they have been shown to live in necromenic association with a range of beetles, including dung beetles (Geotrupes stercorosus) on which, for example, Pristionchus entomophagus is commonly found. It has been argued that the formation of dauer larvae and the association with invertebrates represent intermediate steps towards parasitism. To better understand necromenic associations, and to gain information on Pristionchus spp. abundance and the general species composition on dung beetles, we extracted all the nematode fauna present on 114 individuals of G. stercorosus. By direct sequencing using the 18S SSU, we provide a barcode for all nematodes isolated from the beetle samples. In total, 5,002 dauer-stage nematodes were sequenced, which included Pristionchus spp., Koerneria spp. (Diplog...
TL;DR: Results indicate that ECG can be used as a non-invasive method to screen for immune-mediated damage resulting in chagasic cardiomyopathy in the murine model.
Abstract: Chagas' disease, induced by Trypanosoma cruzi, is a common cause of infectious myocarditis. Recent clinical treatment trials and vaccine studies indicate that chagasic immunopathology is directed against the parasite and not self-antigens. Therefore, vaccines may have the potential to protect against disease progression. Certain combinations of mouse and parasite strains produce significant histopathology and can be used for safety analyses of new vaccination strategies. The goals of this study were to determine (1) whether the development of chagasic cardiomyopathy in the murine model could be identified by electrocardiogram (ECG); and (2) whether these potential chagasic ECG changes would correlate with histopathologic findings. Groups of BALB/c, C57BL/6, and C3H mice were infected with different parasite strains (Tulahuen, Brazil, or Sylvio-X10/4) and evaluated weekly by ECG. Selected tissues from subsets of mice were harvested periodically for blinded histologic evaluation. Significantly incr...
TL;DR: In the total population, the prevalence of T. gondii infection was significantly higher in workers living in suburban areas, without education, workers that consumed chorizo, and those who suffered from any disease (P < 0.05).
Abstract: Water, sewage, and soil are potential sources of infection for Toxoplasma gondii. Therefore, we sought to determine the prevalence of T. gondii infection and associated characteristics in 61 plumbers, 203 construction workers, and 168 gardeners in Durango City, Mexico. Participants were tested for T. gondii IgG and IgM antibodies with the use of enzyme-linked immunoassays. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. IgG T. gondii antibodies were found in 4 (6.6%) plumbers, 17 (8.4%) construction workers, and 10 (6.0%) gardeners; T. gondii IgM antibodies were found in 3 (1.5%) construction workers and 4 (2.4%) gardeners, but in none of the plumbers. In the total population, the prevalence of T. gondii infection was significantly higher in workers living in suburban areas, without education, workers that consumed chorizo, and those who suffered from any disease (P < 0.05). In gardeners, prevalence of infection was significantly higher...
TL;DR: Data indicate that the distribution of B. procyonis within Georgia is increasing and only limited genetic variation is present in the rRNA and ITS gene regions among B.procyonis from the southern United States and introduced populations in Japan.
Abstract: Baylisascaris procyonis is an intestinal nematode of raccoons (Procyon lotor) that can cause fatal larval migrans in numerous species of birds and mammals, including humans. Although this parasite has historically been absent in the southeastern United States, it has been found in isolated regions in the Appalachian Mountains and was recently documented in DeKalb County, Georgia. The first objective of the current study was to investigate the distribution and prevalence of B. procyonis in selected populations of raccoons in Georgia. Intestinal tracts of 312 raccoons from 25 Georgia counties were examined for B. procyonis. The only county where B. procyonis was detected was Clarke County, where 12 of 116 (10.3%) raccoons were infected. In Clarke County, significantly more juveniles (P 5 0.049) were infected compared with adults, and no differences in prevalence were noted by sex, season of capture, or land use (rural vs. urban); however, significantly (P 5 0.0370) higher worm burdens were found in infected raccoons from urban/suburban locations compared with rural areas. In addition, Toxascaris leonina, a morphologically similar ascarid, was found in 3 raccoons from Clarke County (n 5 2) and Morgan County (n 5 1). A second objective was to determine if sequence polymorphisms were associated with B. procyonis from different geographic regions. Because sequences from a single worm from Japan had been entered into GenBank, we obtained nematodes from Kentucky and Texas for comparison with our samples from Georgia. Sequence analysis of the 18S and 5.8S rRNA genes and the internal transcribed spacer (ITS) -1 and ITS-2 regions confirmed Georgia samples were B. procyonis. Although several polymorphic bases were observed within both ITS regions, none was associated with a particular geographic location. These data indicate that the distribution of B. procyonis within Georgia is increasing and only limited genetic variation is present in the rRNA and ITS gene regions among B. procyonis from the southern United States and introduced populations in Japan.
TL;DR: Data are shown explicitly how Bd infection reduces foraging efficiency of anuran tadpoles by altering feeding kinematics and elucidate a mechanistic link between the pathogen infection and reduced host fitness.
Abstract: Pathogens can alter host life-history traits by affecting host feeding activities. In anuran tadpoles, keratinized mouthparts (teeth and jaw sheaths) are essential for feeding. Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus of amphibians that can infect these mouthparts and reduce tadpole survival. However, the precise way that Bd-induced changes in tadpole mouthparts impact tadpole feeding is unknown. We use high-speed (500 frames/sec) videography to study how Bd-induced mouthpart deformities affect the feeding kinematics of Fowler's toad (Anaxyrus [ = Bufo] fowleri) and grey tree frog (Hyla chrysoscelis) tadpoles. We tested for species-specific patterns of Bd-induced mouthpart deformities to assess how deformations to specific areas of tadpole mouthparts alter feeding kinematics. The teeth of tadpoles from the Bd-exposed treatment slipped off of surfaces on which tadpoles graze and were in contact with an algal-covered substratum for a shorter duration in each gape cycle compared t...
TL;DR: Results indicate that mouse-virulent atypical T. gondii genotypes are also circulating in wildlife in North America.
Abstract: Most strains of Toxoplasma gondii isolated in North America and Europe are grouped into 3 (Types I, II, III) genotypes and are considered clonal. Recent evidence suggests that illness due to toxoplasmosis in immunocompetent persons may be related to infection with an atypical genotype; these strains are mouse virulent. In the present study, a new mouse-virulent atypical T. gondii genotype was isolated from an asymptomatic black bear (Ursus americanus) from Alaska. The bear had a titer of 1∶1,600 using the modified agglutination test for T. gondii. Swiss Webster out-bred mice inoculated with bear heart homogenate died of acute toxoplasmosis, 12 days post-inoculation (PI). Cats fed tissues from chronically infected animals (day 30 PI) shed oocysts, but only 1 of 3 cats fed acutely infected mice (12, 16, 18 days PI) shed oocysts. The isolate (designated TgBbUS1) was mouse virulent; mice inoculated with 1 oocyst or 1 tachyzoite died of acute toxoplasmosis. The restricted fragment length polymorphism ...
TL;DR: Results based on phylogenetic analysis of the mitochondrial DNA suggest that the larval stages of T. multiceps gaigeri and C. cerebralis, which showed similar morphological criteria, are monophyletic species.
Abstract: Coenurus gaigeri is the larval stage of Taenia multiceps gaigeri, which infects the muscles of goats and, to a lesser extent, sheep. Metacestodes of the goat such as Coenurus cerebralis, Cysticercus tenuicollis, Cysticercus ovis, and hydatid cysts have been extensively studied. However, because of the uncommon occurrence of C. gaigeri, very few records exist of its biology, pathogenesis, and pathology. Therefore, an investigation was conducted in the summer of 2008 at Shiraz Slaughterhouse, where 2.6% of the goats were infected with intramuscular cysts. Scolices from coenuri were collected for morphologic analysis, and the cysts were identified as C. gaigeri, the intermediate stage of T. multiceps gaigeri. In addition, molecular genetic markers of mitochondrial DNA were applied phylogenetically to resolve the questionable relationship between C. gaigeri and C. cerebralis. All coenuri fluids were aspirated and centrifuged separately; the supernatants were analyzed for biochemical features that included glucose, total protein, urea nitrogen, uric acid, triglycerides, cholesterol, creatinine, calcium, sodium, potassium, alanine aminotransferase, and aspartate aminotransferase. The pathologic changes around the coenuri included mechanical destruction of the affected tissues, associated with degenerative and necrotic changes, infiltration by polymorphonuclear and mononuclear cells, proliferation of fibroblasts, and development of adventitious tissue. Results based on phylogenetic analysis of the mitochondrial DNA (CO1 and ND1) suggest that the larval stages of T. multiceps gaigeri and C. cerebralis, which showed similar morphological criteria, are monophyletic species. However, C. gaigeri interestingly were situated in the biceps femoris, triceps, and abdominal muscles without localization in the nervous system.
TL;DR: This study indicates that R. africae and African tick-bite fever are widespread in the Caribbean.
Abstract: We used PCRs with ompA primers to determine if spotted fever group rickettsiae occurred in Amblyomma variegatum from 6 Caribbean islands. Positive amplicons were obtained from ticks from the U.S. Virgin Islands (9/18; 50%), Dominica (39/171; 30%), Montserrat (2/5; 40%), Nevis (17/34; 50%), St. Kitts (46/227; 20%), and St. Lucia (1/14; 7%). Sequences for a convenience sample of reaction products obtained from A. variegatum on St. Kitts (7), American Virgin Islands (4), Montserrat (2), and St. Lucia (1) were 100% homologous with that of Rickettsia africae, the agent of African tick-bite fever. To determine if transmission of R. africae occurred, we used Rickettsia rickettsii antigen in IFA tests and found positive titers (≥1/80) with sera from cattle, goats, and sheep from Dominica (24/95 [25%], 2/136 [2%], 0/58 [0%]), Nevis (12/45 [27%], 5/157 [3%], 0/90 [0%]), St. Kitts (2/43 [5%], 1/25 [4%), 1/35 [3%]), and St. Lucia (6/184 [3%] cattle), respectively. No seropositive animals were found in Grenad...
TL;DR: In this paper, a muscle digestion of 2,483 carnivorous wild animals from 9 host species during 1999-2005 showed 617 positive animals (24.8%) were infected with Trichinella sp. infection in pork.
Abstract: Although human infections caused by Trichinella sp. have not been reported in Finland for several decades and Trichinella sp. infection in pork has become virtually extinct in the last decade, sylvatic Trichinella spp. infection is still highly prevalent in Finland. Muscle digestion of 2,483 carnivorous wild animals from 9 host species during 1999–2005 showed 617 positive animals (24.8%). Molecular identification from 328 larval isolates revealed 4 different endemic Trichinella species, i.e., T. nativa, T. spiralis, T. britovi, and T. pseudospiralis. Seven percent of the infected animals carried mixed infections. Trichinella nativa was the most common species (74%), but T. spiralis was identified in 12%, T. britovi in 6%, and T. pseudospiralis in 1% of the animals. Host species showed different sample prevalence and Trichinella species distribution. Geographical distribution also varied, with the southern part of the country having significantly higher percentages than the northern part. Infectio...
TL;DR: An outbreak of 81 cases of angiostrongyliasis cantonensis occurred in Beijing, China, during June through September 2006, with the main symptoms were fever, severe headache, neck stiffness, and skin paresthesia.
Abstract: An outbreak of 81 cases of angiostrongyliasis cantonensis (AC) occurred in Beijing, China, during June through September 2006. Epidemiological characteristics, clinical signs and symptoms, laboratory tests, imaging, and treatment data from the 81 AC patients were collected and analyzed. All cases had a history of eating raw freshwater snails, and acquired Angiostrongylus cantonensis as a result. The incubation period ranged from 1 to 36 days. The main symptoms were fever, severe headache, neck stiffness, and skin paresthesia. A significant increase in eosinophilia occurred in the peripheral blood of 62 cases and in cerebrospinal fluid of 64 cases; 36 patients presented a linearly enhanced abnormal signal of the leptomeninges site during a cranial MRI examination, indicative of meningitis; 18 cases had a significant nodule shadow and spot flaky ground-glass shadow on chest computerized tomography. All patients were relieved of their illness with a 7-day treatment of albendazole.
TL;DR: In this article, three subtractive cDNA libraries were constructed for three stages of Eimeria tenella including unsporulated oocysts, sporulated oocytests, and sporozoites.
Abstract: Avian coccidiosis, a major parasitic disease of poultry, is caused by Eimeria spp. infection. It inflicts severe economic losses on the poultry industry worldwide. To further understand the molecular basis of sporulation and invasion of Eimeria spp., suppression subtractive hybridization and microarray approaches were combined to identify novel and important genes involved in the development and invasion of the early stages of Eimeria tenella. Three subtractive cDNA libraries were constructed for 3 stages of E. tenella including unsporulated oocysts, sporulated oocysts, and sporozoites. A subset of clones was selected from the 3 subtractive libraries to construct cDNA microarrays. Microarray analysis was used to assay expression changes of these clones. A total of 657 valid expressed sequence tags (ESTs) was obtained, including 119 unique sequences, 31 from sporulated oocysts and 88 from sporozoites. Homology searches of the public sequence databases showed that, among the 119 ESTs, 32 genes encoded proteins homologous with previously reported proteins including microneme proteins and surface antigen proteins of E. tenella, small heat shock proteins, rhoptry proteins of Toxoplasma gondii, and calcium-dependent protein kinase of Plasmodium spp. Thus, the remaining 87 ESTs have not previously been reported. Further characterization of these differentially expressed genes will be useful in understanding those responsible for sporulation, invasion, growth, and development of E. tenella.
TL;DR: Ground-feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of T. Gondii prevalence in rodents and other small mammals.
Abstract: Ground-feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of T. gondii prevalence in rodents and other small mammals. Cats excrete environmentally resistant oocysts after consuming tissues of T. gondii–infected birds. In the present study, sera and tissues from 382 wild birds from Colorado were tested for T. gondii infection. Antibodies to T. gondii were found in 38 birds with the use of the modified agglutination test (MAT, 1∶25 titer). Tissues (brains, hearts) of 84 birds were bioassayed in mice. Viable T. gondii was isolated from 1 of 1 barn owl (Tyto alba), 1 of 5 American kestrels (Falco sparverius), 1 of 7 ferruginous hawks (Buteo regalis), 1 of 4 rough-legged hawks (Buteo lagopus), 2 of 13 Swainson's hawks (Buteo swainsoni), and 1 of 25 red-tailed hawks (Buteo jamaicensis). This is the first time T. gondii has been isolated from the barn owl, ferruginous hawk, ro...