Showing papers in "Journal of Parasitology in 2017"
TL;DR: A practical guide outlining how experimentalists can contribute to fill data gaps by measuring the temperature dependence of host and parasite performance traits in ways that are systematic, statistically rigorous, and consistent with the requirements of life cycle–based host–parasite models is provided.
Abstract: Climate change will affect host-parasite dynamics in complex ways. The development of forecast models is necessary for proactive disease management, but past studies have frequently reported thermal performance data in idiosyncratic ways that have limited use for parameterizing thermal host-parasite models. Development of improved forecast models will require strong collaborations between experimental parasitologists and disease modelers. The purpose of this article is to facilitate such collaborations by reviewing practical considerations for describing thermal performance curves of parasite and host performance traits, and using them to predict climate change impacts on host-parasite systems. In the first section, we provide an overview of how thermal performance curves can be embedded in life-cycle-based dynamical models of parasitism, and we outline how such models can capture the net effect of multiple nonlinear temperature dependencies affecting the host-parasite dynamics. We also discuss how macroecological generalities based on the metabolic theory of ecology (MTE) can be used to determine a priori parameter estimates for thermal performance curves to derive null models for data-deficient species, but we note that most of the generalities suggested by MTE remain to be tested for parasites. In the second section, we discuss empirical knowledge gaps for the temperature dependence of parasite and host performance traits, and we outline the types of data that need to be collected to inform MTE-based models for data-deficient species. We specifically emphasize the importance of (1) capturing the entire thermal response of performance traits, including lower and upper temperature thresholds, and (2) experimentally or statistically separating out the thermal responses of different performance traits (e.g., development and mortality) rather than only reporting composite measures (e.g., apparent development). Not adhering to these principles can lead to biased climate change impact predictions. In the third section, we provide a practical guide outlining how experimentalists can contribute to fill data gaps by measuring the temperature dependence of host and parasite performance traits in ways that are systematic, statistically rigorous, and consistent with the requirements of life cycle-based host-parasite models. This guide includes recommendations and practical examples illustrating (1) the use of perturbation analyses to determine experimental priorities, (2) experimental design tips for quantifying thermal response curves, and (3) statistical methods for estimating the parameters of thermal performance curves. Our hope is that this article helps researchers to maximize the value and use of future data collections for both empirical and modelling studies investigating the way in which temperature influences parasitism.
50 citations
TL;DR: These results might help to explain why, at some colonies, epizootics of plague are more likely to occur during or shortly after periods of reduced precipitation, and might have important ramifications for plague, a bacterial disease transmitted by fleas that devastates populations of prairie dogs.
Abstract: Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that can reduce the fitness of vertebrate hosts. Laboratory populations of fleas decline under dry conditions, implying that populations of fleas will also decline when precipitation is scarce under natural conditions. If precipitation and hence vegetative production are reduced, however, then herbivorous hosts might suffer declines in body condition and have weakened defenses against fleas, so that fleas will increase in abundance. We tested these competing hypotheses using information from 23 yr of research on 3 species of colonial prairie dogs in the western United States: Gunnison's prairie dog (Cynomys gunnisoni, 1989–1994), Utah prairie dog (Cynomys parvidens, 1996–2005), and white-tailed prairie dog (Cynomys leucurus, 2006–2012). For all 3 species, flea-counts per individual varied inversely with the number of days in the prior growing season with >10 mm of precipitation, an index of the number of precipitation events that might...
29 citations
TL;DR: The data suggest that proximity to the park, provision of veterinary care, and breed are significant risk factors for hemoparasites in this population of ruminants, and that, in general, cattle are more susceptible than goats.
Abstract: Livestock production is a major sector of the Ugandan economy. Ugandan ruminant livestock (principally cattle and goats) are susceptible to hemoparasites that can cause serious clinical disease and production losses. Kibale National Park, in western Uganda, is a protected forest ecosystem surrounded by small-scale farms where cattle and goats are raised. We conducted a cross-sectional study of cattle and goats in this area and diagnosed hemoparasite infections by microscopy. We collected data on animal characteristics and management practices to assess risk factors associated with infection. We studied 186 cattle and 317 goats from 20 villages, including 16 villages directly adjacent to Kibale and 4 villages ≥3 km from the park boundary. Hemoparasites detected in cattle and goats were of the genera Theileria, Anaplasma, and Trypanosoma with a prevalence of 15.1%, 1.6%, and 4.3% respectively in cattle, and 10%, 6.0%, and 0.0%, respectively in goats. Trypanosomes infected approximately 8% of cattle...
28 citations
TL;DR: High intensity infections by either lernaeopodid are surveillance-worthy because they are potentially pathogenic to trout in the southeastern United States and 100% sequence similarity among the sympatric, morphologically-conspecific isolates is demonstrated.
Abstract: Salmincola californiensis infected 25 of 31 (prevalence 0.8; intensity 2–35 [mean 6.6 ± standard deviation 7.7; n = 25]) rainbow trout, Oncorhynchus mykiss, from a private trout farm connected to the Watauga River, North Carolina. Salmincola edwardsii infected all of 9 (1.0; 2–43 [9.3 ± 13.0; 9]) brook trout, Salvelinus fontinalis, from Big Norton Prong, a tributary of the Little Tennessee River, North Carolina. Both lernaeopodids are well-known salmonid pathogens, but neither is native to, nor has been previously taxonomically confirmed from, the southeastern United States. Herein, we (1) use light and scanning electron microscopy to identify and provide supplemental morphological observations of these lernaeopodids, (2) furnish complementary molecular sequence data from the 28S rDNA (28S), and (3) document the pathological effects of gill infections. We identified and differentiated these lernaeopodids by the second antenna (exopod tip with large [S. californiensis] vs. slender [S. edwardsii] s...
22 citations
TL;DR: The prevalence of C. felis in ticks and bobcats from south Illinois is found to be higher than reported by previous surveys, which suggests risk of transmission to domestic cats.
Abstract: Cytauxzoon felis is an intraerythrocytic apicomplexan of felids enzootic in the southeastern United States. In domestic cats (Felis catus), this parasite can result in the highly fatal disease cytauxzoonosis or bobcat fever. Bobcats (Lynx rufus) are the wild animal reservoir host. To date, the characterization of prevalence of C. felis in bobcats is mostly based on broad-scale surveys from hunter-harvested specimens collected across large geographic areas, usually consisting of multiple states. Detailed studies on the development, transmission, distribution, effects, and prevalence of C. felis in the tick vectors are scarce. To fill some of these gaps in the literature, such as prevalence in ticks and bobcats in a discrete region, we examined bobcats and ticks in an 8,000-km2 portion of southern Illinois. We screened for C. felis using a nested polymerase chain reaction that amplifies a fragment of the nuclear small subunit (SSU) 18S rRNA. We screened 125 individual bobcats collected in southern ...
22 citations
TL;DR: The findings further strengthen the idea that the genetic complexity and diversity among Dictyocaulus lungworms infecting wildlife ruminants is larger than previously believed and warrants further investigation.
Abstract: Lungworms from the genus Dictyocaulus cause parasitic bronchitis (dictyocaulosis) characterized by coughing and severe lung pathology in both domestic and wild ruminants. In this study we investigated the interrelationships of Dictyocaulus spp. from European bison (Bison bonasus L.), roe deer (Capreolus capreolus), and red deer (Cervus elaphus) by nucleotide sequence analysis spanning the 18S RNA gene (small subunit [SSU]) and internal transcribed spacer 2 (ITS2) regions of the ribosomal gene array as well as the mitochondrial cytochrome c oxidase subunit 1 (cox1). Molecular analyses of sequence data obtained partly with novel primers from between 10 and 50 specimens from each host were carried out. Bayesian inference analysis revealed that each host species was infected with different genotypes. Analysis of cox1 sequence data showed a diverse genetic background and high evolutionary potential of Dictyocaulus taxa. Data from lungworms of European bison revealed a distinct genotype of Dictyocaulus viviparus, whereas Dictyocaulus capreolus was only found in roe deer. In contrast, red deer were infected with a taxon with unique SSU, ITS2, and cox1 sequences. These results indicate the occurrence of a novel genotype from red deer, which differs significantly from the National Center for Biotechnology Information reference sequence of Dictyocaulus eckerti. The molecular evidence was consistent with a morphological study with description and imaging of Dictyocaulus cervi n. sp. recovered from red deer. Dictyocaulus cervi n. sp. can be distinguished from D. eckerti on the basis of the absence of cervical papillae, the occurrence of a single ring of 4 symmetrical submedian cephalic papillae, length of the tail in females, morphometry of the female reproductive system, and measurements of gubernacula in males. In conclusion, our findings further strengthen the idea that the genetic complexity and diversity among Dictyocaulus lungworms infecting wildlife ruminants is larger than previously believed and warrants further investigation.
21 citations
TL;DR: It is suggested that the increasing number of S. scabiei cases in northeastern black bears is not due to the emergence and expansion of a single parasite strain, but rather, sequences from black bears grouped into a large clade that included S. SCABiei from numerous hosts from Europe, Asia, Africa, and Australia.
Abstract: Since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (Ursus americanus) population in Pennsylvania. Although there are 3 species of mites associated with mange in bears, Sarcoptes scabiei has been identified as the etiologic agent in these Pennsylvania cases. Historically, S. scabiei-associated mange in bears has been uncommon and sporadic, although it is widespread and relatively common in canid populations. To better understand this recent emergence of sarcoptic mange in bears in Pennsylvania and nearby states, we genetically characterized S. scabiei samples from black bears in the eastern United States. These sequences were compared with newly acquired S. scabiei sequences from wild canids (red fox [Vulpes vulpes] and coyote [Canis latrans]) and a porcupine (Erethizon dorsatum) from Pennsylvania and Kentucky and also existing sequences in GenBank. The internal transcribed spacer (ITS)-2 region and cytochrome c oxidase subunit 1 (cox1) gene were amplified and sequenced. Twenty-four ITS-2 sequences were obtained from mites from bears (n = 16), red fox (n = 5), coyote (n = 2), and a porcupine. The sequences from bear samples were identical to each other or differed only at polymorphic bases, whereas S. scabiei from canids were more variable, but 2 were identical to S. scabiei sequences from bears. Eighteen cox1 sequences obtained from mites from bears represented 6 novel haplotypes. Phylogenetic analysis of cox1 sequences revealed 4 clades: 2 clades of mites of human origin from Panama or Australia, a clade of mites from rabbits from China, and a large unresolved clade that included the remaining S. scabiei sequences from various hosts and regions, including sequences from the bears from the current study. Although the cox1 gene was more variable than the ITS-2, phylogenetic analyses failed to detect any clustering of S. scabiei from eastern U.S. hosts. Rather, sequences from black bears grouped into a large clade that included S. scabiei from numerous hosts from Europe, Asia, Africa, and Australia. Collectively, these data suggest that the increasing number of S. scabiei cases in northeastern black bears is not due to the emergence and expansion of a single parasite strain.
21 citations
TL;DR: It is unclear if the observed distribution pattern of schistosomes in Siphonaria is a result of sampling bias and/or indicative of a specific bird–snail–schistosome association, but it is clear they are sharply differentiated from the basal marine clade of avian schistoomes that includes Austrobilharzia.
Abstract: In the blood fluke family Schistosomatidae, marine snails are well known as intermediate hosts. Eight families of marine snails have thus far been reported to host schistosomes across the world, most of which have been implicated in human cercarial dermatitis (HCD) outbreaks. As part of our larger effort to define the species diversity and biology of schistosomes in Argentina, in particular their role in causing HCD, we searched in the marine pulmonate snail (Siphonaria lessoni) for a schistosome species described previously from S. lessoni from southern Argentina. Additionally, gulls (Larus dominicanus) collected from a different project locality (inland) were examined, because they are known to spend time in the intertidal regions. Schistosome sporocysts were found in S. lessoni, and a small worm fragment was retrieved from a gull. Molecular phylogenies for 28S, ITS1-5.8S-ITS2, and cox1 genes revealed that the specimens from the gull and S. lessoni grouped closely together, suggesting they are ...
19 citations
TL;DR: Phylogenetic analyses indicate that the 3 species of Echeneibothrium hosted by the yellownose skate are not each other's closest relatives, suggesting multiple colonization events of D. chilensis have occurred.
Abstract: Much progress has recently been made in revising the taxonomic assignments of genera originally classified in the polyphyletic “Tetraphyllidea.” Many of these genera, including Echeneibothrium, were accommodated in the order Rhinebothriidea. However, beyond this larger taxonomic action, little work has been conducted on this genus over the past 50 yr. Consequently, the criteria used for characterizing species of Echeneibothrium have lagged behind those typically used in more modern descriptions of elasmobranch-hosted cestode taxa. A series of collecting trips to Chile to obtain cestodes from the yellownose skate, Dipturus chilensis, provided a unique opportunity to apply modern morphological and molecular methods to investigate the 3 species of Echeneibothrium reported parasitizing this skate, specifically Echeneibothrium megalosoma, Echeneibothrium multiloculatum, and Echeneibothrium williamsi. In addition to redescribing all 3 species, using morphological data from light and scanning electron m...
17 citations
TL;DR: Investigating the infections of ovine and bovine Babesia and Theileria species in ticks collected from cattle, yaks, sheep, horses, and camels in several regions of China found some piroplasm species were carried by ticks that were not previously reported to be vectors.
Abstract: Piroplasmosis, a disease of domestic and wild animals, is caused by tick-borne protozoa in the genera of Theileria and Babesia. There is limited information available about the prevalence of piroplasmosis in ticks in China, and to assess the potential threat of piroplasmosis in China, we investigated the infections of ovine and bovine Babesia and Theileria species in ticks collected from cattle, yaks, sheep, horses, and camels in several regions of China where tick-borne diseases have been reported. In total, 652 ticks were collected from the animals in 6 provinces of China. Babesia spp. and Theileria spp. were detected with a PCR-RLB method and identified by sequencing. Overall, 157 ticks (24.1%) were infected with 5 Babesia and 4 Theileria species. Among tested tick samples, 134 (20.6%) were single infections with 1 of 7 piroplasm species, with Theileria annulata (118/652, 18.1%) being dominant. Only 23 (3.5%) tick samples were double or triple infected, Theileria luwenshuni and Theileria sinen...
16 citations
TL;DR: The process of multi-level ecological fitting, in which the lancet fluke possesses pre-existing traits to utilize host resources, rather than host species, at each life-cycle stage provides a mechanism for the establishment of this complex life cycle in a novel habitat and in novel hosts.
Abstract: The expansion of parasite distributions outside of their native host and geographical ranges has occurred repeatedly over evolutionary time. Contemporary examples include emerging infectious diseases (EIDs), many of which pose threats to human, domestic animal, and wildlife populations. Theory predicts that parasites with complex life cycles will be rare as EIDs due to constraints imposed by host specialization at each life-cycle stage. In contrast to predictions of this theory, we report 2 new intermediate hosts in the 3-host life cycle of the liver fluke Dicrocoelium dendriticum in Cypress Hills Provincial Park, Alberta, Canada. Results of sequence analysis of the cytochrome oxidase 1 (cox1) mitochondrial gene identified the terrestrial snail Oreohelix subrudis and the ant Formica aserva as first and second intermediate hosts, respectively, in the region. Neither of these intermediate hosts, nor their suite of domestic and wild mammalian grazers used in the life cycle, occurs within the native range of D. dendriticum in Europe. Our results from host surveys show that the prevalence of D. dendriticum in samples of O. subrudis varied between 4% and 10%, whereas mean metacercariae intensity in F. aserva varied between 33 and 41 (n = 163, mean ± SD = 38 ± 35). These results are the first to describe the complete life cycle of emerging lancet fluke in western North America. The process of multi-level ecological fitting, in which the lancet fluke possesses pre-existing traits to utilize host resources, rather than host species, at each life-cycle stage provides a mechanism for the establishment of this complex life cycle in a novel habitat and in novel hosts.
TL;DR: The present report shows for the first time the occurrence of antibodies and N. caninum DNA in waterfowl, which would be able to ingest oocysts excreted by final canid hosts and could contribute to parasite transmission in the sylvatic cycle.
Abstract: Thirty-five adult waterfowl (14 males and 21 females) representing various orders and species were sampled during the hunting season from 2015 to 2016. Antibodies to Neospora caninum were detected by IFAT on blood samples, while heart and brain were subjected to molecular analysis for the detection of Neospora caninum DNA. Twelve birds (34.3%) (6 Anas crecca, 3 Anas platyrhynchos, 2 Anas penelope, 1 Anas acuta) showed antibodies versus N. caninum, while 10 animals out of 35 (4 A. crecca, 2 A. platyrhynchos, 2 A. penelope, 1 A. acuta, and 1 Vanellus vanellus) scored positive for at least 1 DNA sample, with an overall prevalence of 28.6%. The present report shows for the first time the occurrence of antibodies and N. caninum DNA in waterfowl. The avian species investigated in the present report, which feed directly from the soil and/or water, would be able to ingest oocysts excreted by final canid hosts and could contribute to parasite transmission in the sylvatic cycle. To achieve a definitive res...
TL;DR: In this paper, the internal transcribed spacer region of the ribosomal RNA gene and the partial mitochondrial cytochrome c oxidase subunit I gene were used to investigate potential diversity among parasite specimens collected from stranded sea turtles.
Abstract: Neospirorchis (Digenea: “Spirorchiidae”) are blood flukes of sea turtles. Trematodes tentatively identified as Neospirorchis sp. infect various sites within sea turtles inhabiting waters of the southeastern United States, but efforts to obtain specimens adequate for morphologic study has proven difficult. Two genetic targets, the internal transcribed spacer region of the ribosomal RNA gene and the partial mitochondrial cytochrome c oxidase subunit I gene, were used to investigate potential diversity among parasite specimens collected from stranded sea turtles. Sequence data were obtained from 215 trematode and egg specimens collected from 92 individual free-ranging cheloniid sea turtles comprising 4 host species. Molecular analysis yielded more than 20 different genotypes. We were able to assign 1 genotype to 1 of the 2 recognized species, Neospirorchis pricei Manter and Larson, 1950. In many examples, genotypes exhibited host and site specificity. Our findings indicate considerable diversity of ...
TL;DR: The new species of Acanthosentis of the Indian subcontinent is described from recently collected acanthocephalan specimens in the Jhelum River in northern Kashmir and is characterized by having a para-receptacle structure in males and females, and having unique double Saefftigen's pouches, large round single-nucleated cells in the proboscis, and hollow hooks high in sulfur but with limited calcium ions.
Abstract: Acanthogyrus (Acanthosentis) kashmirensis n. sp. is described from recently collected acanthocephalan specimens in the Jhelum River in northern Kashmir that are conspecific with Neoechinorhynchus kashmirensis Fotedar and Dhar, 1977 originally described in a Ph.D. thesis in 1972 from 4 species of cyprinid fishes: Tor tor Hamilton, Bangana diplostoma (Heckel) (syn. Labeo diplostoma Heckel), Labeo rohita Hamilton, and Ptychobarbus sp. Steindachner. The poor unpublished diagnosis was followed by 1 uninformative abstract in a scientific meeting in 1977. The acanthocephalan was later designated as invalid because of the lack of a formal published description and absence of information on deposited type or voucher specimens. Recent collections of specimens of the same species were made from 2 other cyprinid species of cyprinid fishes, Schizothorax plagiostomus Heckel and Schizothorax labiatus (McClelland) from the Sandran River, a tributary of the Jhelum River, in southern Kashmir. It is now possible to provide a full description of these specimens and reassign them in the subgenus Acanthosentis Verma and Datta, 1929 based on the finding of circles of vestigial spines at the anterior end of the trunk of male and female specimens. These vestigial spines are barely visible and easy to miss with optical microscopy. The new species is also characterized by having (1) a para-receptacle structure in males and females, (2) unique double Saefftigen's pouches, (3) large round single-nucleated cells in the proboscis, and (4) the lemnisci being either equal or distinctly unequal with no intermediate states. A key to the species of Acanthosentis of the Indian subcontinent is provided. Histopathological sections show extensive damage to the host intestine with subsequent blood loss, cell necrosis, and attempted encapsulation. Results of the energy dispersive X-ray analysis (EDAX) study show hollow hooks high in sulfur but with limited calcium ions. Hooks of most acanthocephalans studied with X-ray scans are solid with high calcium and low sulfur ions.
TL;DR: It is shown that the presence of B-1 cells contributes to improved animal resistance to parasites, suggesting that these cells are involved in the control of cutaneous infection caused by L. (L.) amazonensis.
Abstract: B-1 cells are a subtype of B cells with peculiar characteristics. These cells are distinct from B-2 lymphocytes in their morphology, ontogeny, tissue distribution, and phenotypic functional features. B-1 cells can participate in the immune response in several ways, for example, by being recruited to inflammatory foci, producing large amounts of IL-10 cytokine, and differentiating into IgM-secreting cells or phagocytes. Nevertheless, the role of B-1 cells in the pathogenesis of experimental leishmaniasis has not been fully elucidated. Here we evaluated the role of B-1 cells in Leishmania ( L.) amazonensis infection using X-linked immunodeficient (XID) mice that possess a mutation in Bruton's tyrosine kinase (Btk) that leads to a reduced number of B-1 cells. The course of infection and the corresponding immune response were analyzed in infected mice. XID mice showed an increase in parasite number in paws, lymph nodes, and spleen compared to BALB/c infected controls. Infected XID mice had higher IL-10 levels and lower anti- Leishmania IgM. The adoptive transfer of peritoneal B-1 cells into XID mice restored peritoneal B-1 cells and parasite burden in the footpad in a pattern similar to that observed in the BALB/c controls at 10 wk. Our results demonstrate the higher susceptibility of XID mice to infection with L. ( L.) amazonensis compared to controls. In addition, we show that the presence of B-1 cells contributes to improved animal resistance to parasites, suggesting that these cells are involved in the control of cutaneous infection caused by L. ( L.) amazonensis.
TL;DR: This is the first demonstration of a definitive host for S. rommeli, and the partial mitochondrial cox1 sequences of these oocysts/sporocysts shared the high identities, that is, 99.4% and 99.2% identity with sequences of Sarcocystis bovini in GenBank, respectively.
Abstract: Sarcocysts of Sarcocystis rommeli were found for the first time in 6 of 34 (17.6%) cattle (Bos taurus) in China. With light microscopy, sarcocysts of S. rommeli were up to 1,130 μm long, with a striated, 4-8-μm-thick cyst wall. Using transmission electron microscopy, the villar protrusions (vp) were 4.7-5.2 × 0.2-0.3 μm, and 0.3-0.5 μm apart from each other. The vp contained microtubules extending from the top of the vp to the middle of the ground substance layer (gsl). A BLAST search of the near full-length 18S rRNA and partial mitochondrial cox1 sequences of S. rommeli revealed 98.7% identity and 99.2% identity with sequences of Sarcocystis bovini in GenBank, respectively. Two domestic cats (Felis catus) fed sarcocysts of S. rommeli shed oocysts/sporocysts in their feces with a prepatent period of 14 to 15 days; the partial mitochondrial cox1 sequences of these oocysts/sporocysts shared the high identities, that is, 99.4% and 99.5%, with cox1 sequences of S. rommeli sarcocysts and S. bovini sarcocysts, respectively. This is the first demonstration of a definitive host for S. rommeli.
TL;DR: The first records of the western blacklegged tick, Ixode pacificus, and Ixodes spinipalpis parasitizing eastern cottontails, Sylvilagus floridanus, are provided and a unique member of the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.) is discovered in Canada.
Abstract: Lyme disease is a serious health problem, with many patients requiring in-depth clinical assessment and extended treatment. In the present study, we provide the first records of the western blacklegged tick, Ixodes pacificus , and Ixodes spinipalpis parasitizing eastern cottontails, Sylvilagus floridanus . We also documented a triple co-infestation of 3 tick species (Ixodes angustus, I. pacificus , I. spinipalpis) feeding on an eastern cottontail. Notably, we discovered a unique member of the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.) in Canada. Ixodes spinipalpis ticks, which were collected from an eastern cottontail on Vancouver Island, British Columbia (BC), were positive for B. burgdorferi s.l. With the use of polymerase chain reaction amplification on the tick extracts and DNA sequencing on the borrelial amplicons, we detected Borrelia genomospecies 2, a novel subgroup of the B. burgdorferi s.l. complex. Based on 416 nucleotides of the flagellin B (flaB) gene, our amplicons are identical to the Borrelia genomospecies 2 type strain CA28. Borrelia genomospecies 2 is closely related genetically to other B. burgdorferi s.l. genospecies, namely Borrelia americana, Borrelia andersonii, and B. burgdorferi sensu stricto (s.s.) that cause Lyme disease. Like some other borrelial strains, Borrelia genomospecies 2 can be missed by current Lyme disease serology. Health-care providers must be aware that Borrelia genomospecies 2 is present in I. pacificus and I. spinipalpis ticks in far-western North America, and patients with clinical symptoms of Lyme disease need to be assessed for potential infection with this pathogen.
TL;DR: The results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent genotype compared to other genotypes in Grenada.
Abstract: The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to o...
TL;DR: A DNA barcoding method was developed that targets the 18S rRNA gene primers for identifying apicomplexans parasitizing certain actinopterygian fishes and successfully confirmed 37 of the 41 parasitized fish blood samples analyzed in this study.
Abstract: Apicomplexan parasites are obligate parasites of many species of vertebrates. To date, there is very limited understanding of these parasites in the most-diverse group of vertebrates, actinopterygian fishes. While DNA barcoding targeting the eukaryotic 18S small subunit rRNA gene sequence has been useful in identifying apicomplexans in tetrapods, identification of apicomplexans infecting fishes has relied solely on morphological identification by microscopy. In this study, a DNA barcoding method was developed that targets the 18S rRNA gene primers for identifying apicomplexans parasitizing certain actinopterygian fishes. A lead primer set was selected showing no cross-reactivity to the overwhelming abundant host DNA and successfully confirmed 37 of the 41 (90.2%) microscopically verified parasitized fish blood samples analyzed in this study. Furthermore, this DNA barcoding method identified 4 additional samples that screened negative for parasitemia, suggesting this molecular method may provide improved sensitivity over morphological characterization by microscopy. In addition, this PCR screening method for fish apicomplexans, using Whatman FTA preserved DNA, was tested in efforts leading to a more simplified field collection, transport, and sample storage method as well as a streamlining sample processing important for DNA barcoding of large sample sets.
TL;DR: Biomphalaria pfeifferi was more likely to become infected and to shed more cercariae than B. sudanica, suggesting that the risk per individual snail of perpetuating transmission in Kenyan streams or lacustrine habitats may differ considerably, and the need to investigate further the role of host breeding systems in influencing transmission of schistosomiasis by snail hosts.
Abstract: In Kenya, schistosomes infect an estimated 6 million people with >30 million people at risk of infection. We compared compatibility with, and ability to support and perpetuate, Schistosoma mansoni of Biomphalaria pfeifferi and Biomphalaria sudanica, 2 prominent freshwater snail species involved in schistosomiasis transmission in Kenya. Field-derived B. pfeifferi (from a stream in Mwea, central Kenya) and B. sudanica (from Nawa, Lake Victoria, in western Kenya) were exposed to S. mansoni miracidia isolated from fecal samples of naturally infected humans from Mwea or Nawa. Juvenile ( 9 mm) were each exposed to a single miracidium. Schistosoma mansoni developed faster and consistently had higher infection rates (39.6–80.7%) in B. pfeifferi than in B. sudanica (2.4–21.5%), regardless of the source of S. mansoni or the size of the snails used. Schistosoma mansoni from Nawa produced higher infection rates in both B. pfeifferi and B. sudanic...
TL;DR: Experimental infections in chickens with metacercariae of Diplostomulum mordax from brains of Odonthestes bonariensis, captured (2015) at Dique Paso de las Piedras, near Bahia Blanca City, Buenos Aires Province, Argentina, resulted in 10 adults 5 days postexposure.
Abstract: Austrodiplostomum compactum from Nannopterum brasilianus, and its metacercaria from Geophagus sp. and Oreochromis mossambicus captured (1979) at its type locality, Valencia Lake, Venezuela, by the author, are redescribed. The adult is characterized by its large body size, and an oral sucker smaller than the pharynx. The metacercaria has a similar body size as the adult, and the small genital primordia occupy 4.1–7.3% of body length. Experimental infections in chickens with metacercariae of Diplostomulum mordax from brains of Odonthestes bonariensis, captured (2015) at Dique Paso de las Piedras, near Bahia Blanca City, Buenos Aires Province, Argentina, resulted in 10 adults 5 days postexposure. These adults correspond to Austrodiplostomum mordax as described from N. brasilianus at Lacombe Lagoon, Buenos Aires Province, and differ from A. compactum in their smaller body size, and an oral sucker larger than the pharynx. The metacercaria has a similar body size as the adult and differs mainly in that...
TL;DR: Micromorphological thin sectioning and Fourier-transform infrared spectrometry analysis confirms the coprolite belonged to a bone-eating carnivore, likely the extinct giant short-faced hyena (Pachycrocuta brevirostris), the earliest evidence for Toxocara sp.
Abstract: The study of fossil parasites can provide insight into the antiquity of host–parasite relationships and the origins and evolution of these paleoparasites. Here, a coprolite (fossilized feces) from the 1.2-million-yr-old paleontological site of Haro River Quarry in northwestern Pakistan was analyzed for paleoparasites. Micromorphological thin sectioning and Fourier-transform infrared spectrometry (FTIR) analysis confirms the coprolite belonged to a bone-eating carnivore, likely the extinct giant short-faced hyena (Pachycrocuta brevirostris). Parasitological analysis shows the coprolite to be positive for Toxocara sp. To our knowledge, this is the earliest evidence for Toxocara sp. found.
TL;DR: The results show that haemosporidian parasites are also infecting central African vertebrates and that new lineages of these parasites are circulating in wild animals of the Gabon forest.
Abstract: Haemosporidian parasites are protozoans that infect many different vertebrate hosts Re-examination of the diversity of haemosporidian parasites, using molecular tools, has generally led to rearrangements of traditional classifications In this study, we explored the diversity of haemosporidian parasites infecting some species of reptile and birds living in the forests of Gabon, Central Africa, by analyzing a collection of 128 samples of reptiles and birds We found that samples from 2 tortoise species (Pelusios castaneus and Kinixys erosa) and 3 bird species (Turtur afer, Ceratogymna atrata, and Agelastes niger) were infected by Haemocystidium spp and Parahaemoproteus spp, respectively From an ecological point of view, these lineages of parasites do not show host specificity because we have found them in several host species (2 tortoise and 3 bird species) that come from different areas of Gabon forest which are infected with these parasites Also, our phylogenetic analyses revealed that the obtained lineages are related to isolates from other continents found in the same groups of vertebrates Thus, our results show that haemosporidian parasites are also infecting central African vertebrates and that new lineages of these parasites are circulating in wild animals of the Gabon forest
TL;DR: All specimens obtained from marmosets in this study were identified as Platynosomum illiciens (Braun, 1901), and the published ranges of the measurements of P. amazonensis and P. marmoseti were completely contained within the ranges found inThis study as revealed by KDE.
Abstract: The trematodes belonging to the genus Platynosomum are biliary parasites of birds and mammals (domestic and wildlife) in tropical and subtropical areas of the globe. Despite several reports on platynosomosis in captive nonhuman primates, mainly in South America, the taxonomy of species of Platynosomum that infect these hosts remains confused, and it is not clear whether the species found in cats is the same that infects nonhuman primates. Because a detailed morphological study of Platynosomum from nonhuman primates is lacking, in this study we analyzed specimens of Platynosomum recovered from the biliary system of Callithrix penicillata kept in captivity in an animal facility. The helminths were submitted to morphological and morphometric analyses in a light microscope and measurements of 16 morphological traits were taken. A kernel density estimation (KDE) was used to estimate density distributions of the measurements obtained as well as the occurrence of overlap with the ranges of the measureme...
TL;DR: Jaguars play an important role in the maintenance of Hepatozoon spp.
Abstract: This study investigated the presence of Hepatozoon spp. in jaguars (Panthera onca) and domestic animals in the Cerrado, Amazon, and Pantanal biomes of Brazil. Between February 2000 and January 2010, blood samples were collected from 30 jaguars, 129 domestic dogs (Canis lupus familiaris), and 22 domestic cats (Felis catus) for molecular tests. All of the jaguars from the Pantanal (n = 22) and Cerrado (n = 4) and 3 of 4 jaguars from the Amazon were positive for Hepatozoon spp. Domestic dogs (62.8%) and cats (31.8%) were also positive for the agent. Hepatozoon nucleotide sequences from jaguars and domestic cats grouped with other Hepatozoon felis, whereas Hepatozoon from domestic dogs showed high similarity to Hepatozoon canis. Different species of Amblyomma were identified as parasitizing the jaguars and may act as vectors for Hepatozoon spp. Jaguars from the 3 sites were healthy and did not seem to be threatened by the hemoparasite within its population or environments. Most likely, jaguars play a...
TL;DR: A LAMP assay with a high specificity and a good sensitivity has been developed to detect H. contortus infection in goats and is useful for clinical diagnosis of H.contortus.
Abstract: Haemonchus contortus is one of the most significant strongylid nematodes infecting small ruminants, and it causes great economic losses to the livestock industry worldwide. Accurate diagnosis of H. contortus is crucial to control strategies. Traditional microscopic examinations are the most common methods for the diagnosis of H. contortus, but they are time-consuming and inaccurate. Molecular methods based on PCR are more accurate, but need expensive machines usually only used in the laboratory. Loop-mediated isothermal amplification (LAMP) is a rapid, simple, specific, and sensitive method that has been widely used to detect viruses, bacteria, and parasites. In the present study, a LAMP method targeting ribosomal ITS-2 gene for detection of the H. contortus in goat fecal samples has been established. The established LAMP method was H. contortus specific, and the sensitivity of LAMP was the same as that of the H. contortus species-specific PCR, with the lowest DNA level detected as being 1 pg. Ex...
TL;DR: This study investigates the systematic position of some species of the genus Saccocoelioides and the species Culuwiya cichlidorum Aguirre-Macedo and Scholz from North and Middle America using new morphological data and partial sequences of 2 nuclear genes, the large subunit and the internal transcribed spacer 2 from ribosomal DNA.
Abstract: This study investigates the systematic position of some species of the genus Saccocoelioides Szidat, 1954, and the species Culuwiya cichlidorum Aguirre-Macedo and Scholz, 2005, from North and Middle America using new morphological data and partial sequences of 2 nuclear genes, the large subunit and the internal transcribed spacer 2 from ribosomal DNA. In total 74 specimens representing 4 species of Saccocoelioides (41 of Saccocoelioides sogandaresi, 3 of Saccocoelioides chauhani, 6 of Saccocoelioides lamothei, and 12 of Saccocoelioides olmecae) plus 12 specimens of Culuwiya cichlidorum were analyzed. The phylogenetic analyses inferred with maximum likelihood method and Bayesian inference showed that the 4 species of Saccocoelioides formed a clade divided into 4 subclades representing each species. In addition, 7 specimens sequenced from the type host and locality of Culuwiya cichlidorum were nested in 2 clades: the first clade with specimens of C. cichlidorum from Costa Rica, and the second clade...
TL;DR: The parasitological findings in Puma concolor coprolites associated with caves suggest the importance of these carnivores in the dissemination of parasites in areas with high re-use of space and steady conditions of temperature, humidity, and radiation.
Abstract: Carnivorous mammals are a trophic guild with an important role in the dissemination of parasite infective stages (larvae, eggs, cysts, and oocysts). In the present study, new samples of coprolites attributed to carnivorous mammals, obtained from 2 archaeological caves, were analyzed for the presence of parasites with the aim to increase the knowledge about parasites in rockshelters that could have spread to humans and other mammals. To this purpose, fragments of 3 coprolites from Cerro Casa de Piedra, cave 5 and cave 7, were examined. Coprolites were rehydrated in aqueous trisodium phosphate and processed by spontaneous sedimentation. High parasite richness was observed and new parasite species for archaeological contexts were found. The parasitological findings in Puma concolor coprolites associated with caves suggest the importance of these carnivores in the dissemination of parasites in areas with high re-use of space and steady conditions of temperature, humidity, and radiation.
TL;DR: Analysis of the number and size of testes, number and shape of rostellar hooks, cirrus sac length, capsules and eggs per capsule, and morphology of the mature proglottid allowed concluding that the present specimens constitute a new record of R. celebensis in South America.
Abstract: Raillietina celebensis is a cestode that parasitizes the small intestine of rats and humans. Here, we detail the morphology and morphometry of R. celebensis based on specimens collected from Rattus norvegicus in the municipality of Sao Goncalo, state of Rio de Janeiro, Brazil, by light and confocal scanning laser microscopies and also report the results of molecular phylogenetic analyses to determine its relationships within the family Davaineidae. Analysis of the number and size of testes, number and shape of rostellar hooks, cirrus sac length, capsules and eggs per capsule, and morphology of the mature proglottid allowed concluding that the present specimens constitute a new record of R. celebensis in South America. Our genetic and phylogenetic analyses, based on the partial small subunit 18S rRNA gene, revealed R. celebensis to be in the family Davaineidae within the genus Raillietina, in agreement with the morphological taxonomy. Phylogenetic trees obtained by neighbor-joining and maximum likelihood methods demonstrated R. celebensis as a unique taxonomic unit, and also demonstrated some taxonomic inconsistences. The incorporation of Brazilian R. celebensis sequences derived from mammals in the phylogeny of davaineids is consistent with the assertion that neither Raillietina nor Fuhrmannetta can be supported as distinct genera.
TL;DR: Two new species of Microsporidia were recognized in skeletal muscle of freshwater fishes from Finland, one from pike-perch Sander lucioperca and the other from burbot Lota lota, placing both organisms on distinct clades within the Marinosporidia.
Abstract: Two new species of Microsporidia were recognized in skeletal muscle of freshwater fishes from Finland. Myosporidium spraguei n. sp. from pike-perch Sander lucioperca occurred as mature spores within sporophorous vesicles (SPVs) within a xenoma. The ovoid spores were 3.8 μm long and 2.4 μm wide, based on transmission electron micrographs (TEM). The exospore and endospore were equally thick, the nucleus was monokaryotic and the polar filament was isofilar with 12 coils in a single rank, entirely adjacent to the prominent posterior vacuole. Small subunit (SSU) rDNA sequence confirmed the presence of M. spraguei n. sp. in burbot Lota lota . The second species, Microsporidium luciopercae n. sp., also from pike-perch, occurred within SPVs that occupied only a fraction of the volume of the otherwise intact myocyte; no xenoma was produced. Myocyte degeneration and necrosis occurred as mature spores dispersed into direct contact with the sarcoplasm. The ovoid spores were 4.6 μm long and 2.8 μm wide (based on TEM); they were monokaryotic and the polar filament was isofilar with 25 coils in a single rank in the posterior of the spore. The exospore was relatively thin with an irregular profile. Neither infection elicited an inflammatory response, although degenerate spores were observed within host cells, suggesting phagocytosis. Phylogenetic analysis of SSU sequences placed both organisms on distinct clades within the Marinosporidia.