Lymphatic filariasis (LF) threatens nearly 20% of the world’s population and has handicapped one-third of the 120 million people currently infected. Current control and elimination programs for LF rely on mass drug administration of albendazole plus diethylcarbamazine (DEC) or ivermectin. Only the mechanism of action of albendazole is well understood. To gain a better insight into antifilarial drug action in vivo, we treated gerbils harbouring patent Brugia malayi infections with 6 mg kg−1 DEC, 0.15 mg kg−1 ivermectin or 1 mg kg−1 albendazole. Treatments had no effect on the numbers of worms present in the peritoneal cavity of treated animals, so effects on gene expression were a direct result of the drug and not complicated by dying parasites. Adults and microfilariae were collected 1 and 7 days post-treatment and RNA isolated for transcriptomic analysis. The experiment was repeated three times. Ivermectin treatment produced the most differentially expressed genes (DEGs), 113. DEC treatment yielded 61 DEGs. Albendazole treatment resulted in little change in gene expression, with only 6 genes affected. In total, nearly 200 DEGs were identified with little overlap between treatment groups, suggesting that these drugs may interfere in different ways with processes important for parasite survival, development, and reproduction.
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All organisms encounter pathogens, and birds are especially susceptible to infection by malaria parasites and other haemosporidians. It is important to understand how immune genes, primarily innate immune genes which are the first line of host defense, have evolved across birds, a highly diverse group of tetrapods. Here, we find that innate immune genes are highly conserved across the avian tree of life and that although most show evidence of positive or diversifying selection within specific lineages or clades, the number of sites is often proportionally low in this broader context of putative constraint. Rather, the evidence shows a much higher level of negative or purifying selection in these innate immune genes - rather than adaptive immune genes - which is consistent with birds' long coevolutionary history with pathogens and the need to maintain a rapid response to infection. We further explored avian responses to haemosporidians by comparing differential gene expression in wild birds (1) uninfected with haemosporidians, (2) infected with Plasmodium, and (3) infected with Haemoproteus (Parahaemoproteus). We found patterns of significant differential expression with some genes unique to infection with each genus and a few shared between "treatment" groups, but none that overlapped with the genes included in the phylogenetic study.
AbstractThis cross-sectional study was undertaken to assess the status of school-based water, sanitation and hygiene (WASH) resources and soil-transmitted helminthiasis (STH) in Odeda, Ogun State, Nigeria. The status and condition of WASH resources were determined in eight selected schools (three with WASH support and five without). Stool samples were also collected from 428 pupils from both school categories and screened for STH infections. Findings showed that water and sanitation conditions of WASH resource programming schools were better than those in schools without WASH support. However, pupils’ knowledge about STH infections and basic hygiene were not significantly different between both categories of school (P > 0·05). The prevalence of Hookworm, Ascariasis and Trichuriasis cases recorded were 26·2, 18·2 and 1·6% respectively, with an overall prevalence of 33·4%. By school categories, Ascariasis (14·9vs20·6), Hookworm (17·7vs32·0), Trichuriasis (1·7vs1·6) and, any STH prevalence (27·4vs37·5) were recorded for schools with WASH resource programming and those without respectively. A greater portion of the infected children 95 (66·4%) were from schools without WASH support. Our findings imply that WASH resource may have very positive impact on the control of STH among school children. However, there is need for improvement on coverage, adequacy and maintenance of WASH facilities in school.
A total of eight foxhound packs in England and Wales were screened for Echinococcus species using a genus-specific coproantigen ELISA and for Echinococcus granulosus sensu lato and Echinococcus equinus by coproPCR. Main screening ( n = 364 hounds) occurred during 2010–2011 wherein a quarter (25.6%) of the foxhound fecal samples tested were Echinococcus coproantigen-positive (93/364). In total, five of eight (62.5%) hunts screened had coproantigen-positive hounds; coproantigen prevalence for individual foxhound packs ranged from 0 to 61.2% and was shown to be >30% in three hunts (in counties of Powys, Wales and Northumberland, England). Foxhound fecal samples from six of the eight tested hunts (four Welsh and two English hunts) were positive by coproPCR for E. granulosus s.l (including one sequence confirmation of E. granulosus sensu stricto) and E. equinus DNA. Analysis of hunt questionnaire data suggested that there was an association between poor foxhound husbandry, especially feeding practices and Echinococcus coproantigen prevalence. Clearer guidelines regarding the risk of canine echinococcosis are required for safe management of foxhound hunts in England and Wales.
AbstractPiroplasms are intraerythrocytic parasites that are often transmitted by ixodid ticks, but vertical transmission is an alternative route for some species. In the USA, raccoons (Procyon lotor) are hosts for two known species, a Babesia microti-like sp. and Babesia lotori (in Babesia sensu stricto group). To better understand the natural history of Babesia in raccoons, we tested young raccoons from Minnesota and Colorado for Babesia spp., examined them for ticks, and assessing for splenomegaly as a sign of clinical disease. Raccoons from both states were infected with B. microti-like sp. and Babesia sensu stricto spp. Infections of B. microti-like were common, even in 1-week-old raccoons, suggesting vertical transmission. Babesia sensu stricto infections were more common in older raccoons. Raccoons infected with Babesia sensu stricto had significantly higher spleen:body weight ratios compared with uninfected or B. microti-like sp.-infected raccoons. Ticks were only found on raccoons from Minnesota. The most common and abundant tick was Ixodes texanus but Ixodes scapularis and Dermacentor variabilis were also found on raccoons. We report piroplasm infections and infestations with several tick species in very young raccoons. Young raccoons infected with Babesia sensu stricto spp. had higher spleen:body weight ratios, suggesting a disease risk.
Parasites of the genus Trypanosoma are unicellular flagellated microorganisms of the Trypanosomatidae. This study describes an isolate of the genus Trypanosoma naturally infecting Rhipicephalus microplus ticks, characterized through molecular, morphological and biological analysis. Trypanosome cultures, designated strain P1RJ, were obtained by isolation from R. microplus haemolymph in cultures of the tick cell line IDE8. After isolation, strain P1RJ grew well axenically in L15B medium at temperatures of 30, 32 and 34 °C. The new trypanosome remained stable in axenic culture over 14 passages in L15B at 30 °C and was successfully cryopreserved and resuscitated. Morphometric analysis was performed on randomly selected developmental forms. 18S rRNA and 24Sα rDNA sequence analyses confirmed that strain P1RJ is a new species of the genus Trypanosoma. The nucleotide sequences described were submitted to Genbank. Pathogenicity, involvement in vertebrate hosts, epidemiology, developmental cycle and transmission mechanisms of strain P1RJ are still unknown. Therefore, more studies will be necessary to determine life cycle aspects of this trypanosome, for which we propose the name Trypanosoma rhipicephalis sp. nov.
Parasites of the genus Trypanosoma are microorganisms that display wide morphological, biological and genetic variability. Here we present the first description of an isolate of the genus Trypanosoma naturally infecting the tick Amblyomma brasiliense. The ticks were collected from a specimen of Tayassu pecari (Queixada, white-lipped peccary) from the Itatiaia National Park, Itatiaia, Rio de Janeiro, Brazil. The isolate was characterised by molecular, morphometric and biological analyses. A Trypanosoma culture was isolated from crushed nymphal and adult ticks, propagated in the tick cell line IDE8 and maintained in L15B culture medium, incubated at 32 °C. The isolate grew well in L15B medium at 30 °C, 32 °C and 34 °C but not at lower or higher temperatures. The culture remained stable in axenic L15B medium at 30 °C. Cryopreserved cultures retained viability after cryopreservation in liquid nitrogen. Growth in axenic medium and developmental forms of the trypanosomes were analysed. Analysis of the 18S rDNA region confirmed the authenticity of this new species and the nucleotide sequence was deposited in Genbank. The species was named Trypanosoma amblyommi sp. nov. strain C1RJ. Characteristics related to pathogenicity, involvement with vertebrate hosts, epidemiology, developmental cycle and transmission mechanisms are still unknown. Therefore, further studies are necessary to understand aspects of the biological cycle of Trypanosoma amblyommi sp. nov.
The Dicyemida and Orthonectida are two groups of tiny, simple, vermiform parasites that have historically been united in a group named the Mesozoa. Both Dicyemida and Orthonectida have just two cell layers and appear to lack any defined tissues. They were initially thought to be evolutionary intermediates between protozoans and metazoans but more recent analyses indicate that they are protostomian metazoans that have undergone secondary simplification from a complex ancestor. Here we describe the first almost complete mitochondrial genome sequence from an orthonectid, Intoshia linei, and describe nine and eight mitochondrial protein-coding genes from Dicyema sp. and Dicyema japonicum, respectively. The 14,247 base pair long I. linei sequence has typical metazoan gene content, but is exceptionally AT-rich, and has a unique gene order. The data we have analysed from the Dicyemida provide very limited support for the suggestion that dicyemid mitochondrial genes are found on discrete mini-circles, as opposed to the large circular mitochondrial genomes that are typical of the Metazoa. The cox1 gene from dicyemid species has a series of conserved, in-frame deletions that is unique to this lineage. Using cox1 genes from across the genus Dicyema, we report the first internal phylogeny of this group.
AbstractA cross-sectional survey was carried out in primary schools to determine prevalence, intensity and spatial co-distribution of Schistosomiasis and soil transmitted helminths (STH) infections in Ogun State, Nigeria. A total of 2148 pupils from 42 schools were examined forSchistosomaand STH infections from urine and fresh fecal samples respectively. Ethyl ether concentration method prepared in sodium acetate – acetic acid – formalin ether was used to concentrate parasites’ ova before microscopic examination. The overall prevalence of schistosomiasis and STH infections were 4.0% (95% CI = 3.21–4.92) and 34.64% (95% CI = 32.62–36.69) respectively.Schistosoma haematobiumandAscaris lumbricoideswere the most prevalent across the study area among theSchistosomaand STH species respectively. Overall, intensity of infection was higher in males than in females for allSchistosomaand STH infections, but with no significant difference (P > 0.05), except forTrichuris trichiura(χ2 = 6.490,P < 0.05). Infection intensity was significantly inversely correlated (χ2 = 12.953,P < 0.05) with an increase in age group. Co-distribution ofSchistosomaand STH infections occurred in 15 (35.7%) out of 42 schools, and only 30 children (1.4%) had co-infection ofSchistosomaand STH. This study provides information on the prevalence and spatial risk of schistosomiasis and STH in Ogun State. This will serve as decision-support tool for Ogun State programme managers to help facilitate integration of schistosomiasis and STH control.
Abstract Lymphatic filariasis is a neglected tropical disease caused by roundworm parasites such as Brugia malayi that spread via a mosquito vector. In vitro culture of these parasites provides controlled conditions to understand parasite biology and provides a cheaper way to screen potential micro- and macrofilaricides. Published studies have used a wide array of approaches and metrics regarding in vitro cultures of B. malayi; as a result, drawing comparisons and identifying the reasons why inability to reproduce outcomes are difficult. This study sought to determine conditions that ensure reproducible outcomes and used evaluation metrics that are easily measured and can be automated to ensure objectivity. We found culturing B. malayi third-stage larvae (L3) in endothelial basal media supplemented with 20% fetal bovine serum and 75 µ m ascorbic acid in a temperature- and humidity-controlled incubator produced better survival and molting rates as well as longer and more motile parasites than previously reported. The benefit of ascorbic acid seemed to be unique to L3 parasites, as the addition of ascorbic acid to adult parasites had no significant impact on survival or motility. The methods reported in this study will help in designing experiments for both parasite behaviour studies and drug screening applications for disease eradication.
Oxyspirura petrowi is a heteroxenous nematode found in northern bobwhite ( Colinus virginianus ) of the Rolling Plains ecoregion of Texas. Despite its impact on this popular gamebird, genetic level studies on O. petrowi remain relatively unexplored. To accomplish this, we chose the previously studied nuclear rDNA 18S region as well as the mitochondrial COX1 gene region of O. petrowi to investigate phylogenetic relations between O. petrowi and other nematode species. In this study, we generate primers using multiple alignment and universal nematode primers to obtain a near-complete 18S and partial COX1 sequence of O. petrowi , respectively. Phylogenetic trees for O. petrowi ’s 18S and COX1 gene regions were constructed using the Maximum Likelihood and Maximum Parsimony method. A comparative analysis was done based on the nuclear and mitochondrial region similarities between O. petrowi and other nematode species that infect both humans and animals. Results revealed a close relation to the zoonotic eyeworm Thelazia callipaeda as well as a close relation with filarial super family (Filarioidea) such as the human eyeworm Loa loa and Dirofilaria repens eyeworm of dog and carnivores.
AbstractThe protozoan parasiteLeishmaniais endemic in large parts of the world which causes leishmaniasis. Its visceral form is fatal if not treated and is caused mostly byLeishmania donovani,Leishmania infantumandLeishmania chagasi. Given the difficulties linked to vector (sandfly) control and the lack of an effective vaccine, the control of leishmaniasis relies mostly on chemotherapy. Unfortunately, the prevalence of parasites becoming resistant to the first-line drug pentavalent antimony (SbV) is increasing worldwide. Few alternative drugs are available that includes amphotericin B, pentamidine and miltefosine (oral). Already, decreases in efficacy, resistance and toxicity have been noted against these drugs. Dry antileishmanial pipeline further indicates the slow pace of drug discovery in this field where resistance as a major barrier. Full understanding of the genetic and molecular basis of the parasite is lagging. Since leishmaniasis is a neglected disease and occurs predominantly in the developing world largely, therefore, it is unaddressed. The pharma industry argues that development of the new drug is too costly and risky to invest in low return neglected diseases is very high. Research is also needed to identify new and effective drug targets. The lack of drug research and development for neglected diseases will require some new strategies. We have discussed the various cause of slow pace of antileishmanial drug discovery in this review to pay attention of researchers and also take the public and private initiative to make the process fast for new antileishmanial drug development.
In Democratic People's Republic of Korea, only Plasmodium vivax malaria is prevalent, which is divided into two forms – long incubation form and short form. Among malaria cases reported in a year, long form accounts for 69% and short form 31%. Incubation period of short form ranges from 10 to 29 days (average 17 days) and long from 5·5 to 16 months (average 8–13 months). The most relapses (90%) were reported from May to September – malaria transmission season in the country. Result from preliminary mass chemoprevention in small size of population before transmission season to find appropriate method showed high protective efficacy in two regimens – one regimen given primaquine 0·25 mg base kg −1 day −1 for 14 days (95%) and another 0·5 mg base kg −1 day −1 for 7 days (94%). During the mass chemoprevention with primaquine, some adverse effects were reported but transient. We consider that mass chemoprevention with primaquine before transmission season is of great significance in disturbing the vivax malaria transmission, in which long incubation form is predominant in countries prevailing seasonal malaria.
A new endoparasitic monogenean of Paradiplectanotrema Gerasev, Gayevskaya & Kovaleva, 1987, Paradiplectanotrema klimpeli sp. nov., is described from the southern Balinese coast, Indonesia. The new species is much larger, wider and characterized by the longest dorsal anchors compared with the congeners. Ventral anchors and ventral bars are the smallest in the genus, with a distinct ratio of 1:1. This is the first species with a gladiator breast-plate-shaped dorsal bar, with a length:width ratio of 1:1. Oesophagi of the Common Grinner Saurida tumbil (Bloch, 1795) (Synodontidae) were infected (prevalence = 17%) at an intensity of 12 (1–21). This is the first record of the genus from the eastern Indian Ocean, and lizardfishes represent a new host family. We provide light microscopy ( in situ in oesophagal folds), three-dimensional confocal illustrations and a morphometric comparison of all congeners, with remarks on the recently described first Indonesian endoparasitic Monogenea Pseudempleurosoma haywardi Theisen, Palm, Al-Jufaili & Kleinertz, 2017. First 28S DNA sequences for Paradiplectanotrema allocate the new species close to endoparasitc freshwater monogeneans. Its ecology differs from Pseudempleurosoma Yamaguti, 1965 by utilizing deep-water fishes instead of coastal, coral reef-associated hosts; however, both are infecting schooling, bottom-dwelling fishes.
AbstractThe African buffalo (Syncerus caffer), a mammal species whose population is declining, can play a role as a reservoir or carrier of a wide number of arthropod-borne pathogens. Translocation procedures have been used as an alternative approach for species conservation. However, the veterinary aspects of this sort of procedures are extremely important to minimize the impact on animal health. In order to detectBartonellaand haemoplasmas, two important group of bacterial that have an impact in both human and animal health, EDTA whole-blood samples were screened for the presence of these bacterial pathogens by molecular techniques. As a result, a molecular occurrence of 4.1 and 15.4% forBartonellaspp. and haemoplasmas, respectively, was reported among 97 wild buffaloes sampled during a translocation procedure from Marromeu to Gorongosa Reserve, Mozambique. Additionally, phylogenetic analyses of the obtained sequences were conducted. At least, three bovine-associated pathogens, namelyB. bovis,M. wenyoniiand ‘CandidatusM. haemobos’, as well as a probably newBartonellagenotype/species were detected inS. caffer.Further studies are needed in order to determine whether these bacterial species may cause impact in buffaloes and other sympatric ruminant species living in the release site.
Visceral leishmaniasis is an important neglected parasitic disease that is generally caused by Leishmania infantum, Leishmania donovani and Leishmania chagasi. However, several causative species of cutaneous leishmaniasis (CL) causes an interstitial form of leishmaniasis which known viscerotropic leishmaniasis. The aim of this paper is a systematic review of the cases of viscerotropic leishmaniasis to present the main causative agents, clinical manifestations, treatment and outcomes of the cases. An electronic search (any date to August 2017) without language restrictions was performed using Medline, PubMed, Scopus and Google Scholar. The searches identified 19 articles with total 30 case reports. Of them, old world Leishmania species was reported from 23 (76.7%) cases, including 20 cases of L. tropica and three cases of L. major; whereas new world Leishmania species were reported in seven (23.4%) cases. The infection was more prevalent in male (24/30, 80%) than female (5/30, 16.7%) patients. Co-morbidity/co-infection was observed in 13 out of 30 cases (43.4%), which the most of them was HIV/AIDS (10 out of 13 cases, 76.9%). The results suggested that viscerotropic leishmaniasis should be more attended in the endemic countries of CL and in immunocompromised patients in order to exact discrimination from other endemic infectious diseases.
AbstractDifferentiation of niche by means of resource partitioning facilitates coexistence of species with similar requirements. Here we analyse the association between different habitats (i.e. nest types) and two Diptera species of the poorly known Family Carnidae that coexist during their larval and pupal stage in the nests of troglodytic bird species. We also describe for the first time the puparium ofHemeromyia anthracinaandHemeromyia longirostrisand offer morphometric data of the puparia of these two species and ofCarnus hemapterus. Both the smaller size and the occurrence of well-developed spiracles allow easy discrimination of the puparium ofC. hemapterus. The puparia of bothHemeromyiaspecies is very similar and only differ in the distance between the small spiracles.Hemeromyia anthracinaandC. hemapteruscoexisted in nest boxes but the former species did not occur in natural sandy cavities where, in turn,C. hemapteruswas highly prevalent.Carnus hemapterusprevalence did not differ between nest boxes and natural cavities but its abundance was higher in the first type of nest. This study shows clear associations of the two dipteran species with specific types of nests. Yet, some conditions are seemingly acceptable for both species.
AbstractThis is the first report on the presence of acanthocephalan parasiteEchinorhynchus truttaein brown trout (Salmo trutta) from Spain. A total of 343 fish were captured by local anglers from 19 rivers in the adjacent Tambre and Ulla watersheds in Galicia (north-western Spain). Macroscopic and microscopic analyses of the intestinal contents revealed the presence of adults and/or eggs ofE. truttaein 53 of the 123 trout from Tambre river basin (43.1%). By contrast, parasitic forms of this acanthocephalan were only observed in eight of the 220 fish from Ulla basin (3.6%), showing significant differences between the prevalences obtained in two adjacent watersheds (P< 0.001, odds ratio 19.0). Prevalence was significantly higher in specimens >3 years (length >26.0 cm) than in younger specimens (P< 0.05). The absence ofGammarus pulexin the region suggests that native gammarid species in Galicia (Echinogammarus lusitanicusandEchinogammarus beriyoni) may act as intermediate host in the life cycle ofE. truttae. Different prevalences ofE. truttaeindicate that the presence/abundance of the intermediate crustacean host may be different in the two river basins, probably as a consequence of various abiotic factors and anthropogenic activities.
