Effects of diethylcarbamazine and ivermectin treatment onBrugia malayigene expression in infected gerbils (Meriones unguiculatus)

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 actionin vivo, we treated gerbils harbouring patentBrugia malayiinfections with 6 mg kg−1DEC, 0.15 mg kg−1ivermectin or 1 mg kg−1albendazole. 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.

Molecular evolution in immune genes across the avian tree of life

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, 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.

Prevalence and diversity of piroplasms and ticks in young raccoons and an association of Babesia sensu stricto infections with splenomegaly

Piroplasms 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.

Optimization of culture and analysis methods for enhancing long-term Brugia malayi survival, molting and motility in vitro

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.

Phylogenetic analysis of eyeworm (Oxyspirura petrowi) in northern bobwhite (Colinus virginianus) based on the nuclear 18S rDNA and mitochondrial cytochrome oxidase 1 gene (COX1)

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.

Endoparasitic Paradiplectanotrema klimpeli sp. nov. (Monogenea: Ancyrocephalidae) from the Greater Lizardfish Saurida tumbil (Teleostei: Synodontidae) in Indonesia

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.

Viscerotropic leishmaniasis: a systematic review of the case reports to highlight spectrum of the infection in endemic countries

Visceral leishmaniasis is an important neglected parasitic disease that is generally caused byLeishmania infantum,Leishmania donovaniandLeishmania 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 worldLeishmaniaspecies was reported from 23 (76.7%) cases, including 20 cases ofL. tropicaand three cases ofL. major; whereas new worldLeishmaniaspecies 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.

Coexistence, habitat associations and puparia description of three dipteran species of the Family Carnidae

Differentiation 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 of Hemeromyia anthracina and Hemeromyia longirostris and offer morphometric data of the puparia of these two species and of Carnus hemapterus. Both the smaller size and the occurrence of well-developed spiracles allow easy discrimination of the puparium of C. hemapterus. The puparia of both Hemeromyia species is very similar and only differ in the distance between the small spiracles. Hemeromyia anthracina and C. hemapterus coexisted in nest boxes but the former species did not occur in natural sandy cavities where, in turn, C. hemapterus was highly prevalent. Carnus hemapterus prevalence 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.

The mitochondrial genomes of the mesozoans Intoshia linei, Dicyema sp. and Dicyema japonicum

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.