The Schistosoma japonicum fatty acid-binding protein (FABP) is used in the cell membrane to absorb and transport fatty acids, which cannot be resynthesized by the organism and combined with hydrophobic ligands. Among the 5 stages of the worm life cycle examined, FABP messenger ribonucleic acid (mRNA) expression was highest in male adult worms, followed by the liver-stage schistosome, and was the lowest in the lung-stage schistosome. The fabp gene-coding region was cloned and expressed to obtain recombinant S. japonicum FABP (rSjFABP) with a molecular weight of approximately 18 kDa. Mice were then immunized against rSjFABP to prepare anti-FABP serum. Using immunohistochemical techniques, FABP protein was found to localize to the eggshell, parenchyma, and digestive tract. Double-stranded RNA-mediated knockdown of FABP mRNA by RNA interference decreased the number of transcripts by >70%. Moreover, the egg production rate decreased, whereas the abnormal egg ratio was significantly increased in the FABP-silenced group compared with the negative control group (P < 0.05). These results demonstrate that FABP localizes in adults and in various stages. FABP contributes to the egg-laying capacity of adults, which may be related to the reproductive function of S. japonicum.

The scarce information on the helminth fauna in otariids from the Southeastern Pacific comes mainly from stranded individuals or killed for that purpose. In this study, we compared the abundance and composition of enteroparasitic assemblages of Otaria flavescens using coprological techniques. Three sampling localities from north to south spanning 2,200 km off the Chilean coast were considered (Iquique, Viñ a del Mar, and Talcahuano). In all, 60 fecal samples were collected, and eggs belonging to 5 taxa were found in 91.6% of the samples. They were the anisakid nematodes Contracaecum and Pseudoterranova, the cestode Adenocephalus (syn. Diphyllobothrium), the trematode Ogmogaster, and the acanthocephalan Corynosoma. Samples from southern Chile (Talcahuano) showed the highest prevalence. Adenocephalus eggs had the highest prevalence and abundance in Iquique and Talcahuano, whereas Ogmogaster was the less prevalent and abundant in all sampling localities. Corynosoma eggs had similar prevalence and abundance among sampling localities, and Pseudoterranova eggs were absent in Iquique and with median prevalence values in Viñ a del Mar and Talcahuano. Thus, the composition of parasite egg assemblages was different between sampling localities. These differences between sampling localities may help to explain differential records of some zoonotic parasitoses such as pseudoterranovosis and diphyllobothriosis in Peru and Chile, where consumption of raw or marinated fish (ceviche) is common. For example, the lower diversity of parasite egg assemblages in the northern Chilean coast may be due to the absence or lower abundance of first intermediate/paratenic hosts of Pseudoterranova.

Both cutaneous (zoonotic cutaneous leishmaniasis [ZCL] and anthroponotic cutaneous leishmaniasis [ACL]) and visceral leishmaniasis (VL) are prevalent in Pakistan, although the cutaneous form is comparatively more widespread. The present study aimed to spatially map different forms of leishmaniasis in Pakistan. In addition, the risk for acquiring leishmaniasis was assessed in different locations of the country. Previously published literature on leishmaniasis distribution and associated risk factors in Pakistan was obtained from PubMed/NCBI and GoogleScholar using specific keywords. Further, 50 articles that focused on geographical distribution and risk factors of the disease in Pakistan were obtained and systematically reviewed. Data regarding location (used in ArcGIS for spatial analysis), number of cases, and risk factors were identified. The present study revealed a high burden of cutaneous leishmaniasis in the northern and western foci of Pakistan. Leishmania major, chiefly a causative agent of ZCL, was observed to be prevalent in the arid and semi-arid climatic zones of the country with elevations between 45 and 2,837 m (maximum number at low elevation). Leishmania tropica cases, associated with ACL, were recorded at elevations ranging from 551 to 2,837 m (majority cases at high elevation). Visceral leishmaniasis (VL) (reportedly caused by Leishmania infantum) was sporadically distributed in the northern areas at elevations 1,432–2,873 m. For VL, particularly, mountainous communities, farming communities, and the presence of dogs were the most commonly reported risk factors. On the other hand, poor preventive measures, migration, presence of domesticated animals, presence of cattle dung, living in mud houses, and outdoor sleeping habits were the principal risk factors associated with cutaneous leishmaniasis (CL). This investigation can guide the health experts and medical entomologists toward targeted and cost-effective surveillance and control of leishmaniasis in Pakistan.

Parasite infection pressure is suggested to be a strong driver of transmission within ecosystems. We tested if infection pressure drives seroprevalence in intermediate host species for Toxoplasma gondii. We defined Toxoplasma infection pressure to intermediate host species as the combined influence of cat abundance, environmental conditions, and its prevalence in the cat population. We sampled and tested 2 species of rodent and collated information on Toxoplasma seroprevalence in koalas, wallabies, kangaroos, and sheep. All species were sampled using equivalent methods, within a 2-yr period, and from adjacent regions of low and high Toxoplasma infection pressure. The seroprevalence of Toxoplasma in kangaroos scaled with infection pressure, but we observed no statistical difference in seroprevalence for any other species between these 2 regions. Within the region of low infection pressure, Toxoplasma seroprevalence did not differ between species. However, within the region of high Toxoplasma infection pressure, we observed large variation in seroprevalence between species. Our results demonstrate that infection pressure is not sufficient by itself, but merely necessary, to drive Toxoplasma seroprevalence in intermediate host species. Where Toxoplasma seroprevalence in an intermediate host species is already low, further reducing infection pressure will not necessarily further decrease seroprevalence in those species. This has important ramifications for the mitigation of parasite infections and suggests that reductions in Toxoplasma infection pressure, intended to reduce infections, may be most effective and applicable to species that are known to experience high rates of infection.

A précis of helminth parasite infections and a host–parasite checklist are presented for the following 14 species of waterfowl from the Chihuahua Desert in the United States and Mexico: Chen rossii, Chen caerulescens, Anas platyrhynchos, Anas diazi, Anas acuta, Anas strepera, Anas americana, Anas clypeata, Anas cyanoptera, Anas crecca, Bucephala albeola, Oxyura jamaicensis, Fulica americana, and Podiceps nigricollis. There was a total of 127 species of helminths recovered from the 14 species of waterfowl. Total abundance, which included data available for 12 species of waterfowl, was 134,202 (mean = 11,184, median = 1,376, and 95% confidence limit [CL] = 14,485). Mean species richness ranged from 1.5 in Ross's goose, C. rossii, to 4.3 in the bufflehead, B. albeola. Host mean abundance ranged from 7.5 in the Mexican duck, A. diazi, and green-winged teal, A. crecca, to a high of 811 for the ruddy duck, O. jamaicensis. Ninety-one percent of the helminth species were generalists. Most specialists were associated with the American coot, F. americana (7), and the eared grebe, P. nigricollis (5). Percent helminth species contribution was cestodes 45%, nematodes 25%, trematodes 22%, and acanthocephalans 8%. The most commonly occurring helminth species among the 14 host species were the trematode Notocotylus attenuatus (12), the cestode Cloacotaenia megalops (10), the acanthocephalan Corynosoma constrictum (9), and the nematode Capillaria anatis (6). Low ingestion of invertebrates may have contributed to the lower number of helminth species and abundance in wintering and spring dabbling ducks (Anatini). Wild dabbling ducks ranging in age from 6 mo to 8 yr and 8 mo were infected with helminth parasites. Helminth parasite data from resident and nesting hosts and pre-fledged young birds indicated as many as 43 helminth life cycles may be occurring in the Chihuahua Desert. Host–parasite species checklists are included.

The Amazon region is an important region for biodiversity, and many new species are described for this region each year. However, the diversity of parasites infecting Amazonian reptiles is still poorly known, and there are few studies about how parasite communities of these hosts are structured. Our study was designed to elucidate the parasite community structure of Thecadactylus rapicauda, one of the largest species of gekkonid lizards in the world, and to discover the relative utility of size, sex, and body mass of Thecadactylus rapicauda as predictive factors of the abundance of helminth parasites. We analyzed 40 individuals of T. rapicauda, of which 34 had parasites (85% of prevalence), with 269 specimens allocated to 10 species. Body size of the host showed a positive influence on the abundance of helminths. Host sex is another important factor related to the abundance of nematodes: females were usually heavily infected. We conclude that T. rapicauda has a high richness of the helminth species and that most of the species found infecting this host were nematodes with a direct life cycle. Additionally, we found new helminth species, which should be described formally in the future.

Neopsilotrema is a small genus of psilostomid digeneans parasitic in the intestine of birds in the Palearctic and Nearctic. At present, the genus includes 4 species: Neopsilotrema lisitsynae from the Palearctic and Neopsilotrema affine, Neopsilotrema lakotae, and Neopsilotrema marilae from the Nearctic. Herein, we describe a new species, Neopsilotrema itascae n. sp., from lesser scaup Aythya affinis collected in Minnesota. The species can be distinguished from congeners on the basis of the ventral sucker:oral sucker width ratio, body width:length ratio, and cirrus sac size, along with other characters. We generated new 28S ribosomal deoxyribonucleic acid (DNA) and NADH dehydrogenase (ND1) mitochondrial DNA sequence data of a variety of psilostomids from the Palearctic and Nearctic along with sequences of the ribosomal internal transcribed spacer (ITS) region (ITS1 + 5.8S + ITS2) from 3 Neopsilotrema species. The molecular phylogenetic affinities of a variety of psilostomid taxa were studied using 28S sequence data. The 28S sequences of psilostomids demonstrated 1–7.9% intergeneric divergence, whereas the sequences of ND1 had 17.7–34.1% intergeneric divergence. The interspecific divergence among members of Neopsilotrema was somewhat lower (0.2–0.5% in 28S; 0.3–0.4% in ITS; 12–15.7% in ND1). Our comparison of DNA sequences along with morphologic study suggests Holarctic distribution of N. lisitsynae.

Forty-nine olive-backed pocket mice, Perognathus fasciatus were collected during 2011 and 2012 from 4 sites in Wyoming and examined for coccidian parasites. Fifteen (31%) were found to be passing oocysts of a new species of Eimeria Schneider, 1875. Sporulated oocysts of Eimeria fasciata n. sp. are ellipsoidal to ovoidal, 23.3 × 20.7 (19–27 × 17–25) µm, with a shape index of 1.1; they typically contain a single, smooth, bubble-like oocyst residuum. Oocysts possess 1–2 polar granules, lack a micropyle, and are bilayered with a thickness of 1.3 µm. Sporocysts are ovoidal, 10.0 × 8.2 (8–12 × 7–10) µm, with a shape index of 1.2; they contain a sporocyst residuum that appears similar to a cluster of 1–8 grapes. The Stieda body is small, appearing flattened to knobby, and there are no subStieda or paraStieda bodies. This new eimerian represents the only coccidian, to date, reported from P. fasciatus, as well as the only species from any heteromyid rodent in Wyoming.

During 9–10 February 2018 and 21–22 February 2020, 7 adult Blue Suckers, Cycleptus elongatus, were collected by hoop nets from the Red River, Little River County (n = 3), and the Black River, Lawrence County (n = 4), Arkansas, and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. All 7 (100%) were infected with an unknown species of gill-infecting Myxobolus sp. Twenty formalin-fixed plasmodia (cysts) of Myxobolus cloutmani n. sp. were elliptoidal, 407 µm long × 270 µm wide. Formalin-fixed myxospores were orbicular to broadly elliptoidal, 8.7 µm long × 7.8 µm wide. Two polar capsules were pyriform and subequal in size, extending over halfway in the myxospore. The larger polar capsule was 5.5 µm long × 3.1 µm wide, while the shorter was 5.1 × 2.9 µm. A coiled polar filament possessed 5 or 6 coils. The myxospore was 3.7 µm thick in sutural view, with a distinct sutural ridge. Qualitative and quantitative morphological data were from formalin-fixed as well as ethanol-preserved spores, while molecular data consisted of a 2,010 base pair sequence of the partial 18S ribosomal RNA gene and a 2,502 base pair sequence of the partial 28S ribosomal RNA gene. Phylogenetic analysis grouped M. cloutmani n. sp. with the other catostomid-infecting myxobolids. This is the first myxozoan reported from C. elongatus.

This study investigated the identity of 2 lepocreadiid digenean species belonging in the genus Opechona Looss, 1907 that infect littoral fishes of the northern Gulf of Mexico. Opechona chloroscombri , a species previously known only from the Caribbean Sea and the Atlantic Ocean off Brazil, is reported herein from the Atlantic bumper, Chloroscombrus chrysurus (L.), in the northern Gulf of Mexico. A second species infects the gulf butterfish, Peprilus burti Fowler, and the American harvestfish, Peprilus paru (L.), and it is described as a new species that occurs in coastal waters of the north-central and northeastern Gulf of Mexico. Metacercariae infecting the mesoglea of pelagic jellyfishes (Bougainvillia carolinensis [McCady], Chrysaora quinquecirrha [Desor], and Stomolophus meleagris Agassiz) and pelagic comb jellies (Mnemiopsis leidyi Agassiz and Beroe ovata Bruguière) were collected that resemble the new species but require further study to identify. Newly generated sequence fragments (28S rDNA) from both species of Opechona plus 2 other lepocreadiids collected during the study were aligned with publicly available sequences from 18 other lepocreadiids, 6 species of Aephnidiogenidae , and 2 species of Gorgocephalidae Manter, 1966. The alignment was subjected to Bayesian inference analysis rooted using a gorgocephalid. The resulting tree estimated the positions of both Opechona spp. as being unresolved within a group of taxa that included all available species of Opechona plus available species from the morphologically similar genera Prodistomum , Preptetos Pritchard, 1960, and Clavogalea Bray, 1985. Although relatively similar in morphology, the 2 studied species of Opechona were surprisingly not closely related. Opechona cablei () is herein considered to be a junior synonym of Opechona pyriformis () .

Recurrent coccidiosis affecting a commercial chukar partridge (Alectoris chukar) farm in Ontario, Canada was investigated. The responsible pathogenic Eimeria species was isolated for biological characterization. The uniformity of oocyst morphometrics supported that only a single Eimeria sp. was present. Experimental infections with coccidia-free chukars were used to describe exogenous and endogenous developmental stages of the parasite. The prepatent period of the causative Eimeria species was 5 days and patency lasted 11 days; fecundity was 1,573 to 30,057, with the highest fecundity recorded with the lowest challenge dose. Endogenous development was elucidated histologically from samples collected at 8 locations along the intestinal tract at 26 time points throughout prepatency. The parasite had 5 asexual generations before oocyst formation that were located from the mid-jejunum to the mid-rectum and in the ceca. Sporulation of oocysts suspended in potassium dichromate at room temperature (22 C) occurred within 24 hr. Oocysts (n = 50) averaged 21.8 by 18.6 µm and featured a polar granule; sporocysts (n = 50) averaged 10.9 by 7.1 µm and possessed a Stieda body, sub-Stieda body, sporozoite refractile bodies, and sporocyst residuum. Comparisons with described Eimeria spp. infecting partridges suggest that the biological features of this pathogenic species are unique; similarly, sequences from both mitochondrial and nuclear loci support the naming of this new Eimeria species.

Nanomedicine has the potential in enhancing the efficacy and bioavailability of anti-infective agents. Here we determined whether conjugation of the Malaysian cultivated seaweed Kappaphycus alvarezii with silver-conjugated nanoparticles enhanced anti-acanthamoebic properties. Silver-conjugated K. alvarezii were successfully synthesized, followed by characterization with Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, and transmission electron microscopy. Amoebicidal effects were evaluated against Acanthamoeba castellanii, and cytotoxicity assays were performed using HaCaT cells. Viability assays revealed that silver nanoparticles conjugated with K. alvarezii extract exhibited significant antiamoebic properties (P < 0.05). Nano-conjugates induced the production of reactive oxygen species. Importantly, silver-conjugated extract inhibited amoeba-mediated host cell damage as established by lactate dehydrogenase release. Neither the nano-conjugates nor the extract showed cytotoxicity against human cells in vitro. Liquid chromatography and mass spectroscopy revealed several molecules, including 2,6-nonadien-1-ol, N-desmethyl trifluoperazine, dulciol B, lucidumol A, acetoxolone, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol, C16 sphinganine, 22-tricosenoic acid, and β-dihydrorotenone, of which dulciol B and C16 sphinganine are known to possess antimicrobial activities. In summary, marine organisms are an important source of bioactive molecules with anti-acanthamoebic properties that can be enhanced by conjugating with silver nanoparticles. Natural products combined with nanotechnology using multifunctional nanoparticle complexes can deliver therapeutic agents effectively and hold promise in the development of new formulations of anti-acanthamoebic agents.

Some antimalarial drugs are immune-modulators that impact multiple pathways of innate immunity in malarial treatment. However, information on the immunomodulatory effects of artequine and rutin in the treatment of malaria remains elusive. Twenty-five Swiss mice (18 ± 2 g) were used for this study. Twenty were infected with Plasmodium berghei (NK65). Parasitemia was confirmed, and the animals were grouped (n = 5) as follows: Group A was not infected but treated orally with vehicle. Groups B to E were infected and treated (B) orally with vehicle (10 ml/kg), (C) with 10 mg/ kg artequine, (D) with 10 mg/kg of artequine supplemented with 100 mg rutin/kg, and (D) with 10 mg/kg of artequine supplemented with 200 mg rutin/kg, for 7 days. Blood was collected for hematological, inflammatory cytokines, and immunoglobulins G and M assays. Post mitochondrial supernatant fraction was used for antioxidant assays. Rutin co-administration (200 mg/kg) significantly (P < 0.001) increased platelet and neutrophil counts (P < 0.01) but significantly (P < 0.01) decreased white blood cell count and lymphocyte relative to parasitized control. Also, it significantly (P < 0.05) decreased lipid peroxidation, xanthine oxidase, and superoxide dismutase activities but significantly (P < 0.05) increased reduced glutathione and glutathione S-transferase activity. Rutin co-administration also caused a significant (P < 0.001) increase in tumor necrosis factor-alpha, interleukin-6, and immunoglobulin M levels, while interleukin-1β and immunoglobulin G decreased significantly (P < 0.001) compared with parasitized control. These results showed that rutin co-administration with artequine improved host antioxidant status and modulated the immune and inflammatory responses.

We are interested in the disease ecology of Sarcocystis species that infect birds of prey as definitive and intermediate hosts. The present study was done to test our hypothesis that a laboratory model can be developed for sarcocystis infection in mammals using gamma interferon gene knockout (KO) mice as a source of Sarcocystis strixi bradyzoites and mammalian cell cultures as a source of sporulated S. strixi oocysts. Sporocysts of S. strixi from a naturally infected barred owl (Strix varia) were fed to KO mice to produce sarcocysts, and the enclosed bradyzoites were obtained by acid-pepsin digestion of abdominal and thigh muscles. Bradyzoites, metrocytes, and an unusual spherical stage were seen in digest before the inoculation of host cells. The spherical stages stained dark with Giemsa stain, but no nucleus was observed, and they were seen free and associated with the concave portion of some bradyzoites. Examination of infected cell cultures demonstrated that macrogamonts and microgamonts were present at 24 hr post-inoculation. Since sporulated oocysts were not observed, we had to reject our current hypothesis.

Several mortality events involving barn swallows (Hirundo rustica) and cliff swallows (Petrochelidon pyrrhonota) were reported in the Upper Midwestern states in 2017 and 2018. Barn swallow mortality followed unseasonal cold snaps, with the primary cause of death being emaciation with concurrent air sac nematodiasis. Lesions in cliff swallows were consistent with blunt force trauma from suspected car impacts. Examination of air sac nematodes from both bird species revealed morphological characters consistent with Diplotriaena obtusa. Sequence analysis of the partial 18S rRNA gene indicated the samples clustered with other species in the genus Diplotriaena. These nematodes provide a link between morphological specimens and DNA sequence data for D. obtusa.

Under Wisconsin state law, the greater prairie chicken (GRPC; Tympanuchus cupido pinnatus) has been listed as a threatened species since 1976. In 2014–15, we conducted a pilot study to determine the prevalence and intensity of gapeworms (Syngamus spp.) in female Wisconsin GRPCs collected from 2 monitored populations. We captured 62 female GRPCs using walk-in-style traps for females and night lighting for juveniles ≥45 days of age. From these individuals, we collected 15 carcasses of radio-marked birds, most of whom died due to predation events. Through dissection, we identified gapeworm in 20% of examined carcasses and report an intensity ranging between 4 and 74 worms.