The diversity of ectoparasites and their relationships with hosts in the fragmented landscape of central Brazil is still poorly understood. This study investigated the ectoparasite communities of mesostigmata mites, ticks, and fleas associated with non-volant small mammals in southern Goi & aacute;s, Brazil. From January 2020 to May 2022, 10 quarterly field campaigns were conducted, with each lasting from 5 to 7 nights. The captured small mammals were screened for ectoparasites. Order Mesostigmata (n = 8 species) was the predominate group of parasites found on the small mammals, while Siphonaptera (n = 2 species) was found only on Gracilinanus agilis. Gigantolaelaps wolffsohni (n = 80 individuals) was the most frequently found parasitic species, occurring on 1 marsupial (Didelphis albiventris) and 3 rodent species (Calomys tener, Hylaeamys megacephalus, and Oecomys cleberi). This study addresses a knowledge gap by documenting the ectoparasite fauna associated with nonvolant small mammals in a fragmented portion of the Cerrado in central Brazil. Knowing the identity of these ectoparasites is essential to understanding species distribution and richness patterns, especially in an anthropogenically altered ecosystems.
Examination of the feces of a star-nosed mole, Condylura cristata, collected from Wisconsin, for coccidian parasites yielded oocysts of Isospora condylurae Duszynski, 1989. Oocysts were mostly ellipsoidal and measured 17.1 x 9.3 mu m (length [L] 3 width [W]) with a L/W ratio of 1.9, and typically 1 polar granule was present. Sporocysts were ellipsoidal and measured 11.4 x 5.7 mu m with a L/W ratio of 2.0; a knoblike Stieda body and trapezoidal sub-Stieda body were present as well as a sporocyst residuum composed of various-sized granules dispersed between the sporozoites or in a compact mass. New photomicrographs are provided for the coccidian, which represents only the second time the species has been reported in 35 yr. We document a new geographic distribution for I. condylurae. We also provide a summary of the 8 isosporans of North American moles.
Cryptosporidium serpentis (Apicomplexa: Cryptosporidiidae) was molecularly detected from cloacal swabs of 3 water snake species, including Nerodia erythrogaster, Nerodia rhombifer, and the state threatened Nerodia harteri, collected from 7 artificial reservoirs along the Brazos and Colorado rivers. While no effects to behavior and body condition were visible in positive individuals at the time of capture, previous studies have shown the potential of infection by Cryptosporidium serpentis to cause chronic gastrointestinal disease. Future studies should aim to increase understanding of the threat Cryptosporidium serpentis poses to water snakes and wildlife conservation.
Five salvaged specimens of Lampropeltis getula (L.) (eastern kingsnake) and 4 of Lampropeltis rhombomaculata (Holbrook) (mole kingsnake) from North Carolina, U.S.A., were examined for gastrointestinal helminths. Ten species of helminths (1 trematode, 8 nematodes, and 1 acanthocephalan) are reported from L. g. getula, representing 2 new host records. Three new host records, all nematodes, are reported from L. rhombomaculata.
The Appalachian trematode currently recognized as Metagonimoides oregonensis utilizes the salamander Desmognathus amphileucus as its primary second intermediate host, although it also infects other salamander species. Previous workers have suggested that D. amphileucus is the most frequently used host because of its relatively large size and long aquatic larval stage, both combining to enhance exposure to trematode cercariae relative to other available salamander species. We tested this hypothesis by comparing relative prevalence and relative intensity between D. amphileucus and the sympatric, distantly related Pseudotriton ruber, which has a similarly sized larval form and a similar length of larval life. We found significantly higher levels of both relative prevalence and relative intensity of metacercarial infection in D. amphileucus, suggesting that cercariae of this trematode actively utilize D. amphileucus as a second intermediate host over more distantly related species.
A supplemental description of Sprostoniella cf. multitestis Bychowsky and Nagibina, 1967 (Monogenoidea: Capsalidae: Trochopodinae) collected from gills of the longfin batfish Platax teira (Fabricius) in Moreton Bay, Queensland, Australia, is provided. The helminth was also found infecting the gills of the orbicular batfish Platax orbicularis (Forsskal) off Lizard Island, Queensland, Australia. These localities represent new geographical records for the helminth and the fi first occurrences of the species in Australia. An emended generic diagnosis for Sprostoniella Bychowsky and Nagibina, 1967 is included. Sprostoniella teira Bannai and Muhammed, 2014 and Sprostoniella teira Bannai and Muhammed, 2015 are unavailable, sensu the International Code of Zoological Nomenclature.
The consumption of digenetic trematode cercariae by nonhosts can affect energy transfer in aquatic ecosystems and simultaneously reduce the numbers of these infectious agents. Recently, crayfish (i.e., Faxonius juvenilis and Procambarus spp.) were documented as predators/nonhosts of the digenetic trematode cercaria of Proterometra macrostoma in laboratory experiments. The objective of this study was to assess additional invertebrate and vertebrate predators of this cercaria species during experiments, which included blue dasher dragonfly nymphs (Pachydiplax longipennis), orange bluet damselfly nymphs (Enallagma signatum), mosquitofish (Gambusia sp.), and Cope's gray tree frog tadpoles (Hyla chrysoscelis). Individuals of each species were divided into 2 groups and exposed to 2 levels of 2-3-hr-old cercariae in 10.8-cm culture dishes filled with 200 ml of spring water. The high exposure (HE; 4-6 cercariae/predator) level was approximately 23 the number of cercariae compared to the low exposure (LE; 2-3 cercariae/ predator) level. All 4 potential predators ingested cercariae, but in terms of the average percentage of cercariae consumed following 7 hr of exposure in the LE and HE trials, Gambusia sp. (LE = 83.3%; HE = 80%) appeared to be the most successful predator, followed by P. longipennis (LE = 67%; HE = 45%), E. signatum (LE = 41.7%; HE = 33.3%), and H. chrysoscelis (LE = 20.8%; HE = 37.5%). There was a significant difference in the mean number of cercariae consumed after 7 hr postexposure (PE) in the LE vs. HE groups for Gambusia sp. For both Gambusia sp. and P. longipennis, LE and HE groups ingested the majority of the cercariae to which they were exposed within the first hour. By comparison, a more gradual consumption was noted for E. signatum and H. chrysoscelis. Living distomes of P. macrostoma were recovered from H. chrysoscelis stomachs following ingestion on days 1 and 6 PE. This suggests that some amphibians may serve as definitive hosts for this parasite, which has only previously been reported from centrarchid fish. Collectively, these results suggest a broad food niche for P. macrostoma cercariae in aquatic food webs with regard to nonhosts.
Dicrocoeliid trematodes were detected in gallbladders and major bile ducts of 2 common marmosets. Their characteristics, including the broadly oval body shape with testes at the level of the anterior rim, ovary dorsal to the large acetabulum, and extracecal, multifollicular vitelline glands interrupted into 2 groups, are typical for a trematode belonging to the genus Euparadistomum. The morphology of the isolated trematodes is closest to the description of Euparadistomum thapari.
Nosemosis is a significant worldwide disease that can cause severe colony and economic losses by reducing adult honeybees' average lifespan, pollen collection, and productivity. This study was carried out in 11 different districts of Ayd & imath;n Province, where migratory beekeeping activities are widespread, in the preharvest period between 2018 and 2020 to detect the presence of Vairimorpha (Microsporidia: Nosematidae) species in the region and to identify the causative species. A total of 560 colonies was sampled from apiaries belonging to 56 different beekeepers. In the apiaries, a minimum of 6 colonies, or 10% of the total bee colonies, was selected through a random process for spore quantification. By microscopic examination, samples collected from 35 of 56 apiaries in Ayd & imath;n districts were positive for Vairimorpha (62.5%) spores. All positive samples were recorded as Vairimorpha ceranae with an amplicon size of 218 base pairs. The sequence results of this study's isolated samples showed very high-level (98-100%) homology with V. ceranae sequences collected that were deposited in the GenBank database. The existence of infection among honeybees, coupled with the molecular identification of the species and the quantification of contamination levels in neighboring apiaries, can elucidate the extent of economic losses attributed to this issue. In addition, for a more comprehensive understanding of the emergence of infection, its prevalence, and the distribution of causative species, it is of great importance in future studies to evaluate and analyze environmental and nonenvironmental variables, including factors such as altitude and temperature of the beehive.
We report the observation of egg-string deposition by females of Gordionus violaceus on the underside of stones in small forest streams in Germany. Egg strings are attached in winding lines to stones, a pattern otherwise known from the genus Chordodes and related genera, but not from the genus Gordionus. The spatial distinction between males (in water) and females (under rocks) may explain observations, in which males dominate in number in collections.
Parabronema skrjabini is a spirurid nematode occurring in the abomasum of ruminants. The parasite's developmental cycle involves insects such as Lyperosia titillans as the intermediate host; the adult worms may cause gastric congestion, ulceration of the mucosa, and reduced weight. The present study uses scanning electron microscopy to describe the morphological features of adult P. skrjabini obtained from the abomasum of sheep. Male and female worm length measured 15 and 36-38 mm, respectively. In both sexes, the mouth was widest dorsoventrally and had 2 lateral pseudolabia each with 2 cephalic papillae and an amphid. The anterior end had dorsal and ventral cuticular shields and 6 horseshoe-shaped cordons. At the anterior end, an excretory pore was located on the ventral side. In addition, 2 lateral ciliated cervical papillae and a single lateral ala were observed. In the female, the vulva was near the anterior end of the body, and the tail end was curved dorsally with a bluntly conical tip and 2 phasmids near its extremity. The male posterior end was coiled spirally, had small caudal alae, interrupted longitudinal ridges, 4 pairs of precloacal papillae, a double papilla near the cloaca, 2 pairs of postcloacal papillae, and 2 phasmids. The shape, size, and arrangement of precloacal and postcloacal papillae were different. Furthermore, 4 pairs of sessile papillae were seen near the phasmids, which were also different in shape and size, but similar in arrangement. The spicules were very unequal and dissimilar.
Sarcocystosis is an emerging disease in yaks, and Sarcocystis infection creates a health threat to humans and animals. During a recent study, Sarcocystis infection was detected in yaks by means of morphological observation using hematoxylin and eosin, Giemsa, and acridine orange staining. The species of Sarcocystis isolated from yaks were analyzed and identified phylogenetically. To establish the best model for culturing sarcocystosis isolated from yaks in vitro, four different cell lines—PAMs, Pk15, HeLa, and Vero cells—were used. The effects of sarcocystosis isolated from yaks on the MAPK signaling pathway in Vero cells were detected using Wes automatic Western blot and RT-qPCR. The results from the phylogenetic tree indicate that the sequences of Sarcocystis obtained from yaks in this study were grouped within the Sarcocystis cruzi clade. Results also have shown that S. cruzi had a higher proliferation rate in Vero cells, suggesting that Vero cells are more suitable for the long-term culturing of S. cruzi in vitro. Results also indicate that S. cruzi infecting Vero cells could cause the activation of ERK1/2 pathway, while inhibiting the ERK1/2 pathway could suppress S. cruzi infection in Vero cells. Therefore, the study and exploration of Sarcocystis-host relationships can effectively provide certain theoretical knowledge and the basis for the treatment of clinical diseases and the development of Sarcocystis drugs.
The genus Scalithrium is one of the most poorly known genera of rhinebothriidean tapeworms. It currently houses 10 morphologically heterogeneous species hosted by stingrays and guitarfishes. This study aimed to expand our understanding of this genus. Two new species, Scalithrium healyae n. sp. and Scalithrium johnvolini n. sp., are described from the giant guitarfish, Glaucostegus typus, off Australia and the lesser guitarfish, Acroteriobatus annulatus, off South Africa, respectively. The microtriches of members of this genus are characterized using scanning electron microscopy for the first time. Existing generic membership is critically assessed in the context of the morphology of the type species of the genus, Scalithrium minutum. As a result, Scalithrium bilobatum, Scalithrium smitii, and Scalithrium trygonis are considered species inquirenda owing to the limited amount of available information and material of both species. Scalithrium palombii and Scalithrium rankini are considered incertae sedis given the numerous morphological differences that exist between these species and the type and six other species in the genus. These differences include a greater length, more proglottids, and a much greater number of testes, the distribution of which extends to the ovary, rather than being restricted to the region anterior to the genital pore. The diagnosis of the genus is revised to accommodate these modifications in membership. We anticipate that the more cohesive concept of Scalithrium developed here will help advance future work circumscribing several of the other problematic genera of rhinebothriideans.
Examination of the feces of an emydid turtle, a watersnake, and a passeriform bird for coccidian parasites yielded some new host and geographic distributional records. Oocysts of Eimeria cooteri McAllister and Upton, 1989, and Eimeria marginata (Deeds and Jahn, 1939) Pellerdy, 1974, occurred in an eastern river cooter, Pseudemys concinna concinna, from Arkansas, U.S.A., Eimeria hydrophis Wacha and Christiansen, 1974, was found in a plain-bellied water-snake, Nerodia erythrogaster, from Arkansas, and Isospora zimmermani McAllister and Hnida, 2023, was found in a barn swallow, Hirundo rustica, from Texas, U.S.A. Mensural data as well as new photomicrographs are provided for each coccidian.
Trophically transmitted parasites have complex life cycles that incorporate multiple hosts at different developmental stages. As part of a study quantifying parasite diversity in the Indian River Lagoon, Florida, we documented immature acanthocephalan cystacanths in the mesentery of the frillfin goby, Bathygobius soporator. Sequencing of a 626-base-pair region of the mitochondrial cytochrome c oxidase subunit I gene yielded a 100% match to Southwellina hispida, a generalist parasite with a worldwide distribution. As a paratenic host for S. hispida, frillfin gobies bridge the trophic gap between first-intermediate (crustaceans) and definitive hosts (piscivorous birds). Frillfin gobies in our system consume a variety of potentially infected prey; however, crustaceans accounted for 87% of all identifiable stomach contents. In turn, gobies are likely preyed upon by multiple species of migratory piscivorous wading birds, which S. hispida uses to complete its life cycle. This is the second confirmed record of a member of the Gobiidae serving as a paratenic host for S. hispida. Our study adds to the limited but expanding knowledge of metazoan parasite diversity in B. soporator.
The tremat ode currently recognized as Metagonimoides oregonesis primarily utilizes the Southern Black-bellied Salamander, Desmognathus amphileucus, as a second intermediate host in southern Appalachian streams. We investigated seasonal variation in relative intensity within larvae of this salamander species in the Broad River system of northeastern Georgia by counting metacercariae visible through the ventral body wall in February, May, August, and November of 2023. Summer hatching and metamorphosis by salamander larvae coupled with likely summer shedding time of trematode cercariae from the snail host explain much of the variation, which showed a peak relative intensity in November. However, this peak remained even after the effect of salamander size (and presumably age) had been removed. The seasonal pattern we observed may be subject to interannual variation.
Differences in parasite infection patterns between hosts can be influenced by numerous factors placed into 2 categories: encounter filters (precontact) and compatibility filters (postcontact). The influence of these factors in shaping the patterns of parasite infection was investigated in Lake Holiday, a 100-ha lake in northern Virginia, U.S.A. In total, 1,586 fish in the family Centrarchidae, encompassing 4 species-Lepomis macrochirus, Lepomis cyanellus, Lepomis auritus, and Micropterus salmoides-were collected and necropsied over a 7-yr period. The length, weight, age, stomach contents, and counts of 2 diplostomid parasites-Posthodiplostomum cf. centrarchi and Uvulifer cf. ambloplitis-were recorded. The prevalence and intensity of P. cf. centrarchi differed between host species, which was likely influenced by both encounter and compatibility filters. However, U. cf. ambloplitis infection showed significant correlations with the prevalence, but not the intensity, of infection. This indicates that encounter filters may play a larger role in shaping the infection patterns of U. cf. ambloplitis than compatibility filters. Furthermore, the infection pattern differences between host species exhibited by P. cf. centrarchi indicate that the parasite species complex are likely specialists, whereas U. cf. ambloplitis represents a true generalist parasite because there are no apparent differences in compatibility between hosts. In addition, P. cf. centrarchi infections follow distinct patterns in the tissues that they infect, thereby allowing single organ counts, particularly the liver, to be proxies for total parasite infection, whereas the correlations in U. cf. ambloplitis are less predictable and do not allow for single tissue infections to be reliable indicators for total parasite load.
The freshwater leech genus Orientobdelloides Bolotov, Eliseeva & Kondakov, 2022, is reported for the fi rst time in Indonesia. Morphological and mitochondrial DNA sequence data identified the specimens as Orientobdelloides tridens (Chiangkul, Trivalairat, Kunya & Purivirojkul, 2021), a species previously known only from Thailand. The external and internal morphological features of the Indonesian O. tridens are provided in detail here, and the species diagnosis is amended based on our observations.
Ticks secrete immunosuppressant proteins that modulate the host's immune system during blood feeding. Five putative genes encoding similar p36 immunosuppressant proteins from other tick species were cloned by sequencing randomly picked plaques from a complementary DNA library constructed from salivary glands of partially engorged Haemaphysalis qinghaiensis. The genes were designated Hq-p36-1, Hq-p36-2, Hq-p36-3, Hq-p36-4, and Hq-p36-5. By doing a Multiple Em for Motif Elicitation (MEME) tool search, 3 potential common motifs, which coincided with 3 conserved regions, were found among the 8 aligned tick p36 homologs. Antigenicity analysis suggested that most of these homologs might be satisfactory antigen candidates, and 2 common antigenic determinants were predicted from each of the 5 proteins, and they overlapped with 2 common motifs. Four out of the 5 Hq-p36 proteins might share a similar 3dimensional model with an exposed big loop overlapped by the motif MEME-1 and a conserved antigenic region. The fi nding of the 5 H. qinghaiensis p36 protein homologs could expand our knowledge of tick immunosuppressant proteins and lay ground for future studies to determine their exact role in tick feeding process.
: Proterometra macrostoma is a digenetic trematode that is widely distributed in the eastern United States. The objective of this study was to assess how the cercariae of P. macrostoma within their redia in the infected intermediate snail host ( Elimia semicarinata) ) respond during an initial 7-d exposure of their snail host to 20 degrees C (mimicking a fall temperature), followed by a cold-water exposure of 7.5 degrees C over a 28-d period (mimicking a winter temperature), and within a week after returning to warmer water at 20 degrees C (mimicking a spring temperature). Specifically, fi cally, we investigated whether cercarial development inside the redia ceases or continues during exposure of the snail host to a winter temperature, which was determined based on changes in the cercarial composition in each redia in the infected snails and the amount of cercarial shedding. Naturally infected snails (E. E. semicarinata) ) were collected from North Elkhorn Creek, Scott County, Kentucky, during June and July 2019. Baseline cercarial emergence was recorded over 7 d at 20 degrees C for 55 snails with patent infections. Infected snails were then maintained at 7.5 degrees C for 28 d and checked daily for any cercarial emergence followed by a post-cold treatment analysis of cercarial emergence over 7 d at 20 degrees C. No cercariae were released during the 28-d cold treatment. Significantly fi cantly more (mean +/- SE) cercariae were released per snail during the 7 d following the cold treatment (4.60 +/- 0.33) compared to the period prior to cold treatment (3.63 +/- 0.35). At the termination of the experiment, 94.6% % of infected snails were found to have living rediae with a mean +/- SE infection intensity of 7.13 +/- 0.51 rediae/snail (range 1-18). Additional sets of snails (pre-cold treatment = 4 snails; post-cold treatment = 5 snails) were dissected at the beginning of the pre- and post-cold treatment periods to observe individual cercarial populations within rediae. No significant fi cant differences were found in the average number of the 4 cercarial stages described within rediae pre- vs. post- cold treatment. These results suggest that additional cercariae within rediae mature during winter months, but this was not detectable by our staging criteria.
