Helminths Of Rodents Research Articles

Range extension and new records of two Oxyuroidea Cobbold, 1864 parasitizing Cliff Chipmunk, Neotamias dorsalis (Baird, 1855), in the Área de Protección de Flora y Fauna Cerro del Mohinora, Chihuahua, México

As part of an inventory of the parasitic helminths of rodents, two species of the class Oxyuroidea (Heteroxynema cucullatum Hall, 1916 and Rauschtineria eutamii (Tiner, 1948) Hugot, 1980) were collected from three Cliff Chipmunk specimens (Neotamias dorsalis (Baird, 1955)) in the Área de Protección de Flora y Fauna Cerro del Mohinora, Mexico. These nematodes have been recorded in different species of the genus Neotamias (Illiger, 1811), which can be found in sympatry mainly along the entire west coast of the USA. This is the first record of both species in Mexico.

Rodent helminths in fragmented Atlantic Forest areas in the western region of the state of Paraná.

Rodents are small mammals that can be parasitized by various helminths. This study aimed to identify and describe the ecological indicators of infection in rodents captured in fragments of the Atlantic Forest in the western region of Paraná State, Brazil. Sixty-eight specimens of five rodent species were collected, necropsied, and inspected in search of helminths. The parasites were stored in 70% ethanol, morphologically identified, and counted for calculation of infection indicators. Fourteen species of helminths and one species of Crustacea were recorded: ten in Akodon montensis, four in Mus musculus, two in Thaptomys nigrita, two in Oligoryzomys nigripes, and one in Euryoryzomys russatus. The registered species of parasites were: Rodentolepis akodontis, Angiostrongylus sp., Protospirura numidica criceticola, Trichuris navonae, Syphacia alata, Syphacia criceti, Syphacia evaginata, Trichofreitasia lenti, Stilestrongylus aculeata, Stilestrongylus eta, Stilestrongylus gracielae, Stilestrongylus franciscanus, Stilestrongylus moreli, Stilestrongylus sp., and Pentastomida gen. sp. A positive correlation between the intensity of infection of T. navonae and T. lenti was observed with the body condition index of the host A. montensis. For all species, this study represents a new register of locality, and for eight of them a new host.

Helminth Parasites among Rodents in the Middle East Countries: A Systematic Review and Meta-Analysis.

Simple SummaryThe review was conducted to establish an overview of rodent helminths in the Middle East as well as their public health importance. Following a systematic search, 65 field research were identified, studied, and analyzed. The overall prevalence of cestodes, nematodes, and trematodes were 24.88%, 32.71%, and 10.17%, respectively. The review detected 21 species of cestodes, 56 nematodes, and 23 trematodes, from which 22 have zoonotic importance. Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris were the most frequent and widespread zoonotic helminths. The review identified that there is an information gap on rodent helminths at the humans-animal interface level in this region. Therefore, the public health importance of rodent-borne helminth parasites is not fully recognized. Countrywide detailed studies on rodent helminths, along with the impact on public health, should be conducted in this region.Rodents can be a source of zoonotic helminths in the Middle East and also in other parts of the world. The current systematic review aimed to provide baseline data on rodent helminths to recognize the threats of helminth parasites on public health in the Middle East region. Following a systematic search on PubMed, Scopus, and Web of Science, a total of 65 research studies on rodent cestodes, nematodes, and trematodes, which were conducted in the countries of the Middle East, were analyzed. The study identified 44 rodent species from which Mus musculus, Rattus norvegicus, and Rattus rattus were most common (63%) and recognized as the primary rodent hosts for helminth infestation in this region. Cestodes were the most frequently reported (n = 50), followed by nematodes (49), and trematodes (14). The random effect meta-analysis showed that the pooled prevalence of cestode (57.66%, 95%CI: 34.63–80.70, l2% = 85.6, p < 0.001) was higher in Saudi Arabia, followed by nematode (56.24%, 95%CI: 11.40–101.1, l2% = 96.7, p < 0.001) in Turkey, and trematode (15.83%, 95%CI: 6.25–25.1, l2% = 98.5, p < 0.001) in Egypt. According to the overall prevalence estimates of individual studies, nematodes were higher (32.71%, 95%CI: 24.89–40.54, l2% = 98.6, p < 0.001) followed by cestodes (24.88%, 95%CI: 19.99–29.77, l2% = 94.9, p < 0.001) and trematodes (10.17%, 95%CI: 6.7–13.65, l2% = 98.3, p < 0.001) in the rodents of the Middle East countries. The review detected 22 species of helminths, which have zoonotic importance. The most frequent helminths were Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris. There was no report of rodent-helminths from Bahrain, Jordan, Lebanon, Oman, United Arab Emirates, and Yemen. Furthermore, there is an information gap on rodent helminths at the humans-animal interface level in Middle East countries. Through the One Health approach and countrywide detailed studies on rodent-related helminths along with their impact on public health, the rodent control program should be conducted in this region.

Zoonotic Gastrointestinal Helminths in Rodent Communities in Southern Guatemala.

Rodents are reservoirs and hosts of several pathogens around the world, including zoonotic parasite species. This study aimed to determine the occurrence of zoonotic gastrointestinal helminths in rodents captured inside households in a rural community from southern Guatemala. Sixty-nine rodents were captured in 33% (49/148) of the surveyed households, including Rattus rattus, Rattus norvegicus, Mus musculus, and Sigmodon hispidus. Thirty-six percent (25/69) of these rodents (3 Rattus and 22 Mus musculus), from 45% (22/49) of the households, were parasitized with at least 1 gastrointestinal helminth species. Helminths from 6 species were identified: Hymenolepis diminuta, Moniliformis moniliformis, Heterakis spumosa, Nippostrongylus sp., Strongyloides sp., and Syphacia sp. Two zoonotic species were found in Rattus, H. diminuta in R. rattus (1/6), and M. moniliformis in R. norvegicus (1/1). Coinfection with other non-zoonotic helminth parasites, such as He. spumosa and Strongyloides sp., also was observed in the Rattus genus. Mus musculus had only non-zoonotic helminths: He. spumosa, Nippostrongylus sp., and Syphacia sp. being the most common, and He. spumosa (96%) followed by Nippostrongylus sp. (48%), with a higher presence in males than females, with a similar proportion in adult and young individuals. This is the first report of zoonotic and non-zoonotic helminths parasites in rodents from Guatemala.

Landscape ecological pecularities of rodent helminths of mountainous and foothill territories of Lankaran natural region of Azerbaijan

The information about the helminthfauna of mouse and landscape-ecological pecularities of mountainous and foothill territories of Lankaran natural region is represented in the article for the first time. As a result of investigation 38 species of helminths have been revealed: 8 thrematods, 14 sestods, 15 nematods and 1 akantotsefal. From revealed helminths 28 species are biohelminths and 10 species geohelminths. 9 spesies have something common with the manʼs and domestic animalʼs helminths.

Survey of intestinal helminths collected from pet rodents in México.

In this survey, intestinal helminths from pet rodents in Mérida, México, were analyzed. A total of 46 mice Mus musculus, 28 hamsters Mesocricetus auratus, 23 rats Rattus norvegicus, and 1 gerbil Meriones unguiculatus were purchased from six pet shops and one black market for wildlife in the city of Mérida. The overall prevalence of helminths in rodents was 61.2% (60/98). Six species of helminths were identified: the zoonotic cestode Rodentolepis nana, and the nematodes Aspiculuris tetraptera, Dentostomella translucida, Syphacia obvelata, Syphacia mesocriceti, and Syphacia muris. Of the 60 infected rodents, 25 (41.7%) harbored 2 or 3 species of helminths. Rodentolepis nana was found in 4.3% of mice and 17.9% of hamsters. This is the first report of infection with S. muris in pet rats. Considering the close physical contact between pet rodents and humans, the presence of R. nana in pets represents a potential risk of transmission, especially to children and immunocompromised individuals.

Research Note. Occurrence of gastrointestinal helminths in commensal rodents from Tabasco, Mexico

Summary The aim of this study was to determine the prevalence and species composition of helminths in commensal rodents captured inside private residences in the city of Villahermosa in Tabasco, Mexico. Trapping was performed at each house for three consecutive nights from October to December 2015. Fifty commensal rodents were captured: 23 Rattus norvegicus, 16 Mus musculus and 11 Rattus rattus. Rodents were transported alive to the laboratory and held in cages until they defecated. Feces were analyzed for helminth eggs using the Sheather’s flotation technique. The overall prevalence of helminths in rodents was 60 %: R. norvegicus was more likely to be parasitized (87.0 %) than R. rattus (63.6 %) and M. musculus (18.8 %). Eggs from at least 13 species of helminths were identified: Hymenolepis diminuta, Rodentolepis nana, Moniliformis moniliformis, Heligmosomoides polygyrus, Heterakis spumosa, Mastophorus muris, Nippostrongylus brasiliensis, Strongyloides ratti, Syphacia obvelata, Syphacia muris, Toxocara sp., Trichosomoides crassicauda, and Trichuris muris. This is the first study to report the presence of H. polygyrus, S. ratti and T. crassicauda in commensal rodents in Mexico. In conclusion, our results suggest that helminths commonly infect commensal rodents in Villahermosa and therefore rodents present a health risk to inhabitants in this region.

Helminths in rodents from Wet Markets in Thailand

Summary Only a few surveys have ever been carried out of the helminths of the commensal rodents found in the traditional wet markets that play such an important part of daily life in South-east Asia. The potential of rodents as reservoirs of zoonoses including helminths is of great interest since in these markets humans and rodents come into closer contact than in other environments and food may be indirectly contaminated via rodent faeces. Helminths in a total of 98 rats belonging to two species (Rattus norvegicus and Rattus exulans) were surveyed in eight traditional wet markets in Udon Thani, Thailand. Thirteen species of helminths were recovered, seven of which are potentially zoo-notic, with an overall prevalence of 89.8 %. Our results show that rodents in wet markets could pose a threat to human health as potential reservoirs of zoonotic helminthiases.

Aonchotheca yannickchavali n. sp. (Nematoda: Capillariidae) in Bandicota indica (Bechstein, 1800) and Bandicota savilei (Thomas, 1916) (Rodentia: Muridae) collected from Thailand

During previous surveys of helminths in rodents from Southeast Asia, an unnamed species of Aonchotheca was recovered from the stomach of several rodent species. In the present study, the description of the new species Aonchotheca yannickchavali n. sp. is provided based on both female and male specimens collected from two bandicoot rat species (Bandicota indica and Bandicota savilei) from Thailand (Buriram and Nan provinces). This nematode can be separated from other known Aonchotheca found in rodents by its microhabitat in the host and by the size of the spicules in males and the vulvar appendage in females.

Description of two new species of Hymenolepis Weinland, 1858 (Cestoda: Hymenolepididae) from rodents on Luzon Island, Philippines.

Our helminthological examination of murid rodents on Luzon Island, Philippines, revealed a remarkable diversity of Hymenolepis Weinland, 1858. Here we describe two new species based on specimens from murid rodents Rattus everetti (Günther) and Apomys datae (Meyer) collected from Luzon Island. Hymenolepis alterna n. sp. differs from all known species of Hymenolepis in having irregularly alternating genital pores. This feature has not been reported from any previously known member of Hymenolepis. Additionally, Hymenolepis alterna n. sp. also differs from other Hymenolepis spp. in the relative position of both poral and antiporal dorsal osmoregulatory canals which are shifted towards the middle of the proglottis in relation to the ventral canals on both sides of the proglottides, and in having curved or twisted external seminal vesicle, covered externally by a dense layer of intensely stained cells. Hymenolepis bilaterala n. sp. differs from all known species of Hymenolepis in the relative position of both poral and antiporal dorsal osmoregulatory canals, which are shifted bilaterally towards the margins of proglottides in relation to the ventral canals, and in possession of testes situated in a triangle and eggs with very thin outer coat. A total of seven species of Hymenolepis are known from the Philippine archipelago. This total includes the cosmopolitan species Hymenolepis diminuta (Rudolphi, 1819), which was likely introduced to the island with invasive rats. Strikingly, all seven known species occur on the island of Luzon alone. By comparison, only six Hymenolepis spp. are known from the whole Palaearctic and seven from the Nearctic despite a much better level of knowledge of rodent helminths in these zoogeographical regions, as well as vast territories, diverse landscapes and very rich rodent fauna. This suggests that Hymenolepis spp. may have undergone an unusually active radiation in the Philippines. Possible explanations of this phenomenon are discussed.

Helminth products bypass the need for TSLP in Th2 immune responses by directly modulating dendritic cell function

Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine, mainly expressed by epithelial cells, and key to the development of allergic responses. The well-documented involvement of TSLP in allergy has led to the conviction that TSLP promotes the development of inflammatory Th2 cell responses. However, we now report that the interaction of TSLP with its receptor (TSLPR) has no functional impact on the development of protective Th2 immune responses after infection with 2 helminth pathogens, Heligmosomoides polygyrus and Nippostrongylus brasiliensis. Mice deficient in the TSLP binding chain of the TSLPR (TSLPR(-/-)) exhibited normal Th2 cell differentiation, protective immunity and memory responses against these two distinct rodent helminths. In contrast TSLP was found to be necessary for the development of protective Th2 responses upon infection with the helminth Trichuris muris (T. muris). TSLP inhibited IL-12p40 production in response to T. muris infection, and treatment of TSLPR(-/-) animals with neutralizing anti-IL-12p40 monoclonal antibody (mAb) was able to reverse susceptibility and attenuate IFN-gamma production. We additionally demonstrated that excretory-secretory (ES) products from H. polygyrus and N. brasiliensis, but not T. muris, were capable of directly suppressing dendritic cell (DC) production of IL-12p40, thus bypassing the need for TSLP. Taken together, our data show that the primary function of TSLP is to directly suppress IL-12 secretion, thus supporting Th2 immune responses.

Three New Species of Heligmonellidae (Nematoda: Trichostrongyloidea) from Melomys, Paramelomys, and Uromys (Rodentia: Muridae) from Papua, Indonesia and Papua New Guinea

Abstract During a study of the helminths of rodents (Muridae: Hydromyinae) from the island of New Guinea 3 undescribed species of trichostrongyloid nematodes were found. Macrostrongylus ingens n. sp. (Heligmonellidae: Brevistriatinae) occurring in Uromys caudimaculatus (type host), Melomys rufescens, Melomys sp., Paramelomys platyops, Paramelomys cf. platyops, and Paramelomys levipes, could be differentiated from its congener Macrostrongylus ratti by its larger size, shorter spicules, and wider cephalic vesicle. Odilia carinatae n. sp. (Heligmonellidae: Nippostrongylinae) occurring in Uromys anak (type host) and Uromys caudimaculatus differs from all other species of Odilia in the combination of number, form, and arrangement of ridges on the synlophe and the shape of the spicule tips. Odilia implexa n. sp., occurring in U. caudimaculatus (type host) and U. anak is closest to Odilia uromyos in the shape of the spicule tips but has fewer ridges on the synlophe. Macrostrongylus ingens is the first of the Bre...

In vitroanthelmintic effects of cysteine proteinases from plants against intestinal helminths of rodents

Infections with gastrointestinal (GI) nematodes are amongst the most prevalent worldwide, especially in tropical climates. Control of these infections is primarily through treatment with anthelmintic drugs, but the rapid development of resistance to all the currently available classes of anthelmintic means that alternative treatments are urgently required. Cysteine proteinases from plants such as papaya, pineapple and fig are known to be substantially effective against three rodent GI nematodes, Heligmosomoides polygyrus, Trichuris muris and Protospirura muricola, both in vitro and in vivo. Here, based on in vitro motility assays and scanning electron microscopy, we extend these earlier reports, demonstrating the potency of this anthelmintic effect of plant cysteine proteinases against two GI helminths from different taxonomic groups - the canine hookworm, Ancylostoma ceylanicum, and the rodent cestode, Rodentolepis microstoma. In the case of hookworms, a mechanism of action targeting the surface layers of the cuticle indistinguishable from that reported earlier appears to be involved, and in the case of cestodes, the surface of the tegumental layers was also the principal location of damage. Hence, plant cysteine proteinases have a broad spectrum of activity against intestinal helminths (both nematodes and cestodes), a quality that reinforces their suitability for development as a much-needed novel treatment against GI helminths of humans and livestock.

Rhythmic behaviour of intestinal helminths in rodents

AbstractIntestinal helminths exhibit two types of circadian rhythms, either involving the migration of adults worms (Hymenolepis and Syphacia) within the gut or periodic release of eggs by female worms (Aspiculuris and Heligmosomoides) to the exterior of the host to maximize transmission efficiency. By modifying the feeding regimes of rodents, there is clear evidence that these rhythmic processes are directly linked with the digestive and defaecating activities of the host with neurohormonal control mechanisms likely to be involved at least in the migratory behaviour of adult worms. Furthermore, in Heligmosomoides polygyrus rhythmic egg output appears to be dependent upon parasite age and the population density of the host and parasite. A brief reference is also made to studies on long‐term rhythms of egg output by intestinal nematodes and their effect on patterns of host faecal production.

Helminth parasites of British rodents and insectivores

AbstractField and laboratory studies on the helminths of rodents have mainly involved direct life‐cycle nematodes (of the super families Rhabditoidea, Oxyuroidea, Trichuroidea and Trichostrongyloidea) and, to a lesser extent, indirect life‐cycle cyclophyllidean cestodes (of the families Catenotaeniidae and Hymenolepididae). In insectivores on the other hand, because of their different feeding habits, the composition of the helminth fauna largely comprises hymenolepid and dilepidid cestodes together with brachylaemid and dicrocoeliid digeneans, the life cycles of which are little known. The value of further studies on the biogeography of helminths of rodents and insectivores in the British Isles is emphasized. The role of rodent nematodes as laboratory models for chemotherapy is also discussed.