A new species of Wellcomia (Nematoda: Oxyuridae) in the plains viscacha (Rodentia: Chinchillidae) from Argentina, an emended diagnosis and an update of the genus Wellcomia

Wellcomia species (Oxyuridae, Syphaciinae) parasitise several families of rodents from Africa, Asia and America with diverse ecological characteristics. A new species of Wellcomia is described based on specimens obtained from the plains viscacha Lagostomus maximus (Chinchillidae) from Argentina. The description includes morphometric and ecological aspects and an emended diagnosis of the genus Wellcomia. In addition, a molecular characterisation (18S rRNA) and an exploratory analysis of the genetic distances of the species included in this genus are provided. The new species, Wellcomia hugoti n. sp., differs from other species of the genus in the morphology of the cephalic plate, the ventral rugose area in males and the vulva in females. The new species showed a low prevalence (7.7%) and a high mean abundance (73.8). The genetic distances detected do not allow a comprehensive assessment of the monophyly of the genus. This is the seventh record of this genus in rodents from the Americas, the second in rodents from Argentina and the first record for the family Chinchillidae.

Syphacia muris infection in rats attenuates colorectal carcinogenesis through oxidative stress and gene expression alterations. Implications for modulatory effects by Bryostatin-1

Accumulating evidence suggest that some infectious agents may interfere in the natural progression of neoplasia. This study examined the association between chronic infection with adult Syphacia muris parasites and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in rats. In addition, the conceivable therapeutic effect of Bryostatin-1, a potent extract of the marine Bryozoan, Bugulane ritina, was investigated against this combined effect.DMH administration has induced aberrant crypt foci (ACF), surrogate biomarkers for colorectal carcinogenesis, while the S. muris infection combined with DMH has significantly increased the total numbers of ACF. Nonetheless, treatment with Bryostatin-1 after infection has significantly reduced the ACF numbers particularly larger ones. This inhibition was concomitant with significant inhibition in the immunohistochemical levels of the ki67, Caspase-3 and IgM levels in colorectal epithelium, as well as serum levels of IgM and IgG. Additionally, treatment with Bryostatin-1 after S. muris + DMH has modulated enzymatic antioxidative markers levels of superoxide dismutase and catalase as well as the non-enzymatic antioxidant markers levels of reduced glutathione, lipid peroxidation, nitric oxide and total antioxidant capacity. Further, treatment with Bryostatin-1 has down-regulated the mRNA expression levels of COX-2 and APC genes in colorectal mucosa. In conclusion, infection with S. muris during colorectal carcinogenesis has significantly modulated the oxidative stress markers in the colorectum, while treatment with Bryostatin-1 has exerted significant curative potential. A mechanism could be explained that Bryostatin-1 treatment has reduced oxidative stress markers activities along with affecting host to parasite immunity possibly leading to changes in the COX-2 and APC expression, retarding cellular proliferation and subsequently reducing the colorectal carcinogenesis events.

Evaluation of Anthelmintic Resistance and Exhaust Air Dust PCR as a Diagnostic Tool in Mice Enzootically Infected with Aspiculuris tetraptera

The entry of infectious agents in rodent colonies occurs despite robust sentinel monitoring programs, strict quarantine measures, and stringent biosecurity practices. In light of several outbreaks with Aspiculuris tetraptera in our facilities, we investigated the presence of anthelmintic resistance and the use of exhaust air dust (EAD) PCR for early detection of A. tetraptera infection. To determine anthelmintic resistance, C57BL/6, DBA/2, and NCr nude mice were experimentally inoculated with embryonated A. tetraptera ova harvested from enzootically infected mice, followed by treatment with 150 ppm fenbendazole in feed, 150 ppm fenbendazole plus 5 ppm piperazine in feed, or 2.1 mg/mL piperazine in water for 4 or 8 wk. Regardless of the mouse strain or treatment, no A. tetraptera were recovered at necropsy, indicating the lack of resistance in the worms to anthelmintic treatment. In addition, 10 of 12 DBA/2 positive-control mice cleared the A. tetraptera infection without treatment. To evaluate the feasibility of EAD PCR for A. tetraptera, 69 cages of breeder mice enzootically infected with A. tetraptera were housed on a Tecniplast IVC rack as a field study. On day 0, 56% to 58% of the cages on this rack tested positive for A. tetraptera by PCR and fecal centrifugation flotation (FCF). PCR from EAD swabs became positive for A. tetraptera DNA within 1 wk of placing the above cages on the rack. When these mice were treated with 150 ppm fenbendazole in feed, EAD PCR reverted to pinworm-negative after 1 mo of treatment and remained negative for an additional 8 wk. The ability of EAD PCR to detect few A. tetraptera positive mice was investigated by housing only 6 infected mice on another IVC rack as a field study. The EAD PCR from this rack was positive for A. tetraptera DNA within 1 wk of placing the positive mice on it. These findings demonstrate that fenbendazole is still an effective anthelmintic and that EAD PCR is a rapid, noninvasive assay that may be a useful diagnostic tool for antemortem detection of A. tetraptera infection, in conjunction with fecal PCR and FCF.

New species of Parapharyngodon (Nematoda: Pharyngodonidae) in Phymaturus spp. (Iguania: Liolaemidae) from Argentina

Parapharyngodon sanjuanensis sp. nov. (Nematoda: Pharyngodonidae) from the large intestines of Phymaturus punae and Phymaturus williamsi (Squamata: Liolaemidae) from province of San Juan, Argentina, is described and illustrated. Parapharyngodon sanjuanensis sp. nov. is the 54th species assigned to the genus and the 8th from the Neotropical region. It differs from other species in the genus in that males possess 8 caudal papillae, 6 of which are large and pedunculate, 2 are small, almost inconspicuous; anterior lip echinate, posterior lip bilobate; females possess prominent vulva and short stiff tail spike.

First Molecular Characterization of Aspiculuris tetraptera (Nematoda: Heteroxynematidae) from Mus musculus (Rodentia: Muridae) in India

Mus musculus (Rodentia: Muridae) were infected by a nematode belonging to the order Oxyurida. According to external morphological characters it was found to be Aspiculuris tetraptera Schulz, 1924. Present communication deals with molecular characterization of A. tetraptera infecting intestine of Mus musculus in Meerut (U.P.), India. A partial sequence of 18S ribosomal and cytochrome c oxidase subunit 1 (Cox 1) mitochondrial DNA analyses were performed. Sequence corresponding to 18S rRNA and mt Cox 1 gene was identical to sequences reported for A. tetraptera on GenBank. These results confirm the taxonomic validation of A. tetraptera parasitizing Mus musculus. This is the first report of molecular study of A. tetraptera in India.

Characterization of rat pinworm (Syphacia muris) epidemiology as a means to increase detection and elimination

Rodent pinworms persist in many institutions, suggesting deficiencies in eradication and diagnostic processes. When pinworms are detected, treatment success is common, but false-negative test results during health surveillance or after treatment likely contribute to the continued presence of this parasite. PCR testing is not always practical, and increased information regarding the life cycle and general epidemiology of pinworm infestations could improve the sensitivity of traditional nonPCR detection methods and improve eradication efforts. We therefore investigated a pinworm (Syphacia muris) infestation in Sprague-Dawley rats (Rattus norvegicus) to develop a more accurate testing strategy. In addition, we sought to determine the duration of egg viability by using an in vitro hatching protocol to assess environmental persistence. Finally, we tested the ovicidal efficacy of a disinfectant used at our institution. Eggs were shed in higher numbers in the midafternoon as compared with other times of the day, and the sex of the host had no consistent effect on egg shedding. Egg shedding showed periodicity over time, with shedding decreasing to 0 at 2- to 3-wk intervals. Neither cecal examination nor tape tests alone reliably predicted pinworm infestation, and results of the 2 tests did not necessarily coincide. Eggs aged for as long as 7 mo remained viable, indicating a potential for recontamination from the environment. Finally, gaseous chlorine dioxide was an effective ovicidal agent, with a kill rate of 99.7%. These results suggest that strategies for S. muris eradication can be optimized to increase detection and elimination.

False-positive results after environmental pinworm PCR testing due to Rhabditid nematodes in Corncob bedding

Modern rodent colonies are housed in individually ventilated cages to protect the animals from contamination with adventitious pathogens. Standard health monitoring through soiled-bedding sentinels does not always detect infections, especially in the context of low pathogen prevalence. Recently proposed alternatives include analyzing environmental samples from the cages or rack exhaust by PCR to improve the detection of rodent pathogens but optimal sampling strategies have not yet been established for different microorganisms. Although generally very sensitive and specific, these molecular assays are not foolproof and subject to false-positive and -negative results and should always be interpreted cautiously with an overall understanding of the intrinsic controls and all the variables that may affect the results. Here, we report a limited Aspiculuris tetraptera outbreak in a mouse barrier facility that was detected by fecal PCR in sentinels and confirmed by fecal flotation and direct cecal examination of both sentinels and colony animals. The outbreak led to a widespread survey of all facilities for pinworms by using environmental PCR from ventilated rack exhaust plenums. Environmental PCR suggested an unexpected widespread contamination of all ventilated racks holding nonautoclaved cages, but results could not be confirmed in sentinel or colony animals by fecal flotation, cecal and colonic examination, or cage PCR testing. After additional investigation, the unexpected environmental PCR results were confirmed as false-positive findings due to the nonspecificity of the assay, leading to the amplification of rhabditid nematodes, which are not infectious in rodents but which contaminated the corncob bedding.

Description of Lemuricola (Lemuricola) pongoi--male (Nematoda: Enterobiinae) parasitising orangutan Pongo abelii

The study presents the first description of male specimen (allotype) of the pinworm species Lemuricola (Lemuricola) pongoi, parasitising Sumatran orangutan (Pongo abelii) from Sumatra (Indonesia). The male specimen morphology presents all features fully corresponding with diagnose of the genus and subgenus Lemuricola. We are agreeing that Protenterobius is synonymous with Lemuricola because the length of tail appendix in males is not a sufficient feature for separation of the genera or subgenera. For L. (L.) pongoi male are characteristic features: body length (4,803 microm), total oesophagus length (530), tail length (235), tip of tail length (188) and spicule length (90).

A new species of Syphacia (Nematoda: Oxyuridae) from Oligoryzomys nigripes (Rodentia: Cricetidae) in Argentina

The aim of this paper is to describe Syphacia kinsellai n. sp. (Nematoda: Oxyuridae) from the cecum of Oligoryzomys nigripes (Olfers 1818) (Sigmodontinae: Oryzomyini) captured in Misiones Province, Argentina. The new species can be differentiated from other species of the genus principally by the shape of the cephalic plate; distribution of submedian papillae and amphids; development of porous badge; presence of derids in females; absence of cervical and lateral alae; shape and structure of accessory hook of gubernaculum; and distance of excretory pore and vulva from the anterior extremity. Until the present, only two species of Syphacia had been reported from Argentina in sigmodontine rodents, the first one parasitizes an Oryzomyini host and the second one an Akodontini host. This new species is the second record of Syphacia from the tribe Oryzomyini in Argentina; however, we propose that the first record, S. oryzomae, should be treated as a nomen dubium.

A NEW SPECIES OF SYPHACIA (NEMATODA: OXYURIDAE) FROM AKODON AZARAE (RODENTIA: CRICETIDAE) IN ARGENTINA

Eight species of Syphacia (Nematoda: Oxyuridae) have been reported from South America in rodents of the Sigmodontinae, only 1 of which has been recorded in Argentina. Syphacia (Syphacia) carlitosi n. sp. is described from the ceca of Akodon azarae bibianae and Akodon azarae hunteri (Sigmodontinae: Akodontini) captured in 3 provinces in the northeast region of Argentina. The new species is differentiated principally by the shape of the cephalic plate; distribution of submedian papillae and amphids; presence, extent, and shape of cervical alae in females; absence of lateral alae; absence of deirids; spicular and gubernaculum length; shape and structure of accessory hook of gubernaculum; and distance of mamelons, excretory pore, and vulva from the anterior extremity. This is the second record of Syphacia parasitizing rodents of the tribe Akodontini.

[Gastrointestinal parasites of rabbits in coproscopic investigations]

BACKGROUND

Parasitological screening was carried out in a breeding herd of the New Zealand White rabbit breed in 2004.

MATERIAL AND METHODS

Mothers, together with their offsprings, were kept in boxes on deep litter, whereas young rabbits were transferred to cages with slatted floor. All the animals were fed a complete balanced pelleted feed with two coccidiostats added alternately (Lerbec, Robenidine), and droplet watering system was applied. No anthelmintic was used in the rabbitry. A total of 170 individual samples of fresh feces from females of breeding stock, and 55 pooled samples in the case of young animals 2-4 months of age, collected on a month intervals, were analyzed according to a modified concentration McMaster's method, using saturated salty water with sugar as a flotation fluid.

RESULTS

The presence of several species of coccidia was evaluated, with Eimeria stiedae, E. perforans, E. media and E. magna being found in great numbers. The dynamics of infection showed that both adults and young animals were affected by coccidia mostly in May (mean intensity reached at that time 24000 opg in young rabbits), and then until August the infection lasted on a high level. As regards coccidiosis, parasitism could be considerably cut back in the herd by frequent changing of the straw litter, which should also always be dry. Only Passalurus ambiguus was found from nematodes, and only in the feces of adults, probably due to the modern forage and watering system applied, which broke the other worms' life cycles.

Two new species of Pharyngodonidae (Nematoda: Oxyuroidea) and other nematodes in Agama caudospina (Squamata: Agamidae) from Kenya, Africa

Parapharyngodon kenyaensis n. sp. and Thelandros samburuensis n. sp. (Nematoda: Pharyngodonidae) from the large intestine of the agamid lizard (Agama caudospina) are described and illustrated. Parapharyngodon kenyaensis n. sp. is the 41st species assigned to the genus, and it differs from other species in that genus by possessing 3 pairs of caudal papillae, cloacal lip adornment, and spicules of 112-120 microm in length. Thelandros samburuensis n. sp. is the 31st species assigned to the genus, and it differs from other species in that genus by possessing swollen posterior annulations, 6 caudal papillae, a smooth anterior cloacal lip, and spicules of 43-52 microm in length. In addition to the 2 new nematode species, Abbreviata ortleppi (Nematoda: Physalopteridae) and Strongyluris ornata (Nematoda: Heterakidae) were found.

Two new genera of the pharyngodonidae (Nematoda: Oxyuroidea) found in rhacophorid frogs of the Ryukyu Archipelago, Japan

Okinawandros goldbergi n. gen., n. sp. and Ataronema sekii n. gen., n. sp. (Nematoda: Pharyngodonidae) are described from rhacophorid frogs of the Ryukyu Archipelago, Japan. Okinawandros n. gen. resembles Batracholandros Freitas et Ibañez, 1965 and Synodontisia Petter, Vassiliades et Troncy, 1972 but is readily distinguished from the former in lacking laterally situated genital papillae and by having anteriorly directed vagina and from the latter by having operculated eggs and lacking a spicule. Ataronema n. gen. most closely resembles Parathelandros Baylis, 1930 but is readily distinguished because the posterior pair of caudal papillae is not rosette shaped and the eggs are not operculated. Morphological notes of Pharyngodon polypedatis Yamaguti, 1941 are included.

Eradication of Syphacia muris from food-restricted rats without environmental decontamination

Rodent pinworms rarely cause clinical disease, but infestation can affect experimental results. Our facility maintained a colony of Wistar rats for behavioral pharmacology studies that had been infested with Syphacia muris for > 15 years. The laboratory in which the animals were housed encompassed several rooms and contained a variety of complex behavioral equipment, including > 60 operant chambers. Several prior attempts to eliminate the pinworms were unsuccessful because of inadequate duration of treatment and incomplete environmental decontamination. Many of the rats in this colony were food-restricted as part of behavioral studies. Pinworms were eliminated from these animals by treating them with 450 ppm fenbendazole-containing feed for 3 consecutive weeks followed by 6 weeks of alternating every other week with standard rodent diet. Rats not on food restriction protocols were treated on the same schedule with 150 ppm fenbendazole-containing feed. Environmental decontamination of eggs from the behavioral equipment was not attempted. One year after treatment, the colony has remained free of S. muris. We adapted previously published protocols to our situation, including the problem of food-restricted rats and unfeasible environmental decontamination, to eradicate S. muris from our colony.

Redescription of four species of Mehdiella from Testudinidae, with a key to the species and discussion on the relationships among the species of this genus

Four species of the genus Mehdiella Seurat, 1918 are redescribed: M. cristata Petter, 1966 and M. stylosa dollfusi Petter, 1966, parasite of Pyxix arachnoides Bell, 1827 from Madagascar, M. s. stylosa (Thapar, 1925) and M. uncinata (Drasche, 1884), parasite of Testudo graeca Linneaus, 1758, Testudo hermanni Gmelin, 1789 and Testudo horsfieldii (Gray, 1844) from Palaearctic region. Light microscopy and scanning electron microscopy (SEM) studies revealed new informations on the morphology of these species. On the basis of this morphological study, the sub-species Mehdiella stylosa dollfusi and M. s. stylosa are raised to level of species. The position of Mehdiella cristata among the species of the genus Mehdiella and the relationships among the species of the genus Mehdiella are discussed. A key to the eight valid species Mehdiella is given.

Expanded Geographical Range, New Host Accounts, and Observations of the Nematode Gyrinicola batrachiensis (Oxyuroidea: Pharyngodonidae) in Tadpoles

We describe the first account of the nematode Gyrinicola batrachiensis in the gastrointestinal tracts of tadpoles of Bufo terrestris, Gastrophryne carolinensis, Hyla femoralis, H. squirella, Rana heckscheri, and R. utricularia. Infection by G. batrachiensis was also noted in tadpoles of R. catesbeiana and R. clamitans, species previously described as harboring these nematodes. These observations represent a major expansion of the known geographical range of G. batrachiensis to include the southeastern United States. In our study, female G. batrachiensis nematodes in ranid host species were didelphic, but females in B. terrestris tadpoles were monodelphic. Furthermore, only female nematodes were found in the latter host species. Such variations in nematode uterine morphology and sex ratios among these tadpole host species are in accordance with the apomictic and haplodiploid reproductive strategies previously reported for G. batrachiensis. These observations also support a generalized pattern relating G. batrachiensis reproductive modes and the life cycles of their tadpole hosts.

Evaluation of coinfection with pinworms (Aspiculuris tetraptera, Dentostomella translucida, and Syphacia obvelata) in gerbils and mice

Mongolian gerbils (Meriones unguiculatus) naturally infected with the nematode Dentostomella translucida and mice (Mus musculus) that were either pinworm-free or harboring either or both Aspiculuris tetraptera and Syphacia abvelata were crossinfected experimentally with these nematode species. Gerbils were susceptible to infections by S. obvelata and A. tetraptera from mice, whereas mice were resistant to infection by D. translucida from gerbils. The data presented are the first regarding coinfections with these three pinworms in gerbils.

The nematode fauna of long-nosed mice Oxymycterus spp. from the Bolivian Yungas

During a long-term survey of the parasites of mammals from all over Bolivia, 44 individuals of Oxymycterus inca and 6 of Oxymycterus paramensis were collected and examined for parasites from the foothills and Eastern Cordillera (Los Yungas) of the Andes of Bolivia. Three species of nematode were found including, from the cecum, a previously unknown genus and species of pinworm, Caroloxyuris boliviensis n. gen, n. sp., aspidoderids representing Nematomystes rodentophilus, and from the stomach, Protospirura numidica criceticola. These helminths occurred in prevalences of 25, 9, and 14%, respectively, in O. paramensis. Caroloxyuris boliviensis resembles species included in the genus Syphacia in the structure of the cephalic mask and copulatory organs, and the extension of lateral alae. However, males of this species possess only 2 mamelons on the ventral surface of the body. Caroloxyuris can be recognized as being distinct from both Helminthoxys and Rauschtineria in the ornamentation of the mamelons and the shape of cephalic mask. A redescription of N. rodentophilus is provided, and Nematomystes scapteromi is transferred from Ansiruptodera to Nematomystes.

Epizootiology of Syphacia obvelata from a domestic mouse population on the subantarctic Kerguelen Archipelago

The effects of abundance, age, and sex of feral domestic mice Mus musculus domesticus on infections with the nematode parasite Syphacia obvelata were analyzed during a long-term study of the mouse population on Guillou Island (1.45 km2), a part of the subantarctic Kerguelen Archipelago. The population dynamics of the nematode did not follow the variation in host abundance. However, depending on the year, differences in pinworm abundance were found between the age classes and sex. Such patterns suggest that parasitic infections may have been modulated by host-intrinsic factors, e.g., either by the way of innate or adaptive immunity, rather than extrinsic factors, e.g., host abundance.

Redescription of some Spauligodon spp. and Parapharyngodon spp., and of skrjabinodon mabuyae (Sandground, 1936) inglis, 1968 (Pharyngodonidae: Oxyuroidea) from insectivorous South African lizards

As part of a study on the helminth parasites of South African lizards several species of saurians were collected from localities in the North West Province, the Northern Province, Mpumalanga Province and Gauteng Province. Spauligodon blydeensis (Hering-Hagenbeck, 2001) from the Cape thick-toed gecko, Pachydactylus capensis, Spauligodon molpoensis (Hering-Hagenbeck, 2001) from Wahlberg's velvet gecko, Homopholis wahibergii, Parapharyngodon margaritiferi, Hering-Hagenbeck, 2001 from the skink, Mabuya margaritifer, Parapharyngodon gerrhosauri, Hering-Hagenbeck, 2001 from the plated lizard, Gerrhosaurus flavigularis and Skrjabinodon mabuyae (Sandground, 1936) Inglis, 1968 from the skinks Mabuya punctatissima, Mabuya spilogaster and Mabuya varia are redescribed. The different Spauligodon spp. in the subcontnent may be separated on the presence or absence of spicules in the males, the presence or absence of spines on the tail of both the males and females, as well as on the size and shape of the eggs, and the configuration of the polar caps. The Parapharyngodon spp. are distinguished mainly by the morphological characters of the males, such as the width of the caudal alae and the size of the pre- and adanal papillae. Female Parapharyngodon spp. closely resemble each other and some could not be identified to the species level since males were absent. Spinose larvae, together with adult Parapharyngodon spp. were recovered from Mabuya margaritifer. All Parapharyngodon spp. larvae described to date are spinose and since the larvae in this study were collected together with adult Parapharyngodon spp., we consider them to belong to the same genus. Skrjabinodon mabuyae differs from the closely related Skrjabinodon mabuiensis in the presence of a spicule in the male and lateral alae in the female. The former nematode is described for the first time from skinks in South Africa.

A review of treatments for the eradication of pinworm infections from laboratory rodent colonies

Oxyurids are common contaminants of both specific pathogen-free and conventional rodent colonies. This paper reviews the biology and life cycles of oxyurid parasites of laboratory rodents, mechanisms of action and potential adverse effects of commonly used treatments, and treatment modalities, both historical and recent.

Redescription of some Thelandros and Tachygonetria spp. (Pharyngodonidae: Oxyuroidea) from the omnivorous plated lizard, Gerrhosaurus validus validus A. Smith, 1849 in South Africa

Thelandros schusteri Hering-Hagenbeck, 2001, Thelandros luciusi Hering-Hagenbeck, 2001, Thelandros boomkeri Hering-Hagenbeck, 2001, Tachygonetria bainae Hering-Hagenbeck, 2001, Tachygonetria chabaudi Hering-Hagenbeck, 2001 and Tachygonetria petterae Hering-Hagenbeck, 2001 from the plated lizard, Gerrhosaurus validus validus A. Smith 1849 from three localities in the north-eastern region of South Africa are redescribed. Classification keys are available only for the males of the species and because male and female nematodes in copula were not observed in this study as well as the similarity of the females, it was not possible to identify the females to the species level. Thelandros schusteri, Thelandros boomkeri and Thelandros luciusi were provisionally paired with female Type E, Tachygonetria bainae with female Type C, Tachygonetria chabaudi with female Type A and Tachygonetria petterae with female Type D. Female Types B and F could not be paired. The richness and composition of species of the Pharyngodonidae of Gerrhosaurus validus validus is close to that of tortoises and differs from the pharyngodonid fauna of the insectivorous lizards that have been studied. In the latter, only the genera Spauligodon, Skrjabinodon and Parapharyngodon were recovered. The pharyngodonid fauna of Gerrhosaurus validus validus seems to have originated by capture from local herbivorous reptiles. The three Tachygonetria spp. most closely resemble forms in South African tortoises. The three Thelandros spp. redescribed here not only show strong similarities to those of herbivorous Agama spp., but also to those parasitic in tortoises and could have been acquired from either.

Syphacia longaecauda n. sp. (Nematoda: Oxyuridae) syphacinea from Melomys spp. (Muridae: Hydromyinae) from Papua New Guinea and Irian Jaya, Indonesia

A new oxyurid nematode Syphacia (Syphacia) longaecauda n. sp. is described from the caecum and colon of the hydromyine rodents Melomys monktoni (type host) and M. rubex from Papua New Guinea and Irian Jaya, Indonesia. Syphacia longaecauda has an oval, laterally extended, relatively large cephalic plateau and can be distinguished from other species of Syphacia with similar characters by, amongst other features, tail length. The significance of the distribution of S. longaecauda, apparently restricted to New Guinea, is discussed.

Epidemiology and genetic variability of two species of nematodes (Heligmosomoides polygyrus and Syphacia stroma) of Apodemus spp

The epidemiology and genetic variability of 2 parasitic nematodes Heligmosomoides polygyrus and Syphacia stroma of Apodemus spp. were investigated. Both are parasites of the same host, exhibit a direct life-cycle and are dioecious. However, H. polygyrus has a diploid and S. stroma a haplodiploid mode of reproduction. Haplodiploidy may lead to a more female biased sex ratio and reduced genetic variability. Levels of genetic diversity were analysed using both isoenzyme electrophoresis and RAPDs (random amplified polymorphic DNA). Both parasites showed a female biased sex ratio with a stronger bias for the haplodiploid parasite. Results showed significantly fewer genetic polymorphisms as measured by RAPDs for the haplodiploid parasite S. stroma in comparison with H. polygyrus. Despite the observed female biased sex ratio this could not be explained by a significant amount of inbreeding. Heterozygote deficiency for individual allozyme loci--which could indicate inbreeding--was not found in either parasite species. Other features of the particular life-history of these species are likely to have an impact on the sex ratio and genetic variability too.

Comparison between patterns of pinworm infection (Aspiculuris tetraptera) in wild and laboratory strains of mice, Mus musculus

Sixteen laboratory and 7 wild-derived strains of mice were infected with the pinworm Aspiculuris tetraptera in order to compare their resistance levels estimated by the intestinal parasite loads. It appears that (i) in 4 strains out of 23, females and males harbour different parasite loads; (ii) wild and laboratory mice display a broad range of infection levels when compared independently; (iii) the laboratory strains are more resistant than the wild ones. We suggest that (i) compared to sex, the strain (i.e. genetic) effect is the main parameter which determines the levels of infection; (ii) resistance was selected in laboratory strains during their breeding because of the parasite pressure present in captivity.

[Microstructural changes in the organs of the rabbit with passaluriasis]

The paper presents the data on morphofunctional changes in some rabbit organs (the liver, kidney, intestine, lung, heart) invaded with the nematode Passalurus ambiguus. The most profound inflammatory and dystrophic changes were found in the cecum which was a site of helminths. The signs of vacuolar dystrophy were also observed in the hepatic and renal parenchyma. There was activation of the immune system and mobilization of overall compensatory responses of the animals.

The effect of Toxoplasma gondii and other parasites on activity levels in wild and hybrid Rattus norvegicus

Using both correlational and experimental evidence, the relationship between parasite load and host activity was assessed in brown rats, Rattus norvegicus. Two hypotheses were tested--(1) that parasites with indirect life-cycles, involving transmission between a prey and its predator, will alter the activity of the intermediate host so as to increase its susceptibility to predation by the definitive host and (2) that activity levels in parasitized rats would be increased rather than decreased. Four groups of rats (n = 140) were examined. One group (n = 50) were wild brown rats trapped from 3 UK farmsteads, with naturally occurring parasites. The others were purpose-bred wild/laboratory hybrid rats with experimentally induced parasitic infections of either (n = 15) adult-acquired or (n = 15) congenitally-acquired Toxoplasma gondii (an indirect life-cycle parasite), or (n = 15) Syphacia muris (a direct life-cycle parasite). Uninfected hybrid rats ( n = 45), matched for sex, age and weight, served as controls. Rats were housed individually in outdoor cages, and their activities were recorded on video-tapes for 6 non-consecutive 10 h nights. Exercise wheels were also available for the hybrid rats. Out of 6 parasite species detected in the wild rats, T. gondii was the only one which required predation by a definitive host to complete its life-cycle, and was also the only parasite to be associated with higher activity levels in infected than uninfected rats. Hybrid rats infected with T. gondii were also more active than those uninfected, whereas there were no differences in activity levels between S. muris infected and uninfected rats. This study shows that the indirect life-cycle parasite T. gondii can influence the activity of its intermediate host the rat. I suggest that this may facilitate its transmission to the cat definitive host.

[A comparative study of the efficacy of medamine, albendazole and embovin in models of syphaciasis and aspiculariasis]

The study covers the study of three antinematodal agents: the original national drug medamine with albendazole and embovin (pyrathel pamoate), which have been reproduced at the E. I. Martsinovskiĭ Institute of Medical Parasitology and Tropical Medicine, with murine Syphacia obvelata and Aspiculuris tetraptera infection models. The quantitative parameters of the anthelmintic action of medamine, albendazole and embivin were comparatively defined for the first time.

[A luminescence microscopy method for studying organ function in Aspiculuris tetraptera (Schulz, 1924)]

The paper proposes the rapid technique for examining the luminescence pattern of individual systems and organs in the murine parasite Aspiculuris tetraptera. The luminescence pattern of the parasite was studied after fluorochrome-plating with rhodamine 6G, rhodamine C, coryphosphine, sodium fluorescein, acridine orange which was found to be the optimum fluorochrome. This technique is to be used in the evaluation of the effects of chemopharmaceuticals on the parasite.

In vitro embryonation of Syphacia obvelata eggs

Mouse infections with the pinworm, Syphacia obvelata, were evaluated as a potential model of human enterobiasis. Eggs of S. obvelata were found to be much less resistant to adverse environmental factors than those of Enterobius vermicularis, perishing rapidly when exposed to desiccation or to water. The average number of eggs produced by a female worm was 317 +/- 29 S.D. (range: 266-347), which is about 2-3% of the fecundity of E. vermicularis. Eggs expressed from gravid S. obvelata were incubated under various conditions, but the only reliable method of supporting complete embryonation was culture on a floating cellophane membrane. At 30 degrees C on this substrate, eggs were found to be infective between 6 and 42 h, inclusive. The pre-patent period in mice fed these eggs was 11-15 days. The more fastidious developmental and survival requirements of Syphacia eggs indicate that transmission of this species depends on much more intimate contact between hosts than is required by E. vermicularis.

On the morphology of the oxyurid nematode Pharyngodon mamillatus (Linstow, 1897) from Chalcides ocellatus from Egypt

The nematode P. mamillatus is described from the lizard Chalcides ocellatus (Forsk.) from Cairo, Egypt. The use of both light and scanning electron microscopy enabled the authors to report new morphological features of the worms, including the cuticular surface, lateral alae and male caudal structures.

Prevalence of Enterobius vermicularis amongst adults living in hostels by six successive day examination

The prevalence of Enterobius vermicularis in four groups of adults, all trainee public health inspectors or public health nurses, aged 18-35 years and all living in hostels on campus was studied. The modified scotch tape technique was used and the subjects were taught to do the examination on themselves to detect the presence of eggs over a period of 6 successive mornings. Each was given an elaborately illustrated diagram on how and when to take the samples and given demonstration in groups. The samples were examined by trained people. Most of the subjects took samples on 6 consecutive days. Of the 119 subjects who returned samples, the overall prevalence of E. vermicularis was 9.2% and this was thought to be high for this particular age group. This was due to the higher prevalence (19.4%) in one group, whereas in the others the range was 3.5-8.0%. Based on the samples returned on the first day none of the subjects were detected as having the infection. After examination on 3 successive days (109 subjects) 10.1% were found to be infected (chi 2 = 10.704; d. f. = 1) and after examination on 6 successive days (72 subjects) 13.9% were found to be infected (chi 2 = 3.026; d. f. = 1). There was no significance between examination over 3 successive days and 6 consecutive days (chi 2 = 0.296; d. f. = 1). There was no difference in the prevalence between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)

Ectopic enterobiasis: a case report and review

Enterobius vermicularis ('pinworm') is rarely found outside the gastro-intestinal tract. We describe a case of extra-intestinal pinworm abscess associated with an inguinal hernia in an adult. A brief review of the literature is given and possible mechanisms of tissue invasion are discussed.

Anthelmintic activity of some 3-substituted phenyl-1-alkyl or phenyl propenones and propenamides

In a search for new anthelmintic compounds, a,beta-unsaturated ketones and amides were synthetized. Their anthelmintic activity was tested against two gastrointestinal worms, a nematode Syphacia obvelata and a cestode Hymenolepis nana. Structure-activity relationships are discussed.

Enterobius egg granuloma of the vulva and peritoneum: review of the literature

Two cases of Enterobius granuloma containing eggs only are reported. The first case involved the vulva, where no such granuloma has been reported previously. The coexistence of peritoneal granuloma and rectal adenocarcinoma in the second case suggests the possibility of direct penetration of the damaged colonic wall by the parasite, as emphasized by several previous reports of neoplastic involvement and perforation of the intestinal wall in cases of ectopic infections. The diagnostic criteria of Enterobius eggs granuloma, which might be a diagnostic dilemma for pathologists who are not familiar with such criteria, are described herein.

[Experience in eradicating enterobiasis in children in the preschool institutions of the Lithuanian SSR]

The efficacy of hygienic measures and drug therapy of patients with enterobiasis has been compared in different organized groups of children in various regions of Lithuania. Nondrug measures and drug therapy were of similar efficacy. Vermox administration twice a year decreased the incidence of enterobiasis in children 1.9-fold, while nondrug measures decreased it 1.5-6.1-fold.

The pinworm, Enterobius vermicularis

The pinworm, Enterobius vermicularis, is the most common intestinal parasite in the primary care setting, regardless of race, socioeconomic or cultural circumstances. This article discusses symptoms, diagnosis, and treatment.

The presence of pinworms (Enterobius sp.) in the mesenteric lymph nodes, liver and lungs of a chimpanzee, Pan troglodytes

This report describes a case of fatal enterobiasis caused by Enterobius sp. in the mesenteric lymph nodes, lymphatic vessels of mesentery, blood vessels of the liver and lungs of a chimpanzee from Qingdao Zoo, China. Based on pathological findings, it is likely that the pinworms obtained access to these organs via the lymphatic or haematogenous pathway. As far as we are aware, this is the first reported case of Enterobius sp. in the mesenteric lymph nodes and blood vessels of the lungs and veins of the hepatic triad in a chimpanzee.

Haplodiploidy in the Oxyurida: decoupling the evolutionary processes of adaptation and speciation

Host distribution and life history variation in the Oxyurida are discussed in the context of haplodiploidy. The Oxyurida have the broadest host distribution of any zooparasitic nematode group but have retained a virtually unchanged life cycle. Like other haplodiploids, oxyuridians have life histories that maintain viscous population structures. It is postulated that this has facilitated speciation but may have discouraged major evolutionary innovation in the group.

Enterobius vermicularis

The benefits of a ring flash in photographing an orifice can be seen in this interesting case where the main subject area is clearly visible. When photographing minors, the legal implications of the subject material needs to be considered to avoid contravening the Protection of Children Act.

Cutaneous manifestations of intestinal helminthic infections

Several intestinal helminths may involve the skin. In cutaneous larva migrans and enterobiasis this is often the only organ involved, whereas hookworm and trichinosis are characterized by multisystem disease. The clinical spectrum of strongyloidiasis may range from a low-grade chronic dermatitis to a fulminant, often fatal, hyperinfection syndrome in the immunocompromised host. In the absence of recent breakthroughs in diagnostic testing, a meticulous history and knowledge of the life cycles and the often characteristic skin manifestations of these parasites remain essential to prompt diagnosis and effective treatment.

Sex, Enterobius vermicularis and the appendix

Examination of 182 appendices containing Enterobius vermicularis demonstrated that male pinworms are seen more commonly than female. There was no association between the sex of pinworms and inflammation in the appendix but inflammation was frequently seen in association with luminal ova. Ova release from female pinworms may be a feature of appendiceal obstruction.

Enterobius vermicularis infection in a children's ward

Following the discovery that two patients on a children's orthopaedic ward were excreting Enterobius, all patients and staff on the ward were screened for the presence of pinworms. None of the staff was infected but 11 (55%) of 20 patients either had Enterobius ova on the anal margin or excreted worms following piperazine treatment. Epidemiological investigations indicated that this was unlikely to be a ward outbreak because four of the infected children had been on the ward for under 3 days, i.e., less than the prepatent period for Enterobius. Although none of the children was symptomatic, all children and staff on the ward were treated with piperazine. Faecal samples were collected from nine children and the majority of their worm load was shed within 32 h of starting therapy. Microscopic examination of the adult male worms showed that each patient was excreting both Enterobius vermicularis and E. gregorii.

Pinworms

The pinworm is one of the most common intestinal parasites in humans. The adult worms reside and mate in the area of the cecum and ascending colon. The females migrate to lay their ova in the perianal area. Perianal itching is the cardinal symptom of pinworm infestation. Collection of pinworms or ova from the perianal area permits diagnosis. Meticulous personal hygiene is essential to prevent spread of the parasites.