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I Beveridge

Publications and source records attributed to I Beveridge.

At least 55 records · Page 3Linked to original sources

Preliminary cladistic analysis of genera of the cestode order Trypanorhyncha Diesing, 1863.

A preliminary cladistic analysis was carried out on the 49 currently recognised genera of the order Trypanorhyncha. Forty-four characters were analysed; a functional outgroup was used for scolex and strobilar characters, while Nybelinia was utilised to polarise characters related to the rhyncheal system. Eight well-resolved clades were evident in the resultant cladogram, which is compared with existing phenetic classifications. An analysis of families resulted in a similar clustering of taxa to that observed in the case of the genera. The results suggest that two key characters used in existing classifications, namely the presence of sensory fossettes on the bothridia and the development of atypical heteroacanth and poeciloacanth armatures from typical heteroacanth armatures, have occurred on several occasions. Some clades provide support for the arrangements used in current classifications. Suggestions are made for future avenues of research which might provide more robust phylogenetic data for the Trypanorhyncha.

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Redescriptions of the species of Physaloptera Rudolphi, 1819 (Nematoda: Spirurida) parasitic in bandicoots (Marsupialia: Perameloidea) in Australia.

The species of Physaloptera Rudolphi, 1819 (Nematoda: Spirurida) occurring in bandicoots (families Peramelidae and Thalacomyidae) in Australia were re-examined and re-described. Physaloptera peramelis Johnston & Mawson, 1939 was found in Perameles nasuta Geoffroy and occasionally in Isoodon macrourus (Gould) in eastern Australia. Ph. peragale Johnson & Mawson, 1940 from Macrotis leucura (Thomas) from the Northern Territory is treated as a junior synonym of Ph. peramelis. Ph. thalacomys Johnston & Mawson, 1940, originally described from Macrotis leucura from the Northern Territory was also found to occur in Perameles gunnii Gray in Victoria. Specimens here identified simply as Physaloptera sp. were found in both Perameles nasuta and Isoodon macrourus from north-eastern New South Wales. They may be Ph. parvicollaris Johnston & Mawson, 1940 or Ph. sarcophili Johnston & Mawson, 1940, but current deficiencies in the descriptions of these two named species preclude an unequivocal identification of the specimens found in bandicoots.

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Haycocknema perplexum n. g., n. sp. (Nematoda: Robertdollfusidae): an intramyofibre parasite in man.

Haycocknema perplexum n. g., n. sp. (Nematoda: Robertdollfusidae) is described from a man in Tasmania, Australia. Adult male and female nematodes and larvae were recovered from myofibres following biopsy of the right vastus lateralis muscle and were associated with a polymyositis. H. perplexum is distinguished from all other genera of the Muspiceoidea by the presence of a large amorphous "cell" supporting a granule-filled, flask- or gourd-shaped reservoir in the rectal region of mature and gravid female nematodes, often containing one or more large, refractile, thick-rimmed "globules" on the external surface of the reservoir, by the small number of ova/eggs/larvae developing in each uterus, by the minute, weakly-sclerotised, almost tubular spicule, by the presence of a pair of ampulla-shaped glands posteriorly and by the presence of lateral bacillary bands comprised of a single row of pore cells spaced irregularly and extending posteriorly to the region of the vulva in immature females.

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Rugonema labiatum n. g., n. sp. (Nematoda: Strongyloidea) from the stomach of Macropus irma (Marsupialia: Macropodidae) from Western Australia.

Rugonema labiatum n. g., n. sp. is described from the stomach of Macropus irma (Jourdan) from Western Australia. The new genus possesses four branches to the dorsal ray, has a cylindrical buccal capsule and lacks a cervical groove, placing it within the subfamily Cloacininae Stossich, 1899. The presence of a prominently striated buccal capsule and labial as well as cephalic collars places the genus within the tribe Pharyngostrongylinea Popova, 1952, but it is distinguished from all existing genera within the tribe by the possession of four lips. The presence of lips is an important characteristic of the related tribe Zoniolaiminea (Popova, 1952) and the characters used in distinguishing these two tribes are discussed.

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Distribution of life cycle stages of Sarcoptes scabiei var wombati and effects of severe mange on common wombats in Victoria.

Seven female and three male common wombats (Vombatus ursinus) collected from forested areas of Victoria (Australia) over a 10 mo period, 10 April 1997 to 22 February 1998 had at least 30% of their skin affected by severe hyperkeratotic sarcoptic mange. Mangy wombats were grazing during the day, could be readily approached, were in poor body condition, and lacked subcutaneous fat. The anterolateral surface of the body was most heavily parasitised with Sarcoptes scabiei var wombati followed by the posterolateral surface, the dorsal region between the ears, the ears, ventral abdomen, medial aspect of the legs, axillary and inguinal areas, and the dorsal midline. Larvae were the most prevalent life-cycle stage followed by eggs, nymphs, females, and males. Mite numbers and the severity of clinical signs, namely thickness of scale crust and the degree of alopecia, were correlated and were symmetrical on each side of the body. Fissuring of crust and skin only occurred when scale crust was present. Bacterial infections occurred in three of 10 wombats within lymph nodes or the pleural cavity. Lymphoid depletion did not occur in lymph nodes or spleens and prescapular lymph nodes contained a greater amount of nuclear debris in germinal centres than non-mangy wombats. Seven wombats had fatty change in their livers. Gonads of mature wombats were not active or had minimal activity. Significant histopathological changes were not seen in the gastrointestinal tract, kidney, brain, myocardium, spleen, thyroid, reproductive tract, and gonads. Hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and concentrations of hemoglobin, lymphocytes, calcium, glucose, creatinine, total solids, total protein, albumin determined both colormetrically and electrophoretically, and globulins were significantly lower and concentrations of neutrophils, monocytes, phosphorus, urea, glutamate dehydrogenase, aspartate aminotransferase and creatine kinase were significantly higher in mangy versus captive wombats. Concentrations of erythrocytes, mean corpuscular hemoglobin, leucocytes, band neutrophils, eosinophils, nucleated erythrocytes, sodium, potassium, chloride, total bilirubin, alkaline phosphatase, and gamma glutamyltransferase for mangy wombats were not significantly different from that reported for captive wombats. Hematological and pathological changes in mangy wombats were consistent with anemia, inflammation, and changes seen with starvation.

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Polymyositis caused by a new genus of nematode.

We report two patients who presented with increasing malaise and myalgia, and had biopsy-proven polymyositis. Their conditions deteriorated after corticosteroid treatment, and repeat muscle biopsies showed adult and larval nematodes. Anthelminthic treatment was completely successful in both cases. The infecting nematode appears to belong to a new genus and is, to our knowledge, the first known muspiceoid nematode to infect humans. Its life cycle and the route of infection are unknown.

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Genetic markers for strongylid nematodes of livestock defined by PCR-based restriction analysis of spacer rDNA.

Twenty-four species of parasitic nematode (order Strongylida) from sheep, goats, cattle or pigs were characterised using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). The ribosomal (r)DNA region spanning the first internal transcribed spacer (ITS-1), 5.8S rRNA gene and the second internal transcribed spacer (ITS-2) (designated ITS) was amplified from genomic DNA by polymerase chain reaction (PCR), digested separately with four restriction endonucleases (RsaI, HinfI, DraI or NlaIII) and the fragments separated by agarose gel electrophoresis. The PCR products amplified from all species appeared as a single band of approximately 870 bp in size, except for Ostertagia ostertagi whose product was approximately 1250 bp. The PCR-RFLP analysis of ITS revealed characteristic restriction patterns for all species, except for C. surnabada and C. oncophora which had identical patterns. The study demonstrated that ITS contains useful genetic markers for the identification of a range of strongylid nematodes of livestock. These markers should be of use in specific PCR assays for the identification of developmental stages of the parasites where morphological characters are unreliable.

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Genetic evidence indicating that Cooperia surnabada and Cooperia oncophora are one species.

Sequences of the second internal transcribed spacer (ITS-2) of ribosomal DNA were determined for the trichostrongylid nematodes Cooperia surnabada and Cooperia oncophora, to test the hypothesis that they represent one species. Also included for comparison were other morphologically distinct species within the genus, namely Cooperia punctata and Cooperia curticei. There were no differences in the consensus ITS-2 sequences between C. oncophora and C. surnabada, whereas each taxon differed from C. punctata and C. curticei by 1.7% and 4.1%, respectively. Also, C. punctata differed from C. curticei by 5.0%. Based on these results and the DNA studies of other trichostrongylid species, it is proposed that C. oncophora and C. surnabada represent a single species.

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Differences in the second internal transcribed spacer of four species of Nematodirus (Nematoda: Molineidae).

Genetic differences among Nematodirus spathiger, Nematodirus filicollis, Nematodirus helvetianus and Nematodirus battus in the nucleotide sequence of the second internal transcribed spacer (ITS-2) of ribosomal DNA ranged from 3.9 to 24.7%. Pairwise comparisons of their ITS-2 sequences indicated that the most genetically similar species were N. spathiger and N. helvetianus. N. battus was the most genetically distinct species, with differences ranging from 22.8 to 24.7% with respect to the other three species. Some of the nucleotide differences among species provided different endonuclease restriction sites that could be used in restriction fragment length polymorphism studies. The ITS-2 sequence data may prove useful in studies of the systematics of molineid nematodes.

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Allozyme electrophoresis--difficulties encountered in studies on helminths.

The literature on the use of allozyme electrophoresis in the identification of species of helminths was selectively examined. Difficulties encountered in deciding upon the extent of genetic differences which indicate the existence of separate helminth species, the application of the criterion of sympatry and the problems for nomenclature are discussed.

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A comparison of the first internal transcribed spacer of ribosomal DNA in seven species of Trichostrongylus (Nematoda: Trichostrongylidae).

The first internal transcribed spacer (ITS-1) of the ribosomal DNA of seven species of Trichostrongylus was sequenced. The length of ITS-1 in the different species varied from 387 to 390 bases. The G + C content of the ITS-1 sequences were approximately 42%. Little or no intraspecific variation was detected in the three species. Trichostrongylus axei, Trichostrongylus colubriformis and Trichostrongylus vitrinus, for which multiple isolates from different geographical regions were sequenced. In contrast, the level of ITS-1 sequence differences between species ranged from 1.3% to 5.7%. The greatest sequence differences were detected between T. tenuis, the parasite species which infects birds and the six species found in mammals. Some of the nucleotide differences occurred at sites corresponding to recognition sites for restriction endonucleases. These results are compared with previous data obtained for the second internal transcribed spacer (ITS-2). The ITS-1 data indicate that this region of rDNA may also be useful for systematic studies in trichostrongylid nematodes.

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Common secondary structures for the second internal transcribed spacer pre-rRNA of two subfamilies of trichostrongylid nematodes.

Sequences of the second internal transcribed spacer ribosomal DNA for the parasitic trichostrongylid nematodes Trichostrongylus probolurus, Trichostrongylus rugatus and Camelostrongylus mentulatus were compared with previously published sequences for five other species within the genus Trichostrongylus. The secondary structures of the second internal transcribed spacer pre-rRNA for these nematodes were predicted using an energy minimisation method. The results indicate that a common secondary structure of the second internal transcribed spacer of these nematodes is maintained despite distinct differences in primary sequence between species. Sequence differences among Trichostrongylus species ranged from 1.3 to 7.6%, but each species differed by 22-26% in sequence when compared with C. mentulatus which belongs to a different subfamily.

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Systematic relationships of some members of the genera Oesophagostomum and Chabertia (Nematoda: Chabertiidae) based on ribosomal DNA sequence data.

The present study characterised seven species of the Chabertiidae (Nematoda: Strongyloidea) belonging to either the subfamily Oesophagostominae (Oesophagostomum radiatum, Oesophagostomum venulosum, Oesophagostomum dentatum, Oesophagostomum quadrispinulatum, Oesophagostomum columbianum, Oesophagostomum bifurcum) or to the subfamily Chabertiinae (Chabertia ovina) by their second internal transcribed spacer rDNA sequence, assessed the extent of intraspecific variation and interspecific differences in the sequence, and inferred the phylogenetic relationship of C. ovina with respect to members of the Oesophagostominae. In both the phenetic and cladistic analyses of the sequence data, Chabertia was nested within Oesophagostomum, suggesting either that the species examined represent members of the same genus, or alternatively, that Oesophagostomum may represent more than one genus.

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Eimeria species in the Pearson Island Rock Wallaby, Petrogale lateralis pearsoni.

Four species of previously described Eimeria were identified from oocysts present in the faeces of Pearson Island rock wallabies, Petrogale lateralis pearsoni from Pearson Island, South Australia. Eimeria petrogale and Eimeria sharmani have been reported in P. lateralis; however, the presence of Eimeria godmani and Eimeria inornata expands the suite of eimerian species known in rock wallabies of the "lateralis" complex. These observations indicate that the host distribution of Eimeria species in rock wallabies is more diverse than previously thought, and supports the hypothesis that these coccidia have an ancient association with rock wallabies which persisted as the hosts radiated.

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Coprological methods for the diagnosis of Anoplocephala perfoliata infection of the horse.

OBJECTIVE: To compare the sensitivities of three coprological techniques for the diagnosis of Anoplocephala perfoliata infection in horses and to assess the value of the methods for diagnosis of horses at risk of clinical cestodiasis. DESIGN: Faecal samples were collected from necropsied horses with or without A perfoliata infection and examined using one sedimentation and two different flotation methods. The coprological results were compared with worm counts performed at necropsy of the horses and the degree of mucosal damage. In addition, the efficiency of recovery of A perfoliata eggs from faeces was tested. RESULTS: The overall sensitivities of the methods ranged from 22.5 to 37.5%, and the capacity of the methods to diagnose infection increased with the intensity of infection. A simple flotation method achieved a better sensitivity (37.5%) at all intensities of infection compared with the other two methods (22.5 to 25%). That method was also more sensitive in detecting eggs in 'negative' faecal samples spiked with known numbers of A perfoliata eggs. CONCLUSION: The results indicated that, despite the low sensitivities of present methods, faecal flotation is likely to be of value in detecting horses at risk of clinical disease.

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The distribution of Anoplocephala perfoliata in the intestine of the horse and associated pathological changes.

The intestinal tracts of 130 horses were examined for infection with Anoplocephala perfoliata at necropsy. Fifty horses (38.5%) harboured the tapeworm, and the site of attachment of each worm was recorded using predetermined anatomical landmarks. The worms were attached in four regions of the gastrointestinal tract: 17% of the worms were found at the ileocaecal junction, 81% on the caecal wall, 1.7% in the terminal ileum and 0.2% in the ventral colon. The severity of lesions produced at the sites of attachment was related to the number of worms attached. Due to the small area of the ileocaecal junction, worms at this site were attached in close proximity, resulting in more severe lesions. The major features of the lesions included ulceration, diphtheritic membranes and thickening of the mucosa, submucosa and lamina propria. There was an increase in the number of eosinophils and a decrease in the number of lymphocytes present at the sites of lesions.

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