Health assessment of wild speckled dwarf tortoises, CHERSOBIUS SIGNATUS.

BACKGROUND: In free-ranging reptile populations, bacterial, fungal, viral and parasitic pathogens may affect hosts through impairment in movements, thermoregulation, reproduction, survival, and population dynamics. The speckled dwarf tortoise (Chersobius [Homopus] signatus) is a threatened species that is mostly restricted to the Succulent Karoo biome in South Africa, and little information on pathogens of this species is available yet. We derived baseline parameters for five males and five females that were captured to genetically enhance a conservation breeding program in Europe. Upon collection of the tortoises, ticks were removed and identified. Immediately upon arrival in Europe, ocular, nasal, oral and cloacal swabs were taken for viral, bacteriological and mycological examinations. Fecal samples were collected before and 1 month after fenbendazole treatment, and analyzed for parasites. A panel of PCR, aiming to detect herpesviruses, adenoviruses and iridoviruses, was carried out. RESULTS: Samples were negative for viruses, while bacteriological examination yielded detectable growth in 82.5% of the swabs with a mean load of 16 × 107 ± 61 × 108 colony forming units (CFU) per swab, representing 34 bacterial species. Cloacal and oral swabs yielded higher detectable growth loads than nasal and ocular swabs, but no differences between sexes were observed. Fungi and yeasts (mean load 5 × 103 ± 13 × 103 CFU/swab) were detected in 25% of the swabs. All pre-treatment fecal samples were positive for oxyurid eggs, ranging from 200 to 2400 eggs per gram of feces, whereas after the treatment a significantly reduced egg count (90-100% reduction) was found in seven out of 10 individuals. One remaining individual showed 29% reduction, and two others had increased egg counts. In five tortoises, Nycthocterus spp. and coccidian oocysts were also identified. Soft ticks were identified as Ornithodoros savignyi. CONCLUSIONS: Our baseline data from clinically healthy individuals will help future studies to interpret prevalences of microorganisms in speckled dwarf tortoise populations. The study population did not appear immediately threatened by current parasite presence.

Trypanoxyuris (Trypanoxyuris) minutus (Schneider, 1866) among Alouatta guariba clamitans (Cabrera, 1940) in the state of Rio de Janeiro, Brazil.

This study reports on infection by Trypanoxyuris (Trypanoxyuris) minutus among Alouatta guariba clamitans through biometry on adults and eggs. A total of 58 adult helminths were recovered from the small segment of the animal's large intestine. This study is the first report of this parasite among A. guariba clamitans in Rio de Janeiro.

Discovery of a 240 million year old nematode parasite egg in a cynodont coprolite sheds light on the early origin of pinworms in vertebrates.

BACKGROUND: We report the discovery of a nematode parasite egg (Nemata: Oxyurida) from a coprolite closely associated with the remains of several species of Cynodontia, dated to 240 million years old. This finding is particularly significant because this is the oldest record of an oxyurid nematode yet discovered, and because the cynodonts are considered a stem-group of the mammals. METHODS: We extracted material from a fully mineralized coprolite by both scraping the surface, and removing fragments from its interior with clean dental instruments used a single time. A single drop of glycerol from a new vial was added as a clearing reagent. Each slide was sealed with wax and examined with an optical microscope at 100× to 400× magnification. RESULTS: From one coprolite, 550 slides were examined; from 275 of these slides, sediment was examined that was scraped from the surface of the coprolite, and from the other 275 slides, material was examined that was extracted from the interior of the coprolite. All microscopic structures encountered were photographed, measured, and identified when possible. CONCLUSIONS: From the coprolite examined, we discovered an egg representing a new species of pinworm that, based on the egg structure, clearly places it in the family Heteroxynematidae. Nematodes of the order Oxyurida have very constrained life-histories, occurring only in animals that are not strictly carnivorous and also ingest large amounts of plant material. This fact enabled us to determine which species of cynodont, from several collected at the site in Brazil, are most likely the depositors of the coprolite, and therefore were the putative host of the parasite.

Prevalence, pathology and risk factors for coccidiosis in domestic rabbits (Oryctolagus cuniculus) in selected regions in Kenya.

BACKGROUND: The potential for rabbit production in Kenya is high. However, high morbidity and mortality of domestic rabbits were reported. OBJECTIVE: The aim of the study was to determine the pathology, prevalence and the predisposing factors to coccidiosis in domestic rabbits in selected regions in Kenya. ANIMALS AND METHODS: A total of 61 farms keeping rabbits in six different counties were visited in the survey. A total of 2680 live rabbits were examined and 61 rabbits and 302 fecal samples were randomly collected from the farms and examined for coccidian oocysts by ante-mortem and post-mortem methods. The predisposing factors to coccidiosis were assessed through questionnaires and direct observation. Chi square (χ(2)) statistics was used with P values < 0.05 considered statistically significant. RESULTS: Of the 302 fecal samples, 85% (P < 0.001) contained coccidian oocysts and 2% harbored nematode eggs (Passalurus ambiguous). The overall prevalence of Eimeria spp. infestation was 85.1% in the study area and 90.2% in the individual rabbits, while prevalence of intestinal coccidiosis and hepatic coccidiosis was 29.5% and 11.5%, respectively. Higher counts of coccidian oocysts per gram of feces were recovered in weaners than in growers and adults rabbits (P < 0.001), rabbits that were kept in high density group housing (P < 0.05) and housing with more than two tiers. CONCLUSION: This study identified group housing of rabbits of different ages and inadequate control of concurrent infections as the major risk factors associated with coccidiosis in domestic rabbits in Kenya.

Survey of co-infection by Salmonella and oxyurids in tortoises.

BACKGROUND: Salmonella spp. and oxyurids are among the most prevalent bacterial and parasitic agents in reptiles. These organisms are routinely isolated in healthy tortoises, although heavy infections may cause significant pathology. Tortoises are considered a common source of reptile-associated salmonellosis, an important zoonosis reported worldwide. A survey of the prevalence of Salmonella spp. and oxyurids in 53 tortoises was conducted in southern Italy and a possible correlation between the two pathogens was therefore investigated. RESULTS: Salmonella spp. and oxyurids were detected with a prevalence of 49.1 and 81.1%, respectively. A significant positive correlation between Salmonella spp. and oxyurids was demonstrated. However, confounding factors related to husbandry could have been involved in determining this correlation. CONCLUSIONS: Our results suggest that caution should be exercised in translocation, husbandry, and human contact with tortoises and other exotic pets. Further studies on the epidemiology, molecular characterization and pathogenesis of Salmonella and oxyurids are needed to assess the actual impact of these organisms, as single or associated infections, on tortoises and on other exotic pets.

Redescription of Ichthyouris bursata Moravec & Prouza, 1995 (Nematoda: Pharyngodonidae), a parasite of wild and aquarium-reared discus Symphysodon spp. (Osteichthyes).

The oxyuroid nematode Ichthyouris bursata Moravec & Prouza, 1995 (Pharyngodonidae) was recorded from the intestine of discus (Symphysodon spp. and hybrids) cultured in discus farms in Bangkok and Nonthaburi, central Thailand, during 2006 and 2007. This material made it possible to study in detail the morphology of this little known parasite species, using both light and scanning electron microscopy (the latter not previously used for the male). The SEM examination showed taxonomically important morphological features not previously reported or erroneously described, including the presence of three bilobed lips, a pair of sclerotised plate-like structures and a median cone-shaped outgrowth on the posterior cloacal lip, short 'hairs' on the cloacal lips, digital phasmids in the male and, sometimes, up to two filaments on the egg poles. This species is of South American origin, which was confirmed by its recent record from a free-living blue discus S. aequifasciatus Pellegrin in Brazil. The reproduction and transmission of I. bursata in the conditions of aquarium tanks is probably permitted by the direct (homoxenous) life-cycle of this parasite.

Efficacy of oxfendazole and fenbendazole against tortoise (Testudo hermanni) oxyurids.

Thirty-six tortoises (Testudo hermanni) with naturally acquired oxyurids infections were used to assess the anthelmintic efficacy of oxfendazole (Dolthene; Merial) and fenbendazole (Panacur; Hoechst Roussel Vet). Animals were randomly assigned to three groups (A, B, and C) based on sex and weight. Animals in group A (seven males and six females) were orally treated with oxfendazole at dose rate of 66 mg/kg, group B animals (nine males and eight females) were orally treated with fenbendazole at dose rate of 100 mg/kg, and group C animals (three males and three females) were not treated and served as controls. All animals were individually stabled in plexiglas boxes under controlled conditions of temperature, humidity, and light beginning 7 days pretreatment and continuing for the duration of the trial. Individual tortoises feces were examined daily by the McMaster technique and drugs efficacy was assessed by the fecal eggs count reduction (FECR) test. Both drugs showed 100% of FECR. However, oxfendazole reached this level 12 days after treatment, whereas 31 days after treatment were necessary to obtain the same stable result with fenbendazole. The two drugs were well tolerated by all the animals and no adverse reactions were observed after treatment.

Molecular characterization of Thelastomatoidea (Nematoda: Oxyurida) from cockroaches in Australia.

A molecular approach was used to genetically characterize 5 species (Aoruroides queenslandensis, Blattophila sphaerolaima, Cordonicola gibsoni, Desmicola ornata and Leidynemella fusiformis) belonging to the superfamily Thelastomatoidea (Nematoda: Oxyurida), a group of pinworms that parasitizes terrestrial arthropods. The D3 domain of the large subunit of nuclear ribosomal RNA (LSU) was sequenced for individual specimens, and the analysis of the sequence data allowed the genetic relationships of the 5 species to be studied. The sequence variation in the D3 domain within individual species (0-1.8%) was significantly less than the differences among species (4.3-12.4%). Phylogenetic analyses, using maximum parsimony, maximum likelihood, and neighbour-joining, tree-building methods, established relationships among the 5 species of Thelastomatoidea and Oxyuris equi (a species of the order Oxyurida). The molecular approach employed provides the prospect for developing DNA tools for the specific identification of the Thelastomatoidea, irrespective of developmental stage and sex, as a basis for systematic, ecological and/or population genetic investigations of members within this superfamily.

The Enterobiinae subfam. Nov. (Nematoda, Oxyurida) pinworm parasites of primates and rodents.

Recent redescriptions of most members of the Oxyuridae Cobbold, 1864 parasitic in primates revealed that they share following derived characters: sexual dimorphism of lateral alae (single-crested in the males, double-crested in the females); in males a second pair of genital papillae always surrounded by strongly cuticularized rings; in females, uterine tube divided into 2 parts by a cellular wall forming a diaphragm. These characters are interpreted as synapomorphies, providing evidence that these taxa represent a monophyletic group, and we propose to classify them in a new subfamily of the Oxyuridae: the Enterobiinae subfam.nov. The Enterobiinae as recognized herein occurs in both Old World and New World Primates and rodents of the family Sciuridae (tribe Sciurini in the Holarctic region and tribe Xerini in the Ethiopian region). The new subfamily includes the following genera: Enterobius Leach, 1853; Colobenterobius Quentin, Betterton & Krishnasamy, 1979; Rodentoxyuris Quentin & Tenora 1974; Xeroxyuris Hugot, 1995; Lemuricola Chabaud & Petter, 1959; Protenterobius Inglis, 1961; Madoxyuris Chabaud, Brygoo & Petter, 1965; Trypanoxyuris Vevers, 1923; Hapaloxyuris Inglis & Cosgrove, 1965 and Paraoxyuronema Artigas, 1936. The genus Paraoxyuronema is revalidated as a subgenus of Trypanoxyuris due to its specialized buccal structures. This genus groups all pinworm nematodes specific for primates of the family Atelidae, including: P. brachytelesi Artigas, 1937 occurring in Brachyteles arachnoides; P. atelis (Cameron, 1929) occurring in Ateles spp., and P. duplicidens (Buckley, 1931) and P. lagothricis (Buckley, 1931), which are parasites of Lagothrix spp. Inglisoxyuris inglisi Chabaud, Petter & Golvan, 1961, included in the monospecific genus Inglisoxyuris and previously classified as a subgenus of the Lemuricola, does not share the characters of the new subfamily and, until its precise classification can be considered with more information, it is proposed to refer to this species as an Oxyuridae sensu lato. A diagnosis and a key of the genera included in the new subfamily are given.

Evolutionary patterns in life histories of Oxyurida.

The Oxyurida comprises some 850 known species that occur in the intestine of arthropods and vertebrates (one species in annelids). Important arthropod hosts include Diplopoda, Blattodea, Gryllotalpoidea, Passalidae, Scarabaeida and Hydrophilidae. The major vertebrate hosts are lizards, tortoises, primates, rodents and lagomorphs. An underlying characteristic of the group is haplodiploid reproduction and like many haplodiploid groups, pinworms tend to have life histories that involve high levels of inbreeding. Unlike Strongylida, Ascaridida and Spirurida, which have diversified in tissue site and life cycle as well as hosts, pinworms show little variation in these features and have radiated only across host groups. Two explanations are advanced for this. Haplodiploidy and its concomitant inbreeding may act to canalise evolutionary change, although diverse groups such as the Hymenoptera belie this. Alternatively, Strongylida, Ascaridida and Spirurida are presumed to have arisen from skin-penetrating ancestors that were forced to undergo a tissue migration before reaching their primitive tissue site, the gut. This migration demanded they adapt to a variety of tissue sites and thus acted as a preadaptation to further diversification. The Oxyurida, in contrast, probably arose using oral contaminative transmission. The lack of exposure to other tissue sites may therefore have relegated pinworms to their position in the posterior gut.