495 research outputs found
Infectivity of Cryptosporidium parvum genotype I in conventionally reared piglets and lambs
Parasites of the genus Cryptosporidium are intracellular parasites that occur throughout the animal kingdom and have been reported in many species of mammals, including human. Most infections in humans are caused by two C. parvum genotypes, genotype I and genotype II; these are the human and the bovine (zoonotic) genotypes, respectively. Successful experimental infection of Cryptosporidium parvum genotype I "human genotype" is described in four conventionally reared piglets and in a lamb. The inoculum was originally obtained from two diarrheic children, and the Cryptosporidium genotypes were determined by PCR and rDNA sequencing. The infective dose was between 106 and 2×106oocysts. No clinical signs were observed in the infected animals, except in a piglet that showed watery diarrhea. The oocyst shedding period in positive animals ranged between 4 and 10 days. Histopathologic examination of the gastrointestinal tract of two positive piglets revealed shortening of the villi and denudation of the villous tips of the jejunum. In one piglet, the colon mucosa revealed numerous Cryptosporidium oocysts. The storage time of the inocula (≤3 weeks in PBS at 4°C) and the age of the animal (newborn) were important for the successful induction of infectio
Genetic characterization of Strongyloides spp. from captive, semi-captive and wild Bornean orangutans (Pongo pygmaeus) in Central and East Kalimantan, Borneo, Indonesia
Orangutans (Pongo spp.), Asia's only great apes, are threatened in their survival due to habitat loss, hunting and infections. Nematodes of the genus Strongyloides may represent a severe cause of death in wild and captive individuals. In order to better understand which Strongyloides species/subspecies infect orangutans under different conditions, larvae were isolated from fecal material collected in Indonesia from 9 captive, 2 semi-captive and 9 wild individuals, 18 captive groups of Bornean orangutans and from 1 human working with wild orangutans. Genotyping was done at the genomic rDNA locus (part of the 18S rRNA gene and internal transcribed spacer 1, ITS1) by sequencing amplicons. Thirty isolates, including the one from the human, could be identified as S. fuelleborni fuelleborni with 18S rRNA gene identities of 98·5-100%, with a corresponding published sequence. The ITS1 sequences could be determined for 17 of these isolates revealing a huge variability and 2 main clusters without obvious pattern with regard to attributes of the hosts. The ITS1 amplicons of 2 isolates were cloned and sequenced, revealing considerable variability indicative of mixed infections. One isolate from a captive individual was identified as S. stercoralis (18S rRNA) and showed 99% identity (ITS1) with S. stercoralis sequences from geographically distinct locations and host species. The findings are significant with regard to the zoonotic nature of these parasites and might contribute to the conservation of remaining orangutan population
Comparative copro-diagnosis of Echinococcus multilocularis in experimentally infected foxes
Faecal samples from 15 foxes experimentally infected with Echinococcus multilocularis were examined until 90days post-infection (dpi) by microscopical identification of eggs isolated by flotation/sieving, by coproantigen-enzyme-linked immunosorbent assay (cELISA), by polymerase chain reaction (PCR) on DNA, respectively, isolated directly from the faecal samples (copro-DNA PCR) and from the eggs obtained by the flotation/sieving procedure (egg-DNA PCR). Based on egg counts, three periods of the infection were defined: pre-patent (2-29dpi), high patent (30-70dpi) and low patent periods (71-90dpi). Whereas all methods were highly sensitive with samples from the high patent period, cELISA was the most sensitive to detect pre-patent infections (63%). Samples from the low patent infections were positive in 77% by microscopy and in 80% by egg-DNA PCR, being significantly more sensitive than cELISA and copro-DNA PCR. The isolation of eggs from the faecal material proved to be more sensitive by the flotation/sieving procedure as compared to the classical concentration McMaster techniqu
Identification and characterisation of putative drug binding sites in human ATP-binding cassette B5 (ABCB5) transporter.
The human ATP-binding cassette B5 (ABCB5) transporter, a member of the ABC transporter superfamily, is linked to chemoresistance in tumour cells by drug effluxion. However, little is known about its structure and drug-binding sites. In this study, we generated an atomistic model of the full-length human ABCB5 transporter with the highest quality using the X-ray crystal structure of mouse ABCB1 (Pgp1), a close homologue of ABCB5 and a well-studied member of the ABC family. Molecular dynamics simulations were used to validate the atomistic model of ABCB5 and characterise its structural properties in model cell membranes. Molecular docking simulations of known ABCB5 substrates such as taxanes, anthracyclines, camptothecin and etoposide were then used to identify at least three putative binding sites for chemotherapeutic drugs transported by ABCB5. The location of these three binding sites is predicted to overlap with the corresponding binding sites in Pgp1. These findings will serve as the basis for future in vitro studies to validate the nature of the identified substrate-binding sites in the full-length ABCB5 transporter
Cross-reactions of sera from dogs infected with Angiostrongylus vasorum in commercially available Dirofilaria immitis test kits
BACKGROUND: Dirofilaria immitis and Angiostrongylus vasorum are both important potentially fatal canine nematodes with overlapping endemic areas, especially in Europe. The preadult and adult stages of both species are living in the Arteria pulmonalis and the right heart, and diagnostically detectable circulating parasite antigens have been demonstrated for both species. For the detection of D. immitis infections, a variety of commercial tests have been developed, however, they have not been evaluated for cross-reactions against circulating antigens of A. vasorum. METHODS: In this study, potential cross-reactions of sera from 16 dogs, which were experimentally infected with A. vasorum and which had circulating antigens as confirmed by a species-specific ELISA, were evaluated for the detection of A. vasorum antigen in six commercially available D. immitis test kits. RESULTS: In three fast tests (Witness® Dirofilaria, SensPERT® Canine Heartworm, SNAP® 4Dx® Plus), all sera were negative. One fast membrane ELISA (SNAP® HTWM RT Test) was positive with four sera (25%), and one serum delivered a non-valid result twice. In the PetChek® HTWM PF Test, depending on the interpretation protocol, 5 or 8 dogs (31.2 - 50%) were positive. With the DiroCHEK®-ELISA, a single A. vasorum-infected dog (6.2%) tested positive. CONCLUSIONS: Due to potential cross-reactions with A. vasorum in commercially available test kits for the detection of D. immitis antigen, the simultaneous use of highly specific diagnostic methods for the differentiation of these two canine heart worms is recommended
Sunflower Treated with Avipel (Anthraquinone) Bird Repellent
Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)
Seroepidemiological survey for canine angiostrongylosis in dogs from Germany and the UK using combined detection of Angiostrongylus vasorum antigen and specific antibodies
Dogs infected with Angiostrongylus vasorum, a potentially lethal parasite parasitizing the heart and pulmonary arteries, may present severe respiratory, haematological and neurological signs. In this first large-scale seroepidemiological survey, 4003 sera originating from Germany and 4030 from the UK were tested by an ELISA for the detection of circulating antigen of A. vasorum, and by a separate ELISA detecting specific antibodies. In Germany, where mainly western federal states were sampled, 0·3% (n = 13, CI: 0·2-0·6%) of dogs were positive in both ELISAs, whereas in total 0·5% (n = 20, CI: 0·3-0·8%) were antigen-positive and 2·25% (n = 90, CI: 1·8-2·8%) were positive for specific antibodies. Regions with antigen- and antibody-positive animals were overlapping. In the UK, where mainly the south of the country was sampled, 0·97% (n = 39, CI: 0·7-1·3%) of dogs were antigen- and antibody positive. In total, 1·32% (n = 53, CI: 1·0-1·7%) were antigen-positive, and 3·2% (n = 129, CI: 2·7-3·8%) were positive for specific antibodies, again in overlapping regions. These results confirm the occurrence of A. vasorum in a random dog population originating from large parts of the countries investigated. The use of the tests alone or in combination was considered as a function of their sensitivities and specificities, in order to guide efficient clinical and epidemiological applicatio
Sunflower Treated with Avipel (Anthraquinone) Bird Repellent
Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)
A priority paper for the societal and ethical aspects of synthetic biology
As synthetic biology develops into a promising science and engineering field, we need to have clear ideas and priorities regarding its safety, security, ethical and public dialogue implications. Based on an extensive literature search, interviews with scientists, social scientists, a 4 week long public e-forum, and consultation with several stakeholders from science, industry and civil society organisations, we compiled a list of priority topics regarding societal issues of synthetic biology for the years ahead. The points presented here are intended to encourage all stakeholders to engage in the prioritisation of these issues and to participate in a continuous dialogue, with the ultimate goal of providing a basis for a multi-stakeholder governance in synthetic biology. Here we show possible ways to solve the challenges to synthetic biology in the field of safety, security, ethics and the science–public interface
Coprological study on intestinal helminths in Swiss dogs: temporal aspects of anthelminthic treatment
Coproscopic examination of 505 dogs originating from the western or central part of Switzerland revealed the presence (prevalence data) of the following helminthes: Toxocara canis (7.1%), hookworms (6.9%), Trichuris vulpis (5.5%), Toxascaris leonina (1.3%), Taeniidae (1.3%), Capillaria spp. (0.8%), and Diphyllobothrium latum (0.4%). Potential risk factors for infection were identified by a questionnaire: dogs from rural areas significantly more often had hookworms and taeniid eggs in their feces when compared to urban family dogs. Access to small rodents, offal, and carrion was identified as risk factor for hookworm and Taeniidae, while feeding of fresh and uncooked meat did not result in higher prevalences for these helminths. A group of 111 dogs was treated every 3months with a combined medication of pyrantel embonate, praziquantel, and febantel, and fecal samples were collected for coproscopy in monthly intervals. Despite treatment, the yearly incidence of T. canis was 32%, while hookworms, T. vulpis, Capillaria spp., and Taeniidae reached incidences ranging from 11 to 22%. Fifty-seven percent of the 111 dogs had helminth eggs in their feces at least once during the 1-year study period. This finding implicates that an infection risk with potential zoonotic pathogens cannot be ruled out for the dog owner despite regular deworming four times a yea
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