Development of adult Dirofilaria immitis worms in the Rag2/Il-2rγ mouse model.

Dirofilaria immitis is the causative agent for one of the major parasitic infections in dogs. It is currently not possible to reliably diagnose the infection before the development of fertile adult female worms and the presence of microfilariae which takes six to 7 months. However, at this point adult worms already reside in the pulmonary arteries and can cause significant damage.

: Genotyping Randomly Selected European Clinical Samples and USA Laboratory Isolates with Molecular Markers Associated with Macrocyclic Lactone Susceptibility and Resistance.

is a parasitic nematode and causes dirofilariosis, a potentially fatal pulmonary infection which primarily infects canids. Dirofilariosis infections are controlled via prophylactic macrocyclic lactone (ML) regimens. Recent evidence has confirmed the development of ML-resistant isolates in the USA, which are genetically distinct from wildtype populations.

The DEG-3/DES-2 Channel Is a Betaine-Gated Receptor Insensitive to Monepantel.

Natural plant compounds, such as betaine, are described to have nematocidal properties. Betaine also acts as a neurotransmitter in the free-living model nematode , where it is required for normal motility. Worm motility is mediated by nicotinic acetylcholine receptors (nAChRs), including subunits from the nematode-specific DEG-3 group.

Seasonality and circadian variation of microfilaremia in dogs experimentally infected with Dirofilaria immitis.

Periodicity, the cyclical rise and fall in microfilaria (mff) numbers in the peripheral blood over time, is observed in many filarial infections. It is correlated with the necessity for these larval stages to be ingested by the blood feeding vector before they can be transmitted to a new vertebrate host. Microfilariae of the dog heartworm Dirofilaria immitis have been described to show periodicity, but the circadian pattern does not seem to be consistent.

Development of a movement-based in vitro screening assay for the identification of new anti-cestodal compounds.

Intestinal cestodes are infecting millions of people and livestock worldwide, but treatment is mainly based on one drug: praziquantel. The identification of new anti-cestodal compounds is hampered by the lack of suitable screening assays. It is difficult, or even impossible, to evaluate drugs against adult cestodes in vitro due to the fact that these parasites cannot be cultured in microwell plates, and adult and larval stages in most cases represent different organisms in terms of size, morphology, and metabolic requirements.

Vaccination with recombinant paramyosin against the bovine lungworm Dictyocaulus viviparus considerably reduces worm burden and larvae shedding.

Background: The lungworm Dictyocaulus viviparus, causing parasitic bronchitis in cattle, induces a temporary protective immunity that prevents clinical disease. A radiation-attenuated larvae based vaccine is commercially available in a few European countries, but has the disadvantages of a live vaccine. As a recombinant subunit vaccine would overcome these disadvantages, the parasite's muscle protein paramyosin (PMY) was tested as a recombinant vaccine antigen.

Recent advances in candidate-gene and whole-genome approaches to the discovery of anthelmintic resistance markers and the description of drug/receptor interactions.

Anthelmintic resistance has a great impact on livestock production systems worldwide, is an emerging concern in companion animal medicine, and represents a threat to our ongoing ability to control human soil-transmitted helminths. The Consortium for Anthelmintic Resistance and Susceptibility (CARS) provides a forum for scientists to meet and discuss the latest developments in the search for molecular markers of anthelmintic resistance. Such markers are important for detecting drug resistant worm populations, and indicating the likely impact of the resistance on drug efficacy.

Worms--a "license to kill".

Worm infections can cause severe harm and death to both humans and numerous domestic and wild animals. Despite the fact that there are many beneficial worm species, veterinarians, physicians and parasitologists have multiple reasons to combat parasitic worms. The pros and cons of various approaches for the discovery of new control methods are discussed, including novel anthelmintics, vaccines and genetic approaches to identify novel drug and vaccine targets.

Distribution patterns of three sodium channel mutations associated with pyrethroid resistance in Rhipicephalus (Boophilus) microplus populations from North and South America, South Africa and Australia.

Resistance to synthetic pyrethroids (SP) in the cattle tick Rhipicephalus (Boophilus) microplus is widespread throughout its distribution area. Three single nucleotide substitutions identified in Domains II and III of the sodium channel gene of R. (B.

Efficacy of monepantel, derquantel and abamectin against adult stages of a multi-resistant Haemonchus contortus isolate.

Drug resistance in gastrointestinal nematodes is a severe problem for sheep farmers. With the recent introduction of monepantel (Zolvix®) and of derquantel plus abamectin (Startect®) in New Zealand, two new anthelmintic classes will be available to control gastrointestinal nematodes. While monepantel covers a broad spectrum of nematodes, the efficacy of derquantel is mid-spectrum and limited to a smaller number of species and stages.

Differences in efficacy of monepantel, derquantel and abamectin against multi-resistant nematodes of sheep.

Drug resistance has become a global phenomenon in gastrointestinal nematodes of sheep, particularly resistance to macrocyclic lactones. New anthelmintics are urgently needed for both the control of infections with multi-resistant nematodes in areas where classical anthelmintics are no longer effective, and the prevention of the spread of resistance in areas where the problem is not as severe. Recently, two new active ingredients became commercially available for the treatment of nematode infections in sheep, monepantel (Zolvix®) and derquantel, the latter used only in a formulated combination with the macrocyclic lactone, abamectin (Startect®).

Causes of mortality and diseases in farmed deer in Switzerland.

To investigate diseases and causes of mortality in Swiss farmed deer, deer found dead or shot due to diseased condition between March 2003 and December 2004 were requested for a complete postmortem examination. One hundred and sixty-two animals were submitted. Perinatal mortality, necrobacillosis in 3 week to 6 month old deer, and endoparasitosis in 6 month to 2 year old deer were identified as the most important causes of loss, followed by ruminal acidosis, which was diagnosed in 22% of deer older than 1 year.

Combined moxidectin and environmental therapy do not eliminate Chorioptes bovis infestation in heavily feathered horses.

Chorioptes bovis infestation is a common cause of pastern dermatitis in the horse, with a predilection in draft horses and other horses with thick hair 'feathers' on the distal limbs. The treatment of this superficial mite is challenging; treatment failure and relapse are common. Furthermore, C.

Quarantine treatment of sheep with monepantel--rapidity of fecal egg count reduction.

In the presence of multiple anthelmintic resistance, effective quarantine treatment of sheep entering a farm has become a crucial tool in nematode management. In the present work, the use of the amino-acetonitrile derivative, monepantel as a quarantine treatment was investigated. Of special interest was the rapidity of decrease in fecal egg counts (FEC) compared to other anthelmintics used in sheep.

The effect of sheep breed, age, and gender on the pharmacokinetics and efficacy of monepantel, an amino-acetonitrile derivative.

This analysis investigated the influence of breed and gender on the pharmacokinetics of monepantel, and influence of breed, age, and gender on its efficacy against gastrointestinal nematodes of sheep. In a comparison of pharmacokinetic profiles from two studies, Merino lambs had significantly greater maximum concentrations of monepantel and monepantel sulfone, and faster times to reach these concentrations than Dorset cross lambs. Males had a statistically greater area under the curve (0-504 h) than females for monepantel sulfone.

A pooled analysis of the efficacy of monepantel, an amino-acetonitrile derivative against gastrointestinal nematodes of sheep.

Monepantel is the first compound from the amino-acetonitrile derivative class of anthelmintics to be developed for the control of gastrointestinal nematodes of sheep. An analysis of pooled data from a series of controlled studies is reported providing a single point of efficacy (+/- 95% confidence interval) for each gastrointestinal nematode tested at the fourth larval and/or adult stages. For most nematode species, the pooled efficacy was greater than 99%, and for the remaining few species, efficacy was greater than 90%.

Efficacy of the amino-acetonitrile derivative, monepantel, against experimental and natural adult stage gastro-intestinal nematode infections in sheep.

Multiple drug resistance by nematodes, against anthelmintics has become an important economic problem in sheep farming worldwide. Here we describe the efficacy of monepantel, a developmental molecule from the recently discovered anthelmintic class, the amino-acetonitrile derivatives (AADs). Efficacy was tested against adult stage gastro-intestinal nematodes (GINs) in experimentally and naturally infected sheep at a dose of 2.

Determination of the effective dose rate for monepantel (AAD 1566) against adult gastro-intestinal nematodes in sheep.

Monepantel (AAD 1566) is the first compound from the recently discovered amino-acetonitrile derivative (AAD) class of anthelmintics to be developed for use in sheep. Three dose determination studies were conducted in Australia and Europe to identify the therapeutic dose of monepantel, when formulated for the oral treatment of sheep, to control adult gastro-intestinal nematodes. In each study, sheep infected with various nematode species were treated with either 1.

A nodular granulomatous posthitis caused by Halicephalobus sp. in a horse.

This report describes a case of nodular posthitis caused by Halicephalobus gingivalis in a 24-year-old warmblood horse. Macroscopic examination revealed a multinodular, partially ulcerated mass on the external lamina of the prepuce. Nematode migration from unfixed biopsy material in phosphate-buffered saline revealed adult nematodes with the typical morphological features of H.

Financial analysis of various strategies for the control of Neospora caninum in dairy cattle in Switzerland.

The present study was conducted to estimate the direct losses due to Neospora caninum in Swiss dairy cattle and to assess the costs and benefits of different potential control strategies. A Monte Carlo simulation spreadsheet module was developed to estimate the direct costs caused by N. caninum, with and without control strategies, and to estimate the costs of these control strategies in a financial analysis.

Simulating the impact of four control strategies on the population dynamics of Neospora caninum infection in Swiss dairy cattle.

A dynamic deterministic simulation model was developed to assess the impact of different putative control strategies on the seroprevalence of Neospora caninum in female Swiss dairy cattle. The model structure comprised compartments of "susceptible" and "infected" animals (SI-model) and the cattle population was divided into 12 age classes. A reference model (Model 1) was developed to simulate the current (status quo) situation (present seroprevalence in Switzerland 12%), taking into account available demographic and seroprevalence data of Switzerland.

Diagnostic significance of Neospora caninum DNA detected by PCR in cattle serum.

A nested PCR that successfully detected Neospora caninum DNA in serum of cattle was used for investigation of selected abortion cases and in a study of healthy pregnant cows at an abattoir. N. caninum DNA was not detected in serum from antibody positive dams that aborted due to N.

Presence of potentially pathogenic Babesia sp. for human in Ixodes ricinus in Switzerland.

We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B.