Due to major problems with drug resistance in parasitic nematodes of animals, there is a substantial need and excellent opportunities to develop new anthelmintics via genomic-guided and/or repurposing approaches. In the present study, we established a practical and cost-effective whole-organism assay for the in vitro-screening of compounds for activity against parasitic stages of the nematode Haemonchus contortus (barber's pole worm). The assay is based on the use of exsheathed L3 (xL3) and L4 stages of H. contortus of small ruminants (sheep and goats). Using this assay, we screened a panel of 522 well-curated kinase inhibitors (GlaxoSmithKline, USA; code: PKIS2) for activity against H. contortus by measuring the inhibition of larval motility using an automated image analysis system. We identified two chemicals within the compound classes biphenyl amides and pyrazolo[1,5-α]pyridines, which reproducibly inhibit both xL3 and L4 motility and development, with IC50s of 14-47 μM. Given that these inhibitors were designed as anti-inflammatory drugs for use in humans and fit the Lipinski rule-of-five (including bioavailability), they show promise for hit-to-lead optimisation and repurposing for use against parasitic nematodes. The screening assay established here has significant advantages over conventional methods, particularly in terms of ease of use, throughput, time and cost. Although not yet fully automated, the current assay is readily suited to the screening of hundreds to thousands of compounds for subsequent hit-to-lead optimisation. The current assay is highly adaptable to many parasites of socioeconomic importance, including those causing neglected tropical diseases. This aspect is of major relevance, given the urgent need to deliver the goals of the London Declaration (http://unitingtocombatntds.org/resource/london-declaration) through the rapid and efficient repurposing of compounds in public-private partnerships.

With the exception of Aelurostrongylus abstrusus, feline lungworms have been poorly studied. Information on their distribution is patchy and mostly limited to case reports. In this study, the occurrence of feline lungworms and co-infecting gastrointestinal parasites has been investigated in 12 European countries (i.e. Austria, Belgium, Bulgaria, France, Greece, Hungary, Italy, Portugal, Romania, Spain, Switzerland and the United Kingdom). An average of 10 domestic cats, with regular outdoor access, was sampled each month for 12months, and freshly passed faeces were collected. Stools were processed using a McMaster assay and a quantitative Baermann-Wetzel method. Animals positive for lungworms and/or gastrointestinal parasites were treated with a formulation containing fipronil, (S)-methoprene, eprinomectin, and praziquantel (Broadline®, Merial), and re-sampled 28days post-treatment. The association between lungworm infection and risk factors was analysed using statistical medians/means and the efficacy of the treatment against each lungworm species was assessed. Of 1990 cats sampled, 613 (30.8%) were positive for at least one parasite, while 210 (10.6%) were infected by lungworms. The prevalence of lungworm infection varied between the sampled sites, with the highest recorded in Bulgaria (35.8%) and the lowest in Switzerland (0.8%). None of the cats from Austria or the United Kingdom were infected by lungworms. Aelurostrongylus abstrusus was the species most frequently detected (78.1%), followed by Troglostrongylus brevior (19.5%), Eucoleus aerophilus (14.8%) and Oslerus rostratus (3.8%). The overall efficacy of the treatment was 99% for A. abstrusus and 100% for T. brevior, O. rostratus and E. aerophilus. Data presented provide a comprehensive account of the diagnosis, epidemiology and treatment of feline lungworms in Europe, as well as of the occurrence of co-infections by gastrointestinal parasites.

BackgroundDomestic cats can be infested by a large range of parasite species. Parasitic infestations may cause very different clinical signs. Endoparasites and ectoparasites are rarely explored in the same study and therefore multiparasitism is poorly documented. The present survey aimed to improve knowledge of the prevalence and risk factors associated with ecto- and endoparasite infestations in owned cats in Europe.MethodsFrom March 2012 to May 2013, 1519 owned cats were included in a multicenter study conducted in 9 veterinary faculties throughout Europe (Austria, Belgium, France, Hungary, Italy, Romania and Spain). For each cat, ectoparasites were checked by combing of the coat surface associated with otoscopic evaluation and microscopy on cerumen samples. Endoparasites were identified by standard coproscopical examinations performed on fresh faecal samples. Risk factors and their influence on parasitism were evaluated by univariate analysis followed by a multivariate statistical analysis (including center of examination, age, outdoor access, multipet status, and frequency of treatments as main criteria) with logistic regression models.ResultsOverall, 50.7% of cats resulted positive for at least one internal or one external parasite species. Ectoparasites were found in 29.6% of cats (CI95 27.3-32.0%). Otodectes cynotis was the most frequently identified species (17.4%), followed by fleas (15.5%). Endoparasites were identified in 35.1% of the cats (CI95 32.7-35.7%), including gastro-intestinal helminths in 25.7% (CI95 23.5-28.0), respiratory nematodes in 5.5% (CI95 4.2-7.0%) and protozoans in 13.5% (CI95 11.8-15.3%). Toxocara cati was the most commonly diagnosed endoparasite (19.7%, CI95 17.8-21.8%). Co-infestation with endoparasites and ectoparasites was found in 14.0% of the cats, and 11.9% harbored both ectoparasites and gastro-intestinal helminths.Age, outdoor access, living with other pets, and anthelmintic or insecticide treatments were significantly associated with the prevalence of various parasites.ConclusionsThis survey demonstrates that parasitism is not a rare event in European owned cat populations. The prevalence of multi-parasitism is significantly greater than expected by chance and hence there is tendency for some individual cats to be more prone to infestation by both endo- and ectoparasites due to common risk factors.

Piglets experimentally infected with 10,000 oocysts of Isospora suis in three identical trials (n = 50) were examined clinically and coproscopically from 5 to 11 days post-infection (d.p.i.), weighed in weekly intervals until the fourth week of life and compared to age-matched asymptomatic controls (n = 17). Furthermore, 17 infected piglets were histologically examined on days 5-14 p.i. Infected animals had a significantly lower weight gain than the controls and showed diarrhoea throughout, with maximum prevalence and intensity on 6 d.p.i. Half of the animals had diarrhoea for only 2 days or less. The number of diarrhoea days was negatively correlated with weight gain. Oocyst excretion started on 5 d.p.i. with peak prevalences and declined afterwards; a smaller peak was seen on 10 d.p.i. All animals excreted parasites at least once, and most of them excreted for 5-7 days. Oocyst excretion intensity paralleled the prevalence and ranged from 220 to 251,501 oocysts per gram of faeces (opg). Most samples contained 4 x 10(3) to 4 x 10(4) opg. The opg values were negatively correlated with faecal scores (samples with diarrhoea contained less oocysts) of the same day and the previous day. Histologically, necrosis followed by atrophy of the villi was most pronounced in the early stage of infection throughout the jejunum and ileum but declined thereafter. On 14 d.p.i., villous atrophy was still noticeable in the jejunum. Histology is difficult to quantify and requires large animal numbers, although the effects are visible for some time. Weight gain and faecal score can be affected by other factors than parasite infection. From the compiled data, we conclude that the established model is suitable to study piglet isosporosis with oocyst excretion being the most reliable parameter, although individual variations are considerable. A negative correlation between excretion and diarrhoea may be responsible for the difficulties in the detection of the parasite in field samples.

No abstract