A single subcutaneous dose of eprinomectin (Eprecis®) is effective against common gastrointestinal nematodes and lungworms in experimentally infected lactating goats.

BACKGROUND: The health and productivity of dairy goats continue to be impacted by gastrointestinal nematodes (GIN) and lungworms (LW). Eprinomectin (EPN) is frequently selected for treatment because it is generally effective and does not require a milk withdrawal period. However, some factors, such as lactation, can have an impact on EPN pharmacokinetics and potentially its efficacy. To evaluate whether this can alter the efficacy of Eprecis® 2%, an eprinomectin injectable solution, a study was performed in lactating goats using the dose currently registered in cattle, sheep and goats (0.2 mg/kg). METHODS: This study was a blinded, randomized, controlled trial performed according to the VICH guidelines. Eighteen (18) worm-free lactating goats were included and experimentally challenged on day 28 with a mixed culture of infective gastrointestinal and lung nematode larvae (Haemonchus contortus, Trichostrongylus colubriformis, Teladorsagia circumcincta, Dictyocaulus filaria). At D-1, fecal samples were collected to confirm patent infection in all animals. On D0, the goats were randomly allocated into two groups of nine goats; group 1 was treated with Eprecis® 2% at 0.2 mg/kg BW by subcutaneous injection, while group 2 remained untreated. Fecal samples for egg counts were collected from all animals on days 3, 5, 7, 9, 11 and 14. On D14, all goats were killed, and the abomasum, small intestine and lungs were removed, processed and subsampled to record the number and species of worms. RESULTS: The treatment was well tolerated. After treatment, the arithmetic mean FEC decreased in the treated group and remained < 5 EPG until the end of the study, while the arithmetic mean FEC in the control group remained > 849.0 EPG. At D14, goats in the treated group had very limited or zero total worm counts, whereas all animals from the control group had a high worm burden. The measured efficacy was 100.0% against H. contortus and T. colubriformis, 99.9% against T. circumcincta and 98.0% against D. filaria. CONCLUSIONS: Eprinomectin (Eprecis®, 20 mg/ml), administered at the label dose (0.2 mg/kg), is highly effective against gastrointestinal nematodes and lungworms in lactating goats.

Biomarkers of gastrointestinal nematodes in beef cattle raised in a tropical area.

Biomarkers are specific molecular, histological, or physiological characteristics of normal or pathogenic biological processes and are promising in the diagnosis of gastrointestinal nematodes (GINs). Although some biomarkers have been validated for infection by Ostertagia sp. in cattle raised in temperate regions, there is a lack of information for tropical regions. The aim of this project was to assess potential biomarkers and validate the most promising. In the first study, 36 bovines (Nelore breed) naturally infected by GINs were distributed into two groups: infected (not treated with anthelmintic) and treated (treated with fenbendazole on days 0, 7, 14, 21, 28, 42, and 56). The variables of interest were live weight, fecal egg count, hemogram, serum biochemical markers, phosphorus, gastrin, and pepsinogen. In the second step, pepsinogen was assessed in cattle of the Nelore breed distributed among three groups: infected (not treated with anthelmintic), MOX (treated with moxidectin), and IVM + BZD (treated with ivermectin + albendazole). In the first study, no difference between groups was found for weight, albumin, hematocrit (corpuscular volume [CV]), erythrocytes, or hemoglobin. Negative correlations were found between pepsinogen and both CV and albumin, and albumin was negatively correlated with the percentage of Haemonchus sp. in the fecal culture. Among the biomarkers, only pepsinogen differentiated treated and infected (beginning with the 28th day of the study). In the second study, a reduction in pepsinogen was found after anthelmintic treatment. Therefore, pepsinogen is a promising biomarker of worms in cattle naturally infected by the genera Haemonchus and Cooperia in tropical areas.

Gastrointestinal anthelmintic plants used on small ruminants in Benin: Traditional use and scientific results - Review.

In Benin, livestock breeders frequently use medicinal plants to treat gastrointestinal diseases in small ruminants. The aim of this review is to list the plants traditionally used in this context and to present the scientific findings on the efficacy of these plants. An extensive search was carried out using PubMed, Scopus, ScienceDirect, Biomed Central and Google Scholar databases to collect data, with combinations of relevant french and english keywords such as "ethnobotanical survey", "anthelmintic properties", "medicinal plants", "gastrointestinal parasites", "digestive strongyles", "Haemonchus", "Trichostrongylus", "small ruminants", "sheep", "goats" and "Benin". A total of 45 published articles met the eligibility criteria. This review listed 123 plants used by breeders to treat gastrointestinal ailments in small ruminants. The most commonly used parts are leaves and barks, and the most common forms are decoction, maceration and powder. Scientific studies have demonstrated the anthelmintic properties of 18 plants, including Zanthoxylum zanthoxyloides, Newbouldia laevis, Mitragyna inermis and Combretum glutinosum. The powders or leaf extracts of these plants showed in vivo significant reductions of over 50% in egg excretion, larval establishment, viability and fertility of gastrointestinal strongyles in small ruminants. Extracts of these plants also revealed in vitro inhibitory activity of over 50% on egg hatching, larval migration and motility of gastrointestinal strongyles. This manuscript highlights the traditional use of anthelmintic plants in small ruminants in Benin and provides scientific results supporting the efficacy of these plants.

Gastrointestinal helminths infection of free-roaming cats (Felis catus) in Southeast Iran.

BACKGROUND: Cats in Iran are definitive hosts for several zoonotic intestinal helminths, such as Toxocara cati, Dipylidium caninum, Toxascaris leonina, Physaloptera praeputialis and Diplopylidium nolleri. OBJECTIVE: This study aimed to determine the prevalence of intestinal helminth infection in free-roaming cats in southeast Iran, a region with a high free-roaming cat population. METHODS: From January 2018 to December 2021, 153 cadavers of free-roaming cats from Southeast Iran were necropsied for intestinal helminth infections. The carcasses were dissected, and the digestive systems were removed. The esophagus, stomach, small intestine, caecum and colon were tightly ligated. All adult helminths were collected, preserved and identified. RESULTS: The prevalence of gastrointestinal helminth infections was 80.39% (123/153). Of the cats from Kerman, 73% (73/100) were infected with at least one helminth, including D. caninum 70% (70/100), T. leonina 8% (8/100) and P. praeputialis 17% (17/100). Concurrent infection with two helminth species was found in 16% (16/100) and of three species infections was found in 3% (3/100) of the cats. Of the cats from Zabol, 94.33% (50/53) were infected with at least one of the helminths, including D. caninum 69.81% (37/53), T. leonina 11.32% (6/53), P. praeputialis 37.73% (20/53) and T. cati 5.66% (3/53). Concurrent infection with two helminth species was found in 28.3% (15/53), and three species were found in 1.88% (1/53) of the cats. Helminth infections were more prevalent in older cats. There was no association between sex and infection rate. CONCLUSION: Based on the very high prevalence of zoonotic intestinal helminth infections in free-roaming cats in southeast Iran, the potential public health risk emphasizes the need for intersectoral collaboration, particularly the provision of health and hygiene education to high-risk populations, such as pre-school and school-age children.

Prevalence of gastrointestinal parasitic infections in wild mammals of a safari park and a zoo in Bangladesh.

In safari parks and zoos, wild animals are kept mainly for recreational purposes. Animals in these enclosures are also crucial for the education, research, and conservation aspect. To ensure better management and good health of wild animals in captivity, it is essential to monitor the occurrence of gastrointestinal (GI) parasitic (helminths and protozoa) infections. The current investigation was undertaken to investigate the prevalence of GI parasitic infections in wild mammals at Bangabandhu Sheikh Mujib (BSM) safari park and Chattogram (CTG) zoo of Bangladesh. A total of 72 individual faecal samples were collected from 25 species of wild mammals. Routine qualitative (e.g. direct smear, sedimentation, and flotation) and quantitative (e.g. McMaster technique) tests were performed to identify the eggs or oocysts of helminths and protozoa. Results demonstrated that wild mammals of both BSM safari park and CTG zoo were infected with a total of 17 genera/species of helminths and protozoa. The overall prevalence of GI parasitic infections in wild mammals of both zoological parks was 65.3% (95% confidence interval [CI]: 53.14-76.12), whereas it was 72.4% (95% CI: 52.76-87.27) in the BSM safari park and 60.5% (95% CI: 44.41-75.02) in the CTG zoo. In both zoological parks, infection with nematodes was more frequent compared to other helminth into the wild mammals. The herbivores were more infected with GI parasites than carnivores and omnivores of both BSM safari park and CTG zoo. The mean eggs/oocysts per gram of faeces was the highest in the carnivores compared to herbivores and omnivores of both enclosures. The findings of the current study demonstrated that wild mammals of both BSM safari park and CTG zoo suffered from various GI parasitic infections. Regular monitoring along with proper therapeutic measures may reduce the severe consequences of GI parasitic infections in captive wild animals.

Gastrointestinal parasites in free-ranging common marmosets (Callithrix jacchus Linnaeus, 1758) in the state of Sergipe, northeastern Brazil.

Ecological interactions resulting from human interference and environmental changes have implications for human health and the host animals involved in the parasite cycles. Considering the scarcity of surveys of the parasitic fauna of non-human primates in northeastern Brazil, the objective of this study was to investigate the infection by gastrointestinal parasites in free-ranging common marmosets (Callithrix jacchus) in the State of Sergipe. Fecal samples were collected from 52 animals captured in three protected areas. Most of the samples consisted of adult females and 57% were infected with at least one of the 12 identified parasite taxa. The most frequent intestinal parasite was Prosthenorchis sp., followed by Spiruridae, Entamoeba spp. and Strongylida order. The presence of gastrointestinal parasites was not dependent on sex, age or weight, although there was an association with the capture biome.

Development of Bovine Gastric Organoids as a Novel In Vitro Model to Study Host-Parasite Interactions in Gastrointestinal Nematode Infections.

Gastro-intestinal nematode (GIN) parasites are a major cause of production losses in grazing cattle, primarily through reduced growth rates in young animals. Control of these parasites relies heavily on anthelmintic drugs; however, with growing reports of resistance to currently available anthelmintics, alternative methods of control are required. A major hurdle in this work has been the lack of physiologically relevant in vitro infection models that has made studying precise interactions between the host and the GINs difficult. Such mechanistic insights into the infection process will be valuable for the development of novel targets for drugs, vaccines, or other interventions. Here we created bovine gastric epithelial organoids from abomasal gastric tissue and studied their application as in vitro models for understanding host invasion by GIN parasites. Transcriptomic analysis of gastric organoids across multiple passages and the corresponding abomasal tissue showed conserved expression of tissue-specific genes across samples, demonstrating that the organoids are representative of bovine gastric tissue from which they were derived. We also show that self-renewing and self-organising three-dimensional organoids can also be serially passaged, cryopreserved, and resuscitated. Using Ostertagia ostertagi, the most pathogenic gastric parasite in cattle in temperate regions, we show that cattle gastric organoids are biologically relevant models for studying GIN invasion in the bovine abomasum. Within 24 h of exposure, exsheathed larvae rapidly and repeatedly infiltrated the lumen of the organoids. Prior to invasion by the parasites, the abomasal organoids rapidly expanded, developing a 'ballooning' phenotype. Ballooning of the organoids could also be induced in response to exposure to parasite excretory/secretory products. In summary, we demonstrate the power of using abomasal organoids as a physiologically relevant in vitro model system to study interactions of O. ostertagi and other GIN with bovine gastrointestinal epithelium.

Diversity, prevalence, and intensity of gastrointestinal helminth infections in migratory, resident, and sedentary plains zebras (Equus quagga) in Masai Mara National Reserve and Lake Nakuru National Park, Kenya.

The diversity, prevalence and intensity of parasitic infections are influenced by factors such as movement patterns and land area available to the host. Zebras are known to harbour various genera of gastrointestinal helminths and facilitate parasite movement across large geographic areas through migration. Despite the harmful effects of helminths and their consequences on host population dynamics, little is known regarding helminth infection patterns in migratory, resident, and sedentary zebras. This study compared the diversity, prevalence, and intensity of helminth infections in zebras with different host movement patterns and space availability. Faecal samples were collected from migratory, resident, and sedentary groups of zebras between 2014 and 2015 and screened for helminth infection. They were infected by diverse groups of helminths including nematodes, trematodes and cestodes with the most prevalent being strongyle type nematodes. No significant difference in the diversity and prevalence was observed between the "three groups". Larvae were also recovered and identified species, cyathostomes, Strongylus edentatus, S.vulgaris, S. equinus, and Trichostronglus in order of abundance. The intensity of infection with the strongyle type nematodes, was highest in the migratory, then sedentary and lowest in resident zebras. It is plausible that the migratory zebras have higher energy demands and poor nutrition, resulting in reduced immune function hence high nematode burdens. Similarly, the sedentary population had high nematode burdens possibly due to high pasture contamination and depressed immunity due to the artificially restricted movement. The latter observation is particularly important in the design and size of sanctuaries in relation to parasitism.

Farmers' perception on the control of gastrointestinal parasites in organic and conventional sheep production in Sweden.

A questionnaire was sent to sheep owners in Sweden to get information about anthelmintic drug use. The survey also investigated how respondents experienced problems with gastrointestinal nematode infections (GIN) focusing on Haemonchus contortus. The response rate was 31% and included both conventional and organic farms. The use of anthelmintics was low (45%), among which a majority (76%) drenched ewes on a single occasion, mostly with ivermectin (59%) followed by albendazole (19%). Other drugs were used rarely, however, unawareness of GIN risk was high (19%), especially among respondents with few animals. Anthelmintic dose calculations were done after visual appraisal by 63% and 22% calibrated the equipment before drug delivery, which is worrying since underdosing is a risk factor for the development of anthelmintic resistance. Like with anthelmintics, the perceived risk for GIN increased with herd size both by conventional and organic farmers. Faecal examination for the presence of GIN was done by 65% of the respondents and, among their sheep, H. contortus was or had been diagnosed in 41% of the herds. Irrespective of new stock had been imported from other countries or not, common problems were reported by 5% and 7% of the organic and conventional producers, respectively. Land use and grazing management strategies differed more in relation to herd size than by production form, with a majority (47%) having their sheep grazed in several paddocks, or at least the lambs were moved when separated from the ewes at weaning (25%). In contrast set stocked grazing was mainly reported on smaller farms. Co-grazing with cattle and horses were also frequently reported irrespective of production form, but with cattle to a somewhat greater degree on larger organic farms. Wild cervids, especially roe deer, were frequently observed on sheep pastures (87%). The veterinary involvement was higher on organic (65%) than on conventional farms (53%), and only 5% considered advice unimportant. Still, some conventional and organic producers treated sheeps routinely without a prior diagnosis, against the national regulations. 46% of the respondents drenched new and replacement stock. In conclusion, although some differences were observed between conventional and organic producers, the divergences were mainly due to herd size categories. Furthermore, despite a high veterinary involvement, we identified factors which can contribute to anthelmintic use, such as poor quarantine procedures, and deworming routines that can contribute to anthelmintic resistance in H. contortus.

Gastrointestinal helminth parasites of the threatened Australasian crested grebe (Podiceps cristatus australis, Gould 1844) in New Zealand, with descriptions of Baruscapillaria kamanae n. sp. (Nematoda: Trichuridae) and Cryptocotyle micromorpha n. sp. (Trematoda: Opisthorchiidae).

The Australasian crested grebe Podiceps cristatus australis, Gould 1844 is restricted to Australia and New Zealand, where it is listed as Threatened and Nationally Vulnerable. For the first time in New Zealand, we report on the parasitic helminths infecting three individuals from Lake Wanaka, Otago, using morphological and molecular tools. Seven helminth species were found in the gastrointestinal tract: 2 nematodes (Contracaecum ovale and Baruscapillaria kamanae n. sp.), 4 trematodes (Australapatemon minor, Cryptocotyle micromorpha n. sp., Tylodelphys darbyi and Neopetasiger neocomensis), and 1 cestode (Confluaria pseudofurcifera). Except for T. darbyi, all are new records for New Zealand. A change of orthography is proposed for Neopetasiger neocomensis and N. pseudoneocomensis. Cryptocotyle micromorpha n. sp. (Opisthorchiidae) is distinguished from similar species by its small size, wholly extracaecal vitellaria and anteriorly looped uterus. Baruscapillaria kamanae n. sp. (Trichuridae) is distinguished from other freshwater species by a combination of vulva and spicule morphology. The helminth parasites found here are mostly the same as those from the grebe in the northern hemisphere, indicating that they have been carried with the host species in its spread to Australasia. However, the parasite fauna may be depauperate due to a diminishing reservoir of intermediate hosts in that geographical migration.

Investigating the development of diarrhoea through gene expression analysis in sheep genetically resistant to gastrointestinal helminth infection.

Gastrointestinal helminths infect livestock causing health problems including severe diarrhoea. To explore the underlying biological mechanisms relating to development and control of diarrhoea, we compared 4 sheep that were susceptible to development of diarrhoea with 4 sheep that were diarrhoea-resistant. Transcriptomes in the tissues where the parasites were located were analyzed using RNASeq. By considering low-diarrhoea sheep as control, we identified 114 genes that were down-regulated and 552 genes that were up-regulated genes in the high-diarrhoea phenotype. Functional analysis of DEGs and PPI sub-network analysis showed that down-regulated genes in the high-diarrhoea phenotype were linked to biological processes and pathways that include suppression of 'antigen processing and presentation', 'immune response', and a list of biological functional terms related to 'suppression in immune tolerance'. On the other hand, up-regulated genes in the high-diarrhoea phenotype probably contribute to repair processes associated with tissue damage, including 'extracellular matrix organization', 'collagen fibril organization', 'tissue morphogenesis', 'circulatory system development', 'morphogenesis of an epithelium', and 'focal adhesion'. The genes with important roles in the responses to helminth infection could be targeted in breeding programs to prevent diarrhoea.

Differential responses of abomasal transcriptome to Haemonchus contortus infection between Haemonchus-selected and Trichostrongylus-selected merino sheep.

Haemonchus contortus is the most prevalent and pathogenic gastrointestinal nematode infecting sheep and goats. The two CSIRO sheep resource flocks, the Haemonchus-selected flock (HSF) and Trichostrongylus-selected flock (TSF) were developed for research on host resistance or susceptibility to gastrointestinal nematode infection. A recent study focused on the gene expression differences between resistant and susceptible sheep within each flock, with lymphatic and gastrointestinal tissues. To identify features in the host transcriptome and understand the molecular differences underlying host resistance to H. contortus between flocks with different selective breeding and genetic backgrounds, we compared the abomasal transcriptomic responses of the resistant or susceptible animals between HSF and TSF flocks. A total of 11 and 903 differentially expressed genes were identified in the innate infection treatment in HSF and TSF flocks between resistant and susceptible sheep respectively, while 52 and 485 genes were identified to be differentially expressed in the acquired infection treatment, respectively. Among them, 294 genes had significantly different gene expression levels between HSF and TSF flock animals within the susceptible sheep by both the innate and acquired infections. Moreover, similar expression patterns of the 294 genes were observed, with 273 genes more highly expressed in HSF and 21 more highly expressed in the TSF within the abomasal transcriptome of the susceptible animals. Gene ontology enrichment of the differentially expressed genes identified in this study predicted the likely differing function between the two flock's susceptible lines in response to H. contortus infection. Nineteen pathways were significantly enriched in both the innate and adaptive immune responses in susceptible animals, which indicated that these pathways likely contribute to the host resistance development to H. contortus infection in susceptible sheep. Biological networks built for the set of genes differentially abundant in susceptible animals identified hub genes of PRKG1, PRKACB, PRKACA, and ITGB1 for the innate immune response, and CALM2, MYL1, COL1A1, ITGB1 and ITGB3 for the adaptive immune response, respectively. Our results offered a quantitative snapshot of host transcriptomic changes induced by H. contortus infection between flocks with different selective breeding and genetic backgrounds and provided novel insights into molecular mechanisms of host resistance.

Association of human disturbance and gastrointestinal parasite infection of yellow baboons in western Tanzania.

Human disturbance is an ongoing threat to many wildlife species, manifesting as habitat destruction, resource overuse, or increased disease exposure, among others. With increasing human: non-human primate (NHP) encounters, NHPs are increasingly susceptible to human-introduced diseases, including those with parasitic origins. As such, epidemiology of parasitic disease is becoming an important consideration for NHP conservation strategies. To investigate the relationship between parasite infections and human disturbance we studied yellow baboons (Papio cynocephalus) living outside of national park boundaries in western Tanzania, collecting 135 fresh faecal samples from nine troops occupying areas with varying levels of human disturbance. We fixed all samples in 10% formalin and later evaluated parasite prevalence and abundance (of isotrichid ciliates and Strongylida). We identified seven protozoan and four helminth taxa. Taxa showed varied relationships with human disturbance, baboon troop size and host age. In four taxa, we found a positive association between prevalence and troop size. We also report a trend towards higher parasite prevalence of two taxa in less disturbed areas. To the contrary, high levels of human disturbance predicted increased abundance of isotrichid ciliates, although no relationship was found between disturbance and Strongylida abundance. Our results provide mixed evidence that human disturbance is associated with NHP parasite infections, highlighting the need to consider monitoring parasite infections when developing NHP conservation strategies.

Survival of the nematophagous fungus Duddingtonia flagrans to in vitro segments of sheep gastrointestinal tract.

The nematophagous fungus Duddingtonia flagrans is used in integrated management of gastrointestinal nematodes in ruminants. The chlamydospores of the fungus, orally administered, pass through the segments of the ruminant digestive tract and, in the feces, capture the nematodes preventing their migration to grasslands. The drastic conditions of the gastrointestinal segments can negatively affect the fungus' biocontrol activity. The aim of this study was to assess the effect of in vitro conditions of the sheep's main gastrointestinal segments on the concentration, viability and nematode predatory ability of D. flagrans chlamydospores. The segments evaluated separately in vitro were the oral cavity, rumen, abomasum, and small intestine. The results showed that chlamydospores concentration was not affected by exposure to the different segments. The viability of the chlamydospores after exposure to the oral cavity (2.53 × 106 CFU/mL) and small intestine (1.24 × 105 CFU/mL) was significantly lower than its control treatment, with values of 6.67 × 106 CFU/mL and 2.31 × 105 CFU/mL respectively. Nematode predatory ability after rumen exposure was reduced by 7% compared to the control treatment, by 25% after abomasum exposure and by 17% after small intestine. This study revealed the individual in vitro effect of each segment of ovine gastrointestinal tract on the integrity of this strain of the fungus D. flagrans affecting its viability and nematode predatory ability under the evaluated conditions. Delivery systems could be designed to protect chlamydospores considering the impact of each gastrointestinal segment.

In vitro efficacy of different concentrations of Duddingtonia flagrans on varying egg densities of gastrointestinal nematodes of cattle.

The nematophagous fungus Duddingtonia flagrans, used for the biological control of gastrointestinal nematodes in livestock, is fed to infected animals so its chlamydospores and the parasite eggs are voided together with faeces where the fungus preys on nematode larvae, thus reducing pasture infectivity. The number of chlamydospores needed for the fungus to be efficient in the presence of a wide range in numbers of parasitic eggs is largely unknown and a matter of discussion. The aim of this study was to determine the fungal efficacy of four different chlamydospore concentrations against three different levels of cattle faecal egg counts. Fungal concentrations of 11000, 6250, 3000 and 1000 chlamydospores/gram of faeces (cpg) were added to cultures containing 840, 480 or 100 eggs/gram of faeces (epg). After 14 days of incubation, the efficacy of D. flagrans, in decreasing order of chlamydospore concentrations, ranged from 100% (P < 0.0001) to 77% (P > 0.0999) in the 100 epg groups; 100% (P < 0.0001) to 92% (P = 0.4625) in the 480 epg groups and 100% (P < 0.0001) to 96% (P = 0.7081) in the 840 epg groups. The results indicate that the numbers of eggs in cattle faeces were not a determining factor on the fungal efficacy against gastrointestinal nematodes.

Practical guide for microscopic identification of infectious gastrointestinal nematode larvae in sheep from Sardinia, Italy, backed by molecular analysis.

BACKGROUND: Gastrointestinal nematodes (GIN) are ubiquitous in small ruminant farming, representing a major health and production concern. Given their differences in pathogenicity and the current problems regarding anthelmintic resistance, specific diagnosis of GIN is of significant importance. At present, the most widely applied method for this entails culture and microscopic analysis of third-stage larvae, allowing for identification at least to the genus level. Overall, a variety of keys for microscopic analysis have been published, showing substantial variation. Given this fact, this study aimed to produce a practical and updated guide for the identification of infective ovine GIN larvae. METHODS: Using existing keys and protocols, a total of 173larvae of the most common species/genera of ovine GIN from pooled faecal samples from Sardinia (Italy) were identified and extracted, and further individual molecular identification was performed. Morphometric and morphological data as well as high-quality photographs were collected and combined to produce the final guide. RESULTS: GIN microscopically and molecularly identified during this research include Trichostrongylus spp., Teladorsagia circumcincta, Haemonchus contortus, Cooperia curticei, and Chabertia ovina. Based on microscopic analysis, 73.5% of the larvae were correctly identified. Based on sheathed tail length, 91.8% were correctly classified into their respective preliminary groups. CONCLUSIONS: It is crucial for the microscopic identification of infectious GIN larvae to examine each larva in its entirety and thus to take multiple characteristics into account to obtain an accurate diagnosis. However, a preliminary classification based on sheathed tail length (resulting in three groups: A, short; B, medium; C, long) was found to be effective. Further identification within group A can be achieved based on the presence of a cranial inflexion, caudal tubercles and full body measurements (Trichostrongylus spp. < 720 µm, T. circumcincta ≥ 720 µm). Larvae within group B can be differentiated based on sheathed tail morphometry (H. contortus > 65 µm, C. curticei ≤ 65 µm), the presence of cranial refractile bodies, total body length measurements (H. contortus ≤ 790 µm, C. curticei > 790 µm) and shape of the cranial extremity. Finally, all characteristics proposed for the differentiation between Oesophagostomum spp. and C. ovina larvae (group C) were found to have considerable restrictions.

The identification and semi-quantitative assessment of gastrointestinal nematodes in faecal samples using multiplex real-time PCR assays.

BACKGROUND: The diagnosis of gastrointestinal nematode (GIN) infections in ruminants is routinely based on morphological/morphometric analysis of parasite specimens recovered by coprological methods, followed by larval culture (LC) techniques. Such an approach is laborious, time-consuming, requires a skilled expert, and moreover suffers from certain limitations. Molecular tools are able to overcome the majority of these issues, providing accurate identification of nematode species and, therefore, may be valuable in sustainable parasite control strategies. METHODS: Two multiplex real-time polymerase chain reaction (PCR) assays for specific detection of five main and one invasive GIN species, including an internal amplification control to avoid false-negative results, were designed targeting SSU rRNA and COI genetic markers, as well as established ITS1/2 sequences. The assays were optimized for analysis of DNA extracted directly from sheep faeces and verified for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis, Nematodirus battus, Chabertia ovina, and Ashworthius sidemi. Semi-quantitative evaluation of infection intensity was enabled using a plasmid construct and a dilution series of sheep faeces with a known number of nematode eggs. Assays were tested on 44 individually collected faecal samples from three farms, and results were compared to those from faecal egg counts (FEC) using the concentration McMaster technique and LC. RESULTS: Multiplex real-time PCR assays showed great specificity to target nematodes. During the analysis of faecal samples, the assays proved to have higher sensitivity in strongylid-type egg detection over FEC by revealing three false-negative samples, while showing moderate agreement in evaluation of infection intensity. The multiplex assays further clarified GIN species identification compared to LC, which had confused determination of Teladorsagia spp. for Trichostrongylus spp. CONCLUSIONS: Our multiplex assays proved to be a rapid and accurate approach enabling simultaneous and reliable GIN species identification from faeces and semi-quantitative estimation of the number of eggs present. This approach increases diagnostic value and may add a high degree of precision to evaluation of anthelmintic efficacy, where it is important to identify species surviving after treatment.

Genetic Analyses and Genome-Wide Association Studies on Pathogen Resistance of Bos taurus and Bos indicus Cattle Breeds in Cameroon.

Autochthonous taurine and later introduced zebu cattle from Cameroon differ considerably in their resistance to endemic pathogens with little to no reports of the underlying genetic make-up. Breed history and habitat variations are reported to contribute significantly to this diversity worldwide, presumably in Cameroon as well, where locations diverge in climate, pasture, and prevalence of infectious agents. In order to investigate the genetic background, the genotypes of 685 individuals of different Cameroonian breeds were analysed by using the BovineSNP50v3 BeadChip. The variance components including heritability were estimated and genome-wide association studies (GWAS) were performed. Phenotypes were obtained by parasitological screening and categorised in Tick-borne pathogens (TBP), gastrointestinal nematodes (GIN), and onchocercosis (ONC). Estimated heritabilities were low for GIN and TBP (0.079 (se = 0.084) and 0.109 (se = 0.103) respectively) and moderate for ONC (0.216 (se = 0.094)). Further than revealing the quantitative nature of the traits, GWAS identified putative trait-associated genomic regions on five chromosomes, including the chromosomes 11 and 18 for GIN, 20 and 24 for TBP, and 12 for ONC. The results imply that breeding for resistant animals in the cattle population from Northern Cameroon might be possible for the studied pathogens; however, further research in this field using larger datasets will be required to improve the resistance towards pathogen infections, propose candidate genes or to infer biological pathways, as well as the genetic structures of African multi-breed populations.

Systematic examination of the cardiopulmonary, urogenital, muscular and gastrointestinal parasites of the Eurasian otters (Lutra lutra) in Denmark, a protected species recovering from a dramatic decline.

The Eurasian otter (Lutra lutra) is a protected species in Denmark and at present, the population is recovering due to conservation efforts. The Danish otters are mainly found in the continental part of Denmark (Jutland), but establishment in the main islands (Fyn and Zealand) has been observed. While there is a lack of systematic studies on the parasite fauna of otters in Denmark, this study aims to screen otters for their parasite fauna, especially those of zoonotic and/or veterinary importance. Thirty-three otter carcasses, road-killed (n = 30), found dead (n = 2) and shot (n = 1), were collected between June 2013 and May 2014 and examined for cardiopulmonary, urogenital, gastrointestinal, and muscle helminths by post mortem examination. Faecal samples were analysed by modified concentration McMaster technique and direct immunofluorescence test for Giardia and Cryptosporidium. At least one parasite was found in 75.8% of animals. The parasite fauna included 13 species, consisting of five nematodes: Molineus patens (30.3%), Aonchotheca putorii (27.3%), Strongyloides sp. (24.2%), Physaloptera sp. (12.1%), Eucoleus aerophilus (10.0%); one cestode: Schistocephalus solidius (6.1%); four trematodes: Metorchis bilis (33.3%), Isthimiophora melis (15.2%), Cryptocotyle sp. (3.0%), Plagiorchis sp. (3.0%); one acanthocephalan: Acanthocephalus ranae (18.2%); and two protozoans: Giardia spp. (3.1%), and Eimeria spp. (3.1%). The study showed that otters carry parasites of zoonotic and veterinary importance. Many of these parasites can also infect native carnivores and birds, and the distribution of these parasites may be affected if the otter population continue to increase in Denmark.

Predictors of aetiology and outcomes of acute gastrointestinal illness in returning travellers: a retrospective cohort analysis.

BACKGROUND: Gastrointestinal illness is a major cause of morbidity in travellers and is a common reason for presentation to healthcare services on return. Whilst the aetiology of imported gastrointestinal disease is predominantly infectious, outcomes are variable due to a range of phenomena such as post-infectious irritable bowel syndrome, drug resistance and occult pathology (both infectious and non-infectious). Previous studies have focussed on predictors of aetiology of gastrointestinal disease in travellers; we present a retrospective study combining both aetiological and early outcome data in a large cohort of returned travellers. METHOD: We identified 1450 patients who attended our post-travel walk-in clinic with gastrointestinal symptoms between 2010 and 2016. Demographic, travel, clinical and laboratory data was collected through case note review. Logistic regression analysis to examine correlates of aetiology and outcome were performed in R (CRAN Project 2017). RESULTS: Of 1450 patients in our cohort 153 reported bloody diarrhoea and 1081 (74.6%) reported non-bloody diarrhoea. A definitive microbiological diagnosis was made in 310 (20.8%) of which 137 (9.4%) had a parasite identified and 111 (7.7%) had a bacterial cause identified. Factors associated with a parasitological diagnosis included history of travel to South Asia (aOR = 2.55; 95%CI 1.75-3.70, p < 0.0001) and absence of bloody diarrhoea (aOR = 0.22; 95%CI 0.066-0.53, p < 0.005). Factors associated with a bacteriological diagnosis included male gender (aOR = 1.69; 95%CI 1.10-2.62, p < 0.05), an age < 37 years on presentation (aOR = 2.04; 95%CI 1.25-3.43, p < 0.01), white cells on stool microscopy (aOR = 3.52; 95%CI 2.09-5.86, p < 0.0001) and a C-reactive protein level of >5iu/dL (aOR = 4.68; 95%CI 2.91-7.72, p < 0.0001). The majority (1235/1450, 82.6%) reported full symptomatic resolution by the first follow up visit; factors associated with lack of symptomatic resolution included female gender (aOR = 1.45 95%CI 1.06-1.99, p < 0.05), dysenteric diarrhoea (aOR = 2.14 (95%CI 1.38-3.25, p < 0.0005) and elevated peripheral leukocyte count (aOR = 1.58 95%CI 1.02-2.40, p < 0.05). CONCLUSIONS: In a cohort of returned travellers, we were able to identify multiple factors that are correlated with both aetiology and outcome of imported gastrointestinal syndromes. We predict these data will be valuable in the development of diagnostic and therapeutic pathways for patients with imported gastrointestinal infections.