Larval Migration Research Articles

Modulatory Effect of Beneficial Enterococci and Their Enterocins on the Blood Phagocytes in Murine Experimental Trichinellosis.

Bacteriocins (enterocins) represent a new therapeutic strategy in various intestinal and non-intestinal infections. In antiparasitic defence, an oxidative inflammation of phagocytes is effective in destroying new-born Trichinella spiralis larvae. The strains Enterococcus faecium CCM8558 and E. durans ED26E/7 and their enterocins, enterocin M and a durancin-like enterocin, respectively, were administered daily, and mice were then infected with T. spiralis larvae on the seventh day of treatment. Phagotest and Bursttest kits were used to detect the phagocytosis and respiratory burst in blood leukocytes. T. spiralis infection inhibited phagocytosis from day 11 post-infection (dpi) during the migration of new-born larvae into the muscles. E. faecium CCM8558, E. durans ED26E/7, and the durancin-like enterocin increased phagocytic activity from day 11 dpi. Both strains and their enterocins (enterocin M and durancin-like) stimulated the ingestion capability of phagocytes from 18 to 32 dpi. Enterococci/enterocins therapy prevented a reduction in cells with respiratory burst caused by T. spiralis infection from 11 dpi. The enzymatic activity of phagocytes was stimulated on 18 and 25 dpi, particularly by E. faecium CCM8558 and enterocin M. Enterocin M and the durancin-like enterocin were as effective in stimulating phagocytosis as the bacterial strains that produce them. The stimulation of phagocytosis could contribute to decreased larval migration and reduced parasite burden in the host.

In vitro anthelmintic activity of Euphorbia forskalii J. Gay aqueous extracts evaluation on different life stages of Haemonchus contortus.

The use of medicinal plants in the control of gastrointestinal parasitosis is a promising solution for improving the productivity of sheep flocks. In order to evaluate the anthelmintic activity of Euphorbia forskallii, in vitro bioassays were performed on three life stages of Haemonchus contortus. Five aqueous extracts concentrations namely 10mg/mL; 5mg/mL; 2.5mg/mL; 1.25mg/mL and 0.62mg/mL were used for adult worm mortality tests. Egg hatch inhibition and L3 larval migration inhibition tests were studied at 5mg/mL; 2.5mg/mL; 1.25mg/mL; 0.62mg/mL and 0.31mg/mL. A negative control PBS and a positive control levamisole 2.5mg/mL were established for each test. A phytochemical screening was performed to determine the presence of some secondary metabolites. The results obtained showed the presence of total polyphenols, total flavonoids and condensed tannins within the aqueous extracts of E. forskalii. A high and significant (P<0.05) morality rate compared to the negative control with an LC50 of 2.30mg/mL was obtained. Inhibition of egg hatch and larval migration were high and significant (p<0.05) compared to the negative control. There was an IC50 of 1.03mg/mL and 0.92mg/mL respectively for inhibition of egg hatching and L3 larval migration. The present study revealed the in vitro anthelmintic activity of E. forskalii aqueous extracts and allows us to consider in perspective complementary studies to confirm this activity.

Anthelmintic Activities of Extract and Ellagitannins from Phyllanthus urinaria against Caenorhabditis elegans and Zoonotic or Animal Parasitic Nematodes.

The aerial parts of Phyllanthus urinaria are used in traditional medicine in West Africa against helminthiasis, but their anthelmintic potential has not been evaluated until now. Within the current study, a hydroacetonic extract (AWE) and fractions and isolated ellagitannins from P. urinaria were, therefore, tested in vitro against Caenorhabditis elegans and the larvae of the animal parasites Toxocara canis, Ascaris suum, Ancylostoma caninum, and Trichuris suis. Compounds 1: - 13: , mainly representing ellagitannins, were isolated using different chromatographic methods, and their structures were elucidated by HR-MS and 1H/13C-NMR. AWE exerted concentration-dependent lethal effects (LC50 of 2.6 mg/mL) against C. elegans and inhibited larval migration of all animal parasites tested (T. suis L1 IC50 24.3 µg/mL, A.suum L3 IC50 35.7 µg/mL, A.caninum L3 IC50 112.8 µg/mL, T. canis L3 IC50 1513.2 µg/mL). The anthelmintic activity of AWE was mainly related to the polar, tannin-containing fractions. Geraniin 1: , the major ellagitannin in the extract, showed the strongest anthelmintic activity in general (IC50 between 0.6 and 804 µM, depending on parasite species) and was the only compound active against A.caninum (IC50 of 35.0 µM). Furosin 9: was least active despite structural similarities to 1: . Among the parasites tested, Trichuris suis L1 larvae turned out to be most sensitive with IC50 of 0.6, 6.4, 4.0, 4.8, and 2.6 µM for geraniin 1: , repandusinic acid A 3: , punicafolin 8: , furosin 9: , and phyllanthusiin A 10: , respectively.

Genetic Diversity, Population Structure and Demographic History of Orange Mud Crab Scylla Olivacea from the Bay of Bengal, Bangladesh and Adjacent Seas in the Northern Indian Ocean Based on Mitochondrial COI Gene Sequences

In this study, we analyzed mitochondrial COI gene sequences to reveal genetic diversity, population structure and demographic history of two Bangladeshi (BD) populations (SB and CK) of the orange mud crab Scylla olivacea of the Northern Bay of Bengal (BoB), and compared these two with other four populations in the Northern Indian Ocean region (Arabian Sea, Andaman Sea and Malacca strait) and South China Sea. For all of the populations, nucleotide diversities were low (0.005–0.01) while the haplotype diversities were as high as 0.70–0.96, indicating that the S. olivacea has undergone a recent population expansion after experiencing bottleneck. The pairwise population statistics (FST) revealed that no genetic variation was made between SB and CK populations of BD in BoB. However, these two BoB populations showed separate genetic structure with each of the Andaman Sea (Myanmar coast, MM) and Malacca strait (West coast of Malaysia, MS) populations. On the other hand, two BoB populations did not form separate genetic structure from the population of Arabian Sea (AS). Larval dispersal-based migration by the East and West India coastal currents probably caused this genetic homogeneity between BoB and AS populations.The MM population had separate genetic structure from all of the populations studied in the present study. The Hierarchical analysis of molecular variance (AMOVA) revealed four large population groups of S. olivacea within its distribution range in the Indo-west Pacific region namely, Arabian Sea, Bay of Bengal, Andaman Sea and South China Sea groups. Some geographical barriers (e.g. Indian peninsula, Andaman and Nicobar Islands) along with seasonally formed marine gyres in the Andaman Sea are responsible for separate genetic structure among different populations and also for establishing four population groups. Star-shaped patterns of haplotype network and neutrality test corroboratethe recent population expansion of all populations except MM and CK. Mismatch distribution analysis reveals that the demographic expansion of the species started during the late Pleistocene period approximately 125,000 to 365,000 years ago. These results will help to establish the conservation and management strategy for orange mud crab in the Northern Indian Ocean region including the Bay of Bengal.&#x0D; J. of Sci. and Tech. Res. 4(1): 101-118, 2022

UPLC-QToF-ESI-MS identification and anthelmintic activity of Mitragyna inermis (Willd.) Kuntze (Rubiaceae)

Medicinal plants attract the attention of many researchers to find natural and safe remedies for various resistant diseases. Leaves of Mitragyna inermis are widely used in traditional veterinary medicine for the treatment of gastrointestinal strongyles of small ruminants. The aim of the current study is to estimate the antioxidant, anthelmintic and the larval toxicity of the aqueous and hydroethanolic extracts of this plant in addition to the hexane, dichloromethane and ethanol fractions of the hydroethanolic extract. Investigation of the most active extract using Ultra Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Electrospray Ionization Mass Spectrometry (UPLC-QToF-ESI-MS). Both plant extracts showed good antioxidant activity by scavenging the 2,2′-diphényl-1-picrylhydrazyl (DPPH) radical and reducing the ferric ion. Similarly, they were no-toxic to Artemia salina larvae (CL50 > 0.1 μg/mL). Also, they significantly reduced larval migration and motility of Haemonchus contortus adult worms (p < 0.001). The hexane, dichloromethane and ethanolic fractions of the hydroethanolic extract showed low activity compared to crude extracts except for the hexane fraction on H. contortus adult worms (p < 0.001) while it showed a poor result on larvae. It thus appears that the anthelmintic activity of the extract may be linked to the synergistic action of these compounds. The UPLC-QToF-ESI-MS analysis revealed the tentative identification of 15 compounds including 7 alkaloids. The results of the present study confirm the anthelmintic activity of M. inermis in traditional veterinary medicine.

Effects of temperature on Anisakis simplex sensu stricto L3 larvae experimentally challenged in rainbow trout (Oncorhynchus mykiss) and Mozambique tilapia (Oreochromis mossambicus)

Human anisakiasis is a foodborne disease that has been increasingly reported worldwide and is caused by the consumption of raw or undercooked seafood infected with zoonotic nematodes of the genus Anisakis Dujardin, 1845. One of the most frequently reported species, both in fish paratenic hosts as well as in human patients, is Anisakis simplex sensu stricto (s.s.), which is distributed within some of the globe's main fishing grounds in the North Pacific and Atlantic oceans. In order to clarify the influence of temperature on this parasite in vivo, third-stage larvae of A. simplex s.s. were surgically challenged in the body cavities of rainbow trouts (Oncorhynchus mykiss) and Mozambique tilapias (Oreochromis mossambicus). Larval survival and tissue migration were then analyzed after 6 and 12weeks. The results showed that survival rates of larvae were lower at 27 and 33°C than at 3, 9, 15 and 21°C. Also, migration to the body muscle was observed to be highest at 9°C. These results suggest that third-stage larvae of A. simplex s.s. are more adapted to lower temperatures in experimentally challenged fish, which may justify its distribution in cold northern waters.

Pulmonary inflammation promoted by type-2 dendritic cells is a feature of human and murine schistosomiasis

Schistosomiasis is a parasitic disease affecting over 200 million people in multiple organs, including the lungs. Despite this, there is little understanding of pulmonary immune responses during schistosomiasis. Here, we show type-2 dominated lung immune responses in both patent (egg producing) and pre-patent (larval lung migration) murine Schistosoma mansoni (S. mansoni) infection. Human pre-patent S. mansoni infection pulmonary (sputum) samples revealed a mixed type-1/type-2 inflammatory cytokine profile, whilst a case-control study showed no significant pulmonary cytokine changes in endemic patent infection. However, schistosomiasis induced expansion of pulmonary type-2 conventional dendritic cells (cDC2s) in human and murine hosts, at both infection stages. Further, cDC2s were required for type-2 pulmonary inflammation in murine pre-patent or patent infection. These data elevate our fundamental understanding of pulmonary immune responses during schistosomiasis, which may be important for future vaccine design, as well as for understanding links between schistosomiasis and other lung diseases.

Development of In Vitro Assays with the Canine Hookworm Uncinaria stenocephala and Assessment of Natural Plant Products for Anti-Parasitic Activity.

Enteric helminth infection is an increasing concern in companion animals due to reports of resistance to commonly used anthelmintic drugs. Thus, the assessment of new therapeutic options such as bioactive dietary additives is of high importance. Here, we adapted egg hatch, larval migration, and larval motility assays to screen extracts of several natural ingredients against the canine hookworm Uncinaria stenocephala, a prevalent parasite of dogs in northern Europe. Egg hatch and larval migration assays were established showing that the anthelmintic drugs levamisole and albendazole had strong anti-parasitic activity against U. stenocephala, validating the use of these assays for the assessment of novel anti-parasitic substances. Subsequently, we identified that extracts from the seaweed Saccharina latissima, but not extracts from grape seed or chicory, significantly inhibited both hatching and larval migration. Finally, we showed that α-linolenic acid, a putative anti-parasitic compound from S. latissima, also exhibited anti-parasitic activity. Collectively, our results established a platform for the screening for anthelmintic resistance or novel drug candidates against U. stenocephala and highlighted the potential use of seaweed extracts as a functional food component to help control hookworm infection in dogs.

Seasonal distribution of the early life stages of the small yellow croaker (Larimichthys polyactis) and its dynamic controls adjacent to the Changjiang River Estuary

AbstractThe distribution of the early life stages of Larimichthys polyactis indicates the availability of suitable spawning and nursing grounds and enables a better understanding of the distribution of its geographic subpopulations and isolation. Large‐scale quantitative ichthyoplankton surveys of L. polyactis were performed from March to July 2018, and a numerical hydrodynamic model was applied to explore the spatiotemporal distribution and habitats of L. polyactis early life stages adjacent to the Changjiang River Estuary. Two distinct early life stage distribution patterns were found. One occurred during March and April in the deep waters seaward of the Changjiang River bottom plume front, to the east and southeast of the Changjiang River Estuary. The other occurred in May and June throughout the entire water column in coastal waters to the east and north of the Changjiang River Estuary. Rising seasonal temperatures, and the local dynamic processes such as the Changjiang River plume, determined the transitions between the two distribution patterns. A potential fish larval migration route from the southern deep shelf waters to the northern coastal waters within the motor‐trawl prohibition line was suggested. This study contributes to our understanding of the mixture of habitats used by the two L. polyactis subpopulations in the southern Yellow Sea and the East China Sea.

Anisakis infection in anchovies (Engraulis encrasicolus) from Iberian waters, southwestern Europe: Post-mortem larval migration

The Anisakis larvae presence in fish for human consumption is a health risk that needs to be monitored. The anchovy is a fish that is highly appreciated by consumers and that can harbour Anisakis. It is thus necessary to periodically evaluate the presence of anisakid larvae in them. So, anchovies from Iberian Peninsula coasts were analysed. Fish examination for macroscopic nematodes showed L3s of both Anisakis type I and Hysterothylacium aduncum. The Anisakis prevalence varies with the catching area and the fish size. The muscle prevalence was 7.45% (mean intensity 1.75; range 1-5). Molecular analysis showed 110 A. simplex s.s. (17 in muscle), 22 A. pegreffii (3) and 7 hybrid genotype individuals (1). Considering that most of the Iberian Peninsula coasts are a sympatry area between these two Anisakis species, it has been observed that A. simplex s.s./A. pegreffii ratio increases from south to north in a clockwise direction. Also, 19 larvae were detected on the fish surface from the Bay of Biscay, indicating the ability of these larvae to migrate after the fish death. The A. simplex s.s./A. pegreffii larvae proportion found on the anchovy surface is similar to the found in viscera and lower than in muscle, suggesting that most of the larvae migrating to the surface must have come from the visceral package. This confirms the importance of removing fish viscera immediately after capture, for those fish species where this is possible. As both species cause anisakiasis/anisakidosis, these data show a real risk to human health, especially in dishes highly prized in Mediterranean countries prepared with raw or semi-raw anchovies.

Synergism of macrocyclic lactones against Haemonchus contortus.

A possible synergistic effect of macrocyclic lactones' (MLs) combination has been previously described against resistant gastrointestinal nematodes of cattle. In addition to synergism, drug-drug interactions between MLs can also result in additive or antagonistic effect, considering the different MLs pharmacokinetics, pharmacodynamics, and interactions with molecular mechanisms of resistance. Therefore, the aim of the current work was evaluated the effect of different MLs combinations against Haemonchus contortus. Infecting larvae of two isolates (one susceptible and one resistant to ivermectin) were used in the larval migration inhibition test. After estimating the half maximal effective concentration of abamectin (ABA), eprinomectin, (EPR), ivermectin (IVM), and moxidectin (MOX) for both isolates, combinations were delineated by a simplex-centroid mixture experiment, and the mixture regression analysis was applied to the special cubic model. A synergistic effect was found for the EPR + MOX against the susceptible isolate as well as the EPR + MOX, IVM + MOX, and ABA + EPR + IVM against the resistant isolate. An antagonistic effect of ABA + IVM + MOX was found against the susceptible isolate. For the susceptible isolate, a higher inhibition was found with greater proportions of EPR and lower proportions of the other drugs compared to the reference mixture. For the resistant isolate, inhibition greater than that of the reference mixture was found with higher proportions of IVM as well as lower proportions of the other drugs. The synergistic and antagonistic effects were dependent on the following: (a) parasite drug resistance profile, (b) the composition of the combination, and (c) the proportions used, with EPR and IVM exerting a greater impact on these effects.

In Vitro Evaluations and Comparison of the Efficacy of Two Commercial Products Containing Condensed Tannins and of Saifoin (Onobrychis viciifolia Scop.) Hay against Gastrointestinal Nematodes of Goats.

Gastrointestinal nematodes (GINs) is a limiting health factor for dairy goats, and the integration of the diet with fodder containing condensed tannins (CT) is becoming increasingly important to control GINs. To preliminary evaluate their potential role as part of GIN control in goat breeding, the in vitro anthelmintic efficacy of the CTs of Silvafeed BYPRO (SBP), Silvafeed Q powder (SQ), and sainfoin hay (SH) was evaluated, and the untargeted metabolomics profiling of the selected formulations was performed. CTs were extracted in water and in ethanol, their concentration was determined, and their chemical characterization was conducted using High-Performance Liquid Chromatography (HPLC) coupled to High-Resolution Mass Spectrometry (HRMS) platform. The in vitro anthelmintic activity of the extracts was evaluated using the Eggs Hatch Test (EHT) and the Larval Migration Inhibition Test (LMIT) using different extract concentrations (150, 300, 600, and 1200 μg/mL). The metabolomic profile of the ethanol extract showed a high number of flavonoids, while the water extract showed higher levels of hydrolysable tannins. The ethanol extracts were effective on both eggs hatching and larvae migration at low concentrations (150 μg/mL) for the three analyzed samples, while the water extracts showed more varied results: SH showed the greatest ovicidal efficacy (concentration 150 μg/mL, %IH = 40.9), while SBP and SQ were more effective against the larvae migration (concentration 600 μg/mL, %LMI = 69.7% and 88%), respectively. The integration of CT-rich fodder into the diet may be considered for the control of GIN infection in goats.

Copper chloride and copper sulphate in combination with nitroxynil against gastrointestinal nematodes of ruminants: A possible hitchhiking synergic effect at low concentrations

Infections caused by Haemonchus spp. and Trichostrongylus spp. are major health problems for sheep and cattle. The objective of this study was to determine the efficacy of copper chloride (CuCl2), and copper sulphate (CuSO4) at 2.0, 7.0, 30.0, 125.0, 500.0, and 2000.0 µM formulations, and nitroxynil 34% (NTX) at 0.235 mM against gastrointestinal nematodes (GINs) of ruminants. Hence, the in vitro egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT) were used. Haemonchus spp. (52%) and Trichostrongylus spp. (38%) were the most frequently found parasites. The data fitted a concentration-dependent shape with the highest efficacies of CuCl2 and CuSO4 at 95.2 and 97.3% for parasites collected from sheep, and 95.8 and 93.4% from cattle, respectively. The combination of the 50% inhibitory concentration (IC50) of CuCl2 and CuSO4 and the IC10 of NTX showed up to a 52% increase in efficacy above the expected additive results, demonstrating a synergic/drug enhancer interaction. NTX may retain Cu-II ions by complexation, in a hitchhiking mechanism carrying the salts across the parasite cell wall, causing oxidative stress as a consequence of free radical production and cell damage. Synergy data between NTX and CuCl2, and CuSO4 represent a viable opportunity to develop new formulations for combating parasites of ruminants (i.e., Fasciola hepatica, Haemonchus spp., and Oesophagostomum spp.).

Anthelmintic Agents from African Medicinal Plants: Review and Prospects.

Soil-transmitted helminthiasis affects more than 1.5 billion people globally and largely remains a sanitary problem in Africa. These infections place a huge economic burden on poor countries and affect livestock production, causing substantial economic losses and poor animal health. The emergence of anthelmintic resistance, especially in livestock, and the potential for its widespread in humans create a need for the development of alternative therapies. Medicinal plants play a significant role in the management of parasitic diseases in humans and livestock, especially in Africa. This report reviews anthelmintic studies that have been conducted on medicinal plants growing in Africa and published within the past two decades. A search was made in various electronic databases, and only full articles in English were included in the review. Reports show that aqueous and hydroalcoholic extracts and polar fractions obtained from these crude extracts form the predominant (80%) form of the extracts studied. Medicinal plants, extracts, and compounds with different chemical groups have been studied for their anthelmintic potential. Polyphenols and terpenoids are the most reported groups. More than 64% of the studies employed in vitro assays against parasitic and nonparasitic nematode models. Egg hatch inhibition, larval migration inhibition, and paralysis are the common parameters assessed in vitro. About 72% of in vivo models involved small ruminants, 15% rodents, and 5% chicken. Egg and worm burden are the main factors assessed in vivo. There were no reports on interventions in humans cited within the period under consideration. Also, few reports have investigated the potential of combining plant extracts with common anthelmintic drugs. This review reveals the huge potential of African medicinal plants as sources of anthelmintic agents and the dire need for in-depth clinical studies of extracts, fractions, and compounds from African plants as anthelmintic agents in livestock, companion animals, and humans.

Vicarious excretion of contrast medium to small intestine in a dog with Toxocara canis infection

A male mixed-breed dog of unknown age was presented with a history of bloody diarrhea and cachexia. Toxocara canis in vomitus was identified by a parasitologist. Hematology revealed low hematocrit, eosinophilia, and low albumin. Computed tomography (CT) revealed an enlarged pulmonary artery with an irregular wall, micronodules in the lung, and vicarious excretion of contrast medium to small intestine. CT scan was helpful for identifying lung lesions and the central organs of larval migration and also show vicarious excretion of contrast medium to the small intestine in T. canis infection.

An Epidemiological Investigation and Drug-Resistant Strain Isolation of Nematodirus oiratianus in Sheep in Inner Mongolia, China.

Nematodirus causes major economic losses in the development of the livestock industry, as they are common gastrointestinal parasites of cattle, sheep, and other ruminants. The present study investigated Nematodirus infections in sheep in the Hulunbuir and Xilingol Grasslands, two well-known natural pastures in Inner Mongolia, China. The results indicated that the average infection rate was more than 50%. Furthermore, a naturally occurring strain of Nematodirus was obtained using numerous isolation methods in the survey region. Conventional morphology and molecular biology were used to identify the strain. The larval migration inhibition test was used to determine the ivermectin level in the isolated strain. The results indicated that the larvae belonged to the species Nematodirus oiratianus. The strain was found to be ivermectin-resistant. Thus, these results recorded the detailed development processes of Nematodirus eggs, providing novel insights regarding the prevention and control of nematodes by using conventional anthelmintic regimens and by offering valuable species resources for studying anthelmintic resistance in nematodes.

Cassia sieberiana root bark used in traditional medicine in Togo: Anthelmintic property against Haemonchus contortus and tannins composition

• UPLC-MS/MS tannins profiling of ethyl acetate extract of C. sieberiana root bark. • 23 flavan-3-ol metabolites newly described in C. sieberiana . • 3 flavan-3-ols reported for the first time in the literature. • Anthelmintic properties of C. sieberiana extracts in Larval Migration Inhibition test. • Validation of C. sieberiana as anthelmintic drug to slow down the infection dynamic. Helminth infections of livestock result in economic losses around the globe. The majority of the people in West Africa treats such infections with medicinal plants related to the local traditional medicine. In a previous ethnomedicinal survey carried out in the north of Togo, traditional healers frequently cited Cassia sieberiana DC to treat helminth infections. The aim of the present study was to validate the traditional application of C. sieberiana root bark as a dewormer and to analyse the metabolite composition in preparations with this activity. Two tannin-rich fractions (FrE14 and FrE15) obtained from ethyl acetate extract were submitted to UPLC-MS analysis. The anthelmintic activity of C. sieberiana extracts and tannins-rich fractions was investigated on the small ruminant parasite Haemonchus contortus using Larval Migration Inhibition tests. The ethyl acetate, butanol and aqueous extracts significantly disrupted larval migration of Haemonchus contortus L3 with inhibition of 30.3%, 22.2% and 26.5% respectively at 2.5 mg/mL, as compared to negative control. The two tannin-rich fractions, FrE14 and FrE15 presented larval migration inhibition of 6.5% and 20.7% respectively at the same concentration. From these two fractions, 28 flavan-3-ols were identified including 3 monomers (catechin, epicatechin and epiafzelechin), 22 dimers (7 homodimers and 15 heterodimers) as well as 3 newly described trimers consisting of (epi)afzelechin, (ent)cassiaflavan or (epi)guibourtidinol subunits.

Evaluation of Strategies to Reduce Equine Strongyle Infective Larvae on Pasture and Study of Larval Migration and Overwintering in a Nordic Climate.

Horses, as grazing animals, are inadvertently exposed to intestinal parasites that, if not controlled, may cause disease. However, the indiscriminate use of anthelmintic drugs has led to drug resistance, highlighting the need for pasture-management practices to reduce the level of parasitic exposure and lessen reliance on drugs. The efficacy of such methods depends both on the epidemiology of the parasites and the prevailing weather conditions. The aim of the study was to investigate the effect of faecal removal and harrowing on reducing the number of parasite larvae in herbage. Moreover, the migratory and survival ability of strongyle larvae in a Nordic climate was studied. Faeces from horses naturally infected with strongyle nematodes were used to contaminate pastures and grass samples were collected to harvest larvae. Twice-weekly faecal removal significantly reduced larval yields, whereas harrowing on a single occasion under dry weather conditions in the summer did not. Strongyle larvae were able to migrate 150 cm from the faecal pats, but most larvae were found within 50 cm. Both Cyathostominae and S. vulgaris survived the winter months with larvae harvested up to 17-18 months after faecal placement. Resting of pastures for one year greatly reduced the parasite level, but two years of rest were required for parasite-free pasture.

Toxocariasis: potential association with bronchial asthma, and pneumonia among pediatric children.

Toxocariasis is an underestimated geohelminthic infection which shows respiratory changes concurrent with larval migration. The purpose of the present study was to detect Toxocara seropositivity in asthmatic and pneumonic children, and in turn to evaluate its association with the children clinical manifestations, laboratory test results, and sociodemographic risk factors. A total of 50 asthmatic, 50 pneumonic children and 50 healthy controls were subjected to stool analysis by direct wet mount and concentration techniques to exclude possible cross reactivity. Blood samples were collected for complete blood count and assessment of eosinophil count. Sera were examined for anti-Toxocara IgG antibodies, and measurement of total IgE level. Anti Toxocara IgG was detected in 27.3% (41/150) of the studied children. It was significantly higher in asthmatic group compared to controls (26%. p value = 0.033) and significantly highest in pneumonia group compared to both bronchial asthma group (46%. p value = 0.030) and control group (10%. p value = 0.001). There was a significant association between anti Toxocara IgG seroprevalence and each of eosinophilia, total IgE and both combined. Anti Toxocara IgG showed significant higher percentage in asthmatic children who recorded history of soil contact and pets contact as compared to control and pneumonic groups. Toxocara IgG seropositivity was highly associated with fever, cough, wheezes and dyspnea with statistical significance. Toxocara seropositivity has to be considered as a vital associated factor for asthmatic and pneumonic children, and eventually better to be considered in differential diagnosis by pediatricians. Further studies are still needed to explore the correlation between toxocariasis and different patient categories.

Adult parasite burden and excretion of first-stage larvae of Angiostrongylus vasorum in dogs: Methodologically relevant diagnostic aspects and associations with serological detection of parasite antigen and specific antibodies

Angiostrongylus vasorum is a widely distributed cardiopulmonary parasite of canids in Europe. Clinical signs in dogs can be highly variable and diagnostically challenging. A correct and early diagnosis is hence indispensable to adequately manage affected patients. First-stage larvae (L1) are excreted in the faeces of definitive hosts and conventionally identified using the Baermann technique. Moreover, ELISAs for the detection of circulating antigen and specific antibodies have been presented. The current study aimed at i) quantitatively assessing larval migration in the Baermann funnel after 12 h and 24 h; ii) investigating the influence of sample storage at 4 °C over the course of three days on the number of detected L1; iii) evaluating potential associations of adult worm burdens with larval shedding in dogs and ELISA optical density (OD) values for circulating parasite antigen and specific antibodies. Faecal samples were obtained from naturally infected dogs (n = 21) and Baermann funnels were set up in duplicate over the course of four consecutive days (days 0–3) starting with the day of sample collection. Funnels were harvested on days 1–4 after 12 and 24 h, respectively, and the number of L1 per gram faeces (LPG) was determined. The LPG did not differ between larval harvest after 12 h from harvest after 24 h. Storage of faecal samples at 4 °C for two and three days entailed a considerable decrease in LPG. Adult worm burdens and larval excretion data from previous experiments demonstrated a correlation between worm burden and LPG. In contrast, no correlations between worm burden and the level of parasite antigen and specific antibody OD values, respectively, were identified. Thus, OD values of both antigen and antibody ELISA did not allow for conclusions on infection intensity reflected by the number of adult parasites. For the detection of L1 in faeces, 12 or 24 h of larval migration time was not discriminating for A. vasorum positivity. Thus, early processing of faecal samples is essential, since larval detection and hence sensitivity of the approach considerably decreased over the course of three days of storage. Therefore, the common recommendation to collect faecal samples for three consecutive days and to subsequently analyse them needs to be reconsidered. The results of this study can be readily translated into precise recommendations for daily practice to adequately assess A. vasorum infected dogs.