Larval Migration Research Articles

Toxocara cati larval migration to mouse fetuses through transplacental infection

To examine the Toxocara cati larval migration in mouse fetuses through vertical transmission, 7 pregnant mice were orally inoculated with 5000 embryonated eggs at day 4 and again with the same dose at day 9 of gestation (total 10,000 eggs / mouse). Seven non-pregnant mice of the same age were also inoculated likewise. All mice were necropsied 12 days after the first inoculation with eggs. The carcass, viscera, uterus, placenta and fetuses were individually removed and digested with pepsin for larval counts. Larvae were recovered from all pregnant and non-pregnant mice. The majority of the larvae were recovered from the carcass, and some from the viscera, uterus, placenta and fetuses. There were no differences between the pregnant and non-pregnant mice for the number of larvae in the carcass, viscera and uterus. Of a total of 103 fetuses from the 7 pregnant mice, larvae were recovered from 74 fetuses (71.8 %). The mean number of larvae recovered per infected fetus was 2.6 (n = 103), and the maximum number of larvae recovered in a fetus was 9. This study showed that most mouse fetuses were infected with T. cati larvae through intrauterine transmission, although the number of larvae was low. Since no significant difference in the number of larvae recovered from the pregnant and non-pregnant mice was observed, it is suggested that pregnancy does not directly affect the vertical transmission of T. cati larvae.

In vitro anthelmintic activity of an aqueous extract of Glycyrrhiza glabra and of glycyrrhetinic acid against gastrointestinal nematodes of small ruminants.

This study evaluated the in vitro anthelmintic activity of a liquorice (Glycyrrhiza glabra) root aqueous extract and of glycyrrhetinic acid at 30, 10, 5, 1, and 0.5mg/mL against sheep gastrointestinal nematodes (GINs), using the egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT). The compounds were applied on a mixture of GIN eggs and larvae, mainly Trichostrongylus spp. and Teladorsagia/Ostertagia spp. Cytotoxicity assays were also performed. In the EHT, both candidates showed significant concentration-dependent efficacy and were significantly more effective (p<0.001) at the highest concentrations (30 and 10mg/mL) than the lowest ones. In the LDT, only G. glabra showed a concentration-dependent effect (R2=0.924), but glycyrrhetinic acid (R2=0.910) had significantly higher efficacy than G. glabra root extract. Moreover, the efficacy of glycyrrhetinic acid at 30, 10, and 5mg/mL was significantly higher (p<0.001) than at lower concentrations. In the LMIT, G. glabra showed concentration-dependent efficacy (R2=0.971), while considerably reduced efficacy was observed for glycyrrhetinic acid (R2=0.855) at the lowest concentrations. These data suggest that the two compounds may have different mechanisms of action. In the LMIT, the 50% lethal concentration (LC50) of glycyrrhetinic acid (~5.12mg/mL) was > 2.0-fold lower when compared to G. glabra (12.25mg/mL). Analysis and previous findings indicated low toxicity for both compounds. The results obtained encourage in vivo studies aimed at evaluating the potential use of the tested compounds as natural de-wormers in ruminants.

Toxocara cati larval migration in rats: experimental histopathological study.

Toxocara spp. (T. canis and T. cati in particular) are the major etiological nematodes that have contributed to visceral larval migrans (VLM). So to show the ability of T. cati to produce such migration in the rats as experimental model and detection through histopathological observations to detect larval migratory patterns. Adult females T. cati were collected from naturally infected feral cats. Eight rats, Rattus norvegicus had acted as a model for experimental infection, each receiving an infectious dose of about 1000 infective T. cati eggs, while 2 rats served as non-infected control group. Two infected rats were sacrificed and examined at 7, 14, 21, and 28 day post infection (dpi) and tissue samples were taken for digestioning order to recover migrated larvae and for histopathological examination. In vitro embryonation of T. cati eggs was successfully carried out, although the percentage of embryonation was 10%, prepared inoculums were also infective to rats. Larvae recovered from the lungs at 7 and 14 dpi and were also present at 21, and 28 dpi. The larvae of T. cati were present in the intestines at 14, and 21 dpi. There were no larvae or less than one larva per gram found in other studied tissues. Histopathological changes in different organs were observed. Generally speaking, a multi-tissue response can be defined as the histopathological response of T. cati larval migration. The migratory larvae of T. cati can cause severe histopathological alterations in various tissues and organs of infected animals, within the current study shows that the lungs are a favorable site of migration for these larvae. T. cati is a zoonotic parasite that is underestimated.

Intra-vitamlarval migration of Anisakis pegreffii in live spotty-bellied greenling, Hexagrammos otakii, at different water temperatures

The present study investigated the intra-vitam larval migration of Anisakis pegreffii, which is naturally infected, from the intestine to the viscera and the musculature of live spotty-bellied greenling, Hexagrammos otakii, under the different seawater temperatures. The results showed that the increase in the ratio of larval migration from the intestine to the viscera correlated with the increase in the water temperature in the aquarium. The intra-vitam larval migration ratios from the intestine to the viscera were 60% (63/105) at 15°C, 1.64% (3/183) at 12°C, 1.16% (2/172) at 9°C and 1.42% (2/141) in the control group (7.5°C). The free larvae showed no, slight and strong movement at 9°C, 12°C and 15°C, respectively, in saline water, and the larvae were present in a coiled state at 9°C and 12°C. The results suggest that temperature plays an important role in the intra-vitam larval migration of A. pegreffii. In addition, the free larval behavior of A. pegreffii in vitro increased with increase in temperature. Therefore, to prevent human anisakiasis caused by the consumption of raw fish, it is important that the temperature of the aquarium must be maintained below 12°C, which is the critical temperature zone.

Three-dimensional characterization of first instar horse and rhinoceros stomach bot fly larvae (Oestridae: Gasterophilinae:Gasterophilus,Gyrostigma): novel morphology and evolutionary implications

AbstractLarval characters are of importance in systematic and evolutionary studies of Diptera but lag behind characters of adults due to difficulties in obtaining relevant information. Larvae of stomach bot flies are obligate parasites completing development exclusively in the alimentary tract of equids and rhinoceroses. They possess diversified morphological adaptations, providing remarkable examples to further our understanding of larval evolution. Herein, three-dimensional structures of first instar Gasterophilus pecorum and Gyrostigma rhinocerontis are compared using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). We suggest CLSM has a large potential for exploiting cryptic character systems of micro fly larvae, as spectral range and intensity of autofluorescence emitted by sclerotized structures and soft tissues are distinct, presenting a high-contrast mechanism for multistructural visualization with non-destructive sample preparation. Five new potential synapomorphies are proposed to corroborate the sister-group Gasterophilus and Gyrostigma. The upward curving mouth-hooks of first instar Gasterophilus and Gyrostigma are distinctive in Cyclorrhapha and possibly serve to facilitate the larval subcutaneous migration within the host. Three types of mouthhooks are recognized in first instar Oestridae, with the gently curved and gradually tapered type optimized as the ancestral state, from which the gasterophiline and hypodermatine types evolved independently.

Experimental Infection with Baylisascaris Potosis in Chickens.

SummaryThe larvae of the genus Baylisascaris can cause larva migrans in mammals and birds. This study investigated the larval migration of Baylisascaris potosis, the roundworm of kinkajou (Potos flavus), in chickens and the associated clinical manifestations of the host. Thirty-six 3-week-old chickens divided into 6 groups were orally inoculated with 3,000 B. potosis eggs/chick. Each group of chicken was necropsied at days 1, 2, 3, 7, 30 and 90 PI (post inoculation), and the number of larvae in various organs were counted until day 90 PI. No clinical signs were observed in chickens during the study. Larvae were detected from the liver, lungs or breast-muscles of 13/36 (36.1%) chickens. The mean total number of larvae in the liver, lungs and breast-muscles at days 1, 2, 3, 7, 30 and 90 PI were 0.34, 0.17, 1.66, 1.01, 0.17 and 0, respectively. No larvae were found in the brain, eyes, hid-limb muscles, heart, kidneys and spleen. Although infectivity of larvae in egg-inoculated chickens was low, the present study demonstrated that B. potosis larvae can migrate in chickens tissues up to day 30 PI. The result suggests that chickens can serve as a paratenic host for B. potosis and may underline a public health importance of B. potosis infection as a potential foodborne disease in humans.

Mentha villosa Hubs., M. x piperita and their bioactives against gastrointestinal nematodes of ruminants and the potential as drug enhancers

Parasitic diseases caused by gastrointestinal nematodes (GIN) are responsible for a major impact on ruminant welfare. Although the available anthelmintics have a safe margin of toxicity to the animals, their indiscriminate use has increased the selection of resistant parasite populations. In this scenario, essential oils (EO) stand out as a promising ecofriendly therapeutic alternative against GIN. The objective of this work was to determine the effect of the EO of Mentha villosa Hubs (MVEO) collected in 2017 and 2018, M. x piperita (MPEO) and their main components, carvone and limonene, against the third stage larvae (L3) of Haemonchus spp. and Trichostrongylus spp. The solutions, including in nanoemulsion preparations, were tested in a range of concentrations using the larval migration inhibition test (LMIT). The EO and carvone were also tested in combination with nitroxynil (NTX) to determine their effect as drug enhancers (additive or synergy). MVEO/2017, MVEO/2018, MPEO and carvone showed 70.6 (73.4 mg/mL), 86.3 (74.9 mL/mL), 95.5 (143.6 mg/mL), and 88.2 % (38.3 mg/mL) efficacy against L3, respectively. Carvone alone had approximately a 3-fold higher efficacy when compared to its concentration in each EO: 68.8 % in MVEO/2017 and 83.9 % in MVEO/2018. Limonene did not show any significant effect on inhibiting L3 migration. The combination of MPEO and NTX, and carvone and NTX showed a statistically significantly (P < 0.05) synergic and additive effect, respectively, when compared to the isolated treatment. The nanoemulsion of MVEO/2017 at 0.367 mg/mL, inhibited L3 migration by 83.1 %, demonstrating to be highly effective (concentration ratio of 1:0.004), when compared to the MVEO/2017 (70.6 % at 73.4 mg/mL) extraction. The in vitro data from the combination of MPEO or carvone plus NTX suggest that these products can be considered for in vivo experiments against the most important GIN of ruminants as drug enhancers, possibly reducing the final concentration of NTX`. The efficacy of carvone was higher (EC50 = 1.96 mg/mL) than its expected efficacy, based on its concentrations on both EO. Therefore, this component does not need the entire EO composition to exert its L3 motility action. The remarkable efficacy demonstrated by the MVEO/2017/nanoemulsion (EC50 = 0.10 mg/mL), supports its potential to be a candidate to the next-generation therapy to alleviate clinical parasite infections and combat GIN resistant populations.

Age at stocking is a decisive factor on growth and survival of the Indian shad, Tenualosa ilisha during nursery rearing in fertilized earthen ponds

Hilsa, Tenulosa ilisha is an important commercial fish of the Indo-Pacific region. The larvae of hilsa can survive for quite long without exogenous feed due to the presence of large yolk sac and oil globule. Therefore it is important to understand the suitable age of hilsa larvae to be used for nursery rearing. In this study, larvae were produced through artificial breeding of mature migratory fish collected from wild. Three different age groups of hilsa larvae, such as three days post hatched (3 DPH, just before yolk sac exhaustion, swim mostly vertically, TL: 4.21 ± 0.02 mm), 5 DPH (with oil globule, swim vertical and horizontal, TL: 5.26 ± 0.12 mm) and 12 DPH (just before oil globule exhaustion, swims very fast, TL: 6.00 ± 0.11 mm) were randomly distributed in nine well prepared rectangular earthen ponds (100 m2) in triplicate (n = 3) at the stocking density of 500 number m−3. The nursery rearing was carried out for 90 days. Results showed no significant difference in water quality parameters in different experimental ponds (p > 0.05). Dissolved oxygen, temperature, pH, total ammonia nitrogen, chlorophyll-a, gross primary productivity, total plankton count ranged from 7.24–7.46 mg L−1, 29.00–30.38 °C, 8.16–8.43, 110–124 μg L−1, 17.33–22.66 μg L−1, 193–203 mg C m−3 h−1, 2.2 × 104–2.4 × 104 numbers mL−1, respectively. After 60 days of the nursery, to imitate the larval migration towards low saline water, salinity was increased at the rate of 0.5 g L−1 on alternate days to 7.4 g L−1. There was no significant difference (P > 0.05) in daily weight gain and final total length and weight of fish in different experimental groups, however specific growth rate varied significantly (p < 0.05). At the end, hilsa larvae attained a total length of 43.3 ± 0.074 mm, 41.4 ± 0.04 mm, 39.2 ± 0.051 mm, in 3, 5 and 12 DPH groups, respectively. Percentage survival was significantly (p < 0.05) highest (3.40 ± 0.81%) in 5 DPH treatment. Water and gut plankton analysis showed that hilsa larvae are not a selective feeder, but feeds on available food items in the ecosystem through filtration. Length-weight relationship indicated the negative allometric growth (b < 3) pattern in all three groups. Overall, this experiment suggested that 5 DPH is an ideal age for shifting hilsa larvae from larval rearing tank to nursery pond.

Host Immunity and Inflammation to Pulmonary Helminth Infections.

Helminths, including nematodes, cestodes and trematodes, are complex parasitic organisms that infect at least one billion people globally living in extreme poverty. Helminthic infections are associated with severe morbidity particularly in young children who often harbor the highest burden of disease. While each helminth species completes a distinct life cycle within the host, several helminths incite significant lung disease. This impact on the lungs occurs either directly from larval migration and host immune activation or indirectly from a systemic inflammatory immune response. The impact of helminths on the pulmonary immune response involves a sophisticated orchestration and activation of the host innate and adaptive immune cells. The consequences of activating pulmonary host immune responses are variable with several helminthic infections leading to severe, pulmonary compromise while others providing immune tolerance and protection against the development of pulmonary diseases. Further delineation of the convoluted interface between helminth infection and the pulmonary host immune responses is critical to the development of novel therapeutics that are critically needed to prevent the significant global morbidity caused by these parasites.

Isolation of pure Trichostrongylus colubriformis strains from naturally infected sheep using two methodologies.

Two methodologies were tested to isolate pure Trichostrongylus colubriformis strains from naturally infected sheep. Also, the in vitro susceptibility status to commercial anthelmintic (AH) drugs was determined in these strains. These methods were performed in a tropical region of Mexico where naturally infected sheep and goats host Haemonchus contortus, T. colubriformis and Oesophagostomum columbianum. For the first strain, a group of 6 naturally infected lambs from the "Paraiso" farm were treated with closantel (subcutaneous (SC), 10mg/kg). On day 10 post-treatment, the eggs per gram (EPG) of faeces were determined with the McMaster technique. The faeces from the two lambs with the highest EPG were used for coprocultures (4days, 28°C). The L3 larvae were recovered and identified as T. colubriformis (69%) and O. columbianum (31%). The latter was removed by 10-day refrigeration (4-5°C) followed by sieving (25μm), resulting in 100% T. colubriformis (PARAISO strain). The second strain was isolated using repeated doses of levamisole (LEV, SC 7.5mg/kg) in an 8-year-old sheep. The sheep had 1700 EPG before the LEV treatments and maintained 1300 EPG after both LEV treatments (day 10). The coproculture (4days, 28°C) after the second treatment contained 100% T. colubriformis (FMVZ-UADY strain). The in vitro AH susceptibility was determined using the egg hatch test for benzimidazole (BZ), and the larval migration inhibition test for ivermectin (IVM) and LEV. The PARAISO strain was BZ- and LEV-susceptible, and IVM-resistant. Meanwhile, the FMVZ-UADY strain was BZ- and IVM-susceptible, and LEV-resistant. The conditions where these two protocols could be used in other parts of the world were discussed.

Distribution of Toxocara cati larvae in experimentally infected BALB/c mice

The experimental infection of mice with Toxocara cati provides one of the best models for pathological and immunological study of the visceral larva migrans syndrome. To broaden our knowledge of T. cati larval migration, BALB/c mice were inoculated with 500 embryonated eggs of T. cati for a period of two months.In the present study, T. cati eggs, obtained from faeces of naturally infected cats, were used for infection. After oral infection of 500 embryonated eggs of T. cati, mice were euthanised at 1, 2, 3, 7, 14, 21, 28, 35, and 70 days post-infection (dpi) in groups of three per day. Systemic cytokine patterns of Th2 cytokines were evaluated 1 and 2 months after the experimental challenge using sandwich ELISA.The mean number of larval recovery from all infected mice was 16.53 % during infection. The highest number of larvae was obtained from the liver at 1 and 2 dpi; from lungs at 2 dpi and from the brain at 28 dpi. In muscles, the highest recovery rates of T. cati were obtained at 28 dpi. Our data showed that experimental infection with T. cati induced Th2 responses during the infection. In addition, IL-4, IL-5, and IL-10 levels increased significantly in the sera of the infected mice compared to the control group.Larval persistence of T. cati in the muscle of BALB/c mice and its migration behaviour highlights the important role of mouse as a paratenic host in the parasite life cycle and the host-parasite relationships, especially in human toxocariasis.

Matrix metalloproteinases activation in Toxocara canis induced pulmonary pathogenesis.

Toxocara canis, a source of visceral larva migrans, causes toxocariasis and induces respiratory symptoms. The reasons by which the pulmonary pathological alteration in the lungs infected with T. canis remain unclear. The involvement of the pulmonary pathological alteration by histology, enzyme activity, and Western blot analysis in the lungs of BALB/c mice after the infection of 2000 embryonated eggs. The pathological effects gradually increased after the infection culminated in severe leukocyte infiltration and hemorrhage from days 4-14 post-inoculation. Gelatin zymography using substrate showed that the relative activity of matrix metalloproteinase (MMP) -9 and MMP-2 significantly increased in T. canis-infected mice. Western blot analysis indicated that the MMPs protein level of fibronectin monomer significantly increased in T. canis-infected mice compared with that in uninfected control. T. canis larvae mainly initiated leukocyte infiltration and hemorrhage in the lungs. These phenomena subsequently induced the activities of MMPs in parallel with the pathological changes in early stage pulmonary inflammation. In conclusion, T. canis larval migration activated the MMPs and caused pulmonary pathogenesis.

Ação in vitro do extrato do botão floral da bananeira (Musa spp.) sobre nematódeos gastrintestinais de ovinos

Uma alternativa para o controle de verminose na ovinocultura é a utilização de plantas bioativas. Diversos estudos têm relacionado plantas taniníferas com propriedades anti-helmínticas, com destaque para a bananeira (Musa spp.). Assim, o objetivo do trabalho foi qualificar e quantificar o potencial anti-helmíntico do extrato hidroalcoólico do botão floral da bananeira a 10% (EHB), nas concentrações de 20, 40, 80, 160 e 320mg mL-1, sobre ovos e larvas de nematódeos gastrintestinais de ovinos. O presente estudo laboratorial, de natureza quantitativa, justifica-se principalmente pelo fato de que estudos in vitro, são exigidos preliminarmente aos ensaios pré-clínicos e clínicos. Dessa forma, foram utilizadas fezes de ovinos naturalmente infectados, selecionados pela contagem mínima de 2.000 ovos por grama de fezes e em quadruplicada, foram avaliados também, os tratamentos controle negativo e positivo. Além disso, foram determinados os teores de polifenóis totais, taninos condensados, flavonoides, e atividade antioxidante. Utilizando os testes de inibição da eclodibilidade de ovos (TEO) e da migração larval (TIML), foi possível verificar 100% de inibição, para ambos os testes, na concentração de 320mg mL-1. O EHB (10mg mL-1) apresentou 0,38mg EAG g-1 de polifenóis totais, 372,70mg EAT g-1 de taninos, 0,42mg RE g-1 de flavonoides, e atividade antioxidante de 43,03% com IC50 correspondendo à 0,2765mg mL-1. Dessa forma, foi possível verificar atividade anti-helmíntica e antioxidante do EHB, demonstrando importante potencial no controle de verminose em ovinos.

Oceanic Environmental Effects on American Eel Recruitment to the East River, Chester, Nova Scotia

AbstractThe effect of oceanic environmental conditions on the recruitment of American Eel Anguilla rostrata to coastal waters is poorly understood. This study examined correlations between the annual elver count index of the East River, Chester, Nova Scotia, seasonal oceanic environmental conditions associated with the larval and glass eel stages, and larval and glass eel migration times between the spawning area and continental recruitment. In recent years, the elver fishery of the East River has started earlier in conjunction with increasing inshore, continental shelf, and Gulf Stream water temperatures, with the strength of the correlation decreasing with distance from shore. A northward shift of the Gulf Stream may also have contributed to earlier arrival dates. Annual elver index values increased over the study period but were not significantly correlated with any atmospheric or oceanic environmental conditions, perhaps due to a relatively short time series, although effect sizes (correlation coefficient r) were often medium, a level potentially considered of biological importance. Elver mean lengths varied annually with no trend and were not significantly correlated with the elver index. Significant correlations occurred between the North Atlantic Oscillation and Sargasso Sea primary productivity (lag of 0) and Emerald Basin (Scotian Shelf) water temperatures (lag of –5), while Scotian Shelf chlorophyll values decreased with increasing water temperatures (lag of –3). The mean migration period from spawning to stream entrance at the East River was estimated at 1.2 years, mostly spent growing in and ultimately leaving the Sargasso Sea, then crossing oceanic and continental shelf waters between the Gulf Stream and coastal streams, with a short period of transport along the Gulf Stream. The estimate of total migration period based on observed recruitment times at various sites and the mean of the estimated spawning period averaged 45.5% greater than those estimated from otolith methods, perhaps due to the effect on otolith daily ring deposition during glass eel migration in oceanic water temperatures &lt;10ºC between the Gulf Stream and coast.

Plant-Induced Transgenerational Plasticity Affecting Performance but Not Preference in a Polyphagous Moth

Environmental variation experienced by a single genotype can induce phenotypic plasticity in various traits, such as behavioural, physiological and developmental characteristics. It can occur within the lifetime of an individual through within-generation phenotypic plasticity (WGP) or vertically across generations through transgenerational phenotypic plasticity (TGP). However, knowledge about TGP and the co-occurrence of WGP and TGP is still limited. In insect host-plant selection, the ability to alter phenotypic traits through WGP is well documented while the importance of TGP and the possible co-occurrence between the two is largely unknown. Host-plant selection of both larvae and adults of the polyphagous moth Spodoptera littoralis can be modified by previous experience through WGP. Thus, the aim of this study was to investigate if parental host-plant experience can influence host-plant choice behaviour and performance of S. littoralis offspring through TGP. For this, we tested effects of rearing parents on different host plants on the offspring’s first instar larval migration and host plant choice, larval development and adult oviposition. A transgenerational effect on larval development was found, with increased pupal weight on a matching host-plant diet to that of the parent, when larvae were reared on cotton (good larval host plant) while no such effect was found on maize (poor larval host plant). These findings indicate that TGP of S. littoralis progeny development traits may only occur under favourable conditions. Parental diet did not affect larval host plant choice or migration. Furthermore, no effect of parental diet was found on offspring oviposition behaviour, indicating that adult female host-plant selection is governed by innate preference hierarchy and WGP, rather than TGP. Thus, parental diet may influence offspring performance but not behaviour, indicating that WGP is most important for host-plant selection behaviours in S. littoralis, but TGP can affect progeny development. If so, the importance of different types of plasticity may vary among traits of S. littoralis associated with host plant utilisation.

Synthesis, bioevaluation and docking studies of some 2-phenyl-1H-benzimidazole derivatives as anthelminthic agents against the nematode Teladorsagia circumcincta

Gastrointestinal nematode infections are the main diseases in herds of small ruminants. Resistance to the main established drugs has become a worldwide problem. The purpose of this study is to obtain and evaluate the invitro ovicidal and larvicidal activity of some 2-phenylbenzimidazole derivatives on susceptible and resistant strains of Teladorsagia circumcincta. Compounds were prepared by known procedures from substituted o-phenylenediamines and arylaldehydes or intermediate sodium 1-hydroxyphenylmethanesulfonate derivatives. Egg Hatch Test (EHT), Larval Mortality Test (LMT) and Larval Migration Inhibition Test (LMIT) were used in the initial screening of compounds at 50μM concentration, and EC50 values were determined for the most potent compounds. Cytotoxicity evaluation of compounds was conducted on human Caco-2 and HepG2 cell lines to calculate their Selectivity Indexes (SI). At 50μM concentration, nine out of twenty-four compounds displayed more than 98% ovicidal activity on a susceptible strain, and four of them showed more than 86% on one resistant strain. The most potent ovicidal benzimidazole (BZ) 3 showed EC50=6.30μM, for the susceptible strain, while BZ 2 showed the lowest EC50 value of 14.5μM for the resistant strain. Docking studies of most potent compounds in a modelled Teladorsagia tubulin indicated an inverted orientation for BZ 1 in the colchicine binding site, probably due to its fair interaction with glutamic acid at codon 198, which could justify its inactivity against the resistant strain of T.circumcincta.

Perda econômica das principais causas de condenações totais de carcaças suínas em abatedouros frigoríficos supervisionados pelo SIF em Santa Catarina de 2010 a 2018

Objetivou-se nesse estudo analisar e determinar a perda econômica das principais causas de condenações totais de carcaças de suínos em abatedouros frigoríficos que são fiscalizados pelo Serviço de Inspeção Federal no estado de Santa Catarina para o período de 2010 a 2018. A perda econômica foi calculada a partir da multiplicação da quantidade de carcaças condenadas totalmente pelo rendimento médio de carne por carcaça e o preço médio anual do quilo de carne suína e os valores monetários foram atualizados para o ano de 2018 por meio do IGP-DI. Os resultados encontrados indicaram uma perda econômica de R$1,65 bilhão para o total de condenações totais de carcaças suínas e as principais causas foram a contaminação (R$ 481,67 milhões), nefrite (R$508,42 milhões), cisto urinário (R$229,05 milhões), pericardite (R$111,65 milhões) e migração larval (R$217,16 milhões). Os principais fatores associados para a ocorrência das condenações totais de carcaças suínas estão as falhas operacionais ocorridas durante a etapa de evisceração e a ocorrência de doenças parasitárias ou infectocontagiosas nos animais. Sendo assim, recomenda-se a adoção de boas práticas de produção e o treinamento de funcionários nos abatedouros frigoríficos para minimizar esse tipo de perda na produção de carne suína em Santa Catarina.

Benefits of heterospecific aggregation on necromass: influence of temperature, group density, and composition on fitness-related traits.

Necrophagous blowflies (Diptera: Calliphoridae) such as Calliphora vicina, a cold-tolerant species, and Lucilia sericata, a warm-adapted species, are pioneer carrion-breeder. Although these two species have different temperature preferences, larvae aggregate actively and often feed simultaneously on carrion. The hypothesis to be tested was that L. sericata benefits from the association with C. vicina at lower temperatures (i.e., 15 °C) and that C. vicina derives greater benefits from this association at higher temperatures (i.e., 28 °C). Therefore, both species were raised at these two constant temperatures from first instars to adults under three different conditions: monospecific low-density, monospecific high-density, and heterospecific high-density. The time until larval migration, surface area of puparia, and survival rates were determined for each condition. Differences between these fitness-related traits were found between species, temperatures, group densities, and species compositions. At 28 °C, C. vicina larvae bred in heterospecific groups migrated significantly earlier and in higher numbers than that under same density conspecific conditions, with a lower mortality rate. At 15 °C, both species benefited from high-density heterospecific associations, expressed by faster development and larger puparia. In conclusion, necrophagous larvae benefited from heterospecific aggregations at suboptimal temperatures by adapting their migration time to that of the faster species. Since temperature changes throughout the day and over the year, the beneficiary of such a collective association also changes. The costs involved and deviations to the temperature-size rule highlight the complexity of the carrion ecosystem.

Artemisia cina 30 CH homeopathic treatment against Haemonchus contortus

The anthelmintic resistance problem is widely recognized in sheep production. Therefore, new methods of control against gastrointestinal nematodes (GIN) need to be integrated. The aim of this work was to assess the toxicity of A. cina 30 CH as a homeopathic product against Haemonchus contortus in in vitro and in vivo assays. A. cina 30 CH was obtained from a commercial laboratory, and confirmation of artemisinin as a key ingredient was performed with mass spectrophotometry. The A. cina 30 CH and the artemisinin pure reagent were used for the inhibition of egg hatching (IEH) and for the inhibition of larval migration of H. contortus L3 (ILM). In addition, three groups of 10 naturally infected lambs with GIN were treated with A. cina 30 CH and albendazole, and 10 were used as control. The parasitic infection was monitored at 0, 7, 14 and 28 d postreatment (PT) to determine the number of eggs per gram (epg) and FAMACHA index. The in vitro data showed 100 % IEH and 64.7 % ILM by A. cina 30 CH, and nonlethal activity was observed with the artemisinin pure reagent. The toxicity of A. cina 30 CH against H. contortus in infected lambs was observed after 7 d of infection. Administration of the A. cina 30 CH yielded a 69 % reduction in the epg at 28 d PT, similar to the albendazole (P&lt;0.05). In conclusion, A. cina 30 CH had the ability to IEH and ILM of H. contortus in in vitro assays and reduced the number of eggs of H. contortus, which is the primary parasitic nematode in grazing lambs, thereby reducing infection.

Spirocerca lupi (SPIRURIDA: SPIROCERCIDAE) INFECTION ASSOCIATED TO SECONDARY MEGAESOPHAGUS AND OBSTRUCTIVE PROCESS IN A SENILE DOG

Spirocerca lupi is a nematode parasite that can be found in the esophagus and aorta of carnivores, including humans. Affected animals may develop mild to severe lesions, depending on the degree of infection, route of larval migration and the inflammatory response. The present work describes the occurrence of S. lupi in a 16-year old male Chow Chow dog, presenting a chronic esophagus infection, associated with a critical obstruction. After the identification of the parasite egg by faecal exam, the patient was treated with milbemycin in combination with praziquantel P.O., in days zero, seven and 28 after the diagnose. An esophagogram was also performed, confirming the secondary megaesophagus. The team of clinicians decide to perform a euthanasia due to the complication of the patient's condition, even after the anthelmintic treatment. This report is important as it describes a case after 18 years of epidemiological silence in the Metropolitan region of Curitiba, PR, Brazil. The present data aims to raise awareness about the prevalence of this zoonotic disease and the importance of a specific clinical and radiographic diagnose in dogs. It is noteworthy to report the difficulty to reduce the size of the associated esophagus mass even after a potent anthelmintic treatment.