Immune gene expression in the spleen of chickens experimentally infected with Ascaridia galli.

Ascaridia galli is a gastrointestinal nematode infecting chickens. Chickens kept in alternative rearing systems or at free-range experience increased risk for infection with resulting high prevalences. A. galli infection causes reduced weight gain, decreased egg production and in severe cases increased mortality. More importantly, the parasitised chickens are more susceptible to secondary infections and their ability to develop vaccine-induced protective immunity against other diseases may be compromised. Detailed information about the immune response to the natural infection may be exploited to enable future vaccine development. In the present study, expression of immune genes in the chicken spleen during an experimental infection with A. galli was investigated using the Fluidigm(®) BioMark™ microfluidic qPCR platform which combines automatic high-throughput with attractive low sample and reagent consumption. Spleenic transcription of immunological genes was compared between infected chickens and non-infected controls at week 2, 6, and 9 p.i. corresponding to different stages of parasite development/maturation. At week 2 p.i. increased expression of IL-13 was observed in infected chickens. Increased expression of MBL, CRP, IFN-α, IL-1ß, IL-8, IL-12ß and IL-18 followed at week 6 p.i. and at both week 6 and 9 p.i. expression of DEFß1 was highly increased in infected chickens. In summary, apart from also earlier reported increased expression of the Th2 signature cytokine IL-13 we observed only few differentially expressed genes at week 2 p.i. which corresponds to the larvae histotrophic phase. In contrast, we observed increased expression of pro-inflammatory cytokines and acute phase proteins in infected chickens, by week 6 p.i. where the larvae re-enter the intestinal lumen. Increased expression of DEFß1 was observed in infected chickens at week 6 p.i. but also at week 9 p.i. which corresponds to a matured stage where adult worms are present in the intestinal lumen.

Immunopathogenesis of Ascaridia galli infection in layer chicken.

Gastro-intestinal nematode infections in mammals are associated with local T lymphocyte infiltrations, Th2 cytokine induction, and alterations in epithelial cell secretion and absorption. This study demonstrates that Ascaridia (A.) galli infection in chicken also elicits local gut-associated immune reactions and changes in the intestinal electrogenic nutrient transport. In A. galli-infected birds we observed infiltrations of different T cell populations in the intestinal lamina propria and accumulation of CD4+ lymphocytes in the epithelium. The Th2 cytokines IL-4 and IL-13 dominated the intestinal immune reactions following A. galli infection. A. galli-specific systemic IgY antibodies were detected after two weeks post infection, and did only poorly correlate with detected worm numbers. Electrogenic transport of alanin and glucose was impaired in A. galli-infected chicken. Our data provide circumstantial evidence that local immune responses and electro-physiological intestinal functions may be connected and contribute to the elimination of worm infection.

Efeito anti-helmíntico dos extratos aquosos e etanólicos da Annona squamosa L. (fruta-do-conde) sobre o nematóide Ascaridia galli / Anthelmintic effect of aqueous and ethanolic extracts from Annona squamosa L. (sweetsop) on the nematode Ascaridia galli

As plantas são fontes importantes de produtos naturais biologicamente ativos. Dentre as plantas usadas na medicina popular a Anonna squamosa conhecida como fruta-do-conde é citada como tendo várias ações medicinais, dentre elas a atividade inseticida e anti-helmíntica. Dentro desta perspectiva, objetivou-se determinar a atividade anti-helmíntica dos extratos aquosos (EA) e etanólicos (EE) das folhas da fruta-do-conde sobre o nematóide de aves Ascaridia galli, in vitro e in vivo. No primeiro, os nematóides foram colocados em placa de Petri contendo diferentes concentrações dos extratos e no segundo foram utilizadas seis galinhas poedeiras por grupo, as quais foram administrados10 mL Kg-1 dos extratos. No teste in vitro o EA da A. squamosa nas concentrações 2,4 e 9,6 mg mL-1 foi capaz de matar 63,33 por cento e 53,33 por cento dos nematóides, respectivamente. O EE não produziu efeito significativo. No teste in vivo, o percentual de eliminação do EA foi de 39 por cento e do EE de 20 por cento. Estes dados sugerem que neste caso a substância responsável pela mortalidade dos parasitos esteja em maior concentração na fração aquosa. Desta maneira, acredita-se que o EA de A. squamosa apresenta uma atividade anti-helmíntica potencial sobre o A. galli.

Plants are important sources of biologically active natural products. Among the plants used in popular medicine, Annona squamosa, known as sweetsop, is reported to have several medicinal actions such as insecticidal and anthelmintic activity. Therefore, this study aimed to assess the anthelmintic activity of aqueous (AE) and ethanolic (EE) extracts from sweetsop leaves on the chicken roundworm Ascaridia galli, both in vitro and in vivo. In the former, nematodes were placed on a Petri plate containing different concentrations of the extracts; in the in vivo test, six egg-laying chickens per group received 10 mL Kg-1 of the extracts. In vitro results indicated that A. squamosa AE at the concentrations 2.4 and 9.6 mg mL-1 could kill 63.33 percent and 53.33 percent nematodes, respectively. However, EE did not have any significant effect. According to the in vivo test, the elimination percentage for AE was 39 percent and for EE, 20 percent. These data suggest that the substance responsible for parasite mortality was present at a higher concentration in the aqueous fraction. Thus, A. squamosa AE is believed to have a potential anthelmintic activity on A. galli.

Infestación múltiple por nemátodos / Nematodes infestation

No disponible

Investigations on the influence of helminth parasites on vaccination of chickens against Newcastle disease virus under village conditions.

Prevalence studies have shown that almost 100% of free-range chickens are infected with a wide range of parasites. The infections are mostly subclinical in nature, resulting in production losses and occasionally mortality. Newcastle disease (ND) on the other hand, results in high mortality rates during epidemics. ND is a limiting factor for increasing poultry production in many tropical countries, where frequent reports indicate vaccination failures. The aim of our study was to investigate the influence of helminths on the antibody response after vaccination against Newcastle disease of free-range chickens naturally infected with parasites. Sixty chickens were divided into six groups, of which three were vaccinated against ND with a live De Soto vaccine, while the other three remained non-vaccinated. One group within the vaccinated groups and the one within the non-vaccinated group was kept naturally infected with helminth parasites, while the other two groups in each set were dewormed with fenbendazole and niclosamide, and one of each of these groups was subsequently infected with Ascaridia galli. After vaccination, all the groups were followed for 5 weeks and their antibody titres were determined weekly using a HI test. All the birds were finally challenged 4 weeks after vaccination with a virulent velogenic ND virus obtained from a field outbreak. All the vaccinated chickens seroconverted and had high antibody levels after 3 weeks, but these dropped to low levels at 4 weeks after vaccination. After challenge, the antibody titres rose in the dewormed groups but not in the parasite-infected groups. After 5 weeks, all the parasite-infected animals had significantly lower antibody titres than the dewormed animals. All the vaccinated chickens survived the challenge infection, emphasizing the importance of the cellular immune response. Further studies are needed to examine the effects of the parasitic infection on protection against ND over a longer period.

Effect of different contents of proteins and vitamin B2 in the feed on the prevalence and infection intensity of Ascaridia galli in chickens.

A group of 10-day-old chickens was experimentally infected with a dose of 500 infective eggs of Ascaridia galli (Schrank, 1788) (Nematoda). Forty-nine days post infection the chickens were necropsied and the infection intensity and prevalence were determined. The group maintained on the feed containing 11% of protein showed higher infection intensity and prevalence compared to the chickens fed a diet containing 19% of protein. The addition of vitamin B2 to the feed containing 11% protein resulted in lower intensity and prevalence of the infection. In both series of experiments no effect of Zn-bacitracin or vitamin B2 on infection intensity or prevalence was observed for chickens fed feed containing 19% of protein.

Cerebral larva migrans in a raccoon (Procyon lotor).

During 1997, gross and histopathologic examinations were performed on an adult female raccoon (Procyon lotor) that was live-trapped in Corvallis, Oregon. Multifocal eosinophilic granulomas indicative of neural and visceral larva migrans were observed. However, within these granulomas, the presence of parasitic larva was seen only in the cerebrum. Morphologic characteristics indicated that the nematode was an ascarid larva. However, it was smaller than the larva of Baylisascaris sp. This appears to be the first documented case of cerebral larva migrans in a raccoon.

[Effect of vitamin A and protein levels in the diet of chickens infected with Ascaridia galli on activity of digestive enzymes in pancreas and small intestine]. / Wplyw poziomu witaminy a i bialka w diecie kurczat zarazonych nicieniem ascaridia galli na aktywnosc enzymów trawiennych w trzustce i jelicie cienkim.

Hybrid chickens Astra S fed vitamin A deficiency diet containing 11 or 19% protein were infected with 500 invasive eggs of Ascaridia galli. One part of them received vitamin A in a dose corresponding to daily requirement, other part in double dose. After 7 weeks the extensity and intensity of ascaridiosis were determined. In pancreas and intestinal contents the activities of alpha-amylase, lipase and trypsin were measured. The invasion index was the highest in the group of chickens fed the protein and vitamin A deficiency diet. Vitamin A in a requirement dose lowered the parasite index. The results with double dose of vitamin A were worse in comparison with single dose. The activities of digestive enzymes were lower in infected animals than in the control groups. Vitamin A acted as moderator of the enzymatic changes during ascaridiosis.

Parasitosis intestinal en ninos menores de 2 anos con gastroenteritis / Intestinal parasitic in childrens of age less than 2 years with gastroenteritis

Se estudiaron 80 casos, de ninos menores de 2 anos, 49 varones y 31 hembras, que consultaron en la emergencia de ninos del Hospital Central de Valencia. A cada uno de ellos se les lleno un protocolo que incluyo antecedentes personales (dieteticos-patologicos), familiares (socio-economicos-culturales) y epidemiologicos, asi como tambien examen fisico completo y examen de heces utilizando metodos directos. Del total de pacientes estudiados se encontro un 55% parasitados y un 45% no parasitados, con una relacion 1 a 1 en ambos sexos, una mayor incidencia en el grupo etario de 18 a 23 meses y un predominio del A.Lumbricoides, T.Trichiura, G.Lambia en ese mismo orden de frecuencia

[Data on the biological cycle of the ascaridoid Ophidascaris trichuriformis, parasite of snakes]. / Données sur le cycle biologique de l'ascaridide Ophidascaris trichuriformis, parasite de serpents.

Ophidascaris trichuriformis is an ascaridoid commonly found in some species of Colubridae snakes. Similarly to what has been observed with several ascaridoid species, in O. trichuriformis the larvae, when still inside the egg-shells, reach the 3th snake stage around the 8th day of incubation in cultures kept at around 25 degrees C. Tentative assays to infect mice, snakes, toads, fish, and tadpoles of Hyla fuscovaria and Bufo sp. was made through the administration of embryonated eggs. Eggs didn't even eclode in mice, snakes or toads in such experiments; while in fish, although the eggs ecloded, its larvae were eliminated after the 4th day. In H. fuscovaria and Bufo sp. tadpoles, larvae were liberated from egg-shells and their development was observed up to the 36th day. They grew from the 6th hour to the above mentioned day, after which larvae were longer in Bufo sp. than in H. fuscovaria. By the 36th day distinction of sexes was possible through examination of genital primordia whose morphology and location differed in male and female larvae. From the 30th day on, following the recognizable beginning of metamorphosis in anuran amphibians and going up to the 65th day after experimental infection, an intense growth of the larvae infecting Bufo sp. was observed; the growth of such larvae was negligible between the 65th and the 85th days. Five snakes (Waglerophis merremii) were given per os larvae obtained from Bufo sp. after the 65th day of infection; these snakes died on the 53th, 54th, 60th, 110th and 116th days after their own infection, respectively, and in each of then 4th stage O. trichuriformis larvae were found in the stomach. The gastric location of such larvae in each snake was identical to the one in which adult worms of this same species are regularly found in natural infections: all of them had the middle part of the body embedded into the stomach wall while both anterior and posterior extremities kept free towards the lumen of the organ.

[Effect of the pH of Ascaridia galli egg culture medium on the experimental infection in chickens]. / Einfluss des pH des Kulturmediums der Eier von Ascarida galli auf die experimentelle Infektion der Küken.

1. A prolonged preservation of Ascaridia galli eggs in acid medium when cultivating them under laboratory conditions inhibits considerably the establishment of Ascaridia galli in the organism of chickens. The neutralization of medium of egg cultivation 3 days before their application for infesting facilitates the increase of larvae established in the organism. 2. In chickens invaded with Ascaridia galli eggs cultivated in medium with pH 8.0, larvae develop in the period of 7--21 days of invasion in the amount of 2.5--69 times more than in chickens receiving the same eggs but which have been cultivated in acid medium (pH 2.2) for the whole cultivation period. 3. With the increase in invasion period, the number of established larvae decreases in both test groups, but in chickens receiving eggs which have been cultivated in medium with pH 8.0, the number of larvae is considerably higher.