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51.
Oliveira AL Costa C Rodella RA Silva BF Amarante AF 《Tropical animal health and production》2009,41(5):775-782
The influence of trichomes on vertical migration and survival of Haemonchus contortus infective larvae (L3) on different forages was investigated. Four different forages showing different distributions of trichomes
(Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Xaraes, Andropogon gayanus, and Stylosanthes spp.), and one forage species without trichomes (Panicum maximum cv. Tanzania), were used. Forages cut at the post-grazing height were contaminated with faeces containing L3. Samples of
different grass strata (0–10, 10–20, >20 cm) and faeces were collected for L3 quantification once per week over four weeks.
In all forages studied, the highest L3 recovery occurred seven days after contamination, with the lowest recovery on A. gayanus. In general, larvae were found on all forages’ strata. However, most of the larvae were at the lower stratum. There was no
influence of trichomes on migration and survival of H. contortus L3 on the forages. 相似文献
52.
M Fayez SH Shehata Heba GA El-Morsy A Rahal AF Shahaby 《Archives of Agronomy and Soil Science》2013,59(4-5):397-419
Twenty-one microbial preparations recommended for controlling pathogenic fungal strains causing root rot and wilt diseases of faba bean were investigated for antibiosis against several symbiotic and associative diazotrophs adopting a modified agar-plate-inhibition-zone assay. Rhizobium and Bradyrhizobium exhibited a somewhat similar susceptibility to biocontrol agents while associative diazotrophs showed variable responses. Azotobacter, compared to others, was severely inhibited by such bio-candidates. The members of the biofertilizer formulation ‘Biofertan’ did bear mixed cultivation with the majority of biocontrol agents. Among those, Bacillus subtilis was deemed the pioneer. In pot experiments, almost all the antagonists significantly restricted the severity of root rot and wilt diseases besides modifying faba bean seedling stand and improving plant development. This was very obvious with shoot biomass increases of >?50%. Moreover, the bioagents successfully recovered the legume establishment, seriously injured due to pathogenic fungal infection. Simultaneous inoculation with Rhizobium and biocontrol agents provided more growth stimulation compared to either when introduced individually. Field-grown faba beans were inoculated with the diazotroph and representatives of biocontrol strains by two different methods, seed coating and over-head soil. Growth parameters determined were the highest when the legume plant was seed-coated by Rhizobium simultaneously over-head soil inoculated with the bacterial bioagents; this was reported with Bacillus subtilis and Pseudomonas aerugenosa. The significance of combined application of biofertilizer and bioagent to ensure cheap, clean and safe farm products is discussed. 相似文献
53.
Carvalho CO Chagas AC Cotinguiba F Furlan M Brito LG Chaves FC Stephan MP Bizzo HR Amarante AF 《Veterinary parasitology》2012,183(3-4):260-268
The indiscriminate use of anthelmintics has resulted in the establishment of parasite resistance. Thus, this study aimed to evaluate the in vitro antiparasitic effect of plant extracts on Haemonchus contortus in sheep and the in vivo effect on Strongyloides venezuelensis in Rattus norvegicus. The plant extracts from Piper tuberculatum, Lippia sidoides, Mentha piperita, Hura crepitans and Carapa guianensis, produced at different research institutions, were chemically analyzed and evaluated through the egg hatch test (EHT) and larval development test (LDT) in H. contortus. P. tuberculatum (150 and 250 mg kg(-1) of body weight) was evaluated for its anthelmintic action on R. norvegicus experimentally infected with S. venezuelensis. In the EHT, the LC(50) and LC(90) of the extracts were respectively as follows: 0.031 and 0.09 mg mL(-1) for P. tuberculatum, 0.04 and 0.13 mg mL(-1) for L. sidoides, 0.037 and 0.10 mg mL(-1) for M. piperita, 2.16 and 17.13 mg mL(-1) for H. crepitans and 2.03 × 10(-6) and 1.22 × 10(-12) mg mL(-1) for C. guianensis. In the LDT, the LC(50) and LC(90) were respectively: 0.02 and 0.031 mg mL(-1) for P. tuberculatum, 0.002 and 0.04 mg mL(-1) for L. sidoides, 0.018 and 0.03 mg mL(-1) for M. piperita, 0.36 and 0.91 mg mL(-1) for H. crepitans and 17.65 and 1890 mg mL(-1) for C. guianensis. The extract of P. tuberculatum showed the following substances: piperamides as (Z)-piplartine, (E)-piplartine, 8,9-dihydropiplartine, piperine, 10,11-dihydropiperine, 5,6 dihydropiperlongumine and pellitorine. The major compounds of the oils were thymol (76.6%) for L. sidoides, menthol (27.5%) for M. piperita and oleic acid (46.8%) for C. guianensis. Regarding the in vivo test, neither dose of P. tuberculatum caused any significant reduction (P>0.05) in worm burden and fecal egg counts compared with the control group. We conclude that the extracts of P. tuberculatum, L. sidoides and M. piperita have effective activity when tested in vitro, but the doses of the extract of P. tuberculatum have no effect when employed in in vivo tests. 相似文献
54.
Amarante AF Bricarello PA Huntley JF Mazzolin LP Gomes JC 《Veterinary parasitology》2005,128(1-2):99-107
This study was carried out to evaluate the relationship of abomasal inflammatory cells and parasite-specific immunoglobulin A (IgA) in mucus, with the resistance to Haemonchus contortus infection in three breeds of sheep naturally infected with gastrointestinal nematodes. The breeds were the native Santa Ines sheep, and the European Suffolk and Ile de France breeds. Mast cells, eosinophils and globule leucocytes were enumerated in abomasal mucosa. Eosinophils within the sub-mucosa also were counted separately. Histamine concentration was estimated in abomasal tissue samples. Enzyme-linked immunosorbent assay was carried out in mucus samples to determine the level of IgA anti-H. contortus third and fifth instar. There were no significant differences among group means of these variables (P>0.05). The correlation coefficients between fecal egg counts (FEC)xmast cells (r=-0.490; P<0.05) and FECxeosinophils in sub-mucosa (r=-0.714; P<0.01) was significant in the Santa Ines sheep. In the Ile de France group, the correlation coefficients between globule leucocytesxFEC (r=-0.879; P<0.001) and histaminexworm burden (r=-0.833; P<0.01) were also significant. In the Santa Ines and Ile de France sheep, correlation coefficients between IgA anti-L3xworm burden and IgA anti-L3xFEC were negative. In general, inflammatory cells and IgA-parasite-specific in abomasum were inversely associated with H. contortus worm burden and FEC indicating that they may impair parasite development or fecundity in the three breeds of sheep. However, similar mean values of inflammatory cells and IgA were found in the resistant (Santa Ines) and in the susceptible (Suffolk and Ile de France) breeds of sheep. The enumeration of cells by histological assessment does not provide information on their functional activity, which may be different among breeds. Thus, the effect of breed on the functional activity of these and other inflammatory cells is an important area for further study. 相似文献
55.
56.
The present study was carried out in the northwestern region of S?o Paulo State, Brazil, to determine the anthelmintic resistance status in cattle naturally infected with gastrointestinal nematodes. The anthelmintics tested were levamisole phosphate (Ripercol, Fort Dodge), albendazole sulphoxide (Ricobendazole, Fort Dodge), ivermectin (Ivomec, Merial) and moxidectin (Cydectin, Fort Dodge), administered at the doses recommended by the manufacturers. From April 2002 to May 2004, 25 cattle farms were evaluated. On each farm, steers were divided into treatment and control (not treated) groups based on fecal egg counts (FEC). Between 7 and 10 days after the anthelmintics administration, fecal samples were collected from each animal for post-treatment FEC. Fecal cultures from each group were also prepared for larval identification. After treatment, mean FEC reduction (FECR) in treatment groups (compared with control groups) was assessed on each farm. FECR was lower than 90% on 23 farms after ivermectin treatment. On 19 farms, FECR of 100% was recorded following moxidectin treatment; on the remaining 6, FECR ranged from 90% to 97.2%. After albendazole treatment, FECR was higher than 90% on 20 farms and ranged from 47.4% to 84.6% on other 5. After levamisole treatment, FECR was higher than 90% on 23 farms and equal to 47.4% and 73.7% on other 2 farms. Results indicated the presence of resistant Cooperia spp. and Haemonchus spp., especially to ivermectin; on some farms, resistance to albendazole and levamisole was also observed. 相似文献
57.
AF Goncharov VV Struzhkin MS Somayazulu RJ Hemley HK Mao 《Science (New York, N.Y.)》1996,273(5272):218-220
Protonated and deuterated ices (H2O and D2O) compressed to a maximum pressure of 210 gigapascals at 85 to 300 kelvin exhibit a phase transition at 60 gigapascals in H2O ice (70 gigapascals in D2O ice) on the basis of their infrared reflectance spectra determined with synchrotron radiation. The transition is characterized by soft-mode behavior of the nu3 O-H or O-D stretch below the transition, followed by a hardening (positive pressure shift) above it. This behavior is interpreted as the transformation of ice phase VII to a structure with symmetric hydrogen bonds. The spectroscopic features of the phase persisted to the maximum pressures (210 gigapascals) of the measurements, although changes in vibrational mode coupling were observed at 150 to 160 gigapascals. 相似文献