Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. IV. The antibody response to natural infestation in grazing sheep and the 'self-cure' phenomenon

1950 ◽  
Vol 1 (4) ◽  
pp. 427 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Antibody Response ◽  
Haemonchus Contortus ◽  
Field Conditions ◽  
Infective Larvae ◽  
Oesophagostomum Columbianum ◽  
Faecal Egg Count ◽  
Immunological Reactions ◽  
Natural Infestation ◽  
Grazing Sheep ◽  
Antibody Levels

Weekly tests, over a period of eighteen months, of the sera of a flock of grazing sheep showed a relationship between the serum titres and the faecal egg counts. This relationship was particularly obvious during the summer months. When egg counts fell, the titres rose, and as the titres dropped, the egg counts usually rose again. This relationship between egg counts and serum titres was more striking in individual sheep than in the whole flock because all the sheep did not behave similarly at the same time. The antibody levels rose in individual sheep irrespective of whether the sheep were heavily or lightly infested at the time. There was no evidence that a permanent resistance to Haemonchus contortus was acquired under field conditions. Seven periods of "self-cure" occurred in the grazing flock during the period of observation. On each occasion, the majority of sheep which showed a drop in egg count also showed a rise in serum titre. This behaviour was strikingly similar to the result when infective larvae of H. contortus were superimposed upon an existing infestation of H. contortus or Trichostrongylus spp. in penned sheep. 'Self-cure' was produced in the field by giving naturally infested sheep large doses of infective larvae of H. contortus by mouth. A statistically significant fall in the faecal egg count of H. contortus and Trichostrongylus spp., but not of Oesophagostomum columbianum was produced by this means. The fact that 'self-cure' takes place in naturally grazing flocks during the summer months after rain indicated that the intake of large doses of infective larvae of H. contortus was the exciting cause of the phenomenon.

Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. III. The antibody response to infestation with Trichostrongylus spp.

1950 ◽  
Vol 1 (4) ◽  
pp. 413 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Antibody Response ◽  
Haemonchus Contortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Immunological Response ◽  
Serological Response ◽  
Apparent Effect ◽  
Relative Resistance ◽  
Infective Larvae ◽  
Immunological Reactions

In infestation of sheep with Trichostrongylus spp., both the intake of larvae and infestation with adult worms stimulated the production of antibodies. The character of the antibody response in infestation with Trichostrongylus spp. thus differed from that caused by Haemonchus contortus. Sera of sheep dying from infestation with Trichostrongylus spp. were negative to the complement fixation test. It was found that older sheep responded serologically earlier and more vigorously to infestation with Trichostrongylus spp. than did young sheep. Subsequent doses of larvae of Trichostrongylus spp. elicited a more rapid and grester serological response, even in young sheep, than an initial dose of larvae. Previous infestation with H. contortus did not result in resistance to Trichostrongylus spp., whereas previous infestation with Trichostrongylus spp. heightened the resistance of sheep to subsequent infestation with the same species. It is concluded that the relative resistance of older sheep to Trichostrongylus spp. is due, a t least in part, to an earlier immunological response which is strengthened by subsequent doses of larvae. When infective larvae of Trichostrongylus spp. were superimposed upon an existing infestation of the same species, the egg count declined ;apidly and the development of the superimposed larvae resisted Doses of infective larvae of Trichostrongylus spp. had no apparent effect on the egg counts of sheep infested with H. contortus.

Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. II. The antibody response to infestation with Haemonchus contortus

1950 ◽  
Vol 1 (3) ◽  
pp. 301 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Antibody Response ◽  
Haemonchus Contortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Critical Studies ◽  
Intravenous Injections ◽  
Infective Larvae ◽  
Third Stage ◽  
Immunological Reactions ◽  
Free Environment

The serological reactions to infestation with H. contortus were studied in penned sheep. For critical studies, sheep born and reared in a worm-free environment were used. In infestation with H. contortus, the antibody response was stimulated by the administration of third-stage infective larvae and as the infestation developed the antibody response declined. Established infestation with mature H. contortus did not stimulate the formation of antibodies. The sera of sheep dying from infestation with H. contortus were negative to the complement fixation test. Ground, mature H. contortus given to sheep by mouth or injected into the rumen did not elicit any antibody response. Infective larvae of H. contortus, killed by heat and given to sheep by month, did not stimulate an antibody response. When heat-killed larvae mere injected into the rumen, a rise in titre at times took place, but it was usually transient. When a dose of infective larvae of H. contortus was superimposed upon an existing infestation of H. contortus or Trichostrongylus spp. either the existing infestation was eliminated or the egg output of the parasites was suppressed. This phenomenon was accompanied by a rise in serum titre. Elimination of the infestation of H. contortus or Trichostrongylus spp. was not usually followed by resistance to the development of the superimposed larvae. The injection into the rumen of heat-killed larvae of H. contortus did not have the same effect as the oral administration of live larvae. Efforts to protect sheep against infestation with either H. contortus or Trichostrongylus spp. by means of vaccines prepared from ground, infective larvae were unsuccessful. Evidence was obtained that the artificial stimulation of antibodies, by means of intravenous injections of formalinized, ground larvae, influenced the course of existing infestations with H. contortus.

Antibody response of carp, Cyprinus carpio to the cestode, Bothriocephalus acheilognathi

Parasitology ◽  
1999 ◽  
Vol 118 (6) ◽  
pp. 635-639 ◽  
Author(s):  
P. NIE ◽  
D. HOOLE
Keyword(s):  
Antibody Response ◽  
Cyprinus Carpio ◽  
Serum Antibody ◽  
Infected Fish ◽  
Immune Protection ◽  
Carp Cyprinus Carpio ◽  
Bothriocephalus Acheilognathi ◽  
Protection Against Infection ◽  
Antibody Levels ◽  
Antibody Secreting Cells

The humoral antibody response and the number of pronephric antibody-secreting cells were examined in naturally Bothriocephalus acheilognathi-infected carp. Cyprinus carpio, and in those injected intraperitoneally with an extract of the cestode. In the extract-injected fish, specific antibody was detected 3 weeks after a second injection given 2 weeks after the primary injection, and antibody levels persisted for more than 200 days. A third injection also enhanced the antibody level in the extract-injected carp. The numbers of antibody-secreting cells were significantly higher in carp injected 3 times with the extract than in the control. In naturally-infected fish, the serum antibody levels and the number of pronephric antibody-secreting cells were higher in infected fish than in uninfected individuals although this difference was not statistically significant. The relevance of these results to immune protection against infection is discussed.

scholarly journals A/H1N1 hemagglutinin antibodies show comparable affinity in vaccine-related Narcolepsy type 1 and control and are unlikely to contribute to pathogenesis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Lind ◽  
Ilaria Marzinotto ◽  
Cristina Brigatti ◽  
Anita Ramelius ◽  
Lorenzo Piemonti ◽  
...  
Keyword(s):  
Antibody Response ◽  
Antigenic Determinant ◽  
Etiological Agent ◽  
Healthy Controls ◽  
Antibody Affinity ◽  
Antibody Titres ◽  
Antibody Levels ◽  
And Control ◽  
Radiobinding Assay

AbstractAn increased incidence of narcolepsy type 1 (NT1) was observed in Scandinavia following the 2009–2010 influenza Pandemrix vaccination. The association between NT1 and HLA-DQB1*06:02:01 supported the view of the vaccine as an etiological agent. A/H1N1 hemagglutinin (HA) is the main antigenic determinant of the host neutralization antibody response. Using two different immunoassays, the Luciferase Immunoprecipitation System (LIPS) and Radiobinding Assay (RBA), we investigated HA antibody levels and affinity in an exploratory and in a confirmatory cohort of Swedish NT1 patients and healthy controls vaccinated with Pandemrix. HA antibodies were increased in NT1 patients compared to controls in the exploratory (LIPS p = 0.0295, RBA p = 0.0369) but not in the confirmatory cohort (LIPS p = 0.55, RBA p = 0.625). HA antibody affinity, assessed by competition with Pandemrix vaccine, was comparable between patients and controls (LIPS: 48 vs. 39 ng/ml, p = 0.81; RBA: 472 vs. 491 ng/ml, p = 0.65). The LIPS assay also detected higher HA antibody titres as associated with HLA-DQB1*06:02:01 (p = 0.02). Our study shows that following Pandemrix vaccination, HA antibodies levels and affinity were comparable NT1 patients and controls and suggests that HA antibodies are unlikely to play a role in NT1 pathogenesis.

scholarly journals Susceptible trichostrongyloid species mask presence of benzimidazole-resistant Haemonchus contortus in cattle

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Khalid M. Mohammedsalih ◽  
Jürgen Krücken ◽  
Ahmed Bashar ◽  
Fathel-Rahman Juma ◽  
Abdalhakaim A. H. Abdalmalaik ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Epidemiological Data ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Molecular Approaches ◽  
Tubulin Genes ◽  
Faecal Egg Count ◽  
Third Stage ◽  
Before And After ◽  
Β Tubulin

Abstract Background Benzimidazole (BZ) anthelmintics are widely used to control infections with parasitic nematodes, but BZ resistance is an emerging threat among several nematode species infecting humans and animals. In Sudan, BZ-resistant Haemonchus contortus populations were recently reported in goats in South Darfur State. The objective of this study was to collect data regarding the situation of BZ resistance in cattle parasitic nematodes in South Darfur using phenotypic and molecular approaches, besides providing some epidemiological data on nematodes in cattle. Methods The faecal egg count reduction test and the egg hatch test (EHT) were used to evaluate benzimidazole efficacy in cattle nematodes in five South Darfur study areas: Beleil, Kass, Nyala, Rehed Al-Birdi and Tulus. Genomic DNA was extracted from pools of third-stage larvae (L3) (n = 40) during trials, before and after treatment, and pools of adult male Haemonchus spp. (n = 18) from abattoirs. The polymorphisms F167Y, E198A and F200Y in isotype 1 β-tubulin genes of H. contortus and H. placei were analysed using Sanger and pyrosequencing. Results Prevalence of gastro-intestinal helminths in cattle was 71% (313/443). Reduced albendazole faecal egg count reduction efficacy was detected in three study areas: Nyala (93.7%), Rehed Al-Birdi (89.7%) and Tulus (88.2%). In the EHT, EC50 values of these study areas ranged between 0.032 and 0.037 µg/ml thiabendazole. Genus-specific PCRs detected the genera Haemonchus, Trichostrongylus and Cooperia in L3 samples collected after albendazole treatment. Sanger sequencing followed by pyrosequencing assays did not detect elevated frequencies of known BZ resistance-associated alleles in codon F167Y, E198A and F200Y in isotype 1 β-tubulin gene of H. placei (≤ 11.38%). However, polymorphisms were detected in H. contortus and in samples with mixed infections with H. contortus and H. placei at codon 198, including E198L (16/58), E198V (2/58) and potentially E198Stop (1/58). All pooled L3 samples post-albendazole treatment (n = 13) were identified as H. contortus with an E198L substitution at codon 198. Conclusions To the knowledge of the authors, this is the first report of reduced albendazole efficacy in cattle in Sudan and is the first study describing an E198L substitution in phenotypically BZ-resistant nematodes collected from cattle.

scholarly journals Mechanisms of autoantibody production in autoimmune MRL mice.

1980 ◽  
Vol 152 (5) ◽  
pp. 1302-1310 ◽  
Author(s):  
D S Pisetsky ◽  
G A McCarty ◽  
D V Peters
Keyword(s):  
Antibody Response ◽  
Time Course ◽  
Fundamental Difference ◽  
Autoantibody Production ◽  
Quantitative Expression ◽  
Autoantibody Response ◽  
Time Courses ◽  
Antibody Levels

The quantitative expression of anti-DNA and anti-Sm antibodies has been investigated in autoimmune MRL-lpr/lpr and MRL-+/+ mice. Anti-Sm antibodies were detected in sera from 21/23 lpr/lpr and 10/16 +/+ mice, with individual animals showing striking variation in the time-course and magnitude of this autoantibody response. The peak antibody levels of the responding animals of each substrain did not differ significantly. For anti-DNA antibody, a different pattern of responsiveness was observed. Individual animals of each substrain produced very similar responses in terms of the magnitude and time-course of serum anti-DNA antibody. The differences in the peak levels of the two substrains were highly significant, with lpr/lpr mice demonstrating a much greater anti-DNA antibody response than +/+ mice. In lpr/lpr mice tested for both autoantibody systems, serum anti-DNA and anti-Sm antibodies showed distinct time-courses. These studies indicate that anti-DNA and anti-Sm antibodies are expressed independently in MRL mice, with the expression of anti-DNA, but not anti-Sm antibody markedly influenced by the presence of the 1pr gene. A fundamental difference in the mechanisms involved in the generation of anti-DNA and anti-Sm antibodies is suggested by the quantitative pattern of the two responses.

scholarly journals Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

2014 ◽  
Vol 23 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Maurício Orlando Wilmsen ◽  
Bruna Fernanda Silva ◽  
César Cristiano Bassetto ◽  
Alessandro Francisco Talamini do Amarante
Keyword(s):  
Haemonchus Contortus ◽  
Natural Infection ◽  
Gastrointestinal Nematode ◽  
Gastrointestinal Nematodes ◽  
Sao Paulo ◽  
São Paulo ◽  
Mean Intensity ◽  
Oesophagostomum Columbianum ◽  
The Mean ◽  
In Parenthesis

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

Improved Methods of Obtaining Clean Larvae of Haemonchus contortus

1963 ◽  
Vol 37 (4) ◽  
pp. 251-254 ◽  
Author(s):  
M. G. Christie ◽  
J. E. Patterson
Keyword(s):  
Free Surface ◽  
Surface Area ◽  
Haemonchus Contortus ◽  
Water Repellent ◽  
Optimum Conditions ◽  
Infective Larvae ◽  
Mucous Coat ◽  
Third Stage ◽  
Free Surface Area ◽  
Improved Methods

A pellet of sheep faeces containing eggs of Haemonchus contortus forms an adequate environment for the development of those eggs to third stage infective larvae, provided that it is kept moist. Observation shows a concentration of developing larvae on the external mucous coat of the pellet. These data suggest that optimum conditions for development would occur when pellets are separated one from another and standing on a water repellent surface, thus presenting the maximum free surface area and minimum opportunity for aggregation and hence of over crowding. The best method of recovering the infective larvae would be one that obtained larvae free from contamination without requiring them to expend energy in separating themselves from the contamination.

Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. I. The preparation of antigens for the complement fixation test and the reactivity of the biochemical fractions of H. contortus

1950 ◽  
Vol 1 (3) ◽  
pp. 285 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Haemonchus Contortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Fixation Test ◽  
Mature Adult ◽  
Infective Larvae ◽  
Lipid Fractions ◽  
Significant Difference ◽  
Third Stage ◽  
Free Material

All antigen was developed to detect circulating antibodies by means of the complement fixation test in sheep infested with Haemonchus contortus and Trichostrongylus spp. Extraction of worm material at 100°C. for 10 minutes was found to be the most satisfactory method for the preparation of antigens. Potent antigens were prepared from young adult H. contortus, from third-stage infective larvae, and from the eggs. Old mature adult H. contortus yielded antigens of low potency. No significant difference was found between the potency of antigens prepared from male and female adult H. contortus collected from the same sheep. Both adult Trichostrongylus spp. and third-stage infective larvae consistently yielded antigens of high potency. No significant difference was found in the results obtained with larval or adult H. contortus antigens, adjusted to the same potency and tested with natural H. contortus antisera. H. contortus and Trichostrongylus spp. absorbed the antiserum to each other. It was shown that a lipid was an essential constituent of the boiled antigen in the complement fixation reaction with natural antisera. Lipid-free antigens from H. contortus failed to react with natural antisera. The lipid was not antigenic when injected into rabbits. The carbohydrate fraction of H. contortus did not fix complement in the presence of natural antisera and was not antigenic when injected into rabbits. The lipid fraction of a variety of nematode parasites reacted with natural antisera to H. contortus infestation. Similar lipid fractions of two species of trematodes did not react with natural antisera to H. contortus infestation. Normal saline suspensions of the lipid-free material from a variety of helminths showed a greater degree of specificity when tested with artificially prepared antisera than did the lipid fractions.

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