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

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.

1950 ◽  
Vol 1 (3) ◽  
pp. 301 ◽  
Author(s):  
DF Stewart

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.


1950 ◽  
Vol 1 (4) ◽  
pp. 413 ◽  
Author(s):  
DF Stewart

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.


Author(s):  
A. Yahia ◽  
K. Hamrat ◽  
K. Saidani ◽  
R. Kaidi

In order to determine the prevalence of bovine brucellosis and the factors affecting its persistence in the province of Djelfa (Algeria), a sero-epidemiological study was carried out on a total of 10827 cattle (7346 females and 3481 males) during the decade from 2004 to 2013. The sera were screened by card agglutination test, and the positive samples were confirmed by the complement fixation test. Some factors (year, age, breed and sex) were considered. Results found an average prevalence of brucellosis during these ten years of 1.4% with a highly significant difference according to year and sex (P Lass Than 0.05). A prevalence of 1.58% for females against a prevalence of 1.03% for males was observed. No significant difference was observed for the different age groups (P>0.05) in the seroprevalence of brucellosis. A higher prevalence of infection (1.53%) was found in imported breeds compared to local and cross breeds with (1.39%) and (1.35%) respectively. The effect of the breed is highly significant (P Lass Than 0.05). In conclusion the bovine brucellosis persists in the province of Djelfa and it is necessary to implement a scheme to fight and prevent this infection.


1952 ◽  
Vol 21 (3) ◽  
pp. 391-399 ◽  
Author(s):  
Elwood Buchman ◽  
Harold J. Kullman ◽  
George F. Margonis

1969 ◽  
Vol 62 (1_Suppl) ◽  
pp. S113-S133 ◽  
Author(s):  
Sam Brody

ABSTRACT This report is a summary of 10 years of experience with the complement fixation test as adopted for the immunoassay of HCG in serum. It is based on published as well as unpublished material. The discussion centers mainly around methodological problems, criteria of reliability, and clinical observations. It is our impression that the complement fixation test is a reasonably rapid and simple technical procedure. It is standard practice in every bacteriological and virological laboratory. The precision of the HCG assay is high. Its accuracy is good. The complement fixation assay, as reported here, fulfils the criteria of specificity. It has been evaluated by means of serological techniques and through comparison between biopotency and immunopotency of HCG in serum with reference to a common standard. Its application for routine as well as research work is illustrated.


2014 ◽  
Vol 17 (2) ◽  
pp. 367-369 ◽  
Author(s):  
K. Rypula ◽  
A. Kumala ◽  
P. Lis ◽  
K. Niemczuk ◽  
K. Płoneczka-Janeczko ◽  
...  

Abstract The study was carried out in seven reproductive herds of pigs. In three of them reproductive disorders were observed. Three herds consisted of 10-50 and four consisted of 120-500 adult sows and they were called small and medium, respectively. Fifty-seven adult sows were randomly selected from herds. Serum samples were tested using the complement fixation test and swabs from both eyes and from the vaginal vestibule were examined using real-time PCR. All serum samples were negative. Infected sows were present in each of the study herds. In total, there were 28 positive samples (53%, 28/48) in real-time PCR in sows with reproductive disorders and 35 (53%, 35/66) in sows selected from herds without problems in reproduction. One isolate proved to be Chlamydophila pecorum, whereas all the remaining were Chamydia suis


1984 ◽  
Vol 61 (7) ◽  
pp. 216-218
Author(s):  
L. C. LLOYD ◽  
R. T. BADMAN ◽  
J. R. ETHERIDGE ◽  
K. McKECHNIE ◽  
H. IYER

1954 ◽  
Vol 24 (8) ◽  
pp. 934-945 ◽  
Author(s):  
Alcor S. Browne ◽  
Martha M. Michelbacher ◽  
Edith M. Coffey

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