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Antibody titres were higher in colostral and milk whey from the vaccinated sows than from non-vaccinated groups. The inoculated gland in the group of sows given vaccine by the intramammary route secreted milk containing markedly more antibodies to the vaccine E. coli strain than did the non-vaccinated glands. Milk from the vaccinated gland did not contain higher titres to heterologous E. coli O antigens than milk from non-vaccinated glands. Serum titres were the same or higher than the titres in colostrum from non-vaccinated glands.
相似文献2. S. pullorum exhibited binding to Concanavalin A (Con A) and wheat germ agglutinin (WGA) but not to soyabean agglutinin (SBA), Ricinus communis agglutinin (RCA) and Ulex europaeus agglutinin (UEA).
3. The ileal epithelium of chicks bound WGA, Con A and SBA. The binding sites for WGA were on the brush border and cytoplasm of columnar enterocytes as well as on goblet cells. The binding of Con A was confined to the cytoplasm of columnar enterocytes, while SBA bound, in a limited way, to the brush border of columnar enterocytes.
4. After an oral dose of S. pullorum, adherence to the ileal epithelium was inhibited by methyl α‐D‐mannopyranoside. 相似文献
2. Among the antigen positive birds, two groups could be distinguished: those which permanently and those which transiently expressed viral antigen. Permanent antigen expression was associated with low antibody titres, while transient antigen expression was associated with high antibody titres.
3. The strain segregated for the two endogenous viral genes ev6 and ev9, both of which express endogenous viral envelope protein, and have been implicated in affecting immune‐responsiveness. The antibody titre in individuals positive for both ev6 and ev9, was significantly lower than in those which had none or only one of the two ev‐genes. In addition, individuals positive for both ev‐genes occurred more frequently in the group permanently positive for viral antigen than in the group transiently antigen positive.
4. The results indicate that there was a strong synergism between ev6 and ev9 in reducing the antibody response to exogenous avian leukosis virus infection, perhaps by inducing immune tolerance or interfering with antibody formation. 相似文献
The fluorescent antibody (FA) conjugate against Vom strain of Mycoplasma mycoides var. capri was Vom strain-specific, no cross reaction with Mexico, Connecticut, or Maryland strains. Similarly, the Mexico strain conjugate was specific for colonies of Mexico, and did not cross with the Vom, strain. Additionally, the conjugate of the PG-2 strain of Mycoplasma agalactiae, which was specific for the colonies of PG-2 was refractory for the strain #99 of M. agalactiae.
It was therefore possible to utilize an immunofluorescent technique (incident ultraviolet light) to demonstrate differences among strains of M. mycoides var. capri and M. agalactiae.
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The incidence of infection was high in horses, cattle and pigs. A few low titres were seen in sheep. The goats were not infected. Apart from a single bovine abortion all the clinical symptoms observed occurred in pregnant sows. Seven of these aborted or gave birth to stillborn pigs within a six week period.
Fifteen species of wildlife were trapped or shot on the farm during the year following the outbreak. L. pomona was isolated from four skunks and a porcupine. Epidemiological studies indicated that wildlife reservoir hosts were the primary source of infection for the domestic livestock.
Leptospiruria and the serological response were studied in a group of eight infected sows. Microscopic agglutination titres of 102 or less could not be associated with leptospiruria and the duration of leptospiruria was found to range from a few weeks to over two years in individual sows. Direct dark-field examination of urine proved superior to guinea-pig inoculation as a method of detecting leptospiruria and it is suggested that the former technique could be adopted with advantage as a routine aid to diagnosis.
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Density gradient centrifugation and DEAE cellulose column chromatography showed the 19S antibody developed first, followed soon after by 7S antibody. The former had disappeared by the 25th day but the latter persisted longer in both sheep. A small amount of 19S antibody was detected in sheep 1 following a booster dose of vaccine but 7S antibody constituted the major secondary response.
The standard tube agglutination test was found to be more efficient than the complement-fixation test for titration of 19S antibody. An increase in the salt concentration to 10% in tube agglutination test rendered it more sensitive in demonstrating 7S antibody.
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The symptoms and pathological changes are described. On an equivalent weight basis it required three to five times the oral dosage to kill the large animals and birds as it did to kill the laboratory animals. The symptoms were less pronounced and the survival times were longer in the more resistant animals. Enlargement and congestion of the liver with necrosis of the hepatic cells were constant and pathognomonic. These findings are in general agreement with the observations of other workers who have examined the toxicity of naturally occurring Microcystis waterblooms.
The toxicities and structures of microcystin and of six other biologically active cyclic polypeptides are summarized. The pathological effects produced by microcystin in laboratory and domestic animals resemble those produced in man but differ from those produced in animals by the toxic peptides of Amanita phalloides.
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This fluorescent antibody (FA) method was developed to identify colonies of Vom strain of Mycoplasma mycoides var. capri, V-5 strain of M. mycoides var. mycoides, and PG-2 strain of M. agalactiaeon agar, using fluorescent ultraviolet light. Fluorescence was not demonstrated when heterologous conjugates or normal rabbit serum conjugate were applied but the reaction appeared to be specific for each strain of mycoplasma.
The FA method was able to differentiate specific mycloplasma colonies in mixed cultures.
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Only the modified direct complement-fixation test in which the guinea-pig complement is supplemented with fresh, normal unheated calf serum was suitable for the detection of mycoplasma antibodies in sera of infected swine. Based on the close correlation between the production of typical lung lesions in experimentally infected pigs and the appearance of significant serum antibody titres, the modified direct complement-fixation test provides for the first time a sensitive, specific in vitro method for the detection of enzootic pneumonia in the live pig. This test also permitted the in vitro differentiation of the mycoplasma causing enzootic pneumonia from M. hyorhinis which causes polyserositis.
Antibodies in the sera of rabbits were demonstrable by the ordinary direct complement-fixation test. However, in contast to the observation made with swine sera, only a slight quantitative antigenic difference between the enzootic pneumonia mycoplasma and M. hyorhinis was seen when the tests were performed with rabbit serum antibodiies.
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Female ferrets, two years of age, were used in the present study. They were divided into four groups. The first three groups were given for one month meat from chickens fed the toxic ration for 2, 4, and 6 weeks, respectively. Each of these three groups contained one control ferret that was fed with the meat of chickens fed a commercial ration for a similar period of time. One half of the 4th group was fed pooled liver from intoxicated birds and one half was fed liver from control birds.
No significant changes in the ferret tissues were observed as a consequence of feeding them with the meat or liver from the chickens chronically poisoned with toxic groundnut meal.
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The two hemolysins were neutralized in vitro only by the antitoxin A. Broiler chickens injected I.V. with a Viande-Foie (VF) broth culture of Clostridium perfringens together with the antitoxin A survived, whereas those receiving antitoxin C died. These results seem to indicate that this organism belongs to the type A. This bacillus was sensitive to a great variety of antibiotics, except neomycin.
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No diarrhea, fluid accumulation, or impairment of the digestive capacity were noted in the pigs infected with the nonenteropathogenic strain of E. coli. The number of viable E. coli detected in the respective segments of the homogenized small intestine was similar in pigs infected with either strain.
Diarrhea occurred continuously starting 18 hours PI in the pigs infected with the enteropathogenic strain and killed 24 or 48 hours PI. The pH of the contents of the cecum and colon became markedly more alkaline simultaneously with the increase in the heterogeneity and fluid content of the cecum and colon and thus appeared to correlate well with the onset of the clinical diarrhea. No enteritis was detected grossly or microscopically.
The characteristics that determine the enteropathogenicity of a strain of E. coli could not be defined from the results, but it was noted that the host response appeared to be quite similar to that of infant rabbits experimentally infected with Vibrio cholera.
相似文献2. The titres of antibody in serum, bile and intestinal scrapings, the distribution of immunoglobulin‐containing cells in the spleen, duodenum and ileum and the expression on peripheral blood leukocytes (PBL) of the T cell surface markers CD3, CD4 and CD8 were determined.
3. Whereas low titres of anti‐flagellin antibody were detected in serum, bile and intestinal scrapings of unimmunised birds, high titres were observed in immunised birds.
4. An increase in antibody of all isotypes was detectable in serum but the elevation in IgA antibody in intestinal scrapings and bile was particularly striking. This response was reflected in a dramatic increase in immunoglobulin‐containing cells, detected by fluorescent histology, particularly diose associated with IgA and IgM isotypes in the spleen and intestine of immunised birds.
5. Secondary oral boosting after hatching resulted in a depression in serum anti‐flagellin antibody in immunised birds compared to pre‐boosting titres (although still significandy higher than in non‐immunised controls) but an increase in IgA antibody in intestinal scrapings and bile. The number of immunoglobulin‐containing cells was also increased after boosting.
6. Neither immunisation regimen caused a significant change in the numbers of circulating CD3, CD4 or CD8 T cells.
7. These results indicate that in ovo oral immunisation with C. jejuni antigens stimulates the precocious development of immunity in chicks. 相似文献
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1. A significant increase of the pH of the chyme in the large intestine during acute dysentery
2. A significant increase of Vibrio, Escherichia coli and Staphylococcus in the colon and cecum during acute dysentery.
3. A significant increase of Shigella in the colon and cecum during subacute dysentery.
4. The almost total disappearance of Aeromonas and of the yeasts in the large intestine during acute, subacute and chronic dysentery.
5. A significant decrease of Klebsiella, in the cecum, during acute dysentery and of the fungi during subacute dysentery.
6. Decrease of Streptococcus in the colon during acute dysentery.
7. The total quantitative flora of the large intestine do not change very much.
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Diarrhea was observed initially two to four hours after feeding the filtrate prepared from the enteropathogenic E. coli. The duration of diarrhea was five to ten hours. No diarrhea was observed after feeding filtrate prepared from uninoculated medium or cultures of nonenteropathogenic E. coli.
The pH values of the feces increased with the onset of diarrhea and decreased to normal after diarrhea stopped.
No histopathological lesions were found.
相似文献In addition, the effects of intrasinus exposure to isolate 1010 were compared with those produced by similar exposure to a different isolate, M. gallisepticum isolate 1150. Isolate 1010 caused a slightly higher incidence of sinusitis, but a much lower incidence of tracheitis than isolate 1150. Air sac lesions did not differ in incidence or severity. The differences observed indicate differences in tissue predilection of the isolates.
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Resistant variants were isolated from some animals in all experiments using S. typhimurium S192. Almost without exception such variants were isolated only after specimen enrichment. The numbers of specimens from test animals yielding resistant variants were more than twice those of control counterparts. Numbers of such variants in material from the former were much greater.
In vitro transfer of resistance to S. typhimurium S192 was demonstrated both in waters from drinking troughs and during specimen enrichment. The former, indicating the risk of transfer in pigs' environments and packing houses, has disturbing implications for public health. The latter emphasizes the difficulties of determining antibiotic sensitivity of pathogens as they occur in the animal body.
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The organ occurs in both sexes and in birds of different ages. It is located in the median sagittal plane dorsal to the cloaca. It is enveloped by a smooth muscle-connective tissue capsule and has a rich blood supply.
The supracloacal body is yellow-brown in color being composed chiefly of islands of pigment cells.
Histochemically, the pigment is a chromolipoid as defined by Ciaccio.
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