Avian spirochaetosis: enhanced recognition of mild strains of Borrelia anserina with bursectomized- and dexamethasone-treated chickens.
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Biomedical subjects
Publications and source records attributed to H E Adler.
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Various concentrations of alkyldimethylbenzyl ammonium chloride (QAC), Na2CO3, and ethylenediaminetetracetic acid (EDTA) were tested for antimicrobial activity singly and in combination against Escherichia coli, Arizona hinshawii, and Pseudomonas aeruginosa. Bactericidal activity of the reagents were evaluated in embryonating eggs, trypticase soy broth, and a medium containing lecithin. Toxicity of the chemicals was assayed in embryonating eggs. An appraisal was made of an egg-washing solution composed of 250 ppm QAC, 100 ppm Na2CO3, and 10 and 100 ppm EDTA. The mixture was effective and nontoxic for this purpose. All egg treatments had an adverse effect on fertility and hatchability. Using the temperature differential procedure in egg dipping, the disinfectant mixture was relatively nontoxic if 10 ppm EDTA was used with 3000 ppm tylosin tartrate. One hundred parts per million of the chelator in the dip solution caused excessive embryo mortality due to synergistic toxicity with the antibiotic. The germicidal action of the QAC solution was markedly increased with Na2CO3. Ten parts per million EDTA did not improve the biocidal effect of QAC solutions in distilled water but increased bactericidal activity in tap water that contained 16 ppm Ca and 22 ppm Mg.
A mild strain of Borrelia anserina was transmitted to chicks by an argasid tick identified as Argas (Persicargas)sanchezi Dugès, 1887. Disease was transmitted regularly to chicks less than 2 to 3 weeks old, and rarely to chicks 4 weeks old or older. This spirochete isolate was demonstrated to be immunologically and serologically diverse from an isolate obtained earlier in Arizona. This is the first report of transmission of B anserina by A(P) sanchezi and of the presence of different serologic and immunologic isolates of this spirochete in the United States.
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A split-litter technique was used to test observational learning in 4 litters of Miniature Dachshund puppies, 21, 28, 38, and 60 days old at the beginning of the experiment. In one side of a duplicate cage, one puppy of a litter, the demonstrator, learned to pull in a food cart on a runner by means of a ribbon, while another puppy, the observer, watched from an adjacent compartment, separated by a wire screen. Observational learning was demonstrated by the saving in time for the 1st trial when the observer was given the same problem to solve. Maturation, particularly the development of visual function and motor coordination, set a lower age limit for the emergence of observational learning.
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A quantitative study of the effect of endotoxin on embryonating chicken eggs revealed the importance of several variables. In the study, the chorioallanotic membrane was detached (i.e.,dropped) from the eggshell membrane on the 9th and 11th incubation days. Various doses of endotoxin in various amounts of diluent were applied on the dropped membrane on the 11th day. Embryo deaths were greater when the membrane was dropped on the 11th day. Within the limits of our trial, the variables were, in decreasing order of significance: 1) the day the membrane was dropped; 2) the amount of endotoxin applied; and 3) an interaction between 1 and 2. The volume of diluent had no significant effect on mortality. The importance of these variables is discussed with reference to the design of additional experiments with endotoxin.
The cultivation of Mycoplasma synoviae (MS) on growth medium requires supplementation with B-nicotinamide adenine dinucleotide (NAD), an expensive and relatively unstable compound. Strains of MS were adapted (selected) to grow in a medium supplemented instead with nicotinamide, a stable and inexpensive substance that can be heat-sterilized in the medium without impairing its growth-promoting properties. MS plate agglutinating antigens grown in nicotinamide-enriched media were comparable in yield and serological reaction to antigens grown with NAD supplementation.
Large doses of purified lipopolysaccharide (LPS) purified from Escherichia coli induced clinical signs but no mortality in chicks. Five chicks survived a mean dose of 517 mg/kg. One individual that received LPS at 577 mg/kg recovered from clinical manifestations within two days. Attempts failed to produce a generalized Shwartzman-like reaction with two intravenous inoculations of LPS at about 24-hour intervals. Prior injection of uric acid did not protect chicks from LPS by intravenous exposure.