The serum iodine test, a simplifyed clinical test as a substitute for the Gross test, has been applied to dairy cows since 1961. The following findings were obtained from the practice of this test. 1. The amount of. a single drop from a given pipette varied according to the condition in which the pipette was held. A rather constant amount of a drop could be obtained when a glass capillary of the same caliber as the syringe of 1/3 gauge was used carefully without shaking. 2. A new pipette must be used for a new serum sample. If a pipette is employed for two or more samples continually, no accurate test can be performed because of mixing of samples. 3. No homolyzed samples should be used, since they may give more intensified tests. 4. The reagent for the test could be used even over a year after preparation when it was stored in a container tightly sealed with a polyethylerfe stopper, protected from exposure to light and contact with metal. 5. Serum samples must be tested within 4 days after collected in summer, although it is not always necessary to keep them in a refrigerator.
1. The most probable numbers (MPN) of Escherichia coil and Enterococcus in feces were determined in 10 head each of 9 animal species, including man, by the A. Y. I.-E. A. C. broth method. E. coli was found in dog, man, sheep, Japanese native ox, chicken, goat, guinea pig, rabbit, and dairy cow in the decreasing order of MPN. Enterococcus was detected in dog, sheep, chicken, man, goat, rabbit, guinea pig, Japanese native oxen, and dairy cow in the same order as above. 2. The number of enterococci was about 1/20 to 1/10 that of E. coli organisms in all the animals, except the chicken, in which it was almost equal to the latter. 3. When 487 samples of food were examined, 20.5 per cent of them was positive for E. coil and 13.7 per cent for Enterococcus. The resultant difference was significant at 1 per cent of a when examined by the X2-test. 4. The isolated organisms were classified into Streptococcus faecium (41.0%), Str. faecalis (36.4%), Str. durans (5.36%), Str. faecalis var. liquefaciens (4.6%), and atypical strains (12.64%). 5. Str. faecium was mostly found among the strains isolated from feces and Str. faecalis among those isolated from food. 6. The differences between the two bacterial species in the numbers of organisms isolated from “soft cream” and fresh milk were not significant at 5 per cent of α when examined by t-distribution. These results seem to indicate that detection of enterococci, -when performed at the same time with that of E. coli organisms, may be useful as additional means for the determination of the degree of food contamination.
A basic experiment was carried out to find a method of treatment of contaminated sera. In it, ultraviolet irradiation and β-propiolactone (PL) administration were examined for effect on canine serum contaminated artificially with infectious canine hepatitis (ICH) virus. When applied independently to the serum to such an extent as not injurious to the serum protein contained, neither of the two inactivating factors gave necessarily satisfactory results. Simultaneous application of the two factors, however, brought about good results within a short period of time, although the amount of ultraviolet irradiation used was less than half the amount applied alone and the concentration of PL one-trird to one-half that employed alone previously. When administered at such concentrations as these, PL exercised little influence upon neutralizing antibody in the serum and gave rise to no noticeable changes in the animal administered.
Fifty-one White Leghorn X Rhode Island Red hybrid chicks of our experiment station from 3 days to 9 weeks of age, were fed a ration containing arsanilic acid at a rate of 100mg per kg of the basal diet. The compostion of the ration is shown in figure 1.(Arsanilic acid used was a product of the Toshiba-Seiyaku Co., Ltd.) At 3 weeks of age, the mean body weight of the chicks fed the ration containing arsanilic acid was 20g heavier than that of chicks fed the same ration without addition of arsanilic acid (P<0.01). The increase of body weight was 727g in the former after 9 weeks, treatment, while it was in 619g the latter at the same period (P<.01). It was clearly shown in the present experiment that arsanilic acid had a growth-promoting effect on chicks when used as feed additive.