1) Lactose (1%) added to P.V.L. demonstrated in a liquid as well as frozen-desiccated condition a good ability of preservation next to lactoalbumin as was reported in the last paper. It preserved even in a liquid conditien a titer sufficient for application, when stored at 35- for 40 days.
2) Bovine serum demonstrated, though a little inferior to lactoalbumin, almost the same degree of preserving activity as lactose against liquid as well as frozen desiccated P. V. L.
3) Bovine serum hydrolysed by pepsin, protease or trypsin and caseopsin (hydrolysed lactocasein) demonstrated no better preserving activity than lactose.

View full abstract

Much work has been done to eliminate non-specific reacting factors from the toxic culture filtrate for Dick test, but it may also be of importance to improve the medium itself as a means of facilitating the preparation of the toxin solution suitable for Dick test.
The diffusate medium from digested beef heart infusion (by Stock, 1942), which has hitherto been applied for that purpose with many advantages, however, has such disadvantages as its troublesome preparation procedure and difficulty in securing a constancy of composition and consequently of toxin production.
The author devised a new culture medium whose principal component is the diffusate obtained from a 10% solution of “MIKUNI's pepton for toxin production” in the place of Stock's digested beef heart. Notable gains due to this modification are:
1) Preparation procedure is relatively simple.
2) Composition of the medium is secured rather constant by using the pepton preparation of the same lot.
3) Through dialysis the toxin is easily isolated from other components of culture fluid.
4) The culture filtrate of our medium contains less non-specific erythrogenic factors.
In connection with the improvement of the medium the author obtained information about several conditions influencing the multiplication and toxin productionof the microbe.
1) As for sugar needed for the culture, maltose was found more effective than glucose in promoting both growth and toxin production of the microbe.
2) An inflence of certain quantity of iron on the toxin production was remark able, the optimum concentration of iron being 0.2 ry/ml.
3) A cultural medium can be made better fitted for the growth of more strains of A group Streptococcus pyogenes by adding several sorts of vitamins. Riboflavine gives the best result in this respect.

View full abstract

According to some previous studies there is no difference in the percentage of toxin producing strains according to their sources, but the relation between the symptom and the toxin among the patients or carriers of streptococcal infection has not been made clear except in the case of scarlet fever.
The author investigated in detail the toxin productivity of each strain in regard to its source, by estimating quantitatively the toxic potency with due consideration to the growth of the microbe during the toxin production. In this study almost 100 strains freshly isolated from patients of the scarlet fever, acute nephritis and other streptococcal infections and carriers have been examined.
The results obtained were as follows:
1) Proliferative ability differed according to the sources of strains under a certain identical cultural condition, and wellgrowing strains were found in the greatest number among those isolated from the scarlet fever group, and in less numbers from the acute nephritis group, other streptococcal infections and carriers, in the order named.
2) By comparing the toxic potency of each strain according to its source, we found more strains producing a higher value of toxin in the scarlet fever group, and less in acute nephritis and carriers' groups.
Inversely the number of strains of very low or negative toxic potency was the largest in the carrier group, and very small in the scarlet fever group.
3) The neutralization test of these toxins by the antitoxic serum of “S8 strain” showed that toxins of about 30% of the strains were neutralized in every group; consequently, there may be no difference among these groups in regard to the ratio of the neutralization.

View full abstract

As stated in the author's preceding paper, the erythrogenic toxin produced by about 70 percent of the strains of Streptococci isolated recently from scarlet fever patients was not neutralized by the antitoxic serum of strain S8. This made it necessary to further investigate the immunological properties of these toxins.
Toxins of 8 strains were investigated: They were strains N. Y. 5, S8, Cook, 55-15 and those of scarlet fever source No.52, No.39 ; No.38, No.35 (the latter two neutralized, and the former two not, by antitoxic serum of strain S8).
Rabbits were subjected to intradermal reaction test by each toxin before and after immunization with these toxins.
By studying the results comparatively, the following informations were obtained as to the difference among the toxins.
Toxins No.38 and No.35 were recognized to behave in the same manner as S8 and N.Y.5 in neutralization, that is, they belong to the same toxic type.
Toxins No.52 and No.39 showed the same neutralization response, but these two differed in neutralization from all other toxins.
Furthermore, toxins of 19 strains isolated from scarlet fever cases, which were not neutralized by and-toxic serum for S8 strain, were inoculated into rabbits immunized with toxin of 55-15 strain, in order to investigate the relation between the toxins of these 19 strains to 55-15 strain toxin.
The result showed that 9 of the 19 strains were neutralized and the remaining 10 were not neutralized.
These results just mentioned suggest two problems: One is that there may be an increase recently of infection by a strain or strains different from the strain S8 in the toxic type, and the other is the possibility of existence of a toxic type which has hitherto remained unknown.

View full abstract

Histoplasmosis known to be caused by histoplasma capsulatum is according to Palmer et al distributed all over the world, especially in the basin of mid-stream of great rivers. This disease is thought to be caused by histoplasma multiplying in podozolic soil. Most of the persons infected with this organism demonstrates positive histoplasmin test.
Histoplasmin test was carried out by the authors with 72 earthworkers working in the basin of mid-stream of Edogawa River in order to investigate the incidence of this disease in our country. The results were as follows:
1) The test proved positive in 36 persons (50%). The diameter of reddening was on an average 4.8 mm, exceeding in no case 10 mm. No case demonstrated an induration over 5mm.
2) From these results, the basin of Edogawa River might be considered as not contaminated yet. However, a further research is requested, because the number of cases examined is not sufficient.

View full abstract

Histoplasmin test was carried out with 1, 150 pupils of S high school in Odawara City, the majority of which was consisted of members of the farmers' families dealing with podozolic soil.
In the right and left upper arm and in the right fore arm, each 0.1 ml of 100 x histoplasmin (kindly sent by Dr. Palmer), solution of histoplasmin and 2, 000 x tuberculin, respectively were injected and after 24hrs the reading was made. The results were as follows:
1) Positive reaction, induration over 7-8 mm after Palmer's new criteria was seen in 3 persons, who showed roentgenologically nothing abnormal in their lungs. These data seem to reaveal that the Komine district of Odawara City is not yet contaminated by histoplasma.
2) Frequency of reddening diameter demonstrated a diagram with a peak at 5 mm. The diameter of reddening was almost the same as that of induration.
3) No obvious relationship was observed between tuberculosis and histoplasmin reaction, the correlation ratio being 0.3.

View full abstract

To study the distribution in nature, Morgonella was isolated in 5.0% from the human stool, in 46.3% from dysentery patients, in 6.7% from rats, 1.3% from dogs and in 6.6% from the nasal cavity of hospital personnel. The strains isolated were classified using the antiserum against 0-antigen into 0-7 (35%), 0-6 (10%), 0-3 (9%) and 0-9 (7%).
Phage typing was performed with the strains isolated from food poisoning cases in order to clarify the epidemiological aspects. The 0-7 type strains were typable in 75% with the phage 6 originating from strains of the same type. Among them, strains isolated from men belonged to A type (1/2/3/4/5) and B type (1/2), those from rats to C type (1/2/4) and D type (3/4/5).
Furthermore, strains probably originating from food poisoning cases belonged mostly to A type and the strains belonging to the A type were mostly endowed with pathogenicity. Consequently, it was concluded that phage typing might be useful for the study of the epidemiological aspects of food poisoning.

View full abstract

0-antigen transduction phenomenon between different serum types was studied using the phage of Morganella and the antigenic relationship between the phage of Morganella and dysentery bacilli of D group was investigated.
The phenomenon was irreversible, demonstrating (10→6) and (10→6, 10). The phenomenon (10→6) alone was difficult to reproduce, but that of (10→6, 10) was observed in a high rate.
It was found that two strains of temperate phage (MA2, MA5) obtained from Morganella lysogenized Sh. sonnei and that Morganella antigen could be induced into Shigella by the phage. Furthermore, a strain of Morganella with the whole antigens of Sh. flex. 2b was isolated from human stool. The variation strains obtained by induction of the antigen of Sh. sonnei into the above mentioned strain and the Morganella (MAII) demonstrated a remarkably lower virulence to mice as compared with the other strains.
These facts might be explained by alteration of pathogenicity caused by antigenic transduction between Morganella and the other pathogenic agents hitherto known. Consequently, Morganella is pathogenic enough to play a role in food poisoning and diarrhea.

View full abstract

Twelve group antisera and 36 type antisera were prepared by the author using standard strains of hemolytic streptococcus originating from Lancefield and Updyke (cordially presented by Institute for Infectious Diseases and Institute for Preventive Medicine). Hemolytic streptococci isolated from scarlet fever patients were classified by means of these sera using precipitation test in order to clarify the relationship between the classification and the clinical pictures.
1) For the preparation of group antisera, chrom vaccine was mainly used, aiming at no high precipitaion titer, so that antisera necessitating no absorption were obtained by 5 inoculations during 20 days. However, the crossing between D group (C3) and F group (H60R) could not be eliminated.
2) For the preparation of type antsera (A group), the antigens obtained by bacterial body destroying method (Conroy, Updyke) were injected to the animals 5 times during 20 days (modification by the author). As a result of comparative examination of various methods of precipitation test, the following was found the best: absorption by the strain of corresponding type according to the serum antibody titer, elimination of the cross reaction by dilution with 1.5% salt solution of gum arabicum, a definite concentration of antigens extracted by HC1. Observing these precautions, 36 type antisera were prepared.
3) The isolation rate of pharyngeal streptococci from scarlet fever patients was 24.2% in the cases treated with antibiotics and 95.6% given no antibiotics according to the study of 1, 373 cases by the author. The isolation rate according to the year did not demonstrate any great difference.
4) Both of the larynx and the nasal cavity demonstrated the isolation rate 14.7%. so that the role of nasal cavity in epidemics did not seem to be great.
5) Six scarlet fever patients were examined on the purity of the streptococci isolated. All of them demonstrated one pure strain belonging to the same group and type excet one case, which proved one colony out of a great number of colonies on a culture medium to be sufficient for the determination of type.
6) Many examinations on the type and group were carried out in the course of the disease in order to study the variation of type. Less than the half of 198 cases investigated demonstrated a variation of type, which was associated with an aggravation of clinical picture twice as frequently as in the cases witnout the variation of type.
On the other hand, aggravation was observed in a high rate in the cases treated with anibiotics at the beginning of the disease as compared with the cases given no antibiotics regardless of the variation of type. Therefore, an improvement must be considered regarding the way of patient's isolation and the duration and method of antibiotic therapy.
7) The strains isolated from scarlet fever patients of 9 families were investigated on the identity of strain, only one family demonstarting different types.
8) Thirty eight families were investigated on the type difference between the strains isolated from patients and those from healthy persons in the same family, the isolation rate being almost the same among patients and healthy members. The families with the same type among the family members were 75%.
9) Scarlet fever patients complicated by nephritis demonstrated no particular type. The appearance of a certain type to predominate is likely to be caused by a high incidence of the type in scarlet fever patients.
10) Among the strains isolated, A group predominated overwhelmingly, followed by C and then by G group.
11) Out of 2, 139 A group strains isolated from 1954 to 1959, 9: 11 was most frequently encountered in 1954-1955 and 6 most frequently in 1956-1959, showing a variation of isolation rate according to the year. A variation according to the month was also confirmed. Furthermore, a variation according to the district was noticed.

View full abstract