During the period of 1976-1977, a total of 779 strains of group A hemolytic Streptococci isolated in Japan was subjected for the serotyping and antibiotic susceptibility test.
The results obtained are as follows:
1) None of the resistant strain against β-lactam group antibiotics was found as well as the consequence of the former survey.
2) The incidence of chloramphenicol resistant strains showed gradual decrease since 1974, and was 43.5%(198/466) in 1976 and 38.1%(119/313) in 1977. Furthermore, none of the highly resistant strain showing greater than 100 tg/ml of MIC was found in 1977.
3) The principal serotype of the isolates was type 12 in both 1976 and 1977. And 66.9%(81/121) of the isolates in 1976 and 70.2%(87/124) in 1977 were found to be the multiple drug resistant strains.
4) The highest incidence of type 12 organisms was 81.9% in 1973, however, it was declined to 37.9% in 1976 and 39.0% in 1977. Instead of the decline of type 12 organisms, remarkable increase was observed on types 1 and 4 organisms.

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We have already reported the annual change of type distribution of group A streptococci until March 1974 and type 12 exhibited a steep rise in percent frequency and reached the highest value in the past such as 71.9%. This was due to the development of the multiple drug resistance of this serotype including, in particular, macrolide resistance. After further increase up to the value 79.4% for another one year, i. e., in 1974-75, it began to decline relatively rapidly toward March 1978. In contrast, type 4 increased from 3.1% in 1974-75 to 27.5% in 1977-78, where the both types came to competitive in frequency. As regards the predominant types other than both types of 12 and 4, such types as 1, 3, 22, 6, 28, and B3264 appeared alternatively during this four-year period. It is interesting to note that there occurred some disturbance or modification in the constituent types of the main predominant pattern consisting of five types such as 12, 4, 6, 22, and 1 which lasted almost unchanged for about ten years until 1973.

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The present study was aimed at investigating, ecologically and etiologically, the group A type 12 Streptococci which seemed to be closely associated with the acute glomerulonephritis (AGN) and the rheumatic fever (RF). Strains from healthy carriers as well as those from patients of scarlet fever, pharyngitis or AGN were examined in relation to M and T antigenicities, the antibiotic sensitivity, the hemolytic activity and the virulence to the mouse.
1. Four patterns were recognized in the type 12 strains according to the combination of M and T a ntigenicities, and the erythromycin (EM) sensitivity. They were pattern I (M12: T12, EM resistant), II (M12: T12, EM sensitive), III (M∗: T 12, EM resistant), and IV (M∗: T 12, EM sensitive).
2. Most of the strains from patients belonged to either the pattern I or II, the strains showing the pattern III (frequently dissociated from the pattern I during subcultures) or IV being very few. Among the carrier strains, however, the pattern IV was dominant followed by the pattern I.
3. Strains belonging to the pattern IV seemed to be essentially different from those of the patterns I and II, in lacking the M 12 antigen, in showing weak hemolysis, and in the one-sided distribution in the carrier origin. The pathogenicity of these strains to humans may be questionable.
4. A strain of the pattern II, isolated in 1970 from an epidemic of AGN in Toyama prefecture, had the strongest virulence to the mouse, this seeming to be related to the stability of M 12 antigen in this strain.

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Using sera from 207 residents in Akita Prefecture 1976 to 1977, a seroepidemiological study on group A streptococci was carried out by measuring type specific antibodies to T antigens of the bacterias. That is, type specific antibodies to type T 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 13, 14, 22, 23, 25, 27, 28, 44, 49, B3264 and Imp. 19 antigens in sera from different age groups, respectively, were measured by microtechnique method and the obtained results were summerized as follows.
1. Positive rates possessing one or more T antibodies were 10% in infants under 1 year of age and in older infants 2 to 3 years of age. However, the rates elevated abruptly with age and reached 76.7% at 10 to 12 year old age group. It was found that incidence of infection with the bacterias was raised remarkablely in 7 to 9 year old age group, because the difference of positive rates between 4 to 6 and 7 to 9 year old age groups was 43.4%. The positive rates gradually decreased with age in groups after the age group and was 60% in adults over 20 years old.
2. When antibody positive rates by type were surveyed, respectively, 23.7% of the rate to type T 12 antigen was the highest, and then the rates to type T 4, 14 and 1 antigens, respectively, followed. Type specific antibodies against type T 6, 9 and Imp.19 antigens, however, not detected in all age groups. It was suggested that the prevalence of type T 4 streptococcus in Akita was more dominant than that of type T 12 streptococcus. Although types of T antibodies increased with age, 75% out of persons with T antibody possessed antibodies against 1 to 3 T antigens.
3. Thus, it was assumed that the indicator of type specific T antibody was useful for analysing serologically epidemiological status of group A streptococci.

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Surveylance of infectious diseases and pathgenic microorganisms was carried in Akita, May 1976 through March 1978, and the obtained results of streptococcal infectious diseases and group A streptococci were summerized aw follows.
1. Out of 27, 747 patients with infectious diseases reported from 31 hospitals in Akita, September 1976 through August 1977, number of patients with scarlet fever was 429 (1.55%), other streptococcal infectious diseases was 610 (2.20%), and acute nephritis or rheumatic fever was 162 (0.58%).
2. Surveylance of pathogenic microorganisms from patients with infectious diseases was carried in 2 hospitals in Akita, May 1976 through March 1978. Group A streptococci out of isolated microorganisms were 62 strains; that is, 42 strains (% isolation: 44.2%) from 95 patients with scarlet fever or streptococcal infectious diseases, 2 strains (33.3%) from 6 patients with acute respiratory infectious disease, 8 strains (29.6%) from 27 patients with pharyngitis, 8 strains (24.2%) from 33 patients with tonsillitis, 1 strain (9.0%) from 11 patients with angina and 1 strain (5.6%) from 18 patients with other infectious diseases were isolated, respectively. Eighteen strains (29.0%) out of isolated streptococci were type T 12 and 17 strains (27.4%) were type T 4, but it was suggested that type T 4 streptococcus might previal more than type T 12 in Akita in near future.
3. It was found on the basis of above mentioned results that streptococcal infectious diseases including acute respiratory infectious disease, pharyngitis, tonsillitis and angina prevailed considerably.

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Yearly survey of healthy children in two primary schools in Osaka city and scarlet fever patients, who served as the control for incidence of M type of group A-hemolytic streptococci for periods of some dozen years revealed:
1) The rate of detection of group A-hemolytic streptococci varied greatly with year, and, ranged from 24.9% to 3.8% in S school and from 28.4% to 4.2% in U school. The maximum rate for S school is for the year of 1962 when scarlet fever was epidemic, and that for U school, for 1968 when most infections due to group A-hemolytic streptococci were unlikely to be scarlet fever.
2) The yearly change in M type of group A-hemolytic streptococci isolated from the throat of healthy children coincided largely with that from patients with scarlet fever, except that the children carried untypable strains more frequently than the patients.
3) The major strains in M type that repeatedly caused group A-hemolytic streptococcal infections included 6, 4, and 12. The rate of detection, in years 1968 and 1969, of M type 6 strain among the children of S school, which is located near the center of the 1962 to 1963 epidemic caused by M type 6 strain, was extremely low.
4) In no year was M type 1 strain the most freguent organism among patients with scarlet fever, though it topped among healthy children in a couple of years during this survey.

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Healthy children in U school in Osaka city were surveyed monthly over 10 years for M type of group A-hemolytic streptococci residing in their throat. Other children suffering scarlet fever admitted to Osaka Municipal Children's Home were also studied for M type of the causative organisms.
1. The rate of detection of group A-hemolytic streptococci from the throat of children was unexceptionally low in August, but was generally high in other months.
2. From the point of view of M types and ASO titers, the number of pairs of siblings bearing little mutual relationship surpassed that of siblings who bore a certain relationship.
3. The rate of infection among children admitted to the children's home was very high for its closed characters.

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Commonly available antibiotics were examined for activity against group A-hemolytic streptococci isolated from the throat of healthy children in two primary schools in Osaka city and from patients with scarlet fever between 1963 and 1977. The antibiotics tested comprised seven penicillins, four cephalosporin antibiotics, three macrolides, and tetracycline and chloramphenicol.
The results were as follows.
1. Penicillins were found to be highly active except CB-PC and SB-PC. SB-PC was the least active, with the MIC value on the test organisms as large as 12.5μg/ml.
2. Cephalosporin antibiotics were in order of decreasing activity of CER, CEZ, CET, and CEX. The activity of CER was similar to that of penicillin V. The MIC of CEX was as large as 12.5μg/ml.
3. Tetracycline varied greatly with the test strains for activity. As early as in 1963 this antibiotic was already resistant to some of the streptococcal strains. The strains resistant to tetracycline were types 12, 4, and 1. The least resistant strain was type 6.
4. Chloramphenicol became increasingly inactive on the isolates. Its MIC values began to increase from 1963 onward, as shown by the doubling MIC values of 3, 12μg/ml in 1963 to 1967, 6.25μg/ml in 1968, 12.5μg/ml in 1969 to 1972, 25μg/ml in 1973, and as large as 50μg/ml in 1976. Type 12 was the most frequently detected strain, which was followed by types 1 and 4.
5. Macrolides were active against all the test strains before 1973, when, all of a sudden, a new strain suppressed only at an MIC as large as 100μg/ml appeared. This year experienced an epidemic caused by type 12 strain, which was replaced by type 1 in 1976 and 1977. These were also resistant to macrolides.
6. Many strains were resistant to five different antibiotics comprising TC, CP, EM, OL, and JM, and were of types 12 (1973 and 1976), 1 (1976), and 4 (1976, only a single strain). The strains resistant to macrolides were also resistant to TC and CP. The number of strain (s) resistant to a single macrolide was (were) to EM and 3 to OL.

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Co-Agglutination test using Phadebact Streptococcus test in short time culture was studied. As a medium, Todd-Hewitt broth (BBL) was offered to the test.
After 2 hours at the bigining of the culture, agglutinations were checked every 1 hours.
As tested p-hemolytic streptococci, laboratory strains and strains isolated from patients were used. At 2 hours later after the culture, no agglutination could be observed in group A, B, C and G. At 3 hours later, agglutination could be obserbed in group B. All groups showed positive agglutination at 6 hours later from these results.
It may be considered that our improved method, i.e. short time culture method, is more rapid and convenient than the usual method.

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During 4 years from 1972 to 1975, from 1.449 cases of scarlet fever patients and 1.831 persons of the patient's families, 1.154 (79.6%) and 442 (241.1%) strains of hemolytic streptococci were isolated respectively.
Monthly, seasonal, and yearly fluctuations of the isolation rates were not so significant through the study period.
Among the families, the rate in brothers and sisters (37.1%) was a little highter than those in mothers (23.8%) and fathers (18.2%).
Serological groupings were carried out with 1, 127 patient-strains and 259 family-strains, and 1, 114 strains (98.9%) and 240 strains (92.7%), respectively, were identified as beolonging to group A.
Type distribution among the group A isolates from the families was nearly equal to that of the patients. Type 12 strains were the most frequent, and were found in 67.5% and 70.4% of the group A isolated from the patients and the families, respectively. Type 1, 3, 4, 6, 18 and 22 were found in 4.6%, 2.9%, 10.7%, 3.4%, 4.8% and 0.8%, of the patients strains, respectively, and in 9.2%, 2.1%, 9.6%, 0.8%, 0.8%, and 0% of the family strains, respectively.
Serotypes of both isolates from a patients and its family could be identified in 213 pairs. Coincidence of the serotypes within a pair was found in 195 pairs (91.5%). In the cases when the patients possessed either of the type 1, 4 or 12 strains, their families possessed strains of the same types in 100%, 89.5% and 94.5%, respectively. Conversely, in the cases when the families possessed either of the type 1.4 or 12 strains, their patients possessed strains of the same types in 81.0%, 81.0% and 94.5%, respectively.
Antibiotic sensitivities of 152 patient strains and 137 family strains against PCG, TC, CP, EM and OL were assayed. Distributions of the MIC values among the family strains were very similar to those of the patient's: PC-resistant strains could not be found, whereas a half or a little more of the strains were resistant against TC, CP, EM or OL.
There were 107 pairs of patient and it's family both of whose isolates were assayed for the antibiotic sensitivities. Coincidence of the antibiotic-sensitivity patterns between patient and its family strains was observed in 77 out of 89 cases of homologous-serotype pairs and in 4 out of 11 cases of serotype-relation unknown pairs, but it was not found in the 7 cases of heterologous-serotype pairs.
These results that there were high rates of coincidence of serotype and antibiotic-sensitivity patterns seemed to demonstrate close mutual relationship between streptococci of patient and its family. Usefulness of parallel assays of serotypes and antibiotic-sensitivity patterns of both patient and family isolates for the elucidation of routes of streptococcal propagation was proposed.

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