Long-term observations on type distribution of clinical isolated of beta-hemolytic streptococci in Sapporo. I. T-type distribution of group A hemolytic streptococci during the thirty one-year period between 1969 and 1999

During the thirty one-year period between 1969 and 1999, a total of 6,876 strains of group A streptococci isolated in Sapporo City General Hospital were classified by T-agglutination method. This research consisted of 5,866 strains of scarlet fever-patients (scarlet fever-strains), 450 of child-patients (child-strains), 141 of adult-patients (adult-strains) and 409 strains of the indistinct. The results were summarized as follows: 1. Total of 6,866 strains were classified to sixteen kinds of T-types such as T12 (44.1%), T4 (21.7%), T1 (9.2%), T6 (4.4%), T3 (2.8%), T22 (2.1%), T18 (1.9%), T28 (1.6%) & others. This pattern of type distribution, three prevailing types of T12/T4/T1, have been reported in other areas generally. But original increase of isolation rates of strains of some T-types as T6, for example, also appeared in Sapporo. 2. Long-term observations demonstrated that the isolation rates of individual T-type, especially T4 or T1, had been forming a small epidemic-wave having a 4 to 8 year-interval and these of type T3 or type T6 on the other hand were repeating sudden prevalence every several years. 3. The isolation rates of type T12 or type T4 in scarlet fever-strains, were significantly higher than in child-strains or adult-strains. It was shown that Type T1 was distributed widely irrespective of patient-group and age-group. It was also characteristic to be distributed to many T-types in adult-strains.     

Decrease of erythromycin resistance in group A streptococci by change of emm distribution

With the increasing resistance of group A streptococci (GAS) to macrolides in some countries including Korea, throat cultures were taken from healthy elementary school children to isolate GAS in 2004. Antibiotic susceptibility, macrolide-resistant phenotypes and genotypes as well as emm genotyping were studied and compared with previous data in 2002. In the present study, resistance rates to erythromycin and clindamycin in 2004 decreased to 9.8 and 8.8%, respectively, compared with 51.0 and 33.7%, respectively, in 2002. While emm44/61 increased from 0 to 29.3%, emm12 decreased from 34.4 to 6.4% during the 2002 - 2004 period. All emm44/61 strains were susceptible to erythromycin, while 81.0% of emm12 strains were resistant to erythromycin. The dramatic decrease of erythromycin resistance during this short period might be related to a change in the distribution of emm types in the community.     

The c protein fractions of group B streptococci: its distribution and relation to heat-labile antigens for the agglutination method

Distribution of the c protein fractions of group B streptococci and relation to heat-labile antigens for agglutination were investigated. The results were summarized as follows: 1. Analysis of antigenicity of the c protein in group B streptococcal strains isolated revealed that 74% of the type Ia/c strains carried only alpha antigen, and 76% of the type Ib/c strains contained both alpha and beta antigens. Component of the c protein fractions in most of type Ia/c strains isolated was different from that in reference strains. 2. Of 37 Ia/c alpha strains, 45.9% were determined non-typable, 32.4% were Ia/W, 13.5% were Ia/S, and 8.1% were Ia/Q in the agglutination for heat-labile antigens. Of 8 Ia/c alpha beta strains, 87.5% were Ia/Q, and 12.5% were Ia/SW. Of 5 Ia/c beta strains, 60% were Ia/Q, and 40% were Ia/QW. Of 19 Ib/c alpha beta strains, 68.4% were Ib/-, and 31.6% were Ib/S. Of 5 Ib/c alpha strains, 60% were Ib/-, and 40% were Ib/S. One Ib/c beta strain was Ib/-. 3. Because trypsin-sensitive portions of the beta antigens were lost, preparation of antigens for agglutination by pancreatic digestion could not exactly reflect results of the precipitation method.     

Serotypes and antibiotic susceptibility of group A and B streptococci clinically isolated in Sapporo in the last five years

During the last five-year period between 1985 and 1989, serotypes of 671 strains of group A and 238 strains of group B streptococci isolated from clinical specimens in Sapporo city general hospital were studied. Results of serotyping were given as under; Type T4 (25.8%), T12 (25.6%), T1 (11.5%), T3 (9.2%), T6 and T28 (6.3% each), T8 and T22 (0.6% each), T13 (0.4%), T9 and B3264 were found in group A. Type T4 and T12 formed main types up to this time and T1, T3, T6 and T28 were other predominant types. The elevated isolation rates of type T3 and T28 were remarkable in this period. In group B, Ia (31.5%), III (16.8%), Ib (14.3%), II (8.0%) and V (4.2%) were observed. On 617 samples (391 group A, 226 group B) out of these strains, antibiotic susceptibility to 9 drugs were examined. No resistant strain (MIC greater than or equal to 25 micrograms/ml) to beta-lactam antibiotics was found in each group. Resistant strains in group A streptococci were demonstrated 24.3% to TC, 0.5% to OL. No resistant strain, however, was observed to CP or EM. In group B, resistant strains were found in 39.8% to TC, 6.6% to CP, 2.2% to EM. Strains resistant to only TC (31.0%) were most prevalent followed by TC.CP (6.2%) and TC.MLs (2.7%). Multi-resistant strain (to TC.CP.MLs) was not found.     

2021年3—4月全球主要疫情回顾

本刊对2021年3—4月全球重点传染病疫情(截至4月25日)汇总如下. 1 全球新冠疫情4月份反弹,印度疫情急剧恶化 2021年1月全球新型冠状病毒肺炎(新冠肺炎)每日新增病例数达到50万～60万例,2月以后增速放缓,每日新增病例数降到30万～40万例,但3月以后每日新增病例数又持续上升,4月中旬开始以每日新增70万～80万例的速度继续上升,达到了新型冠状病毒肺炎疫情(新冠疫情)发生以来的峰值.见图1.     

2021年3-4月全球主要疫情回顾

本刊对2021年3—4月全球重点传染病疫情(截至4月25日)汇总如下. 1 全球新冠疫情4月份反弹,印度疫情急剧恶化 2021年1月全球新型冠状病毒肺炎(新冠肺炎)每日新增病例数达到50万～60万例,2月以后增速放缓,每日新增病例数降到30万～40万例,但3月以后每日新增病例数又持续上升,4月中旬开始以每日新增70万～80万例的速度继续上升,达到了新型冠状病毒肺炎疫情(新冠疫情)发生以来的峰值.见图1.