To determine the carrier rate of beta-hemolytic streptococci (BHS), throat cultures were taken from healthy elementary school children in four separate areas of Korea from 1992 to 1995, including Inje, Nonsan, Seoul and Chinju. The strains of Streptococcus pyogenes had been serotyped with anti-T, -OF and -M sera. The isolation rates of BHS and S. pyogenes ranged from 14.1-32.4% and 10.9-18.5% respectively. More than half of the carriers showed heavy growth of BHS. M78 (48.6%) and M28 (22.2%) were most common in Inje, M12 (23.6%) and M5 (20.3%) in Nonsan, M12 (48.8%) and M5 (14.6%) in Seoul, and M12 (26.3%) and M22 (14.5%) in Chinju, respectively. About 15% of school children were positive for S. pyogenes in throat cultures, and the distribution of serotypes varied according to geographical regions.
Carrier State ; Child ; Child, Preschool ; Female ; Human ; Male ; Pharynx/microbiology* ; Schools ; Serotyping* ; Streptococcus pyogenes/isolation & purification* ; Streptococcus pyogenes/classification*

OBJECTIVETo study the prevalence rate of upper respiratory tract group A Streptococcus (GAS) carriage in school-age children from Xinjiang Province.

METHODSA total of 478 children at age of 9-12 years from Tulufan City and Buerjin County of Xinjiang Province were enrolled by random cluster sampling. Throat swab cultures were performed once each season for the determination of presence of GAS.

RESULTSIn the 1 827 samples, 196 GAS strains were isolated, with a GAS carrier rate of 10.7%. The prevalence rate of GAS carrier in Tulufan City ranged from 3.7%-16.5% compared with 4.7%-21.4% in Buerjin County (P < 0.05). The prevalence rate of GAS carrier in winter is the highest, followed by in autumn, spring and summer in both regions. There were significant differences in the GAS carriage rate in autumn between the two regions. There were no significant differences in the GAS carriage rate between boys and girls. Of the 196 GAS strains, 133 from Han, 22 from Uygur and 41 from Hazakh children. There were significant differences in the prevalence rate of GAS carriage among children with different ethic groups.

CONCLUSIONSThe prevalence rate of GAS carriage is high in school-age children from Tulufan and Buerjin of Xinjiang Province. The GAS carrier rate is associated with the season and ethic group. The children from Buerjin County present a higher GAS carrier rate than those from Tulufan City.

Carrier State ; microbiology ; Child ; China ; Female ; Humans ; Male ; Prevalence ; Respiratory System ; microbiology ; Streptococcus pyogenes ; isolation & purification

Lysins are murein hydrolases produced by bacteriophage that act on the cell wall of host bacteria to release progeny phages. Research indicated that lysins could kill bacteria effectively and specifically in vitro. To prepare recombinant bacteriophage lysin of Streptococcus (PlyC) and analyze its biological activity, we obtained two genes of PlyC named PlyCA and PlyCB by PCR amplification and inserted them into pET-32a(+), then transformed the recombinant expression vectors pET-32a(+)-PlyCA and pET-32a(+)-PlyCB into E. coli BL21(DE3) respectively. After induction with 0.7 mmol/L IPTG at 30 degrees C for 7 h, PlyCA and PlyCB were successfully expressed, SDS-PAGE analysis determined that they all constituted above 30% of the total cell proteins. After Ni(2+)-NTA affinity chromatography, the purity was more than 95%. With the denaturation and protein refolding, we gained the recombinant PlyC. To determine its biological activity, we adopted turbidimetry and plate count method. Before and after lysin treatment, the cell morphology was studied by scanning electron microscopy (SEM). The results showed that the recombinant PlyC could specifically cleavage Streptococcus pyogenes (group A beta-hemolytic streptococci). Under the incubation time of 60 min with 4 microg/mL PlyC in Streptococcus pyogenes dilution which OD600 was 0.56, the germicidal effect was up to 99.6%, while SEM observations showed that cell wall cracked and presented cell debris. This finding laid the foundation for the further study and achieving an effective treatment for streptococcal infection.
Bacteriolysis ; Enzymes ; biosynthesis ; genetics ; isolation & purification ; Escherichia coli ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Streptococcus pyogenes ; drug effects

Seventy-seven Streptococcus pyogenes strains isolated of children of three elementary schools located in Kangwon-do in spring, 1992 were serotyped with M, opacity factor (OF) and T typing antisera. In the M/OF typing results, M-78 (46.8%) and M-28 (22.1%) were most frequently encountered, while M-4 (6.5%), M-12 (5.2%), M-3 (1.3%), M-5 (1.3%) and M-6 (1.3%) were rarely observed. Twelve strains (15.6%) were not typable with M or OF typing system. In the T typing results, T-11 (35.1%) and T-28 (27.3%) were most common. We were able to identify 77.9% of S. pyogenes strains by T typing, 94.8% with T typing and OF typing. With the addition of M typing, 97.4% were typable. Through the serotypings, we could know the basic distribution of serotypes of S. pyogenes of healthy children which could be comparable to those of rheumatic fever, poststreptococcal glomerulonephritis and other severe streptococcal disease.
Adolescent ; Bacterial Typing Techniques ; Child ; Female ; Humans ; Korea ; Male ; Pharynx/microbiology ; Rheumatic Fever/microbiology ; Serotyping ; Streptococcus pyogenes/*classification/isolation & purification

PURPOSE: Erythromycin-resistant beta-hemolytic streptococci (BHS) has recently emerged and quickly spread between and within countries throughout the world. In this study, we evaluate the antimicrobial susceptibility patterns and erythromycin resistance mechanisms of BHS during 2003-2004. MATERIALS AND METHODS: The MICs of seven antimicrobials were determined for 204 clinical isolates of BHS from 2003 to 2004. Resistance mechanisms of erythromycin-resistant BHS were studied by the double disk test as well as by polymerase chain reaction (PCR). RESULTS: Compared with our previous study, resistance among Streptococcus pyogenes isolates to a variety of drugs decreased strikingly: from 25.7% to 4.8% in erythromycin; 15.8% to 0% in clindamycin; and 47.1% to 19.0% in tetracycline. The prevalent phenotypes and genotypes of macrolide-lincosamide-streptograminB (MLSB) resistance in Streptococcus pyogenes isolates have been changed from the constitutive MLSB phenotype carrying erm(B) to the M phenotype with mef(A) gene. In contrast with Streptococcus pyogenes, resistance rates to erythromycin (36.7%), clindamycin (43.1%), and tetracycline (95.4%) in Streptococcus agalactiae isolates did not show decreasing trends. Among the Streptococcus dysgalactiae subsp. equisimilis isolates (Lancefield group C, G), resistance rates to erythromycin, clindamycin, tetracycline and chloramphenicol were observed to be 9.4%, 3.1%, 68.8%, and 9.4%, respectively. CONCLUSION: Continual monitoring of antimicrobial resistance among large-colony-forming BHS is needed to provide the medical community with current data regarding the resistance mechanisms that are most common to their local or regional environments.
Anti-Bacterial Agents/*pharmacology ; Drug Resistance, Multiple, Bacterial ; Erythromycin/*pharmacology ; Genes, Bacterial ; Genotype ; Hospitals ; Humans ; Incidence ; Korea ; Microbial Sensitivity Tests ; Streptococcus/*drug effects/genetics/isolation & purification ; Streptococcus agalactiae/drug effects/genetics/isolation & purification ; Streptococcus pyogenes/drug effects/genetics/isolation & purification

BACKGROUND: Acute pharyngitis is a very common respiratory tract infection. Rapid antigen tests (RATs) that detect group A streptococci (GAS) have an advantage over conventional throat culture in determining the cause of acute pharyngitis quickly. The efficiency of RAT should be good enough to be used in the laboratory or in the clinics. METHODS: From October 2008 through February 2009, throat swabs were taken from 293 children with acute pharyngitis and conveyed to the Gyeongsang National University Hospital in a transport medium. Two swabs from each patient were inoculated onto a blood agar plate, then returned to the transport medium and stored at -20 degrees C for several months. After the samples were thawed at room temperature, the SD Bioline Strep A RAT (SD, Korea) was performed. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of SD Bioline Strep A compared with throat culture were 95.9% (95% confidence interval [CI]: 93.6-98.2%), 91.8% (95% CI: 88.5-95.1%), 95.9% (95% CI: 93.6-98.2%), and 91.8% (95% CI: 88.5-95.1%), respectively. CONCLUSIONS: The SD Bioline Strep A RAT kit can be useful as an alternative to throat cultures in the clinics for rapid diagnosis of GAS pharyngitis and for an early decision on the use of antibiotics.
Acute Disease ; Antigens/analysis/immunology ; Child ; Female ; Hospitals, Pediatric ; Humans ; Male ; Pharyngitis/*diagnosis ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Streptococcus pyogenes/*isolation & purification

Anti-Bacterial Agents ; Child ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; Humans ; Molecular Epidemiology ; Streptococcus pyogenes ; genetics ; isolation & purification ; pathogenicity ; Virulence Factors ; genetics

We describe the first case of primary peritonitis in Korea of a healthy person due to Streptococcus pyogenes. In the absence of comorbid conditions, such as liver cirrhosis, immunosuppression, or nephrotic syndrome, primary peritonitis is uncommon in a young healthy woman. Abdomen computed tomography revealed ascites in the lower abdomen and peritoneal enhancement suggesting peritonitis. In diagnostic laparoscopy, purulent ascites was found in the pelvic cavity but both ovaries and fallopian tubes were intact. There were no intra-abdominal abnormalities such as bowel perforation, appendicitis, or necrosis. The reports of blood culture, ascites culture, and cervical swab culture confirmed S. pyogenes. After use of antibiotics, the patient was cured and discharged without sequelae.
Adult ; Anti-Bacterial Agents/therapeutic use ; Female ; Humans ; Laparoscopy ; Peritonitis/*diagnosis/drug therapy/microbiology ; Streptococcal Infections/*diagnosis/drug therapy/microbiology ; Streptococcus pyogenes/*isolation & purification ; Tomography, X-Ray Computed

No abstract available.
Acute Disease ; Adolescent ; Alkaline Phosphatase/*blood ; Anti-Bacterial Agents/*therapeutic use ; Arthritis, Infectious/*drug therapy/*enzymology/microbiology ; *Bacterial Infections/drug therapy/enzymology/microbiology ; Child ; Child, Preschool ; Haemophilus influenzae type b/isolation & purification ; Humans ; Infant ; Osteomyelitis/*drug therapy/*enzymology/microbiology ; Staphylococcus aureus/isolation & purification ; Streptococcus pneumoniae/isolation & purification ; Streptococcus pyogenes/isolation & purification

BACKGROUND: Group A streptococcus (GAS) is the most common cause of bacterial pharyngitis in children. Antibiotic resistance rates and emm genotypes of GAS isolated from patients with acute pharyngitis were studied in 2009. METHODS: Throat cultures were taken from 499 children with acute pharyngitis in Jinju, Korea, in 2008-2009. A total of 174 strains (34.9%) of GAS were isolated, and antimicrobial susceptibility testing was performed using the disk diffusion method. The phenotypes of macrolide resistance and macrolide resistance genes were determined. The emm genotypes were identified using PCR and sequencing. The data were compared with those acquired in 2002 in the same region. Data on the annual macrolide production were collected between 1999 and 2008. RESULTS: The resistance rates of GAS to erythromycin, clindamycin, and tetracycline were 4.6%, 2.9%, and 2.3%, respectively. The constitutive resistance rate was 62.5% for the erm(B) gene and 37.5% for the M phenotype of the mef(A) gene. emm4 was most frequently detected (28.2%), followed by emm89 (20.1%). Most of the erythromycin resistant strains had the emm28 genotype. We noted a gradual increase in macrolide production during the study period. CONCLUSIONS: The erythromycin resistance rate of GAS isolated from children with acute pharyngitis was significantly lower in 2009 (4.6%) than in 2002 (44.8%). We observed a remarkable change in the distribution of emm genotypes during the 7-yr period. The significant decline in erythromycin resistance in 2009 might be associated with a prominent decrease in the resistant genotype emm12 (3.4% in 2009 vs. 28.0% in 2002) rather than restriction of macrolide use.
Acute Disease ; Adolescent ; Anti-Bacterial Agents/*pharmacology ; Child ; Child, Preschool ; Disk Diffusion Antimicrobial Tests ; Drug Resistance, Bacterial/genetics ; Erythromycin/*pharmacology ; Female ; Genotype ; Humans ; Male ; Pharyngitis/drug therapy/*microbiology ; Phenotype ; Sequence Analysis, DNA ; Streptococcus pyogenes/*drug effects/*genetics/isolation & purification