Clinical Features of Infections Caused by Streptococcus pyogenes in Children and their Antimicrobial Susceptibility / 감염

ABSTRACT

BACKGROUND: Streptococcus pyogenes causes most often pharyngitis or tonsillitis but may also be responsible for severe diseases including bacteremia and pneumonia. Recent publications from several geographic areas showed high rates of resistance to erythromycin and newer macrolides, often used in patients allergic to penicillin, in clinical isolates of S. pyogenes. METHODS: Minimum inhibitory concentration of 31 strains of S. pyogenes, isolated at the Seoul National University Children's Hospital from October 1991 through April 1998, were determined for penicillin, ceftriaxone, vancomycin, clindamycin, erythromycin, roxythromycin, and clarithromycin by agar dilution method or E-test. In addition, clinical features of the patients from whom the organisms were isolated were reviewed retrospectively. RESULTS: Of the 28 patients whose medical records were reviewed, the most common clinical presentations were soft-tissue infection (8 cases) and pharyngitis (5 cases). Other presentations included bacteremia without focus, pneumonia, vaginitis, lymphadenitis, omphalitis (two of each); primary peritonitis, rheumatic fever with carditis, scarlet fever, acute otitis media, and disseminated disease (one of each). All of the isolates were susceptible to penicillin, ceftriaxone, and vancomycin. However, 5 isolates (16%) were resistant to erythromycin, and all of the erythromycin-resistant strains were resistant to roxythromycin and clarithromycin as well. Three of these erythromycin-resistant strains were also resistant to clindamycin. CONCLUSION: S. pyogenes may cause serious infections in children. Emergence of resistance in clinical isolates of S. pyogenes to macrolides and clindamycin should be considered in empirical antimicrobial therapy of suspected group A streptococcal infections and in establishment of antibiotic policy in Korea.