RESUMEN
OBJECTIVE: To evaluate the in vitro activities of 13 antimicrobial agents against 47 group A Streptococcus pyogenes (GAS) strains, and to determine the presence of genes encoding streptococcal pyrogenic exotoxin A (SpeA) and the M-protein serotypes. MATERIALS AND METHODS: A cross-sectional study was conducted at Centro de Salud Dr. José Castro Villagrana, during a scarlet fever outbreak occurring between December 1999 and January 2000, among 137 children at Colegio Espíritu de América. Minimum Inhibitory Concentrations (MICs) were obtained by the semiautomated microdilution method. Automated DNA sequencing was used for analysis of sequence variation in genes encoding the M protein, and SpeA. RESULTS: All strains were sensitive to betalactams and clindamycin. Six (12.7%) were resistant to erythromycin. The M2 type was the most frequently isolated GAS (27); almost all (96%) bacteria with the SpeA gene had the gene encoding the M2 protein. CONCLUSIONS: The recent resurgence of GAS infections calls for molecular epidemiology research and studies on the sensitivity to macrolides and beta-lactams.
Asunto(s)
Brotes de Enfermedades , Resistencia a Medicamentos , Escarlatina/microbiología , Streptococcus pyogenes/efectos de los fármacos , Adolescente , Proteínas Bacterianas/genética , Niño , Preescolar , Trazado de Contacto , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple , Exotoxinas/genética , Femenino , Humanos , Masculino , Proteínas de la Membrana/genética , México/epidemiología , Pruebas de Sensibilidad Microbiana , Faringe/microbiología , Escarlatina/epidemiología , Instituciones Académicas , Serotipificación , Streptococcus pyogenes/clasificación , Streptococcus pyogenes/genética , Streptococcus pyogenes/aislamiento & purificaciónRESUMEN
OBJECTIVE: To evaluate the in vitro activities of 13 antimicrobial agents against 47 group A Streptococcus pyogenes (GAS) strains, and to determine the presence of genes encoding streptococcal pyrogenic exotoxin A (SpeA) and the M-protein serotypes. MATERIALS AND METHODS: A cross-sectional study was conducted at Centro de Salud Dr. JosÚ Castro Villagrana, during a scarlet fever outbreak occurring between December 1999 and January 2000, among 137 children at Colegio EspÝritu de AmÚrica. Minimum Inhibitory Concentrations (MICs) were obtained by the semiautomated microdilution method. Automated DNA sequencing was used for analysis of sequence variation in genes encoding the M protein, and SpeA. RESULTS: All strains were sensitive to betalactams and clindamycin. Six (12.7) were resistant to erythromycin. The M2 type was the most frequently isolated GAS (27); almost all (96) bacteria with the SpeA gene had the gene encoding the M2 protein. CONCLUSIONS: The recent resurgence of GAS infections calls for molecular epidemiology research and studies on the sensitivity to macrolides and beta-lactams.
Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Escarlatina , Streptococcus pyogenes , Resistencia a Medicamentos , Brotes de Enfermedades , Faringe , Escarlatina , Instituciones Académicas , Streptococcus pyogenes , ADN Bacteriano , Pruebas de Sensibilidad Microbiana , Serotipificación , Trazado de Contacto , Exotoxinas , México , Proteínas Bacterianas/genética , Proteínas de la Membrana/genética , Farmacorresistencia Bacteriana MúltipleRESUMEN
TITLE: Serotypes and antimicrobial susceptibility of group B Streptococcus isolated from pregnant women in México BACKGROUND: Group B streptococci (SGB) are a leading cause of neonatal sepsis and meningitis. Women colonized might also develop pregnancy-associated infections including urinary tract infection, bacteremia and postpartum endometritis. There are nine different capsular types, and with the possibility of a GBS vaccine in the future; it is essential to understand which of these types are circulating. We determined the serotype distribution of isolated rectovaginal and urine GBS obtained from an obstetric population, and also their antibiotic sensitivity patterns. METHODS: A total of 101 strains were studied: SGB were confirmed by latex agglutination (Slidex Strepto-Kit bioMérieux), and the serotype was confirmed by latex agglutination (Pastorex Streptococcus B. Becton Dickinson, EUA). Antimicrobial susceptibility testing was performed by a Kirby-Bauer disk diffusion. RESULTS: All SGB were serologically typeable; 61.3% were type I, 25.7% were type II and only 12.8 were type III. All of them were 100% susceptible to beta lactam agents. Only 5.9% strains were resistant to erythromycin. CONCLUSION: In the last years, no major changes have been observed in the distribution of serotypes of SGB in México, serotype I is still the most common. This makes us think of the possibility of a vaccine that includes serotypes I and II that represent close to 90% of the isolations.