RESUMEN
We recovered a non-beta-hemolytic Streptococcus pyogenes strain from a severe soft tissue infection. In this isolate, we detected a premature stop codon within the sagC gene of the streptolysin S (SLS) biosynthetic operon. Reintroduction of full-length sagC gene on a plasmid vector restored the beta-hemolytic phenotype to our clinical isolate, indicating that the point mutation in sagC accounted for loss of hemolytic activity. To the best of our knowledge, this is the first report to demonstrate that a severe soft tissue infection can be caused by a non-beta-hemolytic S. pyogenes strain lacking a functional SagC.
Asunto(s)
Proteínas Bacterianas/genética , Codón sin Sentido , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidad , Adulto , Proteínas Bacterianas/biosíntesis , Vías Biosintéticas/genética , Prueba de Complementación Genética , Hemólisis , Humanos , Masculino , Análisis de Secuencia de ADN , Infecciones de los Tejidos Blandos/patología , Infecciones Estreptocócicas/patología , Streptococcus pyogenes/aislamiento & purificación , Estreptolisinas/biosíntesis , Factores de Virulencia/genéticaRESUMEN
Pneumococcal surface protein A (PspA) is a possible candidate for the development of a pneumococcal vaccine that has the potential to offer a broad range of protection. PspA genes of pneumococcal meningitis isolates (n=40) isolated as part of an ongoing population-based nation-wide surveillance program on invasive pneumococcal disease in children in Germany were analyzed to expand our knowledge on the distribution of PspA families of this important vaccine candidate in Germany. The serotype distribution of the strains was as follows: serotype 4 (n=3), 6B (5), 9V (2), 14 (8), 18C (6), 19F (5), 23F (6), and 7F (5). The pspA genes of these strains could be assigned to 2 families containing 20 pneumococcal strains each. Family I could be subdivided into 2 clades with 17 strains in clade 1 and 3 strains in clade 2, and family II could be subdivided into 3 subgroups (clades 3-5) containing 16, 3, and 1 strain, respectively. Pneumococcal serotypes were distributed evenly over all clades and families. Interestingly, the distribution of the PspA gene families in Germany was seen to differ slightly that found in other countries.
