Invasive Group B Streptococcal Disease: The Emergence of Serotype V

Abstract

Group B streptococci (GBS) cause invasive disease in neonates, pregnant adults, and nonpregnant adults with underlying or chronic disease. Previous studies found capsular serotypes Ia, Ib, II, and III cause invasive disease. Prospective population-based surveillance of invasive GBS disease was done from June 1992 to June 1993 in metropolitan Atlanta: 279 patients had invasive disease. Of these, 43% were < or = 6 months old, and 57% were adults. The incidence among all adults was 7.7/100,000/year, 33% higher than in 1989-1990 (P < .01). The incidence in nonpregnant adults was 5.9/100,000/year, 37% higher than in 1989-1990 (P < .02). Serotyping of 178 patient isolates revealed that 34% had GBS serotype Ia or Ia/c, 8% had Ib/c, 6% had II or II/c, 29% had III, 0% had IV, 21% had V, and 2% were nontypeable. Serotype V was recovered from all groups and was the most common serotype from nonpregnant adults. Serotype V isolates appeared to be highly related genetically. The increasing incidence of GBS disease in adults, the changing distribution of serotypes, and the emergence of serotype V will impact vaccine strategies.

Mosaicism in the alpha-like protein genes of group B streptococci

“…This polysaccharide͞protein concordance is in contrast to the distribution of PspA, for example, which is independent of capsular serotype (15). This concordance may reflect clonal lineages within a species that is naturally incompetent and is consistent with several studies showing a predominance of individual clones among clinical GBS isolates (35,36). Alternatively, it is conceivable that there is a functional linkage between the alpha-like proteins and polysaccharide serotypes that would require this specificity.…”

Serotipos y susceptibilidad antimicrobiana de Streptococcus agalactiae

“…Este serotipo es uno de los más frecuentes en la actualidad en infecciones invasivas en adultos con condiciones predisponentes y menos frecuente en infecciones invasivas maternas y neonatales 14,27,28 .…”

Virulence properties of type VII Streptococcus agalactiae (group B streptococci) and immunochemical analysis of capsular type polysaccharide

“…Therefore, some new serotypes were defined on the basis of the structural differences of the capsular polysaccharide [9-131. In the 1970s and early 1980s, types Ia, Ib and I11 were the most common serotypes associated with neonatal GBS diseases [ 1,2]. More recently, important changes in serotype distribution have been observed in the USA and in Japan where serotypes V and VIII (JM9), respectively, have emerged as significant causes of diseases both in children and in adults [8, [14][15][16][17].…”