CLONAL ANALYSIS OF STREPTOCOCCUS-AGALACTIAE ISOLATED FROM INFANTS WITH NEONATAL SEPSIS OR MENINGITIS AND THEIR MOTHERS AND FROM HEALTHY PREGNANT-WOMEN

The purpose of this study was to evaluate if group B streptococci (GBS ) isolated from infants with neonatal sepsis or meningitis and their m others differ from GBS isolated from healthy pregnant women who gave b irth to healthy infants. Danish clinical isolates of GBS (n = 118) wer e characterized by multilocus enzyme electrophoresis, a method recentl y used to identify virulent clones of GBS type III from North American infants. By analysis of allelic profiles of 11 metabolic enzyme loci, 43 different electrophoretic types were found. Clustering analysis re vealed two primary phylogenetic divisions at a distance of >0.8, both containing serotype III isolates. One division, comprising virtually a ll disease isolates, showed a population structure like that of tradit ional pathogens. The other division, containing the majority of carrie r isolates, had a structure reminiscent of that of mucosal commensals, with each isolate being different.