Role of Adherence in the Pathogenesis of Neonatal Group B Streptococcal Infection

Abstract

The ability of group B streptococci to attach to buccal epithelial cells from adult volunteers, healthy neonates, and infants with invasive group B streptococcal infection was assessed by using 3 H-labeled bacteria incubated at a bacteria-to-cells ratio of 1,000:1. Type III group B streptococcal clinical isolates adhered significantly better to the epithelial cells of healthy neonates than to those of adults (mean bacteria per cell of 31 versus 7, respectively; P < 0.005). In contrast, no statistically significant differences in adherence of type Ia or type II strains to cells of neonates and adults were noted. The adherence of strains isolated from 15 infants with invasive group B streptococcal infection was significantly greater to the cells of infected infants than to those of age-matched controls (mean bacteria per cell of 39 versus 18, respectively; P < 0.005). In contrast, no significant difference was noted in the adherence of a usually adherent type Ia strain and a nonadherent type III strain to the cells of infected infants compared with control infants. These results indicate that the serotype of group B streptococci with the greatest virulence for neonates (type III) adheres better to neonatal than to adult epithelial cells. Infants who develop invasive infection may have an increased number of epithelial cell surface receptor sites for attachment of group B streptococci, the bacteria may elaborate products which unmask receptor sites, or both.

Adherence of group B streptococci to human endothelial cells in vitro

“…Previous studies have revealed that GBS, serotype I11 adheres better to epithelial cells from infants compared to adults. There is also a significantly better attachment to epithelial cells from newborns with an invasive GBS infection compared with age-matched controls (5). These studies suggest that the higher susceptibility of neonates to GBS infection correlates with increased adherence to epithelial cells.…”

“…The higher adherence of type I11 GBS to endothelial cells could contribute to the higer ability of these strains to cause neonatal bacteremia. Furthermore, type 111 GBS is more adherent to epithelial cells of susceptible neonates than to those of the relatively nonsusceptible adult host (5). Strains bound about twice as well to HUVEC as to the plastic surface.…”

“…Previous studies have shown that GBS serotype I11 adheres better to vaginal and oral epithelial cells compared with other serotypes (1, 3, 21). Transmission from the mother's genital tract to the offspring is a key factor in invasive neonatal GBS infection, at least in early-onset disease (5). Vaginal colonization with GBS as an early step in such infections has therefore been the subject of a number of reports (3, 10, 14).…”

What is the rationale for the use of granulocyte and granulocyte‐macrophage colony‐stimulating factors in the neonatal intensive care unit

“…As an example of a model organism, GBS is readily adherent to mucosal epithelial cells of neonates, particularly sick premature neonates, which facilitates its colonization at these surfaces (13). The exact mechanism for this selectivity in adherence properties still remains to be de ned, but cell-surface adhesion molecules and low levels of secretory immunoglobulin A (IgA) may be important contributory factors.…”

Involvement of locomotion of granulocytes in the phagocytosis of glass-adherent group B streptococci in the absence of opsonins

“…Bacteria adherent to solid substrata or cell monolayers have been shown to be more prone to phagocytosis by PMN than bacteria maintained in suspension in a fluid medium 1[,2 l. In these studies, serum demonstrated phagocytosis-enhancing capacities, which were attributed to opsonins. Group B streptococci (GBS) are able to adhere massively to intrauterine contraceptive devices [31 or to human and bovine epithelial cells [4,5]. Ad.…”