Comparative analysis of the localization of lipoteichoic acid in Streptococcus agalactiae and Streptococcus pyogenes

Abstract

The cellular locations of deacylated lipoteichoic acid (dLTA) and lipoteichoic acid (LTA) were examined in late-exponential-phase cells of a serotype III strain of Streptococcus agalactiae (group B streptococci [GBS]) isolated from an infant with late-onset meningitis and compared with a fresh clinical isolate of Streptococcus pyogenes (group A streptococci [GAS]). LTA and dLTA were found to be associated with the protoplast membranes of both organisms, with only dLTA found in mutanolysin cell wall digests. Both organisms released dLTA during growth, but only the GAS released substantial levels of LTA into the culture medium. However, penicillin treatment (5 ,ug/ml for 60 min) of GBS resulted in the recovery of LTA in cell wall digests as well as in the culture medium. These results suggest that under normal growth conditions, the hydrophobic region (glycolipid) of LTA remains associated with the cytoplasmic membrane of GBS and unavailable for hydrophobic interactions at the cell surface with epithelial cells. In contrast, release of LTA into the environment by the GAS allows the fatty acid moieties to interact with hydrophobic domains on the surface of epithelial cells. These results may help explain the marked differences in the specificity of binding between these two major streptococcal pathogens for human fetal and adult epithelial cells.

Adhesion of glucosyltransferase phase variants to Streptococcus gordonii bacterium-glucan substrata may involve lipoteichoic acid

“…Our results clearly establish that LTA is a significant component of the S. gordonii BPM and that a fraction of this LTA is released by sucrose. These findings agree with those of others, which showed that LTA complexes with glucans synthesized by oral streptococci (4,30) and that LTA may be released from these complexes by sucrose (4,24). The concentration of LTA released from the BPM by sucrose, however, was more than 15-fold less than the amount of exogenous strain Challis LTA required to inhibit adhesion to the same extent as sucrose.…”

Roles of the bacterial cell wall and capsule in induction of tumor necrosis factor alpha by type III group B streptococci

“…The purified material was tested by ELISA inhibition using specific rabbit antiserum for the presence of the group-specific antigen. GBS LTA, purified as previously described, was a gift from Stephen J. Mattingly, University of Texas Health Science Center-San Antonio (20). Briefly, LTA was obtained from GBS cell pellets by extraction with 90% phenol and chloroform-methanol (2:1, vol/ vol).…”

In vitro method to differentiate isolates of type III Streptococcus agalactiae from symptomatic and asymptomatic patients

“…Sialic acid was released by hydrolyzing the antigen with 1 N HCl at 840C for 15 min and quantitated by the Aminoff method (1). Extraction, purification, and quantification of LTA has been detailed in previous work (9,12).…”