lipoteichoic-acid and Streptococcal-Infections

Topics: Adhesins, Bacterial; Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Adhesion; Bacterial Outer Membrane Proteins; Bacterial Proteins; Carrier Proteins; Fibronectins; Humans; Lipopolysaccharides; Mice; Models, Immunological; Receptors, Immunologic; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids

Author reviews relations between streptococcal infections and rheumatic fever, particularly biological characteristics of streptococo, genetic and pathogenic factors. Special emphasis is placed on diagnostic criteria to avoid overdiagnosis. Finally, the basis for a program directed to eradicate the disease: screening of susceptible, individuals selection of rheumatogenic serotypes and vaccine preparation against this antigenic strains are reviewed.

Topics: Anti-Bacterial Agents; Antigens, Bacterial; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Vaccines; Carrier Proteins; Disease Susceptibility; Humans; Lipopolysaccharides; Phosphatidic Acids; Rheumatic Fever; Rheumatic Heart Disease; Streptococcal Infections; Streptococcus; Streptolysins; Teichoic Acids

Gram-positive bacteria such as Streptococcus gordonii causing life-threatening infective endocarditis are mainly recognized by Toll-like receptor 2 (TLR2). Lipoteichoic acid (LTA) and lipoproteins are representative TLR2 ligands that play important roles in bacterial infection and in host inflammatory responses. In the present study, we generated an LTA-deficient mutant (ΔltaS) and a lipoprotein-deficient mutant (Δlgt) and investigated the contributions of LTA and lipoproteins to bacterial morphology and their effect on induction of proinflammatory cytokines in THP-1 and mouse bone-marrow derived macrophages (BMDMs). Deletion of ltaS and lgt was confirmed by PCR analysis of genomic DNA from each mutant. The mutants with absence of LTA or lipoproteins were examined by SDS-PAGE followed by Western blotting with anti-LTA antibodies and silver staining, respectively. Interestingly, scanning and transmission electron microscopies showed no difference in the bacterial cell morphology or size between the wild-type and the mutants even though substantial changes in the cell size and/or morphology have been reported in other Gram-positive bacteria such as Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis. However, S. gordonii wild-type and ΔltaS potently induced the expression of proinflammatory cytokines including TNF-α, IL-8, and IL-1β at the mRNA and protein levels, while Δlgt did not have these effects. Furthermore, lipoproteins purified from S. gordonii also induced the expression of the aforementioned cytokines more potently than the purified LTA. Neither LTA nor lipoprotein induced TNF-α, KC (IL-8 counterpart in mouse), and IL-1β in TLR2-deficient BMDMs. S. gordonii Δlgt was less virulent than the wild-type or ΔltaS in a mouse intraperitoneal infection model. Collectively, these results suggest that S. gordonii lipoproteins, but not LTA, are mainly responsible for the infection and inflammatory responses.

Topics: Animals; Cell Wall; Cytokines; Humans; Inflammation; Inflammation Mediators; Lipopolysaccharides; Lipoproteins; Mice, Inbred C57BL; Mutation; Streptococcal Infections; Streptococcus gordonii; Teichoic Acids; THP-1 Cells; Toll-Like Receptor 2

Group A

Topics: Animals; CARD Signaling Adaptor Proteins; HEK293 Cells; Humans; Lectins, C-Type; Lipopolysaccharides; Membrane Proteins; Mice; Mice, Inbred C57BL; Monocytes; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids

Extraplacental membranes define the gestational compartment and provide a barrier to infectious microorganisms ascending the gravid female reproductive tract. We tested the hypothesis that bioactive metabolites of trichloroethylene (TCE) decrease pathogen-stimulated innate immune response of extraplacental membranes. Extraplacental membranes were cultured for 4, 8, and 24h with the TCE metabolites trichloroacetate (TCA) or S-(1,2-dichlorovinyl)-l-cysteine (DCVC) in the absence or presence of lipoteichoic acid (LTA) or lipopolysaccharide (LPS) to simulate infection. In addition, membranes were cocultured with DCVC and Group B Streptococcus (GBS). DCVC (5-50μM) significantly inhibited LTA-, LPS-, and GBS-stimulated cytokine release from tissue cultures as early as 4h (P≤0.05). In contrast, TCA (up to 500μM) did not inhibit LTA-stimulated cytokine release from tissue punches. Because cytokines are important mediators for host response to infectious microorganisms these findings suggest that TCE exposure could potentially modify susceptibility to infection during pregnancy.

Topics: Chorion; Cysteine; Decidua; Disease Resistance; Extraembryonic Membranes; Female; Humans; Immunity; Lipopolysaccharides; Pregnancy; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Tissue Culture Techniques; Trichloroacetic Acid; Trichloroethylene; Tumor Necrosis Factor-alpha

Streptococcus agalactiae infection causes high mortality in cardiovascular disease (CVD) patients, especially in case of setting prosthetic valve during cardiac surgery. However, the pathogenesis mechanism of S. agalactiae associate with CVD has not been well studied. Here, we have demonstrated the pathogenicity of S. agalactiae in rat cardiomyocytes (H9C2). Interestingly, both live and dead cells of S. agalactiae were uptaken by H9C2 cells. To further dissect the process of S. agalactiae internalization, we chemically inhibited discrete parts of cellular uptake system in H9C2 cells using genistein, chlorpromazine, nocodazole and cytochalasin B. Chemical inhibition of microtubule and actin formation by nocodazole and cytochalasin B impaired S. agalactiae internalization into H9C2 cells. Consistently, reverse‒ transcription PCR (RT‒PCR) and quantitative real time‒PCR (RT-qPCR) analyses also detected higher levels of transcripts for cytoskeleton forming genes, Acta1 and Tubb5 in S. agalactiae‒infected H9C2 cells, suggesting the requirement of functional cytoskeleton in pathogenesis. Host survival assay demonstrated that S. agalactiae internalization induced cytotoxicity in H9C2 cells. S. agalactiae cells grown with benzyl penicillin reduced its ability to internalize and induce cytotoxicity in H9C2 cells, which could be attributed with the removal of surface lipoteichoic acid (LTA) from S. agalactiae. Further, the LTA extracted from S. agalactiae also exhibited dose‒dependent cytotoxicity in H9C2 cells. Taken together, our data suggest that S. agalactiae cells internalized H9C2 cells through energy‒dependent endocytic processes and the LTA of S. agalactiae play major role in host cell internalization and cytotoxicity induction.

Topics: Animals; Cell Line; Endocytosis; Humans; Lipopolysaccharides; Myocytes, Cardiac; Rats; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Virulence

Cationic antimicrobial peptides (CAMPs) serve as the first line of defense of the innate immune system against invading microbial pathogens. Gram-positive bacteria can resist CAMPs by modifying their anionic teichoic acids (TAs) with D-alanine, but the exact mechanism of resistance is not fully understood. Here, we utilized various functional and biophysical approaches to investigate the interactions of the human pathogen Group B Streptococcus (GBS) with a series of CAMPs having different properties. The data reveal that: (i) D-alanylation of lipoteichoic acids (LTAs) enhance GBS resistance only to a subset of CAMPs and there is a direct correlation between resistance and CAMPs length and charge density; (ii) resistance due to reduced anionic charge of LTAs is not attributed to decreased amounts of bound peptides to the bacteria; and (iii) D-alanylation most probably alters the conformation of LTAs which results in increasing the cell wall density, as seen by Transmission Electron Microscopy, and reduces the penetration of CAMPs through the cell wall. Furthermore, Atomic Force Microscopy reveals increased surface rigidity of the cell wall of the wild-type GBS strain to more than 20-fold that of the dltA mutant. We propose that D-alanylation of LTAs confers protection against linear CAMPs mainly by decreasing the flexibility and permeability of the cell wall, rather than by reducing the electrostatic interactions of the peptide with the cell surface. Overall, our findings uncover an important protective role of the cell wall against CAMPs and extend our understanding of mechanisms of bacterial resistance.

Topics: Alanine; Amino Acid Sequence; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Cell Wall; Drug Resistance, Microbial; Humans; Lipopolysaccharides; Microbial Sensitivity Tests; Microscopy, Atomic Force; Microscopy, Electron, Transmission; Molecular Sequence Data; Osmolar Concentration; Protein Processing, Post-Translational; Streptococcal Infections; Streptococcus; Surface Properties; Teichoic Acids

Toll-like receptors (TLRs) are key sensors of pathogen-associated molecular patterns (PAMPs). Their role in immunity is difficult to examine in species of veterinary interest, due to restricted access to the knockout technology and TLR-specific antibodies. An alternative approach is to generate cell lines transfected with various TLRs and to examine the recognition of PAMPs or relevant bacteria. In this report, we examined whether recognition of various PAMPs and mastitis-causing bacteria is achieved by transfection of recombinant bovine TLR2 (boTLR2). Therefore, human embryonic kidney (HEK) 293 cells were transfected by whole boTLR2. A clonal analysis of stably transfected cells disclosed variable recognition of several putative TLR2 agonists although expressing similar amounts of the transgene and endogenous TLR6. One clone (clone 25) reacted by copious interleukin-8 (IL-8) production to several stimulants of TLR2 such as di-palmitoylated cysteyl-seryl-lysyl-lysyl-lysyl-lysine (Pam2), a biochemical preparation of lipoteichoic acid from Staphylococcus aureus, a commercial preparation of peptidoglycan from S. aureus, and heat-killed Listeria monocytogenes (HKLM). TLR2-dependent induction of IL-8 release was stronger in medium containing human serum albumin than in medium containing fetal calf serum. Clone 25 cells responded to high concentrations of S. aureus and to Escherichia coli causing mastitis, but not to Streptococcus uberis and to Streptococcus agalactiae which also cause mastitis. Stimulation by S. aureus was relatively weak when compared (i) with stimulation of the same cells by HKLM and PAMPs derived from S. aureus, (ii) with a clone stably transfected with TLR4 and MD-2 and stimulated by E. coli causing mastitis, and (iii) with interferon-gamma-costimulated bovine macrophages stimulated by S. aureus and S. agalactiae. Thus, clone 25 is suitable for studying the interaction of putative TLR2 agonists with bovine TLR2-transfected cells, provides a cell to search for TLR2-specific antibodies, and is a tool for studying the interaction of TLR2 with bacteria causing disease, e.g. mastitis, in cattle.

Topics: Animals; Cattle; CD36 Antigens; Cell Line; Cloning, Molecular; Female; Flow Cytometry; Humans; Interleukin-8; Lipopolysaccharides; Mastitis, Bovine; Nitric Oxide; Peptidoglycan; Receptors, Pattern Recognition; Reverse Transcriptase Polymerase Chain Reaction; RNA; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Toll-Like Receptor 2; Transfection

We generated by allelic replacement a DeltadltA mutant of a virulent Streptococcus suis serotype 2 field strain and evaluated the contribution of lipoteichoic acid (LTA) d-alanylation to the virulence traits of this swine pathogen and zoonotic agent. The absence of LTA D-alanylation resulted in increased susceptibility to the action of cationic antimicrobial peptides. In addition, and in contrast to the wild-type strain, the DeltadltA mutant was efficiently killed by porcine neutrophils and showed diminished adherence to and invasion of porcine brain microvascular endothelial cells. Finally, the DeltadltA mutant was attenuated in both the CD1 mouse and porcine models of infection, probably reflecting a decreased ability to escape immune clearance mechanisms and an impaired capacity to move across host barriers. The results of this study suggest that LTA D-alanylation is an important factor in S. suis virulence.

Topics: Alanine; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacterial Adhesion; Bacterial Proteins; Carbon-Oxygen Ligases; Cell Line; D-Alanine Transaminase; Endothelial Cells; Female; Gene Deletion; Lipopolysaccharides; Magnetic Resonance Spectroscopy; Mice; Microbial Viability; Neutrophils; Streptococcal Infections; Streptococcus suis; Survival Analysis; Swine; Teichoic Acids; Virulence

In recent years, there has been considerable interest in using the oral commensal gram-positive bacterium Streptococcus gordonii as a live vaccine vector. The present study investigated the role of d-alanylation of lipoteichoic acid (LTA) in the interaction of S. gordonii with the host innate and adaptive immune responses. A mutant strain defective in d-alanylation was generated by inactivation of the dltA gene in a recombinant strain of S. gordonii (PM14) expressing a fragment of the S1 subunit of pertussis toxin. The mutant strain was found to be more susceptible to killing by polymyxin B, nisin, magainin II, and human beta defensins than the parent strain. When it was examined for binding to murine bone marrow-derived dendritic cells (DCs), the dltA mutant exhibited 200- to 400-fold less binding than the parent but similar levels of binding were shown for Toll-like receptor 2 (TLR2) knockout DCs and HEp-2 cells. In a mouse oral colonization study, the mutant showed a colonization ability similar to that of the parent and was not able to induce a significant immune response. The mutant induced significantly less interleukin 12p70 (IL-12p70) and IL-10 than the parent from DCs. LTA purified from the bacteria induced tumor necrosis factor-alpha and IL-6 production from wild-type DCs but not from TLR2 knockout DCs, and the mutant LTA induced a significantly smaller amount of these two cytokines. These results show that d-alanylation of LTA in S. gordonii plays a role in the interaction with the host immune system by contributing to the relative resistance to host defense peptides and by modulating cytokine production by DCs.

Topics: Alanine; Animals; Anti-Bacterial Agents; Cell Line; Dendritic Cells; Lipopolysaccharides; Mice; Streptococcal Infections; Streptococcus; Teichoic Acids; Virulence

The present study was carried out to gain insight into the mechanisms involved in the pathogenesis of streptococcal toxic shock syndrome (TSS) and other acute invasive diseases caused by Streptococcus pyogenes (GAS). Specifically, since both whole bacteria and their soluble products are often present in the blood in these conditions, we sought to detect possible synergic activities of somatic and extracellular products in inducing mediators release. For this purpose, whole blood cultures from healthy donors were incubated with different concentrations of streptococcal pyrogenic exotoxin A (SpeA), which is considered a major molecular effector of TSS, heat-killed GAS and cell-wall components such as lipoteichoic acid (LTA) and soluble peptidoglican (sPGN). Significant levels of TNF-alpha, IL-1 alpha and IFN-gamma were found in supernatants from cultures incubated with each of the four inducers alone. Whole GAS and both cell-wall components were more effective (p < 0.05) than SpeA in inducing cytokine release. Whole GAS, at weight basis, was a more potent inducer than LTA and sPGN and LTA, at weight basis, was a more potent inducer than sPGN. In order to verify possible additive or synergic effects of exotoxic and parietal compounds in inducing cytokine release, whole blood cells were incubated with mixtures of SpeA and LTA at different molecular ratio. TNF-alpha, IL-1 alpha and IFN-gamma levels in supernatants were significantly (p < 0.05) higher in supernatants of cultures stimulated simultaneously with the two components than those of cultures stimulated with a single agent. Moreover, these levels were significantly higher than the sum of cytokine levels induced by single components. This study shows that parietal compounds can act in synergy with exotoxins in inducing the release of cytokines, which appear to be the major mediators of TSS.

Topics: Bacterial Proteins; Blood Cells; Cells, Cultured; Cytokines; Exotoxins; Humans; Interferon-gamma; Interleukin-1; Lipopolysaccharides; Membrane Proteins; Shock, Septic; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids; Tumor Necrosis Factor-alpha

Lipoteichoic acid (LTA) is thought to play a role in the interactions between Streptococcus pyogenes and host cells. We have examined the effect of exogenous LTA on the adherence and entry of S. pyogenes JRS4 strain into HEp-2 epithelial cells. LTA markedly inhibited bacterial entry in a concentration-dependent manner, up to 250 microg ml(-1). In contrast, LTA had only a slight inhibitory effect on adherence. LTA also inhibited the entry but not adherence of Salmonella typhimurium strain into HEp-2 cells. Binding experiments showed a dose-dependent binding of LTA to cells up to 10 microg ml(-1). Confocal laser microscopy imaging and analysis revealed that LTA was internalized by the epithelial cells and colocalized with F-actin. These results might imply that, following binding, exogenous LTA enters HEp-2 cells and exerts a cytotoxic effect that interferes with bacterial internalization. A possible target for LTA activity might be the actin cytoskeleton, which is known to be essential for bacterial uptake.

Topics: Bacterial Adhesion; Cytoplasm; Epithelial Cells; Humans; Lipopolysaccharides; Microscopy, Confocal; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids; Tumor Cells, Cultured

Topics: Bacterial Proteins; Base Sequence; Carrier Proteins; Cell Wall; Choline; DNA Primers; DNA, Bacterial; Humans; Lipopolysaccharides; N-Acetylmuramoyl-L-alanine Amidase; Streptococcal Infections; Streptococcus pneumoniae; Teichoic Acids; Virulence

Topics: Adult; Cytokines; Humans; In Vitro Techniques; Interleukin-1; Interleukin-6; Interleukin-8; Lipopolysaccharides; Polysaccharides, Bacterial; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Tumor Necrosis Factor-alpha

The subcellular components of type III group B streptococci (GBS) that contribute to the host inflammatory response were determined by measuring production of the proinflammatory cytokine interleukin (IL)-6 by cord blood monocytes. Monocytes were stimulated with encapsulated (COH1) or unencapsulated (COH1-13) whole type III GBS or with purified GBS components, including type III capsular polysaccharide (III-PS), group B antigen (GB-Ag), lipoteichoic acid (LTA), or Escherichia coli lipopolysaccharide. Monocytes exposed to COH1 and COH1-13 released similar amounts of IL-6. GBS III-PS, GB-Ag, and LTA each induced IL-6. However, IL-6 release by monocytes was significantly greater after stimulation by GB-Ag than by III-PS or LTA (P < .05). Sera from 16 neonates with systemic GBS disease had IL-6 levels of 8 pg/mL to 4.28 ng/mL. GB-Ag is a potent inducer of IL-6 and may play an important role in tissue inflammation during GBS infection.

Topics: Adult; Antigens, Bacterial; Bacterial Capsules; Cells, Cultured; Fetal Blood; Humans; Infant, Newborn; Interleukin-6; Lipopolysaccharides; Monocytes; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids

Topics: Adhesins, Bacterial; Antibodies, Bacterial; Bacterial Adhesion; Collagen; Epithelium; Humans; Immunity, Innate; Immunoglobulin A, Secretory; Lipopolysaccharides; Mouth; Mucous Membrane; Pharyngitis; Pharynx; Recurrence; Rheumatic Fever; Rheumatic Heart Disease; Saliva; Salivary Proteins and Peptides; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids

Infective endocarditis is caused by bacterial colonization of the endocardium. Because endocardium modulates mechanical performance of subjacent myocardium, we studied acute effects of bacteria on isolated cardiac muscle and on the functional role of the endocardium. Bacteria, grown in broth at 37 degrees C, were added at increasing concentrations (10(2) to 10(6) bacteria/ml) to cat papillary muscles in Krebs-Ringer solution (1.25 mM Ca2+, 35 degrees C). The endocardial surface was damaged by exposing muscles to a stream of dry air for 30 s. Streptococcus (Enterococcus) faecalis induced significant increases in total peak isometric twitch tension (TT) and maximal velocity of unloaded shortening (Vmax) and significant decreases in time to TT (TtTT) and time to half isometric twitch tension decline (RT 1/2), both before and after removal of endocardial endothelium. This response could also be elicited with bacterial filtrate, after boiling the filtrate or after extracting the polysaccharides from it with KIO4. Increasing Ca2+ concentrations progressively reduced the response to the filtrate. Propranolol slightly, although not significantly, diminished the effects on TT and Vmax while abolishing the effects on TtTT and on RT 1/2. By contrast, Streptococcus bovis and Staphylococcus aureus did not affect TT or Vmax but induced a slight but significant decrease in TtTT at the highest concentration of bacteria. Accordingly, the filtrate of Strep. faecalis induces a positive inotropic effect. The active component is neither a protein nor a polysaccharide, and its effect may be partly beta-adrenoceptor mediated. Strep. bovis and Staph. aureus have negligible acute effects on contractility.

Topics: Adrenergic beta-Antagonists; Animals; Arrhythmias, Cardiac; Calcium; Cats; Endocarditis, Bacterial; Endocardium; Endothelium; Enterococcus faecalis; Hot Temperature; Kinetics; Lipopolysaccharides; Microscopy, Electron, Scanning; Myocardial Contraction; Polysaccharides; Propranolol; Stimulation, Chemical; Streptococcal Infections; Teichoic Acids

Previous studies have shown that lipoteichoic acid (LTA) of group A streptococci plays a central role in the adherence of these organisms to epithelial cells. In this study, intranasal instillation of purified LTA but not deacylated LTA in mice blocked colonization and prevented death after intranasal challenge infection with group A streptococci. Bacteria pretreated with rabbit antisera against LTA also failed to colonize or infect mice after intranasal challenge. In vitro studies showed that LTA and M protein inhibited adherence of type 24 streptococci to mouse pharyngeal cells. Passive intranasal administration of purified type 24 M protein protected mice from death after challenge infection with type 24 streptococci but had no significant effect on pharyngeal colonization. Surface LTA and M protein may mediate adherence of streptococci to mouse pharyngeal cells, and blocking adherence with LTA prevents colonization and infection in this animal model.

Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Adhesion; Bacterial Outer Membrane Proteins; Bacterial Proteins; Carrier Proteins; Female; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Nasal Mucosa; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids

Pregnant Swiss-Webster mice were vaginally inoculated with 10(5) virulent and avirulent serotype III Streptococcus agalactiae and treated 4 days later with topical vaginal inhibitor solutions. Preparations containing lipoteichoic acid (LTA) or glycerophosphate (GP), the repeating linear backbone of LTA, significantly reduced neonatal colonization and bacteremia by the virulent isolate and colonization by the avirulent strain. Similar results were obtained if bacteria were preincubated with LTA or GP at 37 degrees C for 30 min before vaginal inoculation. Human serum albumin (HSA), a known inhibitor of binding of LTA to human fetal epithelial cells, also resulted in reduction in colonization and bacteremia of neonatal mice. However, maternal treatment with a combination of HSA (2%) and GP (1%) completely prevented neonatal colonization and bacteremia without altering the normal aerobic bacterial vaginal flora. These results provide impetus to the development of an alternative means of preventing neonatal group B streptococcal infections in humans without requiring maternal immunization or chemoprophylaxis.

Topics: Animals; Animals, Newborn; Female; Glycerophosphates; Lipopolysaccharides; Mice; Pregnancy; Serum Albumin; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Vaginal Creams, Foams, and Jellies

Sera from patients with subacute bacterial endocarditis (SBE) due to Streptococcus mutans or other oral streptococci and from normal subjects were assayed by enzyme-linked immunosorbent assay for antibodies to defined S. mutans antigens. Antibodies of IgG and IgA isotypes to Ag I/II and Ag III were greatly elevated in S. mutans-SBE sera, and the IgA antibodies in 3 sera included both polymeric and monomeric forms. Elevated IgM and IgG anti-lipoteichoic acid and IgG and IgA anti-serotype c polysaccharide antibodies were also found. The sera of 4 of 6 patients infected with other oral streptococci also displayed antibodies to S. mutans Ag I/II. Sera of 3 patients infected with Streptococcus mitis or Streptococcus oralis, but none of the S. mutans-infected cases, showed elevated antibodies to human heart sarcolemma, and all SBE sera had elevated rheumatoid factor. These results suggest that the known surface protein antigens of S. mutans are immunodominant in humans, and are not likely to be heart cross-reactive.

Topics: Antibodies, Bacterial; Antigens, Bacterial; Antigens, Surface; Cross Reactions; Endocarditis, Subacute Bacterial; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Lipopolysaccharides; Rheumatoid Factor; Sarcolemma; Streptococcal Infections; Streptococcus; Streptococcus mutans; Streptococcus sanguis; Teichoic Acids

While there is considerable evidence that both interleukin-1 (IL-1) and tumor necrosis factor (TNF) are central mediators of inflammation caused by gram-negative bacteria and endotoxin, the roles of these two mediators in gram-positive infection are unknown. Pneumococcal infections are characterized by an intense inflammatory reaction in infected tissues. Current evidence suggests that the component of the pneumococcus which causes this inflammation in many body sites is the cell wall. We determined the ability of native pneumococcal cell wall, lipoteichoic acid, and cell wall subcomponents to stimulate secretion of IL-1 and TNF from human monocytes. Each pneumococcal cell surface component was found to have a different specific activity for induction of IL-1. Teichoication was an important determinant of this activity: teichoicated species were at least 10,000-fold more potent than endotoxin and 100-fold more potent than teichoic acid-free peptidoglycan. IL-1-inducing activity was greatly reduced by chemical alteration of the teichoic acid. In contrast to endotoxin, cell wall did not induce production of TNF. This dissociation of the production of IL-1 and TNF during the response of the human monocyte to pneumococcal surface components suggests that, in at least some circumstances, the mechanisms for generation of an inflammatory response to infection may be fundamentally different between gram-positive and gram-negative disease.

Topics: Cell Wall; Humans; Interleukin-1; Lipopolysaccharides; Monocytes; Streptococcal Infections; Streptococcus pneumoniae; Teichoic Acids; Tumor Necrosis Factor-alpha

Streptococcus agalactiae (group B streptococci) isolates from infected infants have been demonstrated to have three- to fourfold or higher levels of cell-associated lipoteichoic acid than isolates from asymptomatically colonized infants, suggesting a role for this cell surface polymer in the relative virulence of these organisms. The present study indicates that symptomatic isolates of type III group B streptococci can be readily differentiated from asymptomatic strains by their response to various levels of phosphate in a chemically defined medium (FMC). Both classes of isolates had the same doubling time (TD of 30 to 35 min) in FMC containing 65 mM sodium phosphate. However, levels of phosphate greater than 125 mM distinguished the two classes of strains. Asymptomatic strains pregrown in 65 mM phosphate to the stationary phase rapidly initiated growth at elevated phosphate levels, while symptomatic strains initiated growth only after a prolonged incubation period (greater than 400 min). These results suggest that the physiological growth response of clinical isolates of group B streptococci to phosphate can serve as a diagnostic aid in screening potentially virulent strains in pregnant women and newborn infants.

Topics: Antigens, Bacterial; Culture Media; Humans; Infant; Lipopolysaccharides; Phosphates; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids

Sixty-three strains of Group D streptococci and viridans streptococci isolated from blood cultures during a two year period were typed to the species level with conventional biochemical tests and API Strep. Streptococcus faecalis was the most common species isolated followed by S. sanguis, S. mitis and S. constellatus (S. milleri). One of the two isolates of S. faecium was a contamination. The reported increasing frequency of this organism and other Group D and viridans streptococci as well as the association of S. bovis with malignant bowel disease indicate the need for full identification of streptococcal isolates from blood cultures. Pronounced surface hydrophobicity as measured with the salt aggregation test (SAT) was expressed by 59/63 (94%) of the blood culture isolates whereas strains isolated from commercial fermentation products and strains passaged several times were hydrophilic. In the presence of human serum albumin which binds to lipoteichoic acid only one strain decreased in surface hydrophobicity. The surface hydrophobicity of two strains even slightly increased indicating that lipoteichoic acid but marginally contributes to surface hydrophobicity of streptococcal cells from these species.

Topics: Adolescent; Adult; Aged; Blood; Child; Child, Preschool; Enterococcus faecalis; Humans; Infant; Lipopolysaccharides; Middle Aged; Phosphatidic Acids; Sepsis; Streptococcal Infections; Streptococcus; Streptococcus sanguis; Surface Properties; Teichoic Acids

Topics: Bacteria; Bacterial Physiological Phenomena; Cell Division; Cystitis; Escherichia coli; Fibronectins; Humans; Lipopolysaccharides; Phosphatidic Acids; Pyelonephritis; Skin Diseases, Infectious; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids; Urinary Tract; Virulence

Topics: Adhesiveness; Antigens, Bacterial; Complement Activation; Humans; Hyaline Membrane Disease; Immunity, Cellular; Infant, Newborn; Lipopolysaccharides; Meningitis; Neuraminidase; Peptide Hydrolases; Phosphatidic Acids; Respiratory Tract Infections; Serotyping; Sialic Acids; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids; Virulence

Topics: Animals; Antigens, Bacterial; Bacterial Proteins; Carbohydrates; Humans; Lipopolysaccharides; Peptidoglycan; Phosphatidic Acids; Polysaccharides, Bacterial; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids

Lipoteichoic acids (LTA) of serotype III strains of group B streptococci (GBS) were shown to mediate adherence of these organisms to human embryonic (HEC), fetal (HFC), and adult buccal (HBEC) epithelial cells. The binding of GBS was temperature dependent, and maximum attachment occurred at 37 degrees C. HEC, HFC, and HBEC preincubated with purified LTA significantly inhibited attachment of GBS, whereas the group B and type III antigens had no effect. Under phosphate-limiting conditions in which cell-associated LTA could not be detected in these organisms, bacterial adherence did not take place. GBS (virulent) that were isolated from infected infants and previously shown to have significantly higher quantities of cell-associated LTA in comparison to GBS strains from asymptomatically colonized infants adhered with greater binding avidity to HEC and HFC and in greater numbers than to HBEC. It was determined that the mechanism of LTA-mediated adherence of GBS to HBEC differed from adherence to embryonic and fetal cells for both virulent and asymptomatic GBS strains bound to HBEC in a similar manner, enhanced by the lipid portion of the LTA. In contrast, the binding of GBS to HEC and HFC was mediated by hydrophobic as well as specific interactions due to the glycerolphosphate polymer of LTA. These results indicate that possible receptor sites for LTA present on cells in prenatal stages of development may differ from those of adult cells, which may result in increased susceptibility of newborn infants to group B streptococcal disease. The implications of LTA-mediated adherence of GBS and their possible role as virulence factors are discussed.

Topics: Adult; Brain; Cell Adhesion; Epithelium; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lipopolysaccharides; Lung; Phosphatidic Acids; Pregnancy; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids

Sera from individuals with Staphylococcus aureus endocarditis and osteomyelitis and from some individuals with other forms of gram-positive endocarditis yielded higher readings in a microenzyme-linked immunosorbent assay against lipoteichoic acid from S. aureus than did sera from individuals with other types of serious staphylococcal infection or non-staphylococcal osteomyelitis, or from unselected inpatients.

Topics: Antibodies, Bacterial; Antigens, Bacterial; Endocarditis, Bacterial; Enzyme-Linked Immunosorbent Assay; Humans; Lactobacillus; Lipopolysaccharides; Osteomyelitis; Phosphatidic Acids; Proteus Infections; Pseudomonas Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Teichoic Acids

Cell-associated lipoteichoic acids (LTAs) from late-exponential-phase cultures (serotypes Ia, Ib, Ic, II, and III) of group B streptococci isolated from infected and asymptomatically colonized infants were quantitated and characterized by growing the organisms in a chemically defined medium containing [3H]glycerol and [14C]acetate. Cell pellets were extracted with 45% aqueous phenol and chloroform-methanol and subjected to DEAE-Sephacel anion-exchange chromatography. Elution profiles resolved three major peaks, I, II, and III, with glycerol and phosphate present in a 1:1 molar ratio in each peak, and results obtained by Ouchterlony immunodiffusion analysis confirmed the presence of poly(glycerol phosphate). Saponification indicated that [14C]acetate was incorporated into fatty acids of peaks I and II only, suggesting that these were cell-associated LTAs. Peak II was of small molecular weight (less than 10,000) and probably represented another species of LTA. Peaks I and II were further demonstrated to be LTA by their ability to sensitize human type O erythrocytes. Peak III lacked fatty acids and was shown to probably be deacylated LTA. Quantitation of cell-associated teichoic acid material produced by the group B streptococcal strains indicated that the clinical isolates from infants with early- or late-onset disease possessed significantly higher levels than did the asymptomatic (clinical isolates from infants without symptoms of disease) group B streptococcal strains.

Topics: Cell Wall; Erythrocytes; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lipopolysaccharides; Phosphatidic Acids; Serotyping; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids

The morphology and pathology of cultured mouse glomeruli were examined at the cellular and subcellular levels after infection with a physiological isotonic L-form of Streptococcus pyogenes type 12 or exposure to streptococcal lipoteichoic acid. These changes, as viewed by light microscopy, were identical regardless of the method used to induce glomerular cytotoxicity. They were characterized by an initial reduction in the outgrowth of cells, some cellular granulation, and later, destruction of the confluent monolayer. Once initiated, cytotoxicity could not be reversed by refeedings, and complete glomerular destruction resulted after 2 weeks. Electron microscope studies revealed that the basement membrane of intact glomeruli exposed to streptococcal lipoteichoic acid had become greatly thickened (two- to fourfold) and electron dense. Our recent biochemical findings have shown that streptococcal lipoteichoic acid increases the amount of collagen formed and retained by mouse fibroblasts in tissue culture as well as causing a reduction in the hydroxylation of proline in both intracellular and secreted collagenous material (Leon and Panos, Infect. Immun. 40:785-794, 1983). These results, together with the present findings, suggest that the thickening of the glomerular basement membrane may be due to defective collagen biosynthesis as a result of streptococcal lipoteichoic acid. The use of cultured glomeruli as a model system for studying the earliest basement membrane alterations in the absence of an immune response as a result of streptococcal lipoteichoic acid is suggested.

Topics: Animals; Basement Membrane; Cells, Cultured; Kidney Diseases; Kidney Glomerulus; L Forms; Lipopolysaccharides; Mice; Microscopy, Electron; Phosphatidic Acids; Streptococcal Infections; Streptococcus pyogenes; Teichoic Acids

The effect of penicillin treatment of Streptococcus sanguis in vitro, on subsequent bacterial density in the bloodstream and on cardiac valves in the rabbit model of endocarditis was studied. As experimental tools for this study, isogenic pairs of S. sanguis differing in resistance to streptomycin or rifampin were prepared by genetic transformation. Rabbits with traumatized heart valves received an intravenous inoculation of penicillin treated (1 mug/ml) and untreated S. sanguis, each marked by resistance to either streptomycin or rifampin. The number of penicillin-treated and untreated bacteria attached to the valvular surfaces was determined by differential counting on streptomycin or rifampin containing media. Penicillin pretreatment reduced cardiac valve colonization 5 min after inoculation ("adherence ratio" x 10(8) was 4.11 for the control and 3.66 for the penicillin-treated bacteria, P < 0.001). The results were not due to differences in serum killing or bacterial densities in the bloodstream. There was no difference in valvular bacterial densities 24 h after bacterial inoculation (adherence ratio x 10(8), 7.26 untreated vs. 6.34 penicillin-pretreated, P > 0.10). In vitro experiments were performed using platelet-fibrin surfaces to test the possibility that penicillin-induced loss of lipoteichoic acid was responsible for decreased streptococcal adherence. Pretreatment of S. sanguis cultures with inhibitory concentrations of penicillin or with antiserum against lipoteichoic acid and precoating of the platelet-fibrin surfaces with lipoteichoic acid, all caused reduction in bacterial adherence. The findings are interpreted as support for the role of lipoteichoic acid as an adhesin in S. sanguis interactions with particular host tissue surfaces.

Topics: Adhesiveness; Animals; Disease Models, Animal; Endocarditis, Bacterial; Heart Valves; Lipopolysaccharides; Microbial Sensitivity Tests; Penicillins; Phosphatidic Acids; Rabbits; Streptococcal Infections; Streptococcus sanguis; Teichoic Acids

An animal model of maternal-newborn transmission of group B streptococci (GBS) was developed. Pregnant Swiss-Webster mice were colonized by applying 10(8) GBS to the oral cavity, vagina, and nipples daily for 3 days before delivery. Lipoteichoic acid (LTA) from type III GBS or phosphate buffered saline was applied topically to the oral cavity, perineum or nape of newborn mice. Cultures of newborn mice at 3 days of age revealed 35 of 75 (47%) controls and 0 of 79 animals given 2 doses of LTA (2 mg/ml) were positive for GBS at one or more sites. One to two% of control and LTA-treated mice remained culture positive at 7 days of age. None developed GBS disease and no obvious toxicity was noted. This is the first in vivo evidence that colonization with GBS can be prevented by interfering with their adherence to epithelial surfaces. LTA also prevented colonization by 60,000 GBS in the oral cavity of 1-day-old newborn mice. A minimum concentration of 0.5 mg LTA/ml was required and similar dose response curves were obtained in preventing maternal-newborn transmission or oral newborn colonization. LTA from type III GBS also protected against types Ia and II. Only 6 of 15 (40%) vaginally colonized, nonpregnant mice became noncolonized 3 days after LTA treatment. Topically applied lipoteichoic acid from group B streptococci may be a useful method of preventing GBS colonization and/or disease in human infants at birth if it is nontoxic. The method avoids the problems associated with antibiotic prophylaxis and vaccine development.

Topics: Animals; Disease Models, Animal; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lipopolysaccharides; Mice; Phosphatidic Acids; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids