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At least 1,243 records · Page 69Linked to original sources
PubMed1990

[Pathology of generalized Streptococcus infection].

7 cases of the generalized streptococcus infection in children aged from 1 year 8 months to 12 years are analyzed. The course of the disease was in all cases extremely rapid and terminated by death within 3-4 days. Results of the autopsy material investigation allowed to conclude that the pathology of the generalized streptococcus infection at present does not differ from that described in classical text-books. The attention is drawn to the connection between the generalized streptococcus infection and herpes-like infections since in all cases studied herpes stomatitis, genital herpes, varicella were noted clinically. The presence of herpes-like infections was confirmed morphologically in some cases.

Child↗
PubMed1990

[Endocarditis caused by Streptococcus bovis and colorectal neoplasms].

PURPOSE: To evaluate the association of Streptococcus bovis endocarditis with large bowel neoplasms. PATIENTS AND METHOD: Twenty episodes (19 patients) of Streptococcus bovis endocarditis (5.05%) selected from 396 episodes of endocarditis followed up from 1978 to 1990. The mean age was 57.68 years, 16 (84.21%) were males. Previous heart disease was not known in nine (45%). Previous manipulation that might induce bacteremia was identified in three patients. Symptoms related to neoplasia of the digestive system were not informed. The mean time of follow up (17 cases) was 33.76 months, standard deviation 27.37 months. Sixteen patients were submitted to colonic evaluation (barium enema in 11, colonoscopy in 5 patients, and both were performed in 5 patients). RESULTS: Bowel neoplasias were diagnosed in 12 (75%) of 16 patients submitted to colonic evaluation, one colonic adenocarcinoma in one (8.33%), patient, histologic benign polyps in eight (66.6%). Two patients are waiting for colonoscopic resection. In one patient the polyp was lost after colonoscopic resection. CONCLUSION: The high incidence of large bowel neoplasia in patients with Streptococcus bovis endocarditis indicates that evaluation of the large bowel must be performed on in patients with S. bovis endocarditis in order to diagnose neoplasias, even in the absence of symptoms of bowel disease.

Adenocarcinoma↗
PubMed1990

[Incidence and severity of cardiac involvement in Streptococcus bovis septicemia. Report of 10 cases].

Endocarditis due to the streptococcus Bovis is an affection which is more and more often recognized and whose link with the colic tumor pathology has been well established those last few years and confirmed in this study with a frequency of 60 p. cent. However, few studies have stated the gravity of the heart affection in streptococcus Bovis septicaemias. In this series of 10 streptococcus Bovis septicaemias, the valvular affection is frequent and serious. The vegetations are found in 9 cases out of 10. The aortic affection is slightly more frequent (8 times out of 10), against 7 times out of 10 for the mitral affection (double mitroaortic affection, 6 times). A valve replacement due to sub-acute or chronic cardiac failure was necessary in 6 cases out of 9, that is 66 p. cent. The mortality was nil.

Aged↗
PubMed1986

Streptococcus mitis endocarditis. Report of 17 cases.

Seventeen patients with Streptococcus mitis endocarditis were treated at a municipal hospital over a three-year period. Thirteen patients were intravenous drug addicts. Streptococcus mitis has a predilection for right-sided endocarditis in intravenous drug addicts and left-sided endocarditis in non-drug addicts. Streptococcus mitis is highly susceptible to therapy with penicillin G potassium (minimal inhibitory concentration less than or equal to 0.1 mg/L of penicillin in all of these 17 cases), and four to six weeks of therapy is safe and effective.

Adult↗
PubMed1983

[Experimental study on synergism between cefotaxime and ampicillin against Streptococcus D group].

Cefotaxime (CTX) disks and ampicillin (ABPC) disks exhibited synergism against 24 strains of Streptococcus D group isolated from various sources in our hospital. We were interested in these synergism effects and compared them with the combination index. Twenty-two out of the 24 strains examined exhibited synergism, and were identified as Streptococcus faecalis by the API strep system. We divided them into 4 groups (combination index: 19, 15, 11, 9) according to the degree of synergism. Another 2 strains showed additive effects (combination index: 1), and were identified as Streptococcus faecium. Among these 24 strains, beta-lactamases were produced by only 1. There was no direct connection between beta-lactamase production and synergism. The mechanism of synergism between CTX and ABPC has not yet been studied.

Adolescent↗
PubMedDate not supplied

Spontaneous bacterial peritonitis caused by a viridans Streptococcus or Neisseria perflava.

Eight patients had nine episodes of presumed spontaneous bacterial peritonitis (SBP) caused by commensal bacteria that usually inhabit the oropharynx, including Neisseria perflava and the viridans streptococci Streptococcus milleri, Streptococcus mitis, and Streptococcus sanguis. Nonpurulent ascites (ascitic fluid WBC count, less than 1,000/cu mm) was present in four episodes, possibly caused by either bacterial colonization or early peritonitis; purulent ascites was present in five episodes. None died of their infection, and three episodes remitted without treatment. Poor condition of gums and teeth may play a pathogenic role in SBP caused by these bacteria.

Adult↗
PubMedDate not supplied

[Role of Streptococcus group D in infections in newborn infants].

Our investigation concerns 14 streptococcus D sepsis neonates, thirteen of which were collected over a six year period during which eighty-two neonate infections were recorded. This rate slightly higher than generally recorded and may be due to the initial prescription of third generation cephalosporin to the mothers. The clinical, hematological and biological data are not specifically those of group D streptococcus. The issue was unfavourable in 15% of our cases and in 8 to 33% of the recorded cases. The sensitivity to antibiotics varies depending on the species of group D streptococcus. The effectiveness of Amoxicillin, of Mezlocillin and of Ampicillin justifies the initial prescription in association with an aminoglycoside because of the possibility of synergy; cephalosporins are contraindicated as they are inactive on this germ.

Anti-Bacterial Agents↗
PubMedDate not supplied

Experimental retrograde pyelonephritis due to group D streptococcus in the rabbit: pathologic, bacteriologic and antibody-coated bacteria studies.

An experimental model of retrograde pyelonephritis in the rabbit using streptococcus D is described. The pathological findings were those of chronic pyelonephritis. The results of the antibody-coated bacteria test (ACB test) were usually negative at the end of follow-up time. Confirming previous results in streptococcus D urinary infection in the child, this experimental model shows that the ACB test is not reliable in urinary infections due to streptococcus D.

Animals↗
PubMed1980

Properties and transforming activities of two plasmids in Streptococcus pneumoniae.

Two plasmids from group B streptococcus were introduced into pneumococcus (Streptococcus pneumoniae) and examined for copy number, stability, and some features of the process by which they transform pneumococcal recipients. The 3.6 Mdal pMV158 (tet) was present at a minimum of 12 to 16 copies per chromosome and was never observed to be cured. The 20 Mdal pIP501 (cat erm) had a minimum copy number of 3 to 4 per chromosome and was lost spontaneously at a frequency near 0.03 per division. The presence of novobiocin increased this frequency 2 to 3-fold. Competence for chromosomal transformation and the membrane endonuclease needed for normal DNA entry were required for plasmid transformation. Plasmid transformants segregated transformed cells one generation ahead of chromosomal transformants. Both single and multiple hit components of the transformation reaction kinetics were observed, but the latter could not be seen in the presence of competing chromosomal DNA. The major of the transforming activity behaved as covalently closed circular DNA in dye-buoyancy gradients. Although most of the activity for both plasmids sedimented in sucrose gradients more rapidly than did monomeric closed circular DNA, a significant fraction was found at a position suggesting that it may have been due to monomeric plasmids.

Centrifugation, Density Gradient↗
PubMed2006

Adjacent location of the bac gene and two-component regulatory system genes within the putative Streptococcus agalactiae pathogenicity island.

A chromosomal DNA fragment of 8992 bp in size that has not been previously identified in Streptococcus agalactiae, was cloned and sequenced from strain 98-D60C. In particular, this 8992-bp fragment contained genes homologous to the sensor histidine kinase gene and the DNA-binding response-regulator gene of Streptococcus pneumoniae, and S. agalactiae bac gene. Structural and genetic features of the 8992-bp fragment were highly similar to those specific for bacterial pathogenicity islands. Analysis of epidemiologically unrelated S. agalactiae strains revealed that this fragment was present only in bac gene-positive strains. The possible origin of the 8992-bp fragment in S. agalactiae and its significance for molecular mechanisms of "bacteria-host" interactions are discussed.

Antigens, Bacterial↗
PubMed2001

Identification of an intragenic integration site for foreign gene expression in recombinant Streptococcus gordonii strains.

A new intragenic chromosomal integration site within the lacG gene of the lac operon has been identified in Streptococcus gordonii for use in the expression of foreign genes. Introduction of a portion of the Streptococcus pyogenes emm6 gene into the lacG locus resulted in the lactose-inducible surface expression of the S. pyogenes M6 protein. This result demonstrates the ability to modulate the in vitro or in vivo expression of a foreign gene in a S. gordonii recombinant using a biosynthetic metabolite.

Antigens, Bacterial↗
PubMed1982

The production of bacteriocin-like substances by the oral bacterium Streptococcus salivarius.

Inhibitory substances produced by six strains of Streptococcus salivarius were isolated and partially characterized. The six prototype producer strains were selected initially on the basis of their differing spectra of inhibitory activity when tested against a set of nine standard indicator strains. Optimal production conditions were defined for each producer strain and inhibitor-containing extracts were obtained for characterization studies. All of the inhibitors appeared to be proteinaceous substances of molecular weight greater than 3500. When tested against a Streptococcus pyogenes indicator strain, one of the inhibitors was bactericidal, but the other five appeared to be bacteriostatic. Some differences between the inhibitors were observed with respect to heat and enzyme sensitivities.

Bacteriocins↗
PubMed1976

Proteolytic activity of Streptococcus mutans (GS-5).

The potential proteolytic ability of cariogenic streptococci was assessed in a strain of Streptococcus mutans (GS-5). Blood-borne S. mutans from rats infected by mouth with GS-5 were cultured, and sterile rat tail tendons were placed on these cultured bacterial colonies. The collagenolytic ability of these organisms was examined under the scanning electron microscope and by testing for reduced tensile strength of the collagen fibers. These experiments showed that GS-5 cariogenic streptococcus can be conditioned to produce significant collagenolytic activity.

Animals↗
PubMed1986

Characterization of the serotype e polysaccharide antigen of Streptococcus mutans.

The structure of the Streptococcus mutans serotype e polysaccharide was studied in order to determine the chemical basis of the immunological cross-reactions observed between it and the streptococcal group E polysaccharide. The chemical structure was established using methylation analysis, periodate oxidation, partial methanolysis and 13C NMR spectroscopy. The polysaccharide was found to consist of a polyrhamnose backbone of alternating 2- and 3-linked alpha-L-rhamnose units and sidechain beta-D-glucosyl units linked to the 2-position of rhamnose units in the backbone. This structure of the oligosaccharide repeating unit of the S. mutans serotype e polysaccharide was identical to that of the group-specific polysaccharide of group E Streptococcus. Possible explanations for the previously reported differences in these two polysaccharides are discussed.

Chemical Phenomena↗
PubMed2006

Alternate structural conformations of Streptococcus pneumoniae hyaluronan lyase: insights into enzyme flexibility and underlying molecular mechanism of action.

Streptococcus pneumoniae hyaluronan lyase is a surface enzyme of this Gram-positive bacterium. The enzyme degrades several biologically important, information-rich linear polymeric glycans: hyaluronan, unsulfated chondroitin, and some chondroitin sulfates. This degradation facilitates spreading of bacteria throughout the host tissues and presumably provides energy and a carbon source for pneumococcal cells. Its beta-elimination catalytic mechanism is an acid/base process termed proton acceptance and donation leading to cleavage of beta-1,4 linkages of the substrates. The degradation of hyaluronan occurs in two stages, initial endolytic cuts are followed by processive exolytic cleavage of one disaccharide at a time. In contrast, the degradation of chondroitins is purely endolytic. Structural studies together with flexibility analyses of two streptococcal enzymes, from S.pneumoniae and Streptococcus agalactiae, allowed for insights into this enzyme's molecular mechanism. Here, two new X-ray crystal structures of the pneumococcal enzyme in novel conformations are reported. These new conformations, complemented by molecular dynamics simulation results, directly confirm the predicted domain motions presumed to facilitate the processive degradative process. One of these new structures resembles the S.agalactiae enzyme conformation, and provides evidence of a uniform mechanistic/dynamic behavior of this protein across different bacteria.

Catalytic Domain↗
PubMed2026

Host Proteome Remodeling During Group A Streptococcus Skin Infection.

Group A Streptococcus (Streptococcus pyogenes, GAS) is a bacterial pathogen that commonly causes local infections in humans and can lead to invasive diseases. GAS infections trigger complex host immune and tissue responses, yet how these processes are coordinated over time and across different tissues remains poorly understood. To explore the spectrum of GAS infection, we examined responses in a skin infection model at multiple proteome levels, characterizing local and distant tissues with variable infection responses. We map changes in canonical innate and adaptive immune signaling while uncovering new mechanisms in the context of skin infection. We uncover the robust and time-dependent expression of one family of proteins, chitinase-like proteins, that coincides with immune cell infiltration of local tissues. Because immunomodulatory networks are tightly regulated through post-translational modifications, we integrated global proteomic data with cytokine signaling and key phosphoproteome changes. This analysis revealed correlations between mTOR and kinase signaling pathways that diverge at local and systemic tissues. Our systems-based approach provides a rigorous evaluation of a GAS skin infection, characterizing host proteome remodeling across experimental groups and individual mice.

Animals↗
PubMed1981

Antibody response to group B streptococcus type III and AB blood group antigens induced by pneumococcal vaccine.

The effect of pneumococcal vaccination on antibodies to Streptococcus pneumoniae type 14, group B streptococcus type III, and AB blood group antigens was studied in 40 vaccinated adults. Fourfold or greater increases in type-specific IgG antibody to Pn-14 were found in 26 of 40 vaccines (mean increase 6.4-fold) and against GBS-III in 16 of the 40 (mean increase 2.9-fold) by an indirect immunofluorescence assay. However, only six of the 26 vaccinees with low levels (titers less than or equal to 20) of GBS-III antibody in prevaccination sera developed titers greater than 20 after vaccination. Thus, vaccination with polyvalent pneumococcal vaccine does not reliably induce high levels of IF antibody to GBS-III. Fourfold or greater increases in IgG isohemagglutinins against blood group A cells were also found in 22 of 27 vaccines (mean increase 4.5-fold) and against blood group B cells in nine of 34 (mean increase 1.7-fold) using the indirect anti-human globulin test. Chromatographic fractionation of selected sera confirmed that the anti-A isohemagglutinins stimulated in group O subjects were of the IgG class. Thus, pneumococcal vaccination during incompatible pregnancy could potentiate AO hemolytic disease of the newborn infant.

ABO Blood-Group System↗
PubMed1979

Immunoprecipitation and opsonic cross-reaction between type-14 pneumococcus and group-B streptococcus type III.

Antisera directed against type-14 pneumococcus was opsonic for several strains of type-III group-B streptococcus. Furthermore, the polysaccharide antigen in the polyvalent pneumococcal vaccine reacted to form precipitation lines with antisera directed against type-14 pneumococcus and group-B streptococcus type III Immunisation with currently available pneumococcal vaccine may provide opsonic antibody against group-B streptococci and provide a method of preventing neonatal group-B streptococcal infections.

Animals↗