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PubMed1985

Fatty acid composition of Streptococcus milleri.

The cellular fatty acids of 31 strains belonging to the Streptococcus milleri group were analysed by capillary gas-liquid chromatography. Results were compared with findings from biochemical differentiation of the strains into Streptococcus constellatus (two strains), Streptococcus anginosus (16 strains) and Streptococcus intermedius (13 strains). Eight strains of various other streptococci were included as internal references, including three strains of streptococcus morbillorum, three strains of beta-hemolytic streptococci, and two strains of enterococci. The Streptococcus milleri strains formed a very homogeneous group according to fatty acid composition and were easily differentiated from other groups. However, within the group, it was not possible to differentiate Streptococcus constellatus, Streptococcus anginosus and Streptococcus intermedius by fatty acid composition alone.

Chromatography, Gas↗
PubMed2000

Comparison of three methods for identification of Streptococcus milleri group isolates to species level.

A collection of 180 clinical isolates of Streptococcus milleri group were identified to species level using two phenotypic methods (a commercial system and the reference method based on differential phenotypic reactions) and a genotypic method (hybridisation of the 16S rRNA gene with species-specific probes) in order to evaluate the performance of the respective methods. A high level of agreement (80%) was observed between the results of the reference method and the genotypic method. The highest level of agreement was found for the species Streptococcus anginosus (83%), a high level of agreement (76%) also being achieved for Streptococcus constellatus and Streptococcus intermedius. The sensitivity of the commercial system compared to the genotypic method was 76% overall, but it was low (57.5%) for Streptococcus intermedius. Twenty-five strains belonged to the recently described CI strains.

Bacterial Typing Techniques↗
PubMed2004

Platelet responses and anaphylaxis-like shock induced in mice by intravenous injection of whole cells of oral streptococci.

Intravenous injection of lyophilized whole cells of various oral streptococcal strains into muramyldipeptide (MDP)-primed C3H/HeN mice induces rapid anaphylactoid shock. Here we examined the mechanism underlying this shock. In non-primed mice, Streptococcus intermedius K-213K (SiK213) and Streptococcus constellatus T21 (ScT21) produced little or no sign of shock. In MDP-primed mice, SiK213 caused lethal shock, while ScT21 only had a weak effect. SiK213 induced decreases in blood platelets and 5-hydroxytryptamine (5HT) preceding the shock, while the effects of ScT21 were weak. The SiK213-induced 5HT decrease and shock were reduced by a complement-C5 inhibitor. These results suggest that (i). streptococcal bacterial cells can induce rapid platelet responses, (ii). complement-dependent degradation of platelets may be involved in streptococcus-induced shock, (iii). the streptococcus-induced platelet degradation or degranulation may occur largely in the systemic circulation, and (iv). platelets may play a role not only in infectious diseases caused by gram-negative bacteria, but also in diseases caused by gram-positive bacteria.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

Association of viridans group streptococci from pregnant women with bacterial vaginosis and upper genital tract infection.

The prevalence and role of viridans group streptococci in the female genital tract have not been well described. In this study of 482 pregnant women, 147 (30%) were culture positive for viridans group streptococci. Of 392 women with predominant Lactobacillus morphotypes by Gram stain (normal), 110 (28%) were colonized with viridans group streptococci, compared with 37 (41%) of 90 women with bacterial vaginosis (BV) (P = 0.02). To determine whether any species were associated with BV, 177 consecutively isolated viridans group streptococci from the vagina were identified to the species level by using the Facklam scheme. The most frequently isolated species from the vagina was Streptococcus intermedius (13%), followed by Streptococcus acidominimus (6%), Streptococcus constellatus (5%), Streptococcus sanguis II (4%), Streptococcus mitis (2%), Streptococcus salivarius (2%), Streptococcus morbillorum (2%), Streptococcus sanguis I (1%), Streptococcus mutans (0.2%), and Streptococcus uberis (0.2%) with an average of 1.2 species per woman. The distribution of the species among women with BV compared with normal women was not significantly different, with the exception of two species which were associated with BV: S. acidominimus (18% versus 3%, P less than 0.001) and S. morbillorum (6% versus 0.7%, P = 0.005). Amniotic fluid and placenta cultures yielded 54 isolates: S. sanguis II (13 isolates), S. acidominimus (9 isolates), S. intermedius (10 isolates), S. constellatus (3 isolates), S. mitis (4 isolates), S. sanguis I (4 isolates), S. morbillorum (5 isolates), S. mutans (2 isolates), S. uberis (1 isolate), mannitol-positive S. intermedius (1 isolate), and 2 isolates which were not classified. The distribution of species isolated from the upper genital tract was not a reflection of the distribution in the lower genital tract. Dextran-producing species of viridans group streptococci may have a greater pathogenic potential in the placenta than the non-dextran-producing species.

Dextrans↗
PubMed1982

Successful prophylaxis against experimental streptococcal endocarditis with bacteriostatic antibiotics.

Because bacteriostatic concentrations of vancomycin are effective in prophylaxis against endocarditis due to Streptococcus sanguis in rats, the efficacy of three other bacteriostatic antibiotics was investigated against three different streptococcal species that cause subacute endocarditis in humans: Streptococcus intermedius. S. sanguis, and Streptococcus mitior. Rats were challenged by intravenous injection of 2 x 10(5) colony-forming units of streptococci 24 hr after intracardiac insertion of a transaortic catheter and 30 min after intravenous injection of various doses of clindamycin, erythromycin, and doxycycline. Significant protection was achieved with all three antibiotics, but only clindamycin was fully effective against all three species at doses that simulated serum levels achievable in humans after oral administration. Endocarditis was prevented by antibiotic concentrations in serum far below minimal bactericidal concentrations for these streptococci. Furthermore, serum at the time of bacterial challenge was not bactericidal. Therefore, single doses of nonbactericidal antibiotics prevented endocarditis in rats by mechanisms other than bacterial killing.

Animals↗
PubMed1985

Bactericidal effects of photoradiation therapy with hematoporphyrin derivative.

Hematoporphyrin derivative (Hpd) localizes selectively in malignant and rapidly metabolizing tissues and undergoes a cytotoxic reaction when exposed to light of a specific wavelength. Hpd has been studied extensively with regard to the diagnosis and treatment of tumors but not with regard to bactericidal activity. This investigation assessed the effect of light-activated Hpd on various microorganisms, on human polymorphonuclear leukocytes, and on the interactions of polymorphonuclear leukocytes and bacteria. Light-activated Hpd was 99.9% bactericidal against Staphylococcus aureus, Streptococcus faecalis, Bacteroides fragilis, Streptococcus M-G intermedius, Streptococcus mutans, Peptostreptococcus anaerobius, Peptococcus magnus, and Clostridium perfringens, but did not affect Escherichia coli, Pseudomonas aeruginosa, or Candida albicans. Photoactivation of Hpd rendered 98% of polymorphonuclear leukocytes inviable. Combinations of light-activated Hpd and polymorphonuclear leukocytes had a 4-log (99.99%) bactericidal effect on both intra- and extracellular S. aureus. The ability of Hpd to localize in inflammatory tissues may have therapeutic applications in the treatment of abscesses.

Bacteria↗
PubMed1989

Activity of amine-stannous fluoride combination and chlorhexidine against some aerobic and anaerobic oral bacteria.

The in vitro susceptibility of 128 bacterial strains was tested to amine fluoride-stannous fluoride (AmF + SnF) and chlorhexidine (CHX) solutions. Actinobacillus actinomycetemcomitans, Streptococcus mutans, and Bacteroides intermedius were among the species investigated. The 50% and 90% minimal inhibitory concentrations (MICs) were assessed by an agar dilution method. The MIC ranges for A. actinomycetemcomitans were 2-32 micrograms/ml for CHX and 0.25-64 micrograms/ml for AmF + SnF. The respective values for S. mutans were 0.5-8 micrograms/ml (CHX) and 2-8 micrograms/ml (AmF + SnF); and 4-8 micrograms/ml (CHX) and 2-4 micrograms/ml (AmF + SnF) for B. intermedius. Streptococcus faecalis and Staphylococcus aureus were most resistant of the control strains (MIC 64 micrograms/ml to CHX and 32 micrograms/ml to AmF + SnF, respectively). Thus, both solutions tested exerted a definite inhibitory action on the dental plaque pathogens studied.

Actinobacillus↗
PubMed1989

[Anaerobic bacteria in intracranial suppuration].

In four cases of intracranial suppurative disease, studied in the laboratory of Anaerobic bacteria of Institute Pasteur of Algiers, three cases are caused by anaerobic bacteria and one remain sterile. Two of them are empyema with unknown origin and the others are brain abscess with bilateral chronic ear infection to one. In the three cases, gram negative anaerobic bacilli were grown in culture: Bacteroides asaccharolyticus, Bacteroides vulgatus and Bacteroides ruminicola brevis. In two cases, the bacilli are associated with gram positive cocci: Streptococcus intermedius (anaerobic bacteria) and Streptococcus NG (facultative anaerobic bacteria).

Adolescent↗
PubMed2006

Identification of oral bacteria associated with crevicular epithelial cells from chronic periodontitis lesions.

Bacterial invasion of host epithelial cells plays an important role in the pathogenesis of periodontal diseases; however, the interactions between subgingival species and the gingival crevice cells are not fully understood. This study determined the prevalence of a group of oral bacterial species on or in epithelial cells derived from periodontal pockets and the gingival crevice of subjects with periodontitis. Samples of epithelial cells were obtained from 120 sites with periodontal pockets > or =4 mm and 92 periodontally healthy sites from 49 patients (mean age 46.3+/-1.4 years; 43% males) with chronic periodontitis. Bacteria in or on epithelial cells were separated from unattached bacteria by Percoll density-gradient centrifugation. The presence and levels of 33 oral species were determined in epithelial cell samples by whole genomic DNA probes and the checkerboard method. The most frequently detected species were Porphyromonas gingivalis (42%), Treponema denticola (38%), Prevotella intermedia (37%), Streptococcus intermedius (36%), Campylobacter rectus (35%), Streptococcus sanguinis (35%) and Streptococcus oralis (34%). Species of Actinomyces were found in low prevalence and levels. The data indicated that there were more micro-organisms on or in epithelial cells obtained from periodontal pockets than from healthy sulci; however, no significant differences regarding the percentage and level of any specific species were found between these sites. Veillonella parvula, S. oralis, Streptococcus gordonii and Streptococcus mitis tended to be more prevalent in sites without disease. These findings demonstrated that a wide range of oral species may be detected on or in crevicular epithelial cells from sites with periodontitis and from periodontally healthy sulci.

Bacteria↗
PubMed2001

Cloning and DNA sequencing of the surface protein antigen I/II (PAa) of Streptococcus cricetus.

We have cloned and sequenced the gene encoding the surface protein antigen PAa (antigen I/II family) from Streptococcus cricetus E49 (serotype a) using degenerate PCR. The deduced amino acid sequence of PAa reveals two repeating regions (A region; alanine-rich region, P region; proline-rich region). Two additional tandem repeats were found in the A region and part of the P region was deleted compared to antigen I/II. Homology and phylogenetic analyses reveal that PAa is homologous to Streptococcus sobrinus PAg rather than Streptococcus mutans PAc. Using degenerate PCR a gene homologous to PAc was identified in Streptococcus intermedius, but not found in Streptococcus rattus or Streptococcus anginosus.

Animals↗
PubMed2003

Genotyping by amplified fragment length polymorphism analysis reveals persistence and recurrence of infection with Streptococcus anginosus group organisms.

Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius, commonly referred to as the Streptococcus anginosus group (SAG), are commensal organisms known for their propensity to cause purulent infections which are difficult to eradicate. In this study, we determined the genetic similarities between SAG isolates consecutively recovered from single patients to assess the duration of infection or colonization. A total of 97 SAG isolates recovered from 30 patients were included; 65 (67.0%) of the isolates were abscess related. The isolates were identified by the 16S rRNA reverse line blot hybridization assay as S. anginosus (n = 34), S. constellatus (n = 55), and S. intermedius (n = 8). Amplified fragment length polymorphism (AFLP) analysis of the SAG isolates produced discriminatory and reproducible patterns. Consecutive SAG isolates with identical AFLP types were found in 27 of 30 (90.0%) patients, and consecutive isolates with only a single AFLP type were demonstrated in 21 (70.0%) patients. The median delay between the times of recovery of the first and last isolates of identical AFLP types from each patient was 36 days, and this delay extended for more than 1 year in patients with both colonizing and abscess-related SAG isolates. In six bacteremic patients, paired blood and nonblood SAG isolates showed identical AFLP types.

Adolescent↗
PubMed2006

Acetaldehyde production from ethanol by oral streptococci.

Alcohol is a well documented risk factor for upper digestive tract cancers. It has been shown that acetaldehyde, the first metabolite of ethanol is carcinogenic. The role of microbes in the production of acetaldehyde to the oral cavity has previously been described in several studies. In the present study, the aim was to investigate the capability of viridans group streptococci of normal oral flora to produce acetaldehyde in vitro during ethanol incubation. Furthermore, the aim was to measure the alcohol dehydrogenase (ADH) activity of the bacteria. Eight clinical strains and eight American Type Culture Collection (ATCC) strains of viridans group streptococci were selected for the study. Bacterial suspensions were incubated in two different ethanol concentrations, 11 mM and 1100 mM and the acetaldehyde was measured by gas chromatography. ADH-activity was measured by using a sensitive spectroscopy. The results show significant differences between the bacterial strains regarding acetaldehyde production capability and the detected ADH-activity. In particular, clinical strain of Streptococcus salivarius, both clinical and culture collection strains of Streptococcus intermedius and culture collection strain of Streptococcus mitis produced high amounts of acetaldehyde in 11 mM and 1100 mM ethanol incubation. All these four bacterial strains also showed significant ADH-enzyme activity. Twelve other strains were found to be low acetaldehyde producers. Consequently, our study shows that viridans group streptococci may play a role in metabolizing ethanol to carcinogenic acetaldehyde in the mouth. The observation supports the concept of a novel mechanism in the pathogenesis of oral cancer.

Acetaldehyde↗
PubMed2003

Additive antimicrobial activity of calcium hydroxide and chlorhexidine on common endodontic bacterial pathogens.

It is an established procedure to use calcium hydroxide [Ca(OH)2] as a therapeutic component to achieve sterilization of infected root canals. Unfortunately, some bacterial species are relatively resistant to Ca(OH)2 and are therefore associated with treatment failures. The objective of this study was to identify combinations of substances that improve antimicrobial activity. Ca(OH)2 was used as a suspension or as a component of gutta-percha points. Efficacy of killing was compared for (a) Ca(OH)2 suspension alone; (b) zinc oxide (ZnO) points alone; (c) Ca(OH)2 suspension combined with ZnO points; (d) Ca(OH)2 suspension combined with ZnO/chlorhexidine points; and (e) Ca(OH)2 points combined with ZnO/chlorhexidine points. Common endodontopathogenic bacterial species (Enterococcus faecalis, Fusobacterium nucleatum, Peptostreptococcus micros, Porphyromonas gingivalis, Streptococcus intermedius) in pure cultures served as target organisms. In the in vitro assay, the antibacterial substances and approximately 10(7) colony forming units of test bacteria were co-incubated in diluted human serum under growth conditions appropriate for the single bacterial species. Samples were taken on days 0, 1, 2, 4, 7, and 14 of incubation and viable counts determined. Gram-negative bacteria were sufficiently killed by Ca(OH)2 alone. Combinations with other agents did not improve the killing kinetics. For the inactivation of the Gram-positive bacteria P. micros and S. intermedius, a combination of Ca(OH)2 and ZnO/chlorhexidine, killed the bacteria faster than Ca(OH)2 alone. For E. faecalis, combining Ca(OH)2 suspension with ZnO/chlorhexidine points lead to a faster decrease in the overall number of viable bacteria, but no test conditions lead to the complete loss of culture viability. The results of this study support the use of a combination of Ca(OH)2 and chlorhexidine for faster eradication of P. micros and S. intermedius from infected root canals.

Anti-Infective Agents, Local↗
PubMed2004

Subacute bacterial endocarditis associated with upper endoscopy.

Transient bacteremia associated with various endoscopic procedures is a well-documented phenomenon. Clinically important bacteremias are very rarely seen, however, this malady has significant morbidity in susceptible patients with valvular heart disease, liver cirrhosis, malignancy and immune deficiency. This bacteremia is a complication that is generally observed secondary to upper endoscopy and other associated invasive procedures in at risk patients, and the more serious manifestations include spontaneous bacterial peritonitis, septic arthritis, meningitis, brain abscess and infective endocarditis. Infective endocarditis is an extremely rare complication of gastrointestinal endoscopy, and it has been convincingly documented in only seven cases. We report a case of native valve endocarditis due to Streptococcus intermedius in a patient with valvular heart disease as a consequence of routine upper endoscopy.

Endocarditis, Subacute Bacterial↗