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PubMed2005

Differential binding specificities of oral streptococcal antigen I/II family adhesins for human or bacterial ligands.

The antigen I/II (AgI/II) family polypeptides, ranging from 1310 to 1653 amino acid (aa) residues, are cell wall anchored adhesins expressed by most indigenous species of oral streptococci. The polypeptides interact with a wide range of host molecules, in particular salivary agglutinin glycoprotein (SAG or gp340), and with ligands on other oral bacteria. To determine the receptor recognition properties of six different AgI/II family polypeptides from strains of Streptococcus gordonii, Streptococcus intermedius and Streptococcus mutans, the genes were cloned and expressed on the surface of the surrogate host Lactococcus lactis. The S. gordonii SspA and SspB polypeptides mediated higher binding levels of L. lactis cells to surface immobilized gp340 than did S. intermedius Pas protein, or S. mutans SpaP or PAc proteins. However, the AgI/II proteins were all similar in their abilities to mediate aggregation of lactococci by fluid phase gp340. The SpaP(I) polypeptide from S. mutans Ingbritt, which was C-terminally truncated by approximately 400 aa residues, did not bind gp340. Lactococci expressing AgI/II proteins, including SpaP(I), were aggregated by a synthetic 16 aa residue peptide SRCRP2 derived from the aa repeat block sequences within gp340. In coaggregation assays, SspB from S. gordonii was unique in mediating coaggregation with only group A and group E strains of Actinomyces naeslundii. All the other AgI/II polypeptides mediated coaggregation with group C and group D strains of A. naeslundii. Analysis of chimeric protein constructs revealed that coaggregation specificity was determined by sequences within the N-terminal half of AgI/II protein. A synthetic peptide (20 aa residues), which defines a putative adhesion epitope within the C-terminal region of polypeptide, inhibited AgI/II-mediated aggregation by gp340 but did not affect coaggregation with A. naeslundii. These results suggest that different mechanisms operate in interactions of AgI/II family polypeptides with native gp340, gp340 SRCR domain peptide, and A. naeslundii. Specificity of these interactions appears to be determined by discontinuous but interacting regions of the polypeptides, thus providing flexibility in receptor recognition for streptococcal colonization of the human host.

Adhesins, Bacterial↗

PubMed1989

DNA-DNA hybridization studies and phenotypic characteristics of strains within the 'Streptococcus milleri group'.

Twenty-five strains resembling 'Streptococcus milleri' were compared by DNA-DNA hybridization, by whole-cell-derived polypeptide patterns on SDS-PAGE, and by biochemical tests. Four homology groups were revealed by DNA-DNA hybridization. DNA homology groups 1, 2 and 3 were closely related and contained the type strains NCDO 2226 (Streptococcus constellatus), NCDO 2227 (Streptococcus intermedius) and NCTC 10713 (Streptococcus anginosus), respectively. DNA homology group 4 consisted of four strains received as variants of Streptococcus intermedius which were found not to be closely related to strains in groups 1-3. The data from SDS-PAGE polypeptide patterns and biochemical tests supported the recognition of three centres of variation within the 'Streptococcus milleri group' corresponding to DNA homology groups 1-3 and indicated that strains of DNA homology group 4 are members of an as yet undescribed species within the viridans streptococci.

Bacterial Proteins↗

PubMed1997

[Effects of globulin preparations on phagocytic killing of oral streptococci].

The phagocytic bacterial activity on Streptococcus intermedius and Streptococcus oralis, clinical isolates from patients suffering from severe oral surgical infections, was evaluated by using sera and neutrophils of patients who had been treated with polyethylene glycal treated human normal immunoglobulin (Venoglobulin-IH). The phagocytic function of the neutrophils against the two strains, approximately 10 cells/neutrophil, was unrelated to the administration of Venoglobulin-IH. The bactericidal function of the serum and neutrophils on the third day following Venoglobulin-IH administration, on the other hand, rose to 10 times that of the sera and neutrophils of patients with mild infections. The agglutinin titer of Venoglobulin-IH against S. intermedius and S. oralis were 32 and 16 times, respectively, indicating an evident rise in these titers against the clinical isolates in comparison with the reference strains of the same organisms. These findings indicated that the oral streptococci that are isolated from patients with grave infections are associated with an antigenicity that is different from the normal bacterial flora; and these organisms are more labile to phagocytosis by neutrophils that were obtained from patients who have been treated with Venoglobulin-IH.

Administration, Oral↗

PubMed1997

Ribotyping of bacteria from root canal and blood of patients receiving endodontic therapy.

DNA restriction patterns and corresponding ribotypes of 26 bacterial isolates (Propionibacterium acnes, Peptostreptococcus prevotii, Fusobacterium nucleatum, Prevotella intermedia, Prevotella nigrescens, Actinomyces israelii, Streptococcus intermedius, and Streptococcus sanguis) recovered from patients with infected root canals and their peripheral blood, collected during and after endodontic therapy, were examined. Eleven additional reference strains including type strains were also examined. Purified DNA was digested with BglI,EcoRI, and HindIII. Hybridization was carried out with a digoxigenin-labeled cDNA probe obtained by reverse transcription of Escherichia coli 16S + 23S rRNA. Ribotypes of the bacteria recovered from root canal and blood showed identical characteristics within the patients, and differed between the patients. The results were confirmed when the similarity coefficient (S(AB)) of the ribotypes from the isolates were assessed by the Dendron computer-assisted system. These results suggested that the bacteria isolated from the blood originated from the root canal.

Journal Article↗

PubMed1995

Evaluation of the automicrobic system for the identification of Streptococcus mutans.

The performance of the Automicrobic System with the Vitek gram-positive identification card (bioMérieux, France) in identifying strains of Streptococcus mutans was studied. Of 160 strains assayed, 72.5% were confirmed to be Streptococcus mutans; the remainder were identified as other species of streptocci (Streptococcus bovis, Streptococcus uberis, Streptococcus anginosus, Streptococcus sanguis I and II, Streptococcus intermedius, and Streptococcus constellatus).

Bacterial Typing Techniques↗

PubMed2001

Interaction between human polymorphonuclear leukocytes and Streptococcus milleri group bacteria.

Because Streptococcus milleri group (SMG) bacteria--Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus--exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less completely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties.

Abscess↗

PubMed2004

Molecular analysis of age-related changes of Streptococcus anginosus group and Streptococcus mitis in saliva.

The purpose of this study was to survey the prevalence of streptococcal species, especially Streptococcus anginosus (which has been reported to be associated with cancer in the upper digestive tract), Streptococcus constellatus, and Streptococcus intermedius in the saliva of different age groups. A sequence analysis of 16S rDNA was performed and DNA quantified using real-time polymerase chain reaction. The S. anginosus level increased with age, whereas the levels of S. constellatus and S. intermedius did not change. Streptococcus mitis was the predominant species in the saliva of all the age groups but, unlike the S. anginosus, the proportion of S. mitis in the salivary bacteria decreased with age. The increase in S. anginosus with age should be carefully monitored because of its association with diseases, including cancer.

Adult↗

PubMed1995

Bacteremia in conjunction with endodontic therapy.

This study characterizes oral microorganisms believed to have spread from the root canal into the blood stream during and after endodontic therapy of teeth with Asymptomatic apical periodontitis. Microbiological samples were taken under aseptic conditions from the root canal of 26 single-rooted teeth in 26 patients. In the endodontic treatment of 13 of the patients (Group 1), the first 3 reamers, sizes 15, 20 and 25, were used to a level 2 mm beyond the apical foramen. In the other 13 patients (Group 2), the instrumentation ended inside the root canal 1 mm short of the apical foramen. Blood samples were taken from the patients during the instrumentation and 10 min after the treatment was completed. Anaerobic microorganisms were isolated from all root canals. In 7 patients of Group 1, Propionibacterium acnes, Peptostreptococcus prevotii, Fusobacterium nucleatum, Prevotella intermedia and Saccharomyces cerevisiae were recovered from the blood. In 4 patients of Group 2, P. intermedia, Actinomyces israelii, Streptococcus intermedius and Streptococcus sanguis were isolated from the blood. Biochemical tests and antibiograms revealed that the isolates from the root canal and blood had identical profiles within the patients, strongly suggesting that the microorganisms isolated from the blood had the root canal as their source.

Actinomyces↗

PubMed2005

Phenotypic and genotypic selection of microbiota surviving under dental restorations.

The effects of sealing infected carious dentine below dental restorations on the phenotypic and genotypic diversity of the surviving microbiota was investigated. It was hypothesized that the microbiota would be subject to nutrient limitation or nutrient simplification, as it would no longer have access to dietary components or salivary secretion for growth. The available nutrients would be limited primarily to serum proteins passing from the pulp through the patent dentinal tubules to the infected dentine. Ten lesions were treated, and infected dentine was sealed below dental restorations for approximately 5 months. Duplicate standardized samples of infected dentine were taken at baseline and after the removal of the restorations. The baseline microbiota were composed primarily of Lactobacillus spp., Streptococcus mutans, Streptococcus parasanguinis, Actinomyces israelii, and Actinomyces gerencseriae. None of these taxa were isolated among the microbiota of the dentine samples taken after 5 months, which consisted of only Actinomyces naeslundii, Streptococcus oralis, Streptococcus intermedius, and Streptococcus mitis. The microbiota of the final sample exhibited a significantly (P < 0.001) increased ability to produce glycosidic enzymes (sialidase, beta-N-acetylglucosaminidase, and beta-galactosidase), which liberate sugars from glycoproteins. The genotypic diversity of S. oralis and A. naeslundii was significantly (P = 0.002 and P = 0.001, respectively) reduced in the final samples. There was significantly (P < 0.001) greater genotypic diversity within these taxa between the pairs of dentine samples taken at baseline than was found in the 5-month samples, indicating that the dentine was more homogenous than it was at baseline. We propose that during the interval between placement of the restorations and their removal, the available nutrient, primarily serum proteins, or the relative simplicity and homogeneity of the nutrient supply significantly affected the surviving microbiota. The surviving microbiota was less complex, based on compositional, phenotypic, and genotypic analyses, than that isolated from carious lesions which were also exposed to salivary secretions and pH perturbations.

Acetylglucosaminidase↗

PubMed1984

Nutritionally variant streptococci from corneal ulcers in horses.

Of 24 isolates of nutritionally variant streptococci recovered from equine corneal ulcers, 22 were tested for growth requirements, physiological and biochemical reactions, and susceptibility to different antimicrobial agents. Satisfactory growth was obtained by supplementing blood agar and Todd-Hewitt broth with pyridoxal hydrochloride, and all of the media for the culture and the biochemical testing were supplemented with 0.002% of this substance. Biochemical patterns of 12 of the isolates resembled those of two viridans streptococcal species, Streptococcus intermedius and Streptococcus constellatus. Patterns of 10 isolates did not resemble those of any recognized viridans species. All of the isolates were inhibited by less than or equal to 0.25 microgram of erythromycin per ml, less than or equal to 4 micrograms of chloramphenicol per ml, and less than or equal to 4 micrograms of gentamicin per ml, and all but two were inhibited by less than or equal to 0.1 microgram of penicillin per ml.

Animals↗

PubMed1989

A qualitative and quantitative study of the cellular fatty acids of 'Streptococcus milleri' with capillary gas chromatography.

Fatty acid analysis was done with GC and GC-MS on 21 strains of 'Streptococcus milleri', representative of the various proposed species. Although no qualitative differences were found in the fatty acid profiles, discriminant analysis of the quantitative data revealed three groups. Streptococcus anginosus and Streptococcus constellatus were indistinguishable but separated from the other two groups which comprised Streptococcus intermedius, with a wide fermentation pattern and Streptococcus intermedius with a narrow fermentation pattern. Three of the strains could be distinguished from the others by a 'fingerprint' of a particularly prominent fatty acid peak. The results support the suggestion that there is more than one species in this group of organisms and that the technique might be of value in epidemiological investigations of 'S. milleri'.

Fatty Acids↗

PubMed2005

Bacterial colonization on different suture materials--a potential risk for intraoral dentoalveolar surgery.

In this in vivo and in vitro study on resorbable (Monocryl and nonresorbable (Deknalon) monofilament sutures used in intraoral dentoalveolar surgery the bacterial colonization was compared. For the in vivo study the sutures were applied in 11 patients during dental surgery. Eight days postoperative the sutures were removed and the adhered bacteria were isolated and identified by biochemistry, morphology, antibiotic susceptibility, and gas chromatography. The colonization was studied by scanning electron microscopy. Aerobic and anaerobic bacteria were isolated in nearly equal colony-forming units (cfu) on each suture. In comparison with Monocryl about 15% more aerobic and anaerobic strains were isolated on Deknalon. Regarding the pathogens only, about three times more anaerobic strains were isolated on both sutures in total. Additionally, more pathogens were found on Deknalon than on Monocryl (aerobic >40%, anaerobic >25%). The variety of bacteria correspond with purulent infections, not with normal oral flora. Intraindividual comparisons of cfu showed differences in dependence of the patient as described for subgingivale plaques. For the in vitro study the sutures were incubated with Streptococcus intermedius and Prevotella intermedia for 0.5 h. Scanning electron microscopy was performed to examine qualitatively the level of bacterial adherence. After 0.5 h the bacteria adhered very well. The colonization rate of Streptococcus intermedius on both sutures was similar. Coccoid bacteria within biofilms were seen. The growth of Prevotella intermedia was much better on Deknalon than on Monocryl. The risk of bacteremia at the time of suture removal is discussed.

Bacteria↗

PubMed2006

[Subdural empyema in children: therapeutic strategy. Five cases].

We report a series of five subdural empyema (SDE) in children and young adults treated in the same neurosurgical department. These five cases were reviewed retrospectively. There were four boys and one girl, aged from three months to 18 years at time of diagnosis (median age: 7 years). SDE following intracranial surgery were excluded from the study. All patients were treated surgically (burr hole evacuation or craniotomy, repeated in some cases), followed by intravenous antibiotic therapy (mean time: 52 days) adapted to the micro-organism. Only the two patients treated by large craniotomy at first had a single surgical procedure. Involved micro-organisms are as follow: Streptococcus intermedius (n=2), Streptococcus pneumoniae (n=1), Escherichia coli (n=1), absence of any identified micro-organism (n=1). The five patients are alive (median follow-up: 22 month) without any sequelae. We advocate an aggressive surgical treatment of SDE in children with a large bone flap to allow the surgeon to remove pus and membranes as much as possible, even in the interhemispheric fissure, followed by intravenous appropriate antibiotherapy and eradication of the source of infection. Even this "aggressive" treatment may sometimes not avoid re-operation. A careful follow-up is mandatory, because of the high risk of recurrence.

Adolescent↗

PubMed2004

Streptococcus sinensis may react with Lancefield group F antiserum.

Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.

Bacteremia↗

PubMed2002

Distribution of mef(A) in gram-positive bacteria from healthy Portuguese children.

We screened 615 gram-positive isolates from 150 healthy children for the presence of the erm(A), erm(B), erm(C), erm(F), and mef(A) genes. The mef(A) genes were found in 20 (9%) of the macrolide-resistant isolates, including Enterococcus spp., Staphylococcus spp., and Streptococcus spp. Sixteen of the 19 gram-positive isolates tested carried the other seven open reading frames (ORFs) described in Tn1207.1, a genetic element carrying mef(A) recently described in Streptococcus pneumoniae. The three Staphylococcus spp. did not carry orf1 to orf3. A gram-negative Acinetobacter junii isolate also carried the other seven ORFs described in Tn1207.1. A Staphylococcus aureus isolate, a Streptococcus intermedius isolate, a Streptococcus sp. isolate, and an Enterococcus sp. isolate had their mef(A) genes completely sequenced and showed 100% identity at the DNA and amino acid levels with the mef(A) gene from S. pneumoniae.

Anti-Bacterial Agents↗

PubMed1980

Biochemical properties of CO2-dependent streptococci.

A total of 153 clinical isolates and 10 reference strains were employed in an investigation of CO2-dependent streptococci. Their selection was based on a lactic acid homofermentative end product. This group of organisms grew best in 5 to 10% CO2, and several species, including Streptococcus mutans, S. intermedius, Streptococcus MG, S. anginosus, and S. constellatus, required increased CO2 for primary recovery. A basal medium of thioglycolate with 0.1% Tween 80 and phenol red was prepared and used with selected carbohydrates. This media provided luxuriant growth. Serological testing failed to give any definitive correlation with species identification. A shortened differentiation scheme, combined from previous studies, was proposed.

Carbohydrate Metabolism↗

PubMed1997

[Bacteremias due to the Streptococcus milleri group. An analysis of 18 episodes].

OBJECTIVE: To study the epidemiological and clinical characteristics of bacteremia caused by Streptococcus milleri group streptococci (SMG). METHODS: Prospective evaluation of all bacteremic episodes with clinical significance from 1990 to 1995 in two general hospitals. In this study all episodes caused by SMG were analyzed. RESULTS: A total of 905 bacteremic episodes with clinical significance were detected; 18 (1.98%) were caused by SMG (0.16/1,000 admissions). The mean age of patients were 43 years and the male/female ratio 1.6. Seventeen patients (94.4%) had some underlying disease; nine patients had diabetes, four were parenteral drug abusers, and two had neoplasms. The most common sources of bacteremia were intraabdominal in four episodes (two liver abscesses, one subphrenic abscess and one pancreatic pseudocyst), cutaneous and/or soft tissues in four, surgical wound in two and respiratory in two; no source was identified in five episodes. Four episodes had a polymicrobial origin. In 13 isolates the identification was at species level (Streptococcus anginosus eight, Streptococcus intermedius four and Streptococcus constellatus one). All strains were susceptible to penicillin. Six patients (33.3%) required surgery. In ten episodes a favorable outcome was recorded, although four patients required surgery. The infection associated mortality rate was 31.2%. The mean age of deceased patients was higher than for cured patients (62.2 +/- 20.2 versus 35.3 +/- 20.3; p < 0.05). CONCLUSIONS: SMB bacteremia is uncommon. It involved mainly diabetic patients or parenteral drug abusers, commonly with an intraabdominal suppurative source or in skin or soft tissues. The mortality rate was high despite surgery in one third of patients. Patients with advanced age had a poorer prognosis. All isolates investigated were susceptible to penicillin.

Adolescent↗

PubMed1993

Enzymatic differentiation and biochemical and serological characteristics of the clinical isolates of Streptococcus angiosus, S. intermedius and S. constellatus.

Of the 29 'Streptococcus milleri' strains tested, all thirteen Streptococcus intermedius (DNA homology group 2) strains but none of the thirteen Streptococcus anginosus (group 1) strains produced beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, alpha-N-acetylneuraminidase, beta-galactosidase, alpha-glucosidase, and hyaluronidase. The three Streptococcus constellatus (group 3) strains produced only the latter two. Glycosidase production divided 274 clinical isolates into 103 S. anginosus, 101 S. intermedius, and 70 S. constellatus strains. Generally, strains of S. anginosus and S. intermedius were non-beta-haemolytic. API II and biotype Ia (lactose positive), but the former contained almost all API III strains and belonged to Lancefield group A/serotype a (A/a), -/b, C/c, -/d, -/e, F/f or G/k, and the latter included most of biotype IId (lactose negative) and serovar -/g, -/h, -/i or -/j. S constellatus strains were beta-, alpha- or gamma-haemolytic, of API I or II but mostly biotype Ib (lactose negative), and of F/- or -/b. S. intermedius was a major member of the oral isolates. Non-oral isolates were virtually all S. anginosus (mainly urogenital isolates) or S. constellatus (the other systemic isolates).

Adult↗