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PubMed2001

Acute epiglottitis in adults: the Royal Melbourne Hospital experience.

BACKGROUND: To examine the common presentations and management of acute epiglottitis in adults. METHOD: Retrospective clinical study of 17 consecutive adult patients who presented to the Royal Melbourne Hospital between January 1988 and December 2000 was undertaken. RESULTS: The mean patient age was 47 years (range 20-87 years) and the male-to-female ratio was 1.8 : 1.0. Peak incidence occurred in September during early spring. All patients presented with sore throat and dysphagia; however, respiratory distress was only noted in 65%. The most common signs were temperature and tachycardia. Four patients (23%) required endotracheal intubation, which was performed electively in three and as an emergency in one. Three of 14 blood cultures were positive, two yielded Haemophilus influenzae type b and one yielded Streptococcus mitis. One of the four throat cultures was positive for Haemophilus influenzae type b. Twelve patients underwent awake flexible laryngoscopy under topical anaesthetic as part of their initial assessment, and there were no complications associated with this procedure. There was no mortality. CONCLUSIONS: The diagnosis of acute epiglottitis in the adult population is difficult as respiratory distress may be absent. Patients who have a significant sore throat with no obvious aetiology should have direct visualization of their larynx by flexible laryngoscopy. Lateral X-ray of neck is of limited value. Once diagnosed, these patients should be hospitalized and monitored as airway obstruction may develop rapidly.

Acute Disease↗

PubMed2002

Varidans streptococci in the oral flora of the patients at risk for infective endocarditis: species and penicillin susceptibilities.

This study examined viridans streptococci (SV) in oral flora of patients at risk of infective endocarditis (IE) by obtaining 57 isolates from gum-tooth margin swabs of 3 groups of patients. Penicillin minimal inhibitory concentrations (MICs) were determined by E test. Group 1 was from 30 patients with prosthetic heart valves who did not receive antimicrobial agents within 3 months prior to recruitment. Group 2 consisted of 21 patients with known rheumatic heart diseases who regularly received penicillin prophylaxis. Group 3 was 2 patients with IE caused by SV in whom dental swabs were performed before and on the third day of treatment. Streptococcus mitis was found most frequently (49% among 51 oral isolates of SV from patients in group 1 and 2) and in both blood cultures of IE patients. Ninety-four per cent of the isolates were penicillin-susceptible and the rest were intermediate-resistant (IR) equally distributed in both groups 1 and 2. In 2 patients with IE, oral SV obtained after 3 days of penicillin therapy had MICs rising 3 and 5 folds of the baselines. It is suggested that surveillance of susceptibilities of oral SV in patients at risk for IE should be kept up since this will affect the dose and type of antimicrobial agents in IE prophylaxis.

Adolescent↗

PubMed1978

Experimental streptococcal endocarditis. The early vegetation.

Aortic valve vegetation were studied in rabbits before and after intravenous injection of streptococcus mitis. Uninfected vegetation sections revealed compact eosinophilic masses with smooth-appearing edges and scattered polymorphonuclear leukocytes inside and on the surface. Scanning electron microscopic views demonstrated erythrocytes, small leukocytes, and platelets; the surface was markedly irregular. Fifteen minutes after injection of 10(10) streptococci, large mononuclear cells and polymorphonuclear leukocytes lined the vegetation edge; scanning electron microscopy showed large and small leukocytes. One and six hours after infection, there were more polymorphonuclear leukocytes inside the vegetation but few superficially. Bacteria were first seen at six hours as microcolonies inside the vegetation. Twenty-four-hour sections showed large bacterial colonies inside with few bacteria at the edges. Despite the smooth appearance of the vegetation edges, all electron microscopic views revealed very rough surfaces.

Animals↗

PubMed1990

Selective modulation of bacterial attachment to oral epithelial cells by enzyme activities associated with poor oral hygiene.

The present investigation explored the hypothesis that elevated levels of certain enzymes in the gingival crevicular environment of individuals with poor oral hygiene and/or gingival inflammation may modify the surfaces of epithelial cells and thereby modulate the types of bacteria which attach and colonize. Buccal epithelial cells treated with neuraminidase and certain proteases were used as a model for study. Bacteria studied included Streptococcus sanguis and Streptococcus mitis which have been associated with gingival health, Actinomyces species which are increased in plaque associated with developing gingivitis, and Bacteroides gingivalis, Bacteroides intermedius, and Actinobacillus actinomycetemcomitans which are associated with destructive periodontal diseases. Treatment of epithelial cells with the enzymes studied produced selective effects on their receptivity for bacteria. Neuraminidase treatment of epithelial cells greatly reduced the attachment of all strains of S. sanguis and S. mitis studied. In contrast, the number of Actinomyces viscosus, A. naeslundii and A. israelii cells which attached was significantly increased. Neuraminidase treatment also appeared to enhance attachment of B. intermedius and B. gingivalis. Treatment of buccal cells with trypsin, chymotrypsin or papain also selectively affected bacterial attachment. Such protease treatment greatly reduced the numbers of streptococci and A. viscosus cells which attached, while the numbers of B. gingivalis and B. intermedius were significantly increased. Treatment of epithelial cells with preparations of lysosomal enzymes derived from human PMNs produced similar selective effects. The changes in bacterial adhesion observed by the enzyme treatments studied are consistent with the shifts in the composition of the gingival crevice flora which occur when oral hygiene is terminated and gingivitis develops.

Actinomyces↗

PubMed2004

A homologue of aliB is found in the capsule region of nonencapsulated Streptococcus pneumoniae.

The epidemiology, phylogeny, and biology of nonencapsulated Streptococcus pneumoniae are largely unknown. Increased colonization capacity and transformability are, however, intriguing features of these pneumococci and play an important role. Twenty-seven nonencapsulated pneumococci were identified in a nationwide collection of 1,980 nasopharyngeal samples and 215 blood samples obtained between 1998 and 2002. On the basis of multilocus sequence typing and capsule region analysis we divided the nonencapsulated pneumococci into two groups. Group I was closely related to encapsulated strains. Group II had a clonal population structure, including two geographically widespread clones able to cause epidemic conjunctivitis and invasive diseases. Group II strains also carried a 1,959-bp homologue of aliB (aliB-like ORF 2) in the capsule region, which was highly homologous to a sequence in the capsule region of Streptococcus mitis. In addition, strains of the two major clones in group II had an additional sequence, aliB-like ORF 1 (1,968 to 2,004 bp), upstream of aliB-like ORF 2. Expression of aliB-like ORF 1 was detected by reverse transcription-PCR, and the corresponding RNA was visualized by Northern blotting. A gene fragment homologous to capN of serotypes 33 and 37 suggests that group II strains were derived from encapsulated pneumococci some time ago. Therefore, loss of capsule expression in vivo was found to be associated with the importation of one or two aliB homologues in some nonencapsulated pneumococci.

Bacterial Adhesion↗

PubMed2001

Simultaneous mitral valve replacement and bypass grafting for mycotic aneurysm of the femoral artery during the active phase of infective endocarditis: a case report.

A 52-year-old woman with a 3-week history of fever and cough was diagnosed as having bacterial endocarditis with vegetation and severe mitral valve insufficiency by echocardiography. Blood culture revealed Streptococcus mitis. After antibiotic treatment for 3 weeks, the patient noticed swelling with pain in her left groin. Computed tomography revealed an occluded aneurysm in the left common femoral artery. Simultaneous surgical treatments of mitral valve replacement and bypass grafting using a saphenous vein following resection of the mycotic femoral arterial aneurysm were performed. Pathohistological examination of surgical specimens revealed acute inflammatory findings, but no microorganisms were found, probably because of the preoperative antibiotic therapy. Her postoperative course was uneventful, and there was no recurrence of mycotic aneurysms in a period of 10 months after the operation. Prompt recognition and urgent simultaneous surgical treatments for mycotic aneurysms complicated with infective endocarditis were effective.

Aneurysm, Infected↗

PubMed1988

Serious infections due to penicillin-resistant strains of viridans streptococci with altered penicillin-binding proteins.

We investigated the mechanism of resistance to penicillin in two penicillin-resistant clinical isolates of viridans streptococci that caused life-threatening infections in two patients not receiving chronic penicillin therapy. The first was a strain of Streptococcus intermedius that was isolated from the cerebrospinal fluid of a patient with post-neurosurgical meningitis. The second was a strain of Streptococcus mitis recovered from the bloodstream of a leukemic patient with neutropenia. Both patients failed to respond to penicillin. The mechanism of resistance in these strains was associated with diminished affinity for penicillin of their penicillin-binding proteins, as compared with those of penicillin-susceptible control strains. We conclude that penicillin-resistant viridans streptococci may cause serious infections even in patients not receiving chronic penicillin therapy, that this resistance is clinically significant and may result in failure of penicillin therapy, and that the mechanism of resistance in these strains is associated with diminished affinity of the penicillin-binding proteins for penicillin.

Adult↗

PubMed1997

Detection of the phosphorylcholine epitope in streptococci, Haemophilus and pathogenic Neisseriae by immunoblotting.

The phosphorylcholine (PC) determinant in Streptococcus pneumoniae is known to be linked to the cell wall polysaccharides (C-Ps) and to the lipoteichoic acid (LTA) (Forssman antigen) of the plasma membrane. Western blotting with two PC specific murine monoclonal antibodies (MAbs) designated 145,F-2 (IgM) and 147,A-1 (IgA) showed a similar ladder-like pattern for all examined strains of S. pneumoniae and Streptococcus mitis. Purified antigens run in parallel indicated that this ladder pattern is due to the PC of LTA. Unlike other techniques, Western blotting thus enables the identification of only one of the streptococcal structures carrying the PC epitope. Gram-negative organisms were also examined, and six of 11 Haemophilus influenzae strains reacted with the MAbs. For this species, unlike the streptococci, only one fast moving band was detected. Analyses by thin-layer chromatography (TLC) detected the PC epitope in lipopolysaccharide (LPS) fraction from H. influenzae. Some strains of the Neisseriaceae family were also positive by Western blotting, but TLC and immunostaining did not detect the PC determinant in LPS.

Animals↗

PubMed2001

Efficacy of clarithromycin in preventing viridans streptococcal bacteremia following autologous stem cell transplantation.

BACKGROUND: In a study involving 200 patients, we previously found that 17.5% of patients developed viridans streptococcal (VS) bacteremia following autologous peripheral blood stem cell transplantation (aPBSCT) when ciprofloxacin or ciprofloxacin plus ampicillin was used for prophylaxis. PATIENTS AND METHODS: A retrospective evaluation of 100 consecutive recipients of aPBSCT was conducted to ascertain the incidence and outcome of VS bacteremia when a combination of ciprofLoxacin and clarithromycin was utilized for antimicrobiaL prophylaxis following transplantation. The 200 patients from our previous study, in which ciprofloxacin alone or ciprofloxacin with ampicillin was used for prophylaxis, were combined with the current group for the purpose of statistical analysis. RESULTS: Streptococcus mitis was isolated from the blood of five individuals at a median of 5 days following stem cell infusion. Each of these patients was neutropenic and presented with fever. Three isolates demonstrated intermediate resistance to macrolides in vitro. However, all episodes of bacteremia were treated successfully with systemic antibiotic therapy. CONCLUSION: Age, duration of neutropenia, type of underlying malignancy and type of conditioning chemotherapy regimen failed to have a significant impact on subsequent VS bacteremia. Only female sex and use of ciprofloxacin without clarithromycin as antimicrobiaL prophyLaxis predicted a significantly increased risk of VS bacteremia in both univariate and Logistic regression analyses.

Adolescent↗

PubMed1990

Molecular aspects of immunoglobulin A1 degradation by oral streptococci.

Using a panel of 143 strains classified according to a novel taxonomic system for oral viridans-type streptococci, we reexamined the ability of oral streptococci to attack human immunoglobulin A1 (IgA1) molecules with IgA1 protease or glycosidases. IgA1 protease production was an exclusive property of all strains belonging to Streptococcus sanguis and Streptococcus oralis (previously S. mitior) and of some strains of Streptococcus mitis biovar 1. These are all dominant initiators of dental plaque formation. Degradation of the carbohydrate moiety of IgA1 molecules accompanied IgA1 protease activity in S. oralis and protease-producing strains of S. mitis biovar 1. Neuraminidase and beta-galactosidase were identified as extracellular enzymes in organisms of these taxa. By examination with enzyme-neutralizing antisera, four distinct IgA1 proteases were detected in S. sanguis biovars 1 to 3, S. sanguis biovar 4, S. oralis, and strains of S. mitis, respectively. The cleavage of IgA1 molecules by streptococcal IgA proteases was found to be influenced by their state of glycosylation. Treatment of IgA1 with bacterial (including streptococcal) neuraminidase increased susceptibility to protease, suggesting a cooperative activity of streptococcal IgA1 protease and neuraminidase. In contrast, a decrease in susceptibility was observed after extensive deglycosylation of the hinge region with endo-alpha-N acetylgalactosaminidase. The effector functions of IgA antibodies depend on the carbohydrate-containing Fc portion. Hence, the observation that oral streptococci may cleave not only the alpha 1 chains but also the carbohydrate moiety of IgA1 molecules suggests that the ability to evade secretory immune mechanisms may contribute to the successful establishment of these bacteria in the oral cavity.

Amino Acid Sequence↗

PubMed1976

Ultrastructural and biochemical alterations effected by viridin B, a bacterocin of alpha-hemolytic streptococci.

Viridin B, a bacteriocin produced by Streptococcus mitis strain 42885, was shown previously to exert a bactericidal effect against a Neisseria sicca strain but only a bacteriostatic effect against a coagulase-negative staphylococcus. In the present report, this dual effect was defined further. Viridin B caused the appearance of mesosomes in both indicator strains early in the course of exposure. Whereas mesosomes were the only noticeable alterations in the staphylococcal strain at all times of exposure to bacteriocin, progressive changes occurred in the N. sicca cells involving the nucleoid and cytoplasmic contents and resulting in the appearance of bacterial ghosts. Biochemical studies indicated a rapid and complete cessation of the incorporation of [3H]thymidine in N. sicca and in the staphylococcus. Whereas the incorporation of [3H]leucine and [3H]uridine in N. sicca was completely stopped, such incorporation was only reduced in the staphylococcus.

Androstenes↗

PubMed1996

Induced candidosis in mice with artificially established oral flora.

The aim of this study was to gauge the effect of an artificially established flora, unnatural for mice, on the induction of oral candidosis in mice. Four groups of BALB/c mice were compared; conventional Candida albicans-free mice, "germ-free" mice which had been inoculated with Candida-free human saliva, germ-free mice which had been exposed to a cocktail of Streptococcus mitis, S. sobrinus and S. sanguis, and uncontaminated germ-free mice. After exposure to C. albicans via drinking water, the four groups of mice were killed and their oral cavities examined for candidal growth and oral lesions. Conventional mice yielded significantly less candidal growth and exhibited significantly fewer oral lesions than the other three groups. Candidal lesions in the two groups of contaminated germ-free mice were significantly fewer than in the uncontaminated germ-free mice. The latter exhibited extensive candidal lesions with little inflammatory infiltrate. It is concluded that mice with human oral micro-organisms have some resistance against candidal infection albeit at a reduced level, that mice with natural oral flora are highly resistant, and that germ-free mice are extremely susceptible to C. albicans infection.

Animals↗

PubMed1991

[Alpha-hemolytic streptococcal septicemia and meningitis in immunocompromised children].

Many kinds of microorganisms can produce toxic septicemia in immunocompromised hosts. We are reporting alpha-hemolytic streptococcal septicemia and meningitis in two children with hematological malignancies. [Case 1] 6 year old girl who had been suffering from acute lymphocytic leukemia. She had sepsis and bacterial meningitis in maintenance-therapy for leukemia. Streptococcus sanguis was isolated from the blood and cerebrospinal fluid (CSF). [Case 2] 11 year old girl who had had malignant lymphoma (non-Hodgkin type). She also had sepsis and bacterial meningitis due to Streptococcus mitis which was isolated from blood and CSF in maintenance-therapy. Both cases had been treated with anti-cancer drugs and had severe granulocytopenia. Positive rate of blood cultures during the recent 6 years (1984.1-1989.12) at our department was 6.0% (total number of cultures were 2,019, positive cultures were 121). Strains of 131 bacteria were determined; Gram-positive cocci were 70 strains (53.4%) and Gram-negative rods were 52 strains (39.7%). Fifteen strains (11.5%) of alpha-hemolytic Streptococci were isolated during 6 years. One hundred thirteen cases of septicemia were analysed in medical charts and 12 cases of alpha-hemolytic streptococcal septicemia were observed (5 cases with infective endocarditis and 7 cases in immunocompromised states).

Child↗

PubMed1995

Streptococci and actinomyces inhibit regrowth of Streptococcus mutans on gnotobiotic rat molar teeth after chlorhexidine varnish treatment.

Clinical studies suggest that the long-term suppression of mutans streptococci on tooth surfaces after intensive chlorhexidine therapy is mainly due to bacterial interference. Other streptococci and also Actinomyces naeslundii are proposed to inhibit regrowth of mutans streptococci after suppression by the agent. We have tested this hypothesis in gnotobiotic rats associated with Streptococcus mutans alone, or associated with S. mutans and strains of Streptococcus oralis, Streptococcus sanguis, Streptococcus gordonii, Streptococcus mitis biovar I, and A. naeslundii. Left lower jaws in these rats were treated with concentrated chlorhexidine varnish, and the return of S. mutans on the treated jaws monitored. In mono-associated rats, S. mutans regained the level of the untreated right lower jaw in approximately 1 week. In contrast, S. mutans remained suppressed for several weeks in rats multi-associated with other streptococci and actinomyces strains. The suppression was more pronounced in the rats fed on basal diet with little free sugars than in rats fed on a sucrose-containing diet. Counts of other streptococci recovered quickly from the intensive chlorhexidine treatment, but A. naeslundii remained suppressed for at least 1 week. The findings demonstrate the crucial importance of the oral microflora in controlling regrowth of mutans streptococci after chemotherapy.

Actinomyces↗

PubMed1994

Cytotoxicity in bacterial cultures: interaction and cell-specificity, possible factors in periodontal disease.

Cytotoxicity in culture media of various growing bacterial strains was estimated by Cr-51 release of labelled target-cells. Interaction studies were made by adding each of the different UV-killed bacteria to the medium with viable bacteria. The reference oral bacterial strains were: Actinobacillus actinomycetemcomitans Y4, Porphyromonas gingivalis, Fusobacterium nucleatum and Streptococcus mitis, which were compared with the reference bacteria Staphylococcus aureus 209 and Staphylococcus epidermidis. The target cells were: gingival fibroblasts (GF), periodontal membrane fibroblasts (PMF), pulpal fibroblasts (PF), HeLa-cells (HeLa), and lymphoid neoplasm cells (LN). Synergistic, as well as antagonistic, effects on target cells were observed. The cytotoxicity of A. actinomycetemcomitans in presence of P. gingivalis is neutralized while in presence of S. aureus it was increased. Bacterial interactions with F. nucleatum and P. gingivalis cytotoxicity were observed. The cytotoxicity of F. nucleatum was increased when cultured together with A. actinomycetemcomitans. Each cell type reacted differently to the toxicity of the supernatant of growth medium in which the same bacterial strain had been cultivated, which indicates cell specificity of the toxins.

Aggregatibacter actinomycetemcomitans↗

PubMed2004

Identification of early microbial colonizers in human dental biofilm.

AIMS: To elucidate the first colonizers within in vivo dental biofilm and to establish potential population shifts that occur during the early phases of biofilm formation. METHODS AND RESULTS: A 'checkerboard' DNA-DNA hybridization assay was employed to identify 40 different bacterial strains. Dental biofilm samples were collected from 15 healthy subjects, 0, 2, 4 and 6 h after tooth cleaning and the composition of these samples was compared with that of whole saliva collected from the same individuals. The bacterial distribution in biofilm samples was distinct from that in saliva, confirming the selectivity of the adhesion process. In the very early stages, the predominant tooth colonizers were found to be Actinomyces species. The relative proportion of streptococci, in particular Streptococcus mitis and S. oralis, increased at the expense of Actinomyces species between 2 and 6 h while the absolute level of Actinomyces remained unaltered. Periodontal pathogens such as Tannerella forsythensis(Bacteroides forsythus), Porphyromonas gingivalis and Treponema denticola as well as Actinobacillus actinomycetemcomitans were present in extremely low levels at all the examined time intervals in this healthy group of subjects. CONCLUSION: The data provide a detailed insight into the bacterial population shifts occurring within the first few hours of biofilm formation and show that the early colonizers of the tooth surface predominantly consist of beneficial micro-organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The early colonizers of dental plaque are of great importance in the succession stages of biofilm formation and its overall effect on the oral health of the host.

Actinomyces↗

PubMed2002

Increased proliferative response of peripheral blood mononuclear cells and T cells to Streptococcus mutans and glucosyltransferase D antigens in the exacerbation stage of recurrent aphthous ulcerations.

BACKGROUND AND PURPOSE: Cytotoxic T lymphocyte-induced lysis of virus-infected oral epithelial cells has been shown to be a cause of early ulcer formation in recurrent aphthous ulcerations (RAU). To test whether bacteria and their associated antigens are involved in the disease process of RAU, the proliferative response (PR) to different streptococcal species in peripheral blood mononuclear cells (PBMC) and T cells isolated from RAU patients at the exacerbation stage was determined. METHODS: PBMC and T cells were isolated from 39 patients with RAU, 21 patients with erosive oral lichen plaus (EOLP, disease control group), and 22 healthy subjects (normal control group). Streptococcus mutans, Streptococcus sanguis, Streptococcus oralis, Streptococcus gordonii, Streptococcus mitis and their associated antigen, glucosyltransferase D (GtfD), were used to stimulate isolated PBMC and T cells in in vitro proliferation assays. RESULTS: PBMC and T cells isolated from RAU patients at the exacerbation stage showed a significantly higher PR to S. mutans antigen and GtfD than those isolated from EOLP patients or healthy control subjects (p < 0.05). GtfD was a more potent stimulation antigen than S. mutans. However, elevated PRs to S. mutans antigen and GtfD were transient and present only in the exacerbation stage of RAU. These elevated PRs declined to normal levels in the postexacerbation and convalescence stages of RAU. Furthermore, the GtfD-stimulated PR in PBMC and T cells was correlated with the severity of RAU. CONCLUSION: In addition to viral infections, streptococci and their associated antigen, GtfD, may be involved in the disease process of RAU, especially in the exacerbation stage.

Adolescent↗

PubMed1987

Etiologic diagnosis of pneumonia by antigen detection: crossreactions between pneumococcal C-polysaccharide and oral microorganisms.

Crossreactions between bacteria occurring more or less frequently in the respiratory tract were investigated using an enzyme-linked immunosorbent assay (ELISA) developed for the detection of pneumococcal C-polysaccharide. A collection of 218 strains was investigated: 30 Streptococcus pneumoniae, 120 alpha-streptococci, and 68 strains representing other species. Strong crossreactions were observed with 36% of the alpha-streptococci and with two of 11 Staphylococcus aureus strains. The collection of alpha-streptococci consisted of 90 fresh clinical isolates and 30 stock strains. Almost all crossreactions of alpha-streptococci were found among the clinical isolates. Among the stock strains only one of four Streptococcus mitis strains was positive. Pneumococcal C-polysaccharide and phosphorylcholine inhibited the reactions in ELISA with monoclonal antibodies against pneumococcal C-polysaccharide, as well as with a polyclonal antiserum against pneumococcal C-polysaccharide. We suggest that the cross reactions between alpha-streptococci and pneumococci depend on the presence of phosphorylcholine as a common antigenic determinant. The crossreaction in the ELISA with some Staphylococcus aureus strains may be explained by the presence of protein A binding to the Fc portion of the antibodies. When the 10 alpha-streptococci that showed the strongest crossreactions and ten pneumococci representing different types were tested in different concentrations the absorbance values were lower for most alpha-streptococci compared with the pneumococci. This explains that false positive results with alpha-streptococci do not seem to constitute a practical problem in this ELISA developed for detection of pneumococcal C-polysaccharide in samples from patients with pneumonia.

Antigens, Bacterial↗