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PubMed1983

Copper-inhibition of the growth of oral streptococci and actinomyces.

Copper ions were found to inhibit the rate of growth in broth culture of Streptococcus mitis, Streptococcus mutans, Streptococcus salivarious, Streptococcus sanguis, Actinomyces viscosus and Actinomyces naeslundii. In all cases, 10(-3) M copper inhibited the rate of growth, whereas 10(-4) M and lower concentrations had little or no effect. At the concentrations used in mouthwashes one mode of action of copper ions is to reduce the rate of growth of oral bacteria in vitro.

Actinomyces↗

PubMed2006

Tigecycline (GAR-936) activity against Streptococcus gallolyticus (bovis) and viridans group streptococci.

Viridans group streptococci including Streptococcus gallolyticus (formerly S. bovis) represent serious invasive pathogens often associated with endocarditis or sepsis among immunocompromised or cancer patients. Tigecycline (GAR-936), the first clinically studied glycylcycline, has a potent gram-positive activity with a potential treatment option for these streptococcal infections. The studied collection (848 strains) included 100 isolates each of Streptococcus anginosus, Streptococcus constellatus, Streptococcus intermedius, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguis, and fewer strains of S. gallolyticus (98 strains) and Streptococcus mutans (50 strains). These strains were isolated from patients on 3 continents in the SENTRY Antimicrobial Surveillance Program and tested for susceptibility and interpreted by Clinical and Laboratory Standards Institute broth microdilution methods and criteria (< or = 0.25 microg/mL for tigecycline per US Food and Drug Administration). Penicillin susceptibility rates for the entire collection varied from 61% (S. sanguis) to 98% (S. constellatus), and macrolide susceptibility was also compromised (49-88%; average, 69%). Tigecycline was active against all isolates tested, in contrast to tetracycline resistance rates of 8-66%, and highest for S. gallolyticus. In conclusion tigecycline was quite active against bacteremic isolates of viridans group streptococci species and S. gallolyticus with an overall MIC90 at < or = 0.06 microg/mL; the highest MIC was only 0.25 microg/mL.

Anti-Bacterial Agents↗

PubMed1995

Antibacterial effects of some root end filling materials.

In addition to having good sealing ability, root end filling materials should "ideally" have some antibacterial activity to prevent bacterial growth. This investigation compared the antibacterial effects of amalgam, zinc oxide-eugenol, Super EBA and a mineral trioxide aggregate on nine facultative bacteria Streptococcus fecalis, Streptococcus mitis, Streptococcus mutans, Streptococcus salivarius, Lactobacillus species, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, and Escherichia coli B and seven strict anaerobic bacteria, Prevotella (Bacteroides) buccae, Bacteroides fragilis, Prevotella (Bacteroides) intermedia, Prevotella (Bacteroides) melaninogenica, Fusobacterium necrophorum, Fusobacterium nucleatum, and Peptostreptococcus anaerobius. After growing these bacteria on solid media, freshly mixed and 24-h set test materials were placed on the surface of these inoculated media and incubated in the appropriate atmosphere for 24 to 48 h at 37 degrees C. Impregnated discs with the Super EBA liquid were used as positive controls. The antibacterial effects of each material were measured in millimeters and the data were analyzed using one-way and two-way analysis of variance and Scheffé tests to determine the statistical differences between the antibacterial effects of the test materials. Impregnated discs with Super EBA liquid caused varying degrees of growth inhibition for both facultative and strict anaerobic bacteria. Both types of amalgam had no antibacterial effect against any of the bacteria tested in this study. Mineral trioxide aggregate had an antibacterial effect on some of the facultative bacteria and no effect on any of the strict anaerobic bacteria. Zinc oxide-eugenol and Super EBA pastes had some antibacterial effects on both types of bacteria tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Compounds↗

PubMed1996

Antibacterial activity of 10% carbamide peroxide bleaching agents.

The antibacterial activity of three commercial 10% carbamide peroxide bleaching agents (Nite White, Karisma, and Opalescence) on Streptococcus mutans, Streptococcus mitis, Streptococcus sanguis, Lactobacillus casei, and Lactobacillus acidophilus was examined. Chlorhexidine (0.2%) was used as a positive control. Test materials and control solution were inserted in wells punched on the surface of disk sensitivity agars seeded with bacteria. After incubation of 24 to 48 h, zones of inhibition were measured. All three of the test materials displayed greater inhibition than the control. The pH of the solutions did not effect the bacterial inhibition.

Anti-Infective Agents, Local↗

PubMed2000

The galU gene of Streptococcus pneumoniae that codes for a UDP-glucose pyrophosphorylase is highly polymorphic and suitable for molecular typing and phylogenetic studies.

The enzyme UTP-glucose-1-phosphate uridylyltransferase (UDP-glucose pyrophosphorylase, UDPG:PP) is synthesized by practically all organisms, although prokaryotic UDPG:PPs are evolutionarily unrelated to the eukaryotic counterparts. The primary structure of prokaryotic UDPG:PPs is well conserved, although little information exists on the polymorphism of the genes coding for these enzymes. It has been reported that the galU gene encoding the Streptococcus pneumoniae UDPG:PP is absolutely required for the synthesis of the capsular polysaccharide, a sine qua non prerequisite for virulence. A 594 bp fragment covering 66% of the galU gene from 37 pneumococcal isolates and the type strains of Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii, Streptococcus sanguinis, Streptococcus salivarius, and Streptococcus sobrinus has been amplified by PCR and sequenced. Up to 21 different alleles were found in S. pneumoniae. They possess a mosaic-like structure and belong to, at least, two evolutionarily distinct families that show a sequence divergence of 15-20%. In spite of its marked polymorphism, phylogenetic relationships among pneumococcal strains deduced from the galU gene matched those previously established by using alternative approaches. Comparison of the pneumococcal galU alleles with those from other streptococci indicated the existence of a complex network of genetic interchange. The galU gene represents an informative marker to be used alone or in conjunction with other molecular typing methods.

Alleles↗

PubMed1983

Distribution and incidence of viridans streptococcal species in routine clinical specimens.

Five hundred consecutive isolates of viridans streptococci were identified to the species level in an effort to determine their distribution and incidence in routine clinical specimens. Viridans streptococci accounted for significant percentages of streptococcal isolates from urine, wounds, body fluids, and blood. The most commonly isolated strains belonged to the Streptococcus milleri, Streptococcus mitis, Streptococcus sanguis I, and Streptococcus sanguis II species. Patient charts were reviewed in order to investigate the possible role as a urinary pathogen of strains belonging to a subgroup of S. milleri. Although these strains frequently are isolated from urine, they appear to play no pathogenic role in urinary tract infections.

Humans↗

PubMed1997

Comparative in-vitro activities of quinupristin-dalfopristin against Gram-positive bloodstream isolates.

The in-vitro activity of quinupristin-dalfopristin was compared with those of vancomycin, teicoplanin, erythromycin, clarithromycin, rifampicin, imipenem, meropenem, ciprofloxacin and sparfloxacin against 414 bloodstream isolates of Gram-positive cocci. Quinupristin-dalfopristin inhibited strains of Streptococcus pyogenes and Streptococcus agalactiae at 0.12 mg/L, methicillin- and/or erythromycin-resistant Staphylococcus aureus and Staphylococcus epidermidis at 0.5 mg/L, Staphylococcus haemolyticus, Enterococcus faecium, Streptococcus pneumoniae, Streptococcus mitis, Streptococcus bovis, Streptococcus sanguis and Streptococcus anginosus at 1 mg/L and Enterococcus faecalis at 8 mg/L.

Anti-Bacterial Agents↗

PubMed2000

Comparative in vitro activity of moxifloxacin against Gram-positive clinical isolates.

The in vitro activity of moxifloxacin was compared with that of 15 antibacterial agents against 513 Gram-positive microorganisms. The MIC(90) (mg/L) of moxifloxacin was 0.06 for quinolone-susceptible Staphylococcus aureus and Staphylococcus epidermidis, 0.12 for Streptococcus pyogenes and Streptococcus agalactiae; 0.25 for Streptococcus pneumoniae, Streptococcus mitis, Streptococcus bovis, Streptococcus anginosus and Actinomyces pyogenes; 0.5 for Streptococcus sanguis and Listeria monocytogenes, 2 for Corynebacterium jekeium and Bifidobacterium bivius. Over 50% of Enterococcus faecalis, Enterococcus faecium, quinolone-resistant staphylococci, Nocardia steroides and Clostridium difficile were susceptible to 2 mg/L moxifloxacin. Moxifloxacin and trovafloxacin demonstrated comparably high activity towards Gram-positive cocci; moxifloxacin and clinafloxacin were most active against Gram-positive bacilli.

Anti-Infective Agents↗

PubMed2001

Infection and mucosal injury in cancer treatment.

The oral and gastrointestinal mucosa acts as an important mechanical barrier that prevents local or systemic invasion by microorganisms. Cytotoxic chemotherapy-induced mucosal injury (MI) of oral cavity and intestinal epithelium occurs in many patients treated for malignancy. Compromise of the mucosal barrier can contribute to local invasion by colonizing microorganisms and, subsequently, to systemic infection. Historically, gram-negative bacteremia has been the most problematic bacterial infection in neutropenic patients, but its incidence has reduced over time because of the use of prophylactic antibiotics. There has been a shift in the type of infecting organisms responsible for bacteremia in these patients, from predominantly gram-negative organisms to gram-positive cocci. The viridans group of streptococci is composed of the most frequent bacterial pathogens associated with MI. When speciated, oral colonizers such as Streptococcus mitis, Streptococcus oralis, and Streptococcus sangulis II are the most frequently identified pathogens. Other systemic infections caused by vancomycin-resistant enterococci, Stenotrophomonas maltophilia, and Candida species have also been associated with MI after cancer treatment. Infection can also exacerbate MI after cancer treatment. The best recognized example is herpes simplex virus type 1 (HSV-1). Latent virus is frequently reactivated in HSV-seropositive patients; this reactivation leads to stomatitis, which can be indistinguishable from MI caused by cytoreductive therapies. Antiviral prophylaxis or treatment can control the virus-induced MI and bring about overall amelioration of MI. Recognition of this infectious cause of MI is important in order for clinicians to anticipate and minimize oral toxicity and to facilitate optimal delivery of the antineoplastic regimen.

Antineoplastic Agents↗

PubMed1992

Isolation and properties of the Capnocytophaga ochracea bacteriocin.

A bacteriocin from a subgingival plaque isolate of Capnocytophaga ochracea was purified and characterized. It was isolated from cell extract and had a molecular weight of 100,000. Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans and Propionibacterium acnes were susceptible to the bacteriocin.

Actinomyces↗

PubMed1994

Changes in root canal microbiota during the development of rat periapical lesions.

Periapical lesions are reproducibly induced in rats by pulp exposure and infection from the oral cavity. Lesions expand rapidly between day 7 and day 15-20 (active phase), with slowed expansion thereafter. In the present study we characterized the root canal microbiota present during the active phase of lesion development in this system. The mandibular first molars of Sprague-Dawley rats were exposed on day 0. The teeth were extracted after 7 days (n = 10 animals) and 15 days (n = 10), and the microbiota present in roots was isolated and characterized. The number of colonies isolated per tooth was similar on day 7 (1.53 +/- 0.64 colony-forming units x 10(3)) and day 15 (1.49 +/- 0.37 colony-forming units x 10(3)). No colonies were isolated from unexposed control teeth. Anaerobic bacteria increased significantly between day 7 (24.3 +/- 5.7%) and day 15 (47.3 +/- 7.5%), and the proportion of gram-negative organisms increased from day 7 (24.3 +/- 6.1) to day 15 (46.9 +/- 6.8). The predominant bacteria included, on day 7: Streptococcus and Bacteroides species; on day 15: species of Streptococcus, Bacteroides, Prevotella, Neisseria and Peptostreptococcus. Streptococcus oralis, Streptococcus mitis, Streptococcus rattus, Bacteroides pneumosintes and Bacteroides ureolyticus were frequently isolated at both points. Although approximately the same mean number of different species (approximately 3.5) was isolated per tooth on both day 7 and 15, the overall diversity of the isolates increased on day 15.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

PubMed1995

Cross-reactivity between human sialyl Lewis(x) oligosaccharide and common causative oral bacteria of infective endocarditis.

The expression of sialy-Lewis(x) (sLe(x); Neu5Ac alpha 2-3 Gal beta 1-4) (Fuc alpha 1-3) GlcNAc-R) on oral bacteria producing infective endocarditis was determined by a whole-cell enzyme linked immunosorbent assay and an immunoelectron microscopy using the well-characterized anti-sLe(x) monoclonal antibody SNH-3 (mAb SNH-3; IgM class). mAb SNH-3 reacted strongly with whole cells of oral bacteria: Streptococcus sanguis, Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Streptococcus intermedius, Streptococcus constellatus, Streptococcus anginosus, Streptococcus pyogenes, Actinobacillus actinomycetemcomitans, Eikenella corrodens and Porphyromonas gingivalis. The negatively stained immuno-electron micrograph of Streptococcus pyogenes showed many reactive gold particles on the cell surface. Our findings demonstrated the existence of immunologic mimicry between the sLe(x) oligosaccharide and cell surface antigens of many species associated with infective endocarditis. We propose the hypothesis that if these bacteria escape their normal habitats, the surface components that mimic the sLe(x) oligosaccharide might bind to host antigens of the selectin family which could promote binding to endothelial cells and, consequently, initiation of the events leading to infective endocarditis.

Antibodies, Monoclonal↗

PubMed1991

Effects of chlorhexidine on proteolytic and glycosidic enzyme activities of dental plaque bacteria.

Chlorhexidine was tested for its ability to inhibit a wide range of glycosidic and proteolytic enzyme activities produced by Treponema denticola, Porphyromonas gingivalis, Bacteroides intermedius, Actinobacillus actinomycemcomitans, Capnocytophaga sputigena, Capnocytophaga gingivalis, Capnocytophaga orchracea, Capnocytophaga sp., Actinomyces viscosus, Streptococcus mitior, Streptococcus mutans, Streptococcus sobrinus, Streptococcus mitis, Streptococcus anginosus, Streptococcus oralis and Streptococcus sanguis. The enzymes produced by Capnocytophaga spp. were the most resistant to inhibition by chlorhexidine while the hydrolysis of proteolytic substrates by all the other species was markedly susceptible to inhibition with less than 0.125 mM chlorhexidine inhibiting enzyme activities by greater than or equal to 50%. Glycosidase activities, of all species, were generally more resistant to inhibition, especially neuraminidase activity. Chlorhexidine at less than 0.032 mM inhibited the degradation of bovine serum albumin by suspensions of dental plaque bacteria. These observations support an hypothesis that chlorhexidine exerts a bacteristatic effect in vivo, in part, by reducing the ability of dental plaque bacteria to degrade host-derived proteins and glycoproteins which normally provide essential nutrients for growth.

Acetylglucosaminidase↗

PubMed2000

IB-367, a protegrin peptide with in vitro and in vivo activities against the microflora associated with oral mucositis.

Although the microflora associated with oral mucositis initiated by cytotoxic therapy is not well characterized, several studies suggest that reduction of the microbial load in the oral cavity has some clinical benefit. The MICs of IB-367, a synthetic protegrin analog, ranged from 0.13 to 64 microgram/ml for gram-positive bacteria (Streptococcus mitis, Streptococcus sanguis, Streptococcus salivarius, and Staphylococcus aureus) and from 0.06 to 8 microgram/ml for gram-negative species (Klebsiella, Escherichia, and Pseudomonas). IB-367 exhibited rapid, microbicidal activity against both log- and stationary-phase cultures of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. At concentrations near the MICs for these two organisms (4 and 2 microgram/ml, respectively), IB-367 reduced viability by more than 3 logs in less than 16 min. Similarly, IB-367 effected a 4-log reduction of the endogenous microflora in pooled human saliva within 2 min at 250 microgram/ml, a concentration readily attained by local delivery. After nine serial transfers at 0.5x the MIC, the MIC of IB-367 for MRSA and P. aeruginosa increased only two to four times. In a phase I clinical study with healthy volunteers, IB-367 was well tolerated, with no detectable systemic absorption. One hour after treatment with 9 mg of IB-367, the prevalence of gram-negative bacteria and yeast was reduced, and the density of the predominant gram-positive oral flora was decreased 1,000 times. IB-367's properties (speed of killing, breadth of spectrum, and lack of resistance) make the compound a strong candidate for the prophylaxis of oral mucositis. Phase II clinical trials with IB-367 are under way for this indication in immunocompromised subjects.

Anti-Bacterial Agents↗

PubMed2001

Identification of the psaA gene, coding for pneumococcal surface adhesin A, in viridans group streptococci other than Streptococcus pneumoniae.

The gene encoding the pneumococcal surface adhesin A (PsaA) protein has been identified in three different viridans group streptococcal species. Comparative studies of the psaA gene identified in different pneumococcal isolates by sequencing PCR products showed a high degree of conservation among these strains. PsaA is encoded by an open reading frame of 930 bp. The analysis of this fragment in Streptococcus mitis, Streptococcus oralis, and Streptococcus anginosus strains revealed a sequence identity of 95, 94, and 90%, respectively, to the corresponding open reading frame of the previously reported Streptococcus pneumoniae serotype 6B strain. Our results confirm that psaA is present and detectable in heterologous bacterial species. The possible implications of these results for the suitability and potential use of PsaA in the identification and diagnosis of pneumococcal diseases are discussed.

Adhesins, Bacterial↗

PubMed1983

Prevalence of viridans streptococci exhibiting lactose-inhibitable coaggregation with oral actinomycetes.

Fresh oral isolates from human dental plaque were selected on the basis of their spherical morphology. In a double-blind experiment, their species identity and ability to coaggregate with human oral Actinomyces viscosus and Actinomyces naeslundii were determined. Of the 110 isolates characterized, 30 were identified as either Streptococcus mutans, Streptococcus anginosus-constellatus, or Veillonella parvula; none of these coaggregated with the actinomycetes. The remaining 80 isolates were identified as Streptococcus sanguis, Streptococcus mitis, Streptococcus MG-intermedius, or Streptococcus morbillorum. Of these 49 isolates (61%) coaggregated with actinomycetes, and nearly 90% (43 of 49 isolates) exhibited lactose-inhibitable coaggregations. Compared with previously characterized coaggregation properties determined with stock culture strains of streptococci, 82% of the fresh isolates exhibited identical coaggregations. The other 18% made up a new coaggregation group that possessed a related lactose-inhibitable coaggregation pattern. Thus, most fresh isolates that coaggregated exhibited lactose-inhibitable coaggregations with human oral actinomycetes. It is suggested that these coaggregations are mediated by a network of lectin-carbohydrate interactions similar to those already characterized in previous studies with stock cultures of actinomycetes and streptococci.

Actinomycetales↗

PubMed1986

Variable colonization by oral streptococci in molar fissures of monoinfected gnotobiotic rats.

Germfree Sprague-Dawley rats, fed a high-sucrose diet, were monoinfected with strains of Streptococcus mitis, Streptococcus sanguis, and Streptococcus mutans. Viable cell recoveries from six molar teeth, considered to reflect mainly bacterial colonization of intact fissures, were in the order of 10(6), 10(7), and 10(8) CFU, respectively. Some of the implications of the variation of bacterial plaque-forming ability in the rat model are discussed.

Animals↗

PubMed1973

Inhibition of enzymes by human salivary immunoglobulin A.

Human whole saliva inhibited bacterial neuraminidases and the inhibition was found to reside in the salivary IgA fraction. Further, salivary immunoglobulin (Ig)A inhibited various bacterial enzymes and toxins: neuraminidases from Streptococcus mitis, Streptococcus sanguis, and Clostridium perfringens, hyaluronidase and chondroitin sulfatase from oral bacteria, diphtheria toxin, and streptolysin O. The inhibitory activity of salivary IgA did not correlate with that of serum on the basis of minimum inhibitory dose. A small amount of salivary IgA was required to inhibit oral bacterial neuraminidases, whereas a large amount was required to inhibit other bacterial neuraminidase. Therefore, it is concluded that the absence of neuraminidase activity of oral bacteria in whole saliva may be due to specific inhibition by salivary IgA.

Animals↗