OBJECTIVEThe aim of this study was to investigate whether the three species of oral Actinomyces have inhibitory effects on the growth of oral Candida albicans in vitro.

METHODSStraight o'clock method was used to observe the bacteriostasis circle. Reverse o'clock and mixed culture method were used to study the quantitative changes of Candida albicans colony respectively.

RESULTS(1) None of the groups had been viewed the bacteriostasis circle. (2) Compared with control groups, there was a significant decrease of Candida albicans colony on Actinomyces viscosus TPY soft agar (P < 0.05). Actinomyces naeslundii and Actinomyces odontolyticus TPY soft agar were both devoid of obvious Candida albicans colony (P < 0.01). The former group (Actinomyces viscosus) and the two latter groups (Actinomyces naeslundii and Actinomyces odontolyticus) showed a striking contrast (P < 0.01). (3) Compared with control groups, a decrease of Candida albicans showed up in the mixed culture, and the difference was significant (P < 0.05). The discrepancies among the three experimental groups were of no statistical value (P > 0.05).

CONCLUSIONOral Actinomyces viscosus, Actinomyces naeslundii and Actinomyces odontolyticus could inhibit the growth of Candida albicans in vitro. However, which of them contributed more to the inhibitory effects was still not affirmed.

Actinomyces ; Actinomyces viscosus ; Candida albicans ; In Vitro Techniques

OBJECTIVEThis research aimed to study the inhibitory effect of xylitol on the growth and acid production of Actinomyces viscosus (A. viscosus).

METHODSWe cultivated A. viscosus in anaerobic conditions with different concentrations (128, 64, 32, 16, 8, and 4 g x L(-1)) of xylitol brain heart infusion liquid medium and determined the minimum inhibitory concentration (MIC). Subsequently, we measured the pH value of the control group, as well as those of 1/2, 1/4, 1/8 MIC, and MIC concentration groups at 1.5, 3, 6, 12, 24, and 48 h. The Delta pH and OD550 at 2, 4, 6, 8, 10, and 12 h were calculated. We discovered that the minimum xylitol concentrations suppressed 50% and 90% A. viscosus biofilm formation (i.e., MBIC50 and MBIC90). SPSS 19.0 was used to analyze the collected data, and conclusions were drawn afterward.

RESULTSXylitol inhibited the growth ofA. viscosus at MIC of 64 g x L(-1). After 12 h, the differences of pH value among groups were all statistically significant (P < 0.05), and Delta pH increased when the MIC concentration decreased. Except for the 1/2 MIC and MIC groups, the differences of OD550 among groups had no statistical significance (P>0.05), and OD550 also increased when the MIC concentration decreased. These results imply that the ability ofA. viscosus to grow and produce acid in 1/2 MIC and MIC conditions will be reduced with the increase in xylitol concentration. The value of MIBC50 was 64 g x L(-1), whereas the value of MIBC90 was 128 g x L(-1). This finding indicates that the xylitol medium can restrict A. viscosus biofilm formation.

CONCLUSIONXylitolcan effectively inhibit the growth, adhesion, and acid production ofA. viscosus, protecting teeth from cariogenic bacteria and preventing caries to a certain extent.

Actinomyces viscosus ; Bacteria ; Dental Caries ; Humans ; In Vitro Techniques ; Xylitol

The purpose of this study was to evaluate the effectiveness of chlorhexidine varnish treatment in the prevention of dental caries in orthodontic patients by observing microbial change in dental plaque after varnish treatment. The sample consisted of 26 patients who were classified into an experimental group and a control group, 13 patients each. The experimental group was treated with cl orhexidine varnish once a week for 4 weeks. The control group was treated with placebo varnish using the same procedure, The microbial change was analysed by indirect immunofluorescenize technique before treatment and 4 weeks, 8 weeks after treatment. The results were as follows. 1. Streptococcus inutans were strongly suppressed until 8 weeks after chlorhexidine varnish treatment(p<0.01). 2 The proportion of Streptococcus sanguis increased temporarily 4 weeks after chlorhexidine varnish treatment(p<0.U5), decreased to original level after 8 weeks. 3. Streptococcus mitts, Actinomyces viscosus, Actinomyces naeslundii did not show significant change after chlorhexidine varnish treatment.
Actinomyces ; Actinomyces viscosus ; Chlorhexidine* ; Dental Caries ; Dental Plaque* ; Humans ; Paint* ; Streptococcus ; Streptococcus sanguis

OBJECTIVETo investigate the changes in the quantity of colonizing Streptococcus mutans(S. mutans) and Actinomyces on the root surface plaque before and after post-core crown restoration of the mandibular first molars in the elderly patients.

METHODSA total of 30 elderly patients, each with one post-core crown restoration of the mandibular first molar, were randomly chosen to participate in the studies. Patients with mandibular first molars with post-core crown restoration and those with healthy contralateral mandibular first molars were divided into the test and control groups, respectively. Root surface plaques of the two groups were collected before tooth preparation, 72 h after preparation, one week after preparation, and one month after restoration. S. mutans, Actinomyces naeslundii (A. naeslundii) and Actinomyces viscosus (A. viscosus), were identified using colony morphology, biochemical techniques, and polymerase chain reaction (PCR). Plaque count was measured using microbial colony count.

RESULTSThe number of S. mutans and A. viscosus and A. naeslundii in the test group, which was statistically significant (P<0.05), increased 72 h after preparation. The quantities of S. mutans, A. viscosus, and A. naeslundii one week after preparation were significantly different (P<0.05). The plaque count of S. mutans, A. viscosus, and A. naeslundii in the test group decreased one month after restoration (P<0.05).

CONCLUSIONThe quantities of S. mutans, A. viscosus and A. naeslundii increase one week after preparation but decrease one month after restoration. The finding suggests that dentists should educate patients about plaque control during the early period after tooth preparation.

Actinomyces ; Actinomyces viscosus ; Aged ; Bacteria ; Crowns ; Dental Plaque ; Humans ; Post and Core Technique ; Streptococcus mutans ; Tooth Root

The authors observed the long term effects of chlorhexidine varnish treatment on microbial of dental plaque in orthodontic patients with fixed appliances. The initial sample was 100 patients who were arranged to be treated with fixed orthodontic appliances. The final sample consisted of 21 patients who could be traced for 32 weeks after application of fixed orthodontic appliances. They were classified into the experimental group (12 patients) and the control group (9 patients). The experimental group was treated with chlorhexidine varnish once a week for 4 weeks before application of fixed orthodontic appliance. The control group was not treated with chlorhexidine varnish before application of fixed orthodontic appliance. The experimental group was treated once more after 20 weeks. The microbial changes of dental plaque were analysed by indirect immunofluorescence technique at pre-treatment 4, 8, 20, and 32 weeks. The result were as follows. 1. In the experimental group, streptococcus mutans was significantly suppressed during experimental period. (p<0.01) But, in the control group, streptococcus mutans was significantly increased after placement of fixed orthodontic appliances during experiment period. (p<0.05) 2. Streptococcus sanguis, streptococcus mitis, Actinomyces viscosus, and Actinomyces naeslundii did not show significant change between the experimental and the control group during experiment period.
Actinomyces ; Actinomyces viscosus ; Chlorhexidine* ; Dental Plaque* ; Fluorescent Antibody Technique, Indirect ; Humans ; Orthodontic Appliances ; Paint* ; Streptococcus mitis ; Streptococcus mutans ; Streptococcus sanguis

Nocardia, aerobic members of the order of Actinomycetaceae, produces infections in human lung. Nocardial infection is associated with underlying diseases of immuno-suppression or treatment with corticosteroid. It is difficult to detect Nocardia by sputum examination or histologic sections and it has rarely been diagnosed by fine needle aspiration of the lung. We describe a case of pulmonary nocardiosis in a 72 year-old man. diagnosed by fine needle aspiration, which was confirmed by culture of aspirates. The aspirates showed neutrophil-predominant inflammatory cells with microoganisms demonstrated by Gomori methenamine silver and Gram stain. The organisms had characteristic long branching filamentous strucutres. The lesions on chest x-ray were in resolution with antimicrobial therapy.
Actinomycetaceae ; Aged ; Biopsy, Fine-Needle* ; Humans ; Lung ; Methenamine ; Nocardia ; Nocardia Infections* ; Sputum ; Thorax

OBJECTIVETo evaluate the effects of Yili dark bee propolis on the main cariogenic biofilm and mechanisms.

METHODSSusceptibilities to the ethanolic extract of propolis against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Streptococcus sanguis (S. sanguis), Actinomyces viscosus (A. viscosus), and Actinomyces naeslundii (A. naeslundii) were analyzed by crystal violet stain method to determine the minimum biofilm eradication concentration (MBEC). The biofilm was initially cultivated for 24 h. Subsequently, the propolis groups with different concentration MBEC and initial pH 7.0 were cultured for 24 h. Moreover, the pH value was measured to evaluate the acid-producing ability of the tested plaque biofilm. The effects of propolis on the insoluble extracellular polysaccharide synthesis of S. mutans biofilm were evaluated by anthrone method.

RESULTSThe MBEC of Yili propolis on S. mutans, S. sobrinus, S. sanguis, A. viscosus, and A. naeslundii were 6.25, 1.56, 3.13, 0.78, and 0.78 mg.mL-1, respectively. Propolis could decrease the ΔpH of the tested plaque biofilm, and the differences between the control and propolis groups were statistically significant (P<0.05). At MBEC, propolis could reduce the ability of S. mutans in synthesizing insoluble extracellular polysaccharides.

CONCLUSIONYili propolis demonstrate remarkable eradicative effects on the cariogenic plaque biofilm, showing inhibition of the synthesis of biofilm-produced acids and insoluble extracellular polysaccharides.

Actinomyces viscosus ; Animals ; Bees ; Biofilms ; Dental Plaque ; Propolis ; Streptococcus mutans ; Streptococcus sanguis ; Streptococcus sobrinus

OBJECTIVEThe purples of this study was to investigate the role of different components of Galla Chinensis extract on the growth of 6 kinds of cariogenic bacteria, and to find out the most effective components of Galla Chinensis extract.

METHODSFour different components (GCE1, GCE2, GCE3 and GCE4) were separated from Galla Chinensis and there antibacterial activities to Streptococcus mutans ATCC 25175, Streptococcus sanguis ATCC 10556, Streptococcus salivarius SS 196, Actinomyces naeslundii WVU 627, Actinomyces viscosus ATCC 19246 and Lactobacillus rhamnosus AC 413 were checked. There effects on the growth curve of Streptococcus mutans ATCC 25175 were also investigated.

RESULTSThe most effective part of Galla Chinensis was found to be GCE2 and GCE4, which were found to be a mixture of polyphenol-rich fractions. All of the different components had an inhibitory effect to the growth of Streptococcus mutans ATCC 25175.

CONCLUSIONAll of the 4 different components of Galla Chinensis extract could inhibit the growth of the tested bacteria. These results suggest that the antibacterial activity of Galla Chinensis extract is caused by a synergistic effect of monomeric polyphenols, which can easily bind to proteins.

Actinomyces viscosus ; Anti-Bacterial Agents ; Bacteria ; Dental Caries ; Drugs, Chinese Herbal ; In Vitro Techniques ; Streptococcus mutans ; Streptococcus sanguis

The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy. Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients. Eight patients with head and neck cancers were involved in this study. For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy. A total of 147,232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis, representing 3,460 species level operational taxonomic units (OTUs) and 140 genus level taxa. Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics. Moreover, the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves. This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.
Actinomyces ; classification ; radiation effects ; Actinomycetaceae ; classification ; radiation effects ; Alcaligenaceae ; classification ; radiation effects ; Bacteria ; classification ; radiation effects ; Capnocytophaga ; classification ; radiation effects ; Carnobacteriaceae ; classification ; radiation effects ; Computational Biology ; Dental Plaque ; microbiology ; Follow-Up Studies ; Gemella ; classification ; radiation effects ; Head and Neck Neoplasms ; radiotherapy ; High-Throughput Nucleotide Sequencing ; Humans ; Middle Aged ; Neisseria ; classification ; radiation effects ; Prevotella ; classification ; radiation effects ; Propionibacteriaceae ; classification ; radiation effects ; RNA, Bacterial ; analysis ; RNA, Ribosomal, 16S ; analysis ; Streptococcus ; classification ; radiation effects ; Veillonella ; classification ; radiation effects

Actinomycosis is caused by filamentous Gram positive anaerobic bacteria from the Actinomycetaceae family, and known as a rare cause of the infection at the eyeball. We report magnetic resonance findings of a 60-year-old Korean man with cervicofacial actinomycosis, including cellulitis in the eye and central nervous system actinomycosis. On orbital magnetic resonance imaging, gadolinium-enhanced T1-weight images showed multiple abnormal enhancing lesions in head and neck including right eye, and some include low signal intensities which considered as abscesses. The lesions was diagnosed as actinomycosis by incisional biopsy, and since then was cured by using antibiotics of penicillin family.
Abscess ; Actinomycetaceae ; Actinomycosis ; Actinomycosis, Cervicofacial* ; Anti-Bacterial Agents ; Bacteria, Anaerobic ; Biopsy ; Cellulitis ; Central Nervous System ; Head ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Neck ; Orbit* ; Penicillins