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PubMed2005

Antibacterial and antiplaque effects of a novel, alcohol-free oral rinse with cetylpyridinium chloride.

Antimicrobial agents are commonly incorporated into hygiene products for the treatment and prevention of plaque and gingivitis. Recently, a new alcohol-free rinse containing 0.07% cetylpyridinium chloride (CPC) in a high bioavailable matrix (Crest Pro-Health Rinse) was introduced to provide antiplaque and antigingivitis benefits. This paper reviews results from an in vitro pre-clinical study and an in vivo clinical study evaluating the antibacterial and antiplaque benefits of this CPC rinse technology. In the in vitro experiment, a no-alcohol 0.065% high bioavailable CPC prototype rinse was evaluated for its hostility against a broad range of microorganisms commonly associated with plaque and gingivitis. The rinse demonstrated greater than 99% germ kill for all organisms tested individually as well as in whole saliva. The benefit of this antibacterial action on plaque inhibition was assessed in a clinical trial. A double-blinded, 3-period, 6-sequence crossover study was conducted evaluating the antiplaque effect of the novel 0.07% high bioavailable, alcohol-free CPC rinse versus a positive control (Listerine Cool Mint containing essential oils) and a negative control (placebo CPC rinse). A modification of the Addy 4-day plaque model was used for this evaluation. Plaque was measured at baseline (Day 1) of each treatment period and at Day 4 using the Turesky modification of Quigley-Hein index. During the treatment period, subjects brushed only their lingual surfaces twice daily for up to 60 seconds. Following brushing, subjects used 20 mls of the mouthrinse product for 30 seconds in the morning and evening. Fifty-five subjects completed the study. For non-brushed sites, both the essential oils and CPC rinse exhibited a 25% reduction in plaque vs. placebo after four days of product usage, which was statistically significant (p < 0.0001). Both treatments also exhibited a statistically significant benefit versus placebo (p<0.0001) for brushed sites (>38% plaque reduction). These data support the antibacterial action of the high bioavailable, alcohol-free CPC rinse and demonstrate antiplaque effects for Crest Pro-Health Rinse that are "at least as good as" the leading essential oils antiseptic, making it well-suited for a broad range of patients, particularly those who are sensitive to products containing alcohol.

Adolescent↗
PubMed2001

[Resistance of Mycobacterium fortuitum against varied physical factors and its survival in different surroundings].

OBJECTIVE: To observe the resistance of Mycobacterium fortuitum against some physical factors and its survival in different surroundings. METHODS: Bacterium solution of Mycobacterium fortuitum was added to the carriers, then it was treated in different interval of time and physical surroundings (high temperature, maximum pressure in ultraviolet ray, dry, sunshine). The treated specimen was cultured to observe the resistance of Mycobacterium fortuitum against physical factors. At the same time, some of bacterium solution were mixed into materials in different surroundings (water, wet soil, and dry soil). The specimen was cultured constantly in different time under the room temperature to observe the growth of Mycobacterium fortuitum in different surroundings. RESULTS: Mycobacterium fortuitum was killed at 60 degrees C in 135 minutes, 80 degrees C in 60 minutes, 100 degrees C in 5 minutes, and high pressure in 5 minutes (6.8 kg at 121 degrees C, 4.5 kg at 115 degrees C). It can also be killed under hot sunshine in one hour and under the ultraviolet ray at 105.5 microW/cm. Mycobacterium fortuitum can exist in water over 27 months, in wet and dry soil and in dry surroundings for more than one and a half year. With the extending of time, quantities of Mycobacterium fortuitum showed a trend of decline. CONCLUSIONS: Mycobacterium fortuitum possesses low resistance against high temperature, but higher resistance against ultraviolet ray. The germ shows stronger endurance in different surroundings and can exist for a long time.

Environment↗
PubMedDate not supplied

Inhibitory activity of glass-ionomer cements on cariogenic bacteria.

This study evaluated the antibacterial activity of the glass-ionomer cements Vitrebond (3M ESPE), Ketac Molar (3M ESPE) and Fuji IX (GC America) against S mutans, S sobrinus, L acidophilus and A viscosus, using the agar diffusion test. Inocula were obtained by the seed of indicators cultures in BHI broth incubated at 37 degrees C for 24 hours. Base layers containing 15 mL of BHI agar and 300 microL of each bacteria suspension were prepared in Petri dishes. Six wells measuring 4 mm in diameter were made in each plate and completely filled with one of the testing materials. A 0.2% chlorhexidine solution applied in round filter papers was used as control. Tests were performed 12 times for each material and bacteria strain. After incubation of the plates at 37 degrees C for 24 hours, the zones of bacterial growth inhibition around the wells were measured. Overall, the results showed the following sequence of antibacterial activity: Vitrebond (despite the activation mode) > 0.2% chlorhexidine > Ketac Molar > Fuji IX, according to Kruskal-Wallis and Mann-Whitney statistical tests. This study confirmed significant antibacterial activity for two conventional glass-ionomers and one resin-modified glass-ionomer material. The resin-modified glass-ionomer cement Vitrebond, regardless of the activation mode, presented the best antibacterial activity against S mutans and S sobrinus. The antibacterial activity against A viscosus for Vitrebond was similar to 0.2% chlorhexidine, while light activation reduced its antibacterial activity against L acidophilus.

Actinomyces viscosus↗
PubMed2005

Sodium bicarbonate and hydrogen peroxide: the effect on the growth of Streptococcus mutans.

PURPOSE: This in vitro experiment studied the effects of sodium bicarbonate and hydrogen peroxide on the cariogenic bacteria Streptococcus mutans through analysis with a spectrophotometer. METHODS: The growth of S. mutans was analyzed using seven different environments. Twelve wells in each of the seven rows of a multi-well plate were used to incubate the test materials. In combinations of 10 microl distilled water, 100 microl broth, 10 microl 10% sucrose, 10 microl S. mutans, 10 microl 10% sodium bicarbonate, and 10 microl 3% hydrogen peroxide, seven different environments were created for testing. Environments had either sodium bicarbonate or hydrogen peroxide with S. mutans, or a combination of sodium bicarbonate and hydrogen peroxide with S. mutans. The plate was incubated at 37 degrees C and measured at 0, 18, 20, 22, 24, 26, 28, 30, and 42 hours by optical density with a spectrophotometer. RESULTS: Results showed bacterial growth was prevented by sodium bicarbonate, hydrogen peroxide, and the combination of sodium bicarbonate and hydrogen peroxide. Although hydrogen peroxide is bacteriocidal and sodium bicarbonate is bacteriostatic, there were no significant differences among the three treatment groups in spectrophotometer readings at any of the nine readings over 42 hours. CONCLUSION: There was no significant difference among the effects of hydrogen peroxide, sodium bicarbonate, or the sodium bicarbonate and hydrogen peroxide combination, as measured by optical density. The hydrogen peroxide, sodium bicarbonate, and the sodium bicarbonate and hydrogen peroxide combination prevented bacterial growth of S. mutans. The results show that products containing these agents have the ability to stop the growth of S. mutans. Products containing sodium bicarbonate and/or hydrogen peroxide may be useful to caries-prone patients. More studies are needed to confirm these results on patients.

Dentifrices↗
PubMed2006

[Construction and functional analysis of the crtl gene disruptant in Deinococcus radiodurans].

With the method of Polymerase Chain Reaction and homologous genetic recombination in vivo, the key gene encoding bacterial-type phytoene desaturase (Crtl) which controls the carotenoids biosynthesis pathway in the non-photosynthetic and extremely radioresistant bacterium Deinococcus radiodurans was deleted from the genome. The colorless mutant obtained was designated as M61. Survival rates of mutant strain and wild type strain were investigated under different doses of gamma-radiation and hydrogen peroxide. The results showed that the radioresistant activity of M61 reduced rapidly under ionization radiation, and it became more sensitive to the treatment of hydrogen peroxide especially to high concentration of hydrogen peroxide compared to that of wild type R1. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) was used to investigate the carotenoid composition of wild type R1 and mutant M61. HPLC results exhibited that the deficient of crtl gene had important effect on pigment biosynthesis pathway, leading to inhibition of the biosynthesis of lycopene and other carotenoids in D. radiodurans. All the results indicated that crtl gene was a key gene controlling the biosynthesis of red carotenoid including lycopene in D. radiodurans. The roles of carotenoids in protecting the bacterial cell from damage by ionization radiation and hydrogen peroxide suggest that the carotenoids contribute to the defense system in D. radiodurans. This study is important for elucidating the radioresistant and antioxidant mechanism in which carotenoids are involved, and it will supply some ideas to the further investigation on the biosynthesis pathway and functions of carotenoids in D. radiodurans.

Bacterial Proteins↗
PubMed2006

[Bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis].

Feasibility of bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis was studied using sewage sludge as a raw material. The fermentation was also compared with conventional medium. Results showed that without any pretreatment, the nutrients contained in sewage sludge were almost sufficient for Bacillus thuringiensis growth, even with a rapid multiplicational rate. Higher viable cells and viable spores values were obtained earlier at 24 h, with 9.48 x 10(8) CFU x mL(-1) and 8.51 x 10(8) CFU x mL(-1) respectively, which was 12 hours earlier and nearly 20 percent higher than conventional medium. SEM of 36 h samples gave a clear phenomenon that the metabolizability in sludge was much faster with spores and crystals spreading around. The crystals in sludge seemed rather bigger and more regular. Also a better crystal protein yield of 2.80 mg x mL(-1) was observed in sludge medium compared to conventional medium at the end of fermentation. Sludge fermentation for Bacillus thuringiensis reduces the producing cost, and gives better fermentation capabilities. It's expected to be a new method for sludge disposal.

Bacillus thuringiensis↗
PubMed2006

Evidence of indigenous NAH plasmid of naphthalene degrading Pseudomonas putida PpG7 strain implicated in limonin degradation.

A well characterized naphthalene-degrading strain, Pseudomonas putida PpG7 was observed to utilize limonin, a highly-oxygenated triterpenoid compound as a sole source of carbon and energy. Limonin concentrations evidenced a 64% reduction over 48 h of growth in batch cultures. Attempts were made to acquire a plasmid-less derivative via various methods (viz. Ethidium Bromide, SDS, elevated temperature & mitomycin C), among which the method involving mitomycin C (20 ug/ml) proved successful. Concomitant with the loss of plasmid in P. putida PpG7 strain, the cured derivative was identified as a lim- phenotype. The lim+ phenotype could be conjugally transferred to the cured derivative. Based on the results of curing with mitomycin C, conjugation studies and presence of ndo gene encoding naphthalene 1,2 dioxygenase, it was demonstrated that genes for the limonin utilization were encoded on an 83 kb indigenous transmissible Inc. P9 NAH plasmid in Pseudomonas putida PpG7 strain.

DNA, Bacterial↗
PubMed2006

Testing of bacteria isolated from HIV/AIDS patients in experimental models.

OBJECTIVES: Bacteria purified from the intestinal tract of HIV/AIDS patients were tested for the capacity to be internalised by cells of the HL-60 cell line. Secondly, the bacteria have been applied to the rabbit's colon in order to test their pathogenic ability. RESULTS: The ability of the bacteria to be internalised by HL-60 cells was found to be very expressive. For a more complex biological characterisation of internalised bacteria, these were applied in 6-day intervals per rectum to NZB x CA rabbits during 8 months. The administered bacteria were detected by dot blot hybridisation using HIV-1 PCR probes in the rabbits' intestinal tract after 2 months. No histological and pathological changes were recorded in the gastrointestinal epithelial cells of rabbits. CONCLUSIONS: The applied bacteria of HIV/AIDS patients were not colonised in the rabbit's colon and disappeared after 2 months. Differences between HL-60 and rabbit model are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Role of bacterial agglutination in wound infection].

Method of study of bacterial agglutination by means of serum taken from patients with wound infections was suggested. It was found out that agglutination suppresses viability of microbial cells in the center of agglutinate and reduces the risk of bacterial spreading from the wound over the body.

Agglutination↗
PubMed1984

[Fatty acid composition of Escherichia coli cells and their viability in air].

Experiments on E. coli used as a model have revealed that fatty-acid composition is one of the characteristics which determine the viability of bacteria in the air. The viability of microbial cells in the air has been shown to increase with the increase of the pool of cyclopropane acids and the palmitic acid/palmitoleic acid ratio in the cells, irrespective of their genotype and the phase of their growth.

Aerosols↗
PubMed1980

[Technic of studying microorganism viability in a simulated aerosol state on fiberglass microfilaments].

A specially developed method of studying the viability of microorganisms in the simulated aerosol state on glass microfibers was used to show that the survival rate of E. coli and F. tularensis on fiber-glass spheres was similar to that in true aerosol, as observed in a static aerosol chamber. The proposed method allows to study the viability of microbial cells after prolonged existence in aerosol under any environmental condition both in open spaces and closed rooms.

Aerosols↗
PubMed2006

Fluorescence microscopy for studying the viability of micro-organisms in natural whey starters.

AIMS: The aim of this work was to study the viability and cultivability of microbial populations of different natural whey starters and to evaluate their resistance to thermal treatments (such as exposure to high or low temperatures). METHODS AND RESULTS: Twenty-three natural whey starters for Grana Padano cheese were investigated and subsequently pH measurement, plate count agar using Man-Rogasa-Sharpe (MRS) pH 5.4 agar and whey agar medium (WAM) were performed using these samples. LIVE/DEAD BacLight bacterial viability kit was used. Total count and viability of all the 23 samples were high and similar to each other (CV 20%). However, the cultivable population was lower in terms of cfu ml(-1) and number of cells per millilitre than the viable fraction and highly variable, although its count value was higher in WAM than in MRS pH 5.4. The heating (60 degrees C for 5 min and 54 degrees C for 1 h) and freezing (-20 and -80 degrees C) treatments affected the cultivability and viability of the microbial population. CONCLUSIONS: This study demonstrated the effectiveness of LIVE/DEAD BacLight bacterial viability kit, which has already been used to evaluate bacterial populations, in investigating microbial viability in a complex ecosystem such as a natural whey starter. SIGNIFICANCE AND IMPACT OF THE STUDY: The aim of this study was to quantify the presence of damaged nonviable bacterial cells in natural whey starters. The Thoma Glass is a useful method to obtain fluorescence microscopy counts to evaluate the technological performance of natural whey starters.

Bacteria↗