Effect of hydroalcoholic extract of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves on the viability and activity of microcosm biofilm and on enamel demineralization

Abstract Objectives: The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention. Methodology: Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05). Results: M. urundeuva All. at 100, 10 and 0.1 μg/mL and Q. grandiflora Mart. at 100 and 0.1 μg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 μg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 μg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions. Conclusions: The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.

Evaluation of an antibacterial orthodontic adhesive incorporated with niobium-based bioglass: an in situ study

Abstract This in situ study aimed to evaluate the antibacterial and anti-demineralization effects of an experimental orthodontic adhesive containing triazine and niobium phosphate bioglass (TAT) around brackets bonded to enamel surfaces. Sixteen volunteers were selected to use intra-oral devices with six metallic brackets bonded to enamel blocks. The experimental orthodontic adhesives were composed by 75% BisGMA and 25% TEGDMA containing 0% TAT and 20% TAT. Transbond XT adhesive (TXT) was used as a control group. Ten volunteers, mean age of 29 years, were included in the study. The six blocks of each volunteer were detached from the appliance after 7 and 14 days to evaluate mineral loss and bacterial growth including total bacteria, total Streptococci, Streptococci mutans, and Lactobacilli. Statistical analysis was performed using GLM model - univariate analysis of variance for microhardness and 2-way ANOVA for bacterial growth (p<0.05). The 20% TAT adhesive caused no difference between distances from bracket and the sound zone at 10-µm deep after 7 and 14 days. After 14 days, higher mineral loss was shown around brackets at 10- to 30-µm deep for TXT and 0% TAT adhesives compared to 20% TAT. S. mutans growth was inhibited by 20% TAT adhesive at 14 days. Adhesive with 20% TAT showed lower S. mutans and total Streptococci growth than 0% TAT and TXT adhesives. The findings of this study show that the adhesive incorporated by triazine and niobium phosphate bioglass had an anti-demineralization effect while inhibiting S. mutans and total Streptococci growth. The use of this product may inhibit mineral loss of enamel, preventing the formation of white spot lesions.

Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal

Abstract This study was conducted to assess the clinical effect of photodynamic therapy (PDT) in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ - 660 nm; 40 mW; 120 J/cm2; 120 s). Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU) for any of the microorganisms assessed (p > 0.05). Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin.

NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying

Abstract The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p < 0.05) survival rate during freeze-drying when subjected to a pre-stressed period under the conditions of 2% (w/v) NaCl for 2 h in the late growth phase. The main energy source for the life activity of lactic acid bacteria is related to the glycolytic pathway. To investigate the phenomenon of this stress-related viability improvement in L. bulgaricus, the activities and corresponding genes of key enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p < 0.05) glucose utilization. The activities of glycolytic enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level.

Efficacy of Papacarie¯ in reduction of residual bacteria in deciduous teeth: a randomized, controlled clinical trial

OBJECTIVES: The aim of the present study was to analyze the efficacy of Papacarie¯ gel compared with the traditional method (low-speed bur) in reducing the counts of total bacteria, Lactobacillus, total Streptococcus and Streptococcus mutans group. METHODS: A randomized, controlled clinical trial with a split-mouth design was performed. The sample comprised 40 deciduous teeth in 20 children (10 males and 10 females) aged four to seven years. The teeth were randomly allocated to two groups: G1, or chemomechanical caries removal with Papacarie Duo¯, and G2, or the removal of carious dentin tissue with a low-speed bur. Infected dentin was collected prior to the procedure, and the remaining dentin was collected immediately following the removal of the carious tissue. Initial and final counts of bacterial colonies were performed to determine whether there was a reduction in the number of colony-forming units (CFUs) of each microorganism studied. ClinicalTrials.gov: NCT01811420. RESULTS: Reductions were found in the numbers of total bacteria, total Streptococcus and Streptococcus mutans group following either of the caries removal methods (p<0.05). A reduction was also noted in the number of Lactobacillus CFUs; however, this difference did not achieve statistical significance (p>0.05). CONCLUSION: Papacarie¯ is an excellent option for the minimally invasive removal of carious tissue, achieving significant reductions in total bacteria, total Streptococcus and S. mutans with the same effectiveness as the traditional caries removal method. .

Screening of Quercus infectoria gall extracts as anti-bacterial agents against dental pathogens.

Background and Objectives: A number of bacteria have now become antibiotic-resistant. This increases the importance of ayurvedic drugs. We report, here, the activity of different extracts (petroleum ether, chloroform, methanol and water) of Quercus infectoria galls against dental pathogens - Streptococcus mutans, Streptococcus salivarius, Staphylococcus aureus, Lactobacillus acidophilus (designated) and Streptococcus sanguis (isolated). Materials and Methods: The cup-plate method was used in anti-bacterial activity of the extracts at concentration of 200 mg/ml against dental pathogens. Minimum inhibitory concentration (MIC) values of most effective extracts against the most susceptible bacteria were determined using a two-fold serial micro dilution method. Results: Methanolic extract showed maximum anti-bacterial activity against all the bacteria. The most susceptible bacteria were S. sanguis followed by S. aureus, S. mutans, S. salivarius and L. acidophilus. The MIC values showed that methanolic extract was more effective than water extract. Conclusion: The plant has the potential to generate herbal metabolites. The crude extracts demonstrating anti-dental caries activity could result in the discovery of new chemical classes of antibiotics. These chemical classes of antibiotics could serve as selective agents for the maintenance of human health and provide bio-chemical tools for the study of infectious diseases.

Selection of microencapsulation method to improve antimicrobial agents production by some lactobacillus species and propionibacterium thoenii in dairy products

The aim of this research is to select the agreeable encapsulation method to improve antimicrobial production from Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus rhamnosus and Propionibacterium thoenii. The effect of different organic acid concentrations [1 and 2 w/v], different pH values [3, 4, 5, 6. 7 and 8], different temperature degrees [0, 7, 25, 37 and 45°C] and storage temperature on viability of encapsulated bacteria were investigated. Also, the efficiency of microencapsulated methods [alginate + NaCI, alginate + oil and K-carrageenan] on enhancement of antimicrobial production were studied. Microencapsulation with alginate + NaCI offered greater production in extreme conditions [low pH, low temperature and in the presence of organic acids]. In addition, this method was more effective against pathogenic bacteria by enhancement of antimicrobial production, thus it may be effectively used to increase the safety and the shelf- life of dairy products

Microbiota intestinal de indivíduos que sofreram acidente ocupacional com materiais biológicos e que realizaram profilaxia anti-retroviral / Intestinal microbiota of individuals who suffered occupational accidents with biological materials and underwent antiretroviral prophylaxis

Avaliar a microbiota intestinal de indivíduos que sofreram acidente ocupacional com materiais biológicos e receberam anti-retrovirais foi o objetivo deste estudo. O grupo de estudo constou de 23 indivíduos com idade entre 18-45 anos, sendo 13 doadores de sangue e 10 que sofreram acidente ocupacional. Foram avaliados a microbiota intestinal, antropometria e exames laboratoriais pré, pós e 30 dias após o término da medicação. Zidovudina mais lamivudina foi utilizada em 70 por cento dos indivíduos associado ao nelfinavir, 20 por cento ao efavirenz e 10 por cento ao ritonavir. As alterações nutricionais e dietéticas-laboratoriais e de microbiota intestinal foram analisadas em três momentos. M1: até dois dias do início da profilaxia; M2: no último dia da profilaxia e M3: 30 dias após o término da profilaxia. Náuseas, vômitos e diarréia estiveram presentes em 50 por cento no segundo momento do estudo. Sobrepeso em 70 por cento, desnutrição e eutrofia em 10 por cento, dos indivíduos, não se modificaram durante o estudo. Transaminases, triglicérides, LDL-colesterol se elevaram no segundo momento e normalizaram 30 dias após término da medicação. Houve redução significativa dos Lactobacillus, Bifidobacterium e Bacteróides nos três momentos. Uso de anti-retrovirais provocou impacto significativo na microbiota intestinal dos indivíduos, sem recuperação em 30 dias.

The aim of this study was to evaluate the intestinal microbiota of individuals who had suffered occupational accidents and had received antiretrovirals. The study group consisted of 23 individuals between 18 and 45 years old, of whom 13 were blood donors and 10 had suffered occupational accidents. Intestinal microflora, anthropometry and laboratory tests were evaluated before, after and 30 days after discontinuation of the medication. Zidovudine plus lamivudine was used in association with nelfinavir for 70 percent of the individuals, with efavirenz for 20 percent and with ritonavir for 10 percent. Nutritional, diet, laboratory and intestinal microbiota abnormalities were analyzed at three times: M1, not more than two days after starting prophylaxis; M2, on the last day of prophylaxis; and M3, 30 days after ending prophylaxis. Nausea, vomiting and diarrhea were present in 50 percent at M2. Overweight in 70 percent, malnutrition and eutrophy in 10 percent of the individuals remained unchanged during the study. Transaminases, triglycerides and LDL-cholesterol because elevated at M2 and normalized 30 days after discontinuation of the medication. There were significant reductions in Lactobacillus, Bifidobacterium and Bacteroides at the three times. The use of antiretrovirals caused a significant impact on the individuals’ intestinal microbiota, without recovery after 30 days.

Use of an aqueous extract of Terminalia chebula as an anticaries agent: a clinical study.

Plant-derived medicines have been a part of our traditional health care system, and the antimicrobial properties of plant-derived compounds are well documented. The purpose of this study is to evaluate the effect of an aqueous extract of Terminalia chebula (a medicinal plant) on salivary samples and its potential for use as an anticaries agent in the form of mouthwash. A concentrated aqueous extract was prepared from the fruit of T. chebula . A mouth rinse of 10% concentration was prepared by diluting the extract in sterile distilled water. The efficacy of the mouth rinse was assessed by testing on 50 salivary samples. Salivary samples were collected from subjects assessed to be at high risk for caries. Salivary pH, buffering capacity, and microbial activity were assessed before rinsing, immediately after, and 10 min, 30 min, and 1 h after rinsing. There was an increase in the pH and buffering capacity and decrease in microbial count. An aqueous extract of T. chebula used as a mouth rinse seems to be an effective anticaries agent.

[Inhibitory effects of NaF-varnish and APF-gel on cariogenic bacteria: an in vitro study]

While there are multiple components of preventive programs developed for caries prevention in children, perhaps none is as important and effective as the appropriate use of fluoride. The primary caries preventive effects of fluoride result from its topical contact with enamel and through its antibacterial actions. Till now bulk of research exists which has compared the antibacterial effects of ordinary topical fluoride gels and solutions. Little or no evidence is seen to tell us which topical fluoride including varnishes is more antibacterial. We suggested further research about antibacterial effect of APF gel and NaF varnish against cariogenic microorganisms [streptococcus mutans and lactobacillus], so use of these may have benefit in reduction of caries. Comparison of inhibitory effect of NaF-varnish versus APF-gel on concentration of cariogenic bacteria [streptococcus mutans and lactobacillus], was the primary goal of this research. In this exprimental study, twenty premolars were sectioned buccolingually. With the use of "window method" certain surfaces of enamel were covered with APF-gel and NaF-varnish. Then, the number of streptococcus mutans and lactobacillus were counted after 18, 24 and 48 hours. In the "Disk diffusion" method the streptococcus mutans with the concentration of 108/ml and volume of 0.1cc were introduced to the M.S.Media culture after application of APF gel and NaF varnish. Then the inhibition zone, measured. Statistical analysis in this research was multilevel modeling. The comparison between gel and varnish after 18, 24 and 48 hours showed that gel has more effect than varnish over the number of lactobacillus. The difference with lactobacillus was statistically significant [p<0.005], but with streptococcus Mutans was not. APF gel was more effective [70.23%] than NaF varnish. Based on the obtained results, APF gel can be used with more thrust than NaF varnish in caries prevention

Intestinal microbiota of patients with bacterial infection of the respiratory tract treated with amoxicillin

The intestinal tract harbors a huge diversity of metabolically-active aerobic and anaerobic bacteria that interact, forming a complex ecosystem. This microbiota has an important role in human metabolism, nutrition, immunity, and protection against colonization by pathogenic microorganisms. Several factors can influence the intestinal microbiota; these include age, diet, inflammatory and infectious processes, and the use of antimicrobials. We investigated the influence of bacterial infection of the respiratory tract and of amoxicillin therapy on the normal intestinal microbiota of patients. Bacterial infectious processes affecting the respiratory tract were found to influence the intestinal microbiota, significantly decreasing the number of colony-forming units (CFUs) of Bacteroides spp. and Lactobacillus spp. per gram of feces. The use of amoxicillin also influenced the intestinal microbiota, significantly decreasing the CFU of Bifidobacterium spp. and Lactobacillus spp. /g of feces. Changes in the composition of the intestinal microbiota need to be observed, since a decrease in the normal microorganisms can pose a number of hazards for hosts, including decreased resistance to colonization. With proper follow-up, health-care teams can minimize such hazards by implementing suitable therapy- and diet-related measures, thus reducing the occurrence of detrimental effects on the gastrointestinal ecosystem.

The effect of indigenous Neem Azadirachta indica [correction of (Adirachta indica)] mouth wash on Streptococcus mutans and lactobacilli growth.

Neem is one of the most widely researched tropical tree, with almost all it's parts being put for a variety of uses. In the present study, the antibacterial effect of Neem mouthwash against salivary levels of streptococcus mutans and lactobacillus has been tested over a period of 2 months. Also it's effect in reversing incipient carious lesions was assessed. While streptococcus mutans was inhibited by Neem mouthwashes, with or without alcohol as well as chlorhexidine, lactobacillus growth was inhibited by chlorhexidine alone. The initial data appears to prove it's effect in inhibiting S. mutans and reversing incipient carious lesions, longer term clinical trials are essential.

Resistência de enterobactérias, estafilococos, streptococus mutans e lactobacillus spp., isolados da cavidade bucal, e o uso de antimicrobianos, clorexidina e mercúrio nas práticas médica e odontológica / Resistance of enterobacteriaceae, staphylococcus, streptococcus mutans and lactobacillus spp., isolated from the oral cavity and the use of antimicrobials, chlorhexidine and mercury in medical and odontological practice

O objetivo dessa investigação foi realizar um estudo caso-controle do impacto do uso de antimicrobianos, clorexidina e mercúrio, na resistência dos microrganismos (enterobactérias, estafilococos, Streptococus mutans e Lactobacillus spp) presentes na cavidade bucal. Foram testados quatro grupos, com dez voluntários cada, a saber: A - com múltiplas restaurações à amálgama, B- em uso de antimicrobianos, C- em uso de digluconato de clorexidina a 0,12 por cento em bochechos diários e, D- sem história de cárie dentária (controle). A resistência foi determinada, in vitro, pelas técnicas de diluição em agar e E test. Uma colonização importante por enterobactérias (50 por cento) foi detectada no grupo em uso de antimicrobianos. Todos os isolados foram resistentes à clorexidina e cloreto de mercúrio, independente de grupo. A colonização por Staphylococcus aureus no grupo B também foi de 50 por cento, contra 30 por cento no grupo controle, onde os isolados desse microrganismo, e os Staphylococcus spp., mostraram-se resistentes à oxacilina (CIM s90 >512mg/L); esses microrganismos, independente do grupo, foram suscetíveis à clorexidina e resistentes ao cloreto de mercúrio, mas com CIM s para o mercúrio, três vezes mais elevadas para aquelas dos grupos com restaurações ou em uso de antimicrobianos. No grupo de voluntários em uso regular de clorexidina, os isolados de Streptococcus mutans do grupo B (8/10) apresentam CIM 90 > 512mg/L para ampicilina e suscetibilidade à clorexidina e mercúrio em todos os grupos de voluntários.

Growth inhibition of pathogens by lactic acid bacteria producing inhibitory substances

71 samples of milk and dairy products were collected from 18 cities throughout Iran. 93 strains of lactic acid bacteria [LAB] were isolated and assayed against four opportunistic pathogens including E. coli, proteus and klebsiella as gram-negative and S. aureus as a gram-positive organism. All indicators [organisms] were hospital strains. Among isolated bacteria, lactobacilli [37 isolates] had stronger activity against gram-negative pathogens. 37 isolates were lactococci out of which 9 strains were leuconostocs and seven strains were S.faecalis. S. aureus was more sensitive to lactococci than lactobacilli. Only one isolate of leuconostoc inhibited the growth of gram-negative indicators, but five isolates inhibited S. aureus. The use of bacteriocin-producing lactic acid bacteria in dairy products provides a natural mean of preservation

Avaliação de dentifrícios com xilitol e/ou flúor / Evaluation of dentifrice with xylitol and/or fluoride

Os autores fizeram um experimento com 65 meninas institucionalizadas divididas entre quatro grupos que durante 3 meses escovaram os dentes utilizando dentifrício contendo xilitol e fluoreto, outro contendo fluoreto, o terceiro um dentifrício sem xilitol e fluoreto. O grupo controle escovou os dentes sem dentifrício. O aumento da ingestão de sacarose ocorrido no experimento não afetou os níveis salivares do Streptococcus Mutans. No entanto ocorreu aumento significativo nos níveis salivares de Lactobacillus. Neste experimento foi verificado que os dentifrícios utilizados não determinaram efeito significativo nos níveis salivares de Streptococcus Mutans e de Lactobacillus, padrão de secreção salivar e condições de higiene oral

Purification, relative molecular mass and subunits of thymidylate synthase from Lactobacillus leichmannii.

Thymidylate synthase (5, 10-methylenetetrahydrofolate: dUMP C-methyltransferase, EC 2.1.1.45) from crude cell extracts of Lactobacillus leichmannii has been purified 190-fold to homogeneity by chromatography on hydroxylapatite, DEAE-cellulose and Sephadex G-100 columns. It has UV absorption maxima at 280 nm. The crude extracts, however, have RNA associated with the native enzyme. This is in line with our earlier observation on the Streptococcus faecium thymidylate synthase [Narasimha Rao K & Kisliuk R L, (1983) Proc Natl Acad Sci USA, 80, 916-920]. Optimal conditions for dTMP synthase activity are: 275 microM (dl)-L-H4PteGlu, 13 mM HCHO, 13 mM MgCl2, 100 microM dUMP and 75 mM 2-mercaptoethanol at pH 7.4 using Tris-HCl buffer. The enzyme has M(r) of 74 kDa, Stokes radius of 1.24 nm and a sedimentation coefficient value of 0.45 S. The enzyme is a dimer composed of 2 identical subunits each with M(r) of 37 kDa.