Effect of light-activation on the antibacterial activity of dentin bonding agents

Aim: This study evaluated the effect of light-activation on the antibacterial activity of dentin bonding systems. Methods: Inocula of Streptococcus mutans and Lactobacillus casei cultures were spread on the surface of BHI agar and the materials were applied and subjected or not to light-activation. Zones of bacterial growth inhibition around the discs were measured. Results: Excite, Single Bond and the bond of Clearfil SE Bond (SE) and Clearfil Protect Bond (CP) did not show any antibacterial activity. The strongest inhibitory activity was observed for the primers of CP and Prompt (PR) against S. mutans and the primers of SE and PB against L. casei. Conclusion: Light-activation significantly reduced or suppressed the antibacterial activity of the initially active uncured dentin bonding systems.

Fatores microbiológicos e imunológicos envolvidos no desenvolvimento da cárie precoce da infância

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relação da diversidade bacteriana e quantidade de endotoxinas com a sintomatologia dolorosa de pulpite reversível em lesões cariosas profundas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da restrição alimentar e do grupo genético sobre a microbiota do trato gastrintestinal, a expressão gênica hepática e a deposição de lipídeos na carcaça de frangos de corte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização de segurança e tecnológica de bactérias acidoláticas termofílicas autóctones e aplicação em queijo parmesão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eradication of Salmonella Typhimurium in broiler chicks by combined use of P22 bacteriophage and probiotic

It has been reported that the phage therapy is effective in controlling the number of colony-forming unit (CFU) of Salmonella spp. in chicken gut. This paper describes the protective effect of phage and Lactobacilli administration on Salmonella infection in 1-day-old chicks. We administered the bacteriophage P22 in a single dose and a probiotic mixture of four species of bacteriocin-producing Lactobacillus once a day for one week. Samples were analyzed every 48 hours, and intestinal eradication of S. Typhimurium was confirmed after treatments. We observed an increase in the size of duodenal villi and cecal crypts, as well as an increase in body weight in groups that received daily doses of Lactobacilli. This study confirms the efficiency of bacteriophage therapy in controlling salmonellosis in chicks and the beneficial effect of Lactobacilli mixtures in the weight gain of the birds.

Diferentes fontes de carboidratos em rações para leitões desmamados com diferentes pesos: pH e microbiota do trato gastrintestinal

Forty eight piglets from a commercial strain weaned at an average age of 21 days were used in order to evaluate effects of carbohydrates sources (lactose or maltodextrin) and the weights of piglets at weaning on the stomach pH, colon and rectum contents, and the amount of total coliform, Escherichia coli and Lactobacillus spp in digesta of ileum and cecum. The experiment was conducted in a randomized block design and analyzed in split plot, considering class of weight and carbohydrates as main plots and the slaughter age of animal as sub-plots. The stomach pH and intestinal contents were not influenced by the diets provided as well as the amount of total coliform. It was found that the presence of lactose in the feed decreased counts of Escherichia coli and Lactobacillus ssp in the ileum. Regarding the class of weight, the lighter piglets had lower counts of Escherichia coli and Lactobacillus. The maltodextrin can be used as an alternative to replace the lactose in the diet, regardless of the piglets weight at weaning, as it does not adversely affect the pH and the Lactobacillus population in the gastrointestinal tract.

P-233-Biodiversity of mucosa associated microbiome of Crohn's disease patients living in middle western São Paulo State, Brazil

Background: The intestinal microbiome (IM) has extensively been studied in the search for a link of bacteria with the cause of Crohn`s disease (CD). The association might result from the action of a specific pathogen and/or an eventual imbalance in bacterial species composition of the gut. The innumerous virulence associated markers and strategies described for adherent and invasive Escherichia coli (AIEC) have made them putative candidate pathogens for CD. IM of CD patients shows dysbiosis, manifested by the proliferation of bacterial groups such as Enterobacteriaceae and reduction of others such as Lactobacillus and Bifidobacterium. The augmented bacterial population comprising of commensal and/or pathogenic organisms super stimulates the immune system, triggering the inflammatory reactions responsible for the clinical manifestations of the disease. Considering the role played by IM in CD and the multiple variables influencing its species composition, resulting in differences among populations, the objective of this study was to determine the bacterial biodiversity in the mucosa associated microbiome of CD patients from a population not previously subject to this analysis, living in the middle west region of Sao Paulo state. Methods: A total of 4 CD patients and 5 controls subjects attending the Botucatu Medical School of the Sao Paulo State University (UNESP) for routine colonoscopy and who signed an informed consent were included in the study. A number of 2 biopsies, one from the ileum and other from any part of the terminal colon, were taken from each subject and immediately frozen at -70[degrees]C until DNA purification. The bacterial biodiversity was assessed by next generation (ion torrent) sequencing of PCR amplicons of the ribosomal DNA 16S V6 region (16S V6 rDNA). The bacterial identification was performed at the genus level, by alignment of the generated DNA sequences with those available at the ribosomal database project (RDP) website. Results: The overall DNA sequence output was based on an average number of 526,427 reads per run, matching 50 bacterial genus 16SrDNA sequences available at the RDB website, and 22 non matching sequences. Over 95% of the sequences corresponded to taxa belonging to the major phyla: Firmicutes, Bacterioidetes, Proteobacteria and Actinobacteria. Irrespective of the intestinal site analyzed, no case-control differences could be observed in the prevalence of Actinobacteria and Firmicutes. The prevalence of Proteobacteria was higher (40%) in the biopsies of control subjects as compared to that of DC patients (16%). For Bacterioidetes, the higher prevalence was observed among DC patients (33% as opposed to 14,5% in controls). The significance for all comparisons considered a p value < 0,05 in a Chi2 test. No mucosal site specific differences could be observed in IM comparisons of CD and control subjects. Conclusions: The rise in the number of Bacterioidetes observed here among CD patients seems to be in agreement with most of studies published thus far. Yet, the reduction in the number of Proteobacteria along with an apparently unaltered population of Actinobacteria and Firmicutes, which include the so called "beneficial" organisms Bifidobacterium and Lactobacillus were rather surprising. These data suggest that the analyses on the role of IM in CD should consider the multiple variables that may influence its species composition.

Influência do suco de laranja na microbiota intestinal humana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aditivo alternativo, associado ou não ao antimicrobiano, na dieta de leitões recém-desmamados

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Growth, organic acids profile and sugar metabolism of Bifidobacterium lactis in co-culture with Streptococcus thermophilus: the inulin effect

The organic acids profile, sugar metabolism and biomass growth of Streptococcus thermophilus (St) and Bifidobacterium lactis (BI) have been studied in pure cultures or binary co-culture (St-BI) in skim milk either containing 40 mg/g of inulin or not. With inulin, the time required by St. BI and St-BI to complete fermentation (i.e., when the pH reached 4.5) was about 14, 8 and 49% shorter than without inulin, respectively. This prebiotic also enhanced the levels of lactic and acetic acids and volatile compounds, showing a positive synbiotic effect between pre- and probiotics. In particular, the St-BI co-culture showed final concentrations of both microorganisms about 15 and 38% higher than in their respective pure cultures, thus highlighting a clear synergistic effect between these microorganisms due to mutual interactions. In addition, the well-known bifidogenic effect of inulin was confirmed. (c) 2012 Elsevier Ltd. All rights reserved.

Resistência de bactérias ácido-láticas a bacteriófagos provenientes de unidades de processamento de queijo Coalho

Este trabalho teve como objetivos isolar bacteriófagos de amostras de leite, soro e queijo de Coalho e avaliar a resistência de cepas de Lactobacillus paracasei, pertencentes à Coleção de Micro-organismos de Interesse para a Agroindústria Tropical da Embrapa Agroindústria Tropical, aos fagos isolados. Posteriormente, a resistência destas cepas a fagos específicos para L. paracasei, da Coleção do Instituto de Lactología Industrial - INLAIN (Santa Fe, Argentina), também foi avaliada. As amostras para isolamento dos fagos foram obtidas em quatro unidades de processamento de queijo de Coalho, sendo duas artesanais e duas industriais, localizadas no Estado do Ceará. Para o isolamento dos bacteriófagos, foi empregado o teste de lise celular (spot), enquanto que a resistência das culturas aos fagos foi avaliada pelos testes de capacidade de produção de ácido e avaliação da turbidez. As cepas avaliadas foram resistentes aos bacteriófagos provenientes das unidades de processamento de queijo de Coalho e aos bacteriófagos da Coleção do INLAIN. Os resultados obtidos indicaram que as culturas láticas testadas, resistentes aos bacteriófagos, podem ser utilizadas na composição de fermento lático destinado à elaboração de queijo de Coalho, a partir de leite pasteurizado.

Enterococcus faecium isolated from Lombo, a Portuguese traditional meat product: characterisation of antibacterial compounds and factors affecting bacteriocin production

Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.

Sardinian goat's milk as source of bacteriocinogenic potential protective cultures

Goat breeding in Sardinia constitutes an important source of income for farming and shepherding activities. In this study 170 LAB strains were isolated from Sardinian goat's milk and tested for bacteriocins production against several food-borne pathogenic microorganisms. Four isolates (SD1, SD2, SD3 and SD4) were selected for their effective inhibition on Listeria monocytogenes. The strains were classified as members of Enterococcus genus, according to their biochemical and physiological characteristics, and then genetically identified as Enterococcus faecium. In MRS broth at 37 degrees C, bacteriocins SD1 and SD2 were produced at much higher levels (51200 AU/ml) compared to bacteriocin SD3 (3200 AU/ml) and bacteriocin SD4 (800 AU/ml). Their peptides were inactivated by proteolytic enzymes, but not when treated with alpha-amylase, catalase and lipase. The four bacteriocins remained stable at pH from 2.0 to 12.0, after exposure to 100 degrees C for 120 min and were not affected by the presence of surfactants and salts (N-Laourylsarcosine, NaCl, SDS, Triton X-100, Tween 20, Tween 80 and urea). Their molecular size was determined to be approximately 5 kDa by tricine-SDS-PAGE. Since the strains exhibited a strong antimicrobial activity against 21 L monocytogenes strains and 6 Salmonella spp. isolates, they should be considered as potential bio-preservatives cultures for fermented food productions. Moreover, due to their technological features, the four strains could be taken in account for using as adjunct NSLAB (non-starter lactic acid bacteria) rather than as starter culture. (C) 2011 Elsevier Ltd. All rights reserved.

Molecular detection of in-vivo microbial contamination of metallic orthodontic brackets by checkerboard DNA-DNA hybridization

Introduction: Knowing the microbiota that colonizes orthodontic appliances is important for planning strategies and implementing specific preventive measures during treatment. The purpose of this clinical trial was to evaluate in vivo the contamination of metallic orthodontic brackets with 40 DNA probes for different bacterial species by using the checkerboard DNA-DNA hybridization (CDDH) technique. Methods: Eighteen patients, 11 to 29 years of age having fixed orthodontic treatment, were enrolled in the study. Each subject had 2 new metallic brackets bonded to different premolars in a randomized manner. After 30 days, the brackets were removed and processed for analysis by CDDH. Data on bacterial contamination were analyzed descriptively and with the Kruskal-Wallis and Dunn post tests (alpha = 0.05). Forty microbial species (cariogenic microorganisms, bacteria of the purple, yellow, green, orange complexes, "red complex + Treponema socranskii," and the cluster of Actinomyces) were assessed. Results: Most bacterial species were present in all subjects, except for Streptococcus constellatus, Campylobacter rectus, Tannerella forsythia, T socranskii, and Lactobacillus acidophillus (94.4%), Propionibacterium acnes I and Eubacterium nodatum (88.9%), and Treponema denticola (77.8%). Among the cariogenic microorganisms, Streptococcus mutans and Streptococcus sobrinus were found in larger numbers than L acidophillus and Lactobacillus casei (P < 0.001). The periodontal pathogens of the orange complex were detected in larger numbers than those of the "red complex + T socranskii" (P < 0.0001). Among the bacteria not associated with specific pathologies, Veillonella parvula (purple complex) was the most frequently detected strain (P < 0.0001). The numbers of yellow and green complex bacteria and the cluster of Actinomyces were similar (P > 0.05). Conclusions: Metallic brackets in use for 1 month were multi-colonized by several bacterial species, including cariogenic microorganisms and periodontal pathogens, reinforcing the need for meticulous oral hygiene and additional preventive measures to maintain oral health in orthodontic patients. (Am J Orthod Dentofacial Orthop 2012;141:24-9)