Different Ultrasound Exposure Times Influence the Physicochemical and Microbial Quality Properties in Probiotic Goat Milk Yogurt.

Despite goat milk having health benefits over cow milk, goat milk yogurt (GY) presents low consistency and viscosity, which reduces its overall acceptability by the consumer. Thus, new innovative methods can be an alternative to improve the quality of GY. Hence, this study aimed to investigate the effect of ultrasound (US) treatment with different sonication times on quality parameters of probiotic GY during refrigerated storage. US treatment was conducted at 20 KHz for 3, 6, and 9 min in yogurt. Lactobacillus bulgaricus and Lactobacillus acidophilus LA-5 were sensitive to US treatment, presenting a decrease in the yogurts stocked. This loss of viability led to reduced post-acidification due to smaller lactose metabolization in yogurt samples submitted to the US. Among tested treatments, the application of 6 min enhanced the apparent viscosity and consistency index of GY yogurts. In addition, this time also reduced tyramine and total biogenic amine (BAs) content. These findings suggest that 6 min of sonication is a promising way to improve the rheological properties and reduce the acidity and BAs content in GY. Further studies should be performed to optimize the US setting conditions to preserve the probiotic culture viability in yogurts.

Potencial efeito preventivo do Lactobacillus acidophilus e Lactobacillus plantarum em pacientes com pólipos ou câncer colorretal / Potential preventive effect of lactobacillus acidophilus and lactobacillus plantarum in patients with polyps or colorectal câncer

ABSTRACT BACKGROUND: Colorectal cancer is one of the major causes of death worldwide. Many studies have been done on the biology of its formation as well as its treatment in recent years. One of the factors involved in the formation or treatment of this malignancy can be attributed to the microbial flora in the intestine. OBJECTIVE: This study investigate the potential preventive effect of Lactobacillus acidophilus and Lactobacillus plantarum in patients with polyps or colorectal cancer (CRC). METHODS: A total of 77 samples were selected in the form of three groups including individuals suffering from CRC, polyps and healthy subjects. Genomic DNA of fecal specimens and standard strains were extracted and amplified employing primers targeting of the 16S rRNA gene for initial detection. Absolute Real Time PCR quantification was used to determine the copy of the bacterial expression per gram of feces. RESULTS: No significant difference were observed between age and gender in the mentioned groups (P=0.06). The average copy number of Lactobacillus acidophilus shows Significant difference between the healthy group and those with polyps (P<0.0001), the healthy group and those with colorectal cancer (P<0.0001), as well as those with polyps and the colorectal cancer patients (P<0.0001). CONCLUSION: These results may indicate that taking Lactobacillus acidophilus in people with a family history of CRC and people with polyps may be a way of preventing, treating or reducing the severity of CRC.

RESUMO CONTEXTO: O câncer colorretal é uma das principais causas de morte em todo o mundo. Muitos estudos têm sido feitos sobre a biologia de sua formação, bem como o seu tratamento nos últimos anos. Um dos fatores envolvidos na formação ou no tratamento desta malignidade pode ser atribuído à flora microbiana no intestino. OBJETIVO: Este estudo investigou o potencial efeito preventivo de Lactobacillus acidophilus e Lactobacillus plantarum em pacientes com pólipos ou câncer colorretal (CCR). MÉTODOS: Um total de 77 amostras foram selecionadas e três grupos foram formados, a saber, indivíduos portadores de CCR, pólipos e indivíduos saudáveis. O DNA genomico de espécimes fecais e de amostras padrão foi extraído e amplificado empregando primers que focalizaram o gene do rRNA 16S para a deteção inicial. A quantificação do PCR em tempo real absoluto foi utilizada para determinar a cópia da expressão bacteriana por grama de fezes. RESULTADOS: Não foram observadas diferenças significativas entre idade e sexo nos grupos citados (P=0,06). O número médio de cópias de Lactobacillus acidophilus mostra diferença significativa entre o grupo saudável e aqueles com pólipos (P<0,0001), o grupo saudável e aqueles com câncer colorretal (P<0,0001), bem como aqueles com pólipos e câncer colorretal pacientes (P<0,0001). CONCLUSÃO: Estes resultados podem indicar que a ingestão de Lactobacillus acidophilus em pessoas com antecedentes familiares de CCR e pessoas com pólipos pode ser uma forma de prevenir, tratar ou reduzir a gravidade da CCR.

Quantitative analysis of biofilm bacteria according to different stages of early childhood caries.

OBJECTIVE: Monitoring selected key species related to health or disease may facilitate caries risk assessment and discovery of novel ecological preventive and therapeutic approaches. This study aimed at quantifying Actinomyces naeslundii, Bifidobacterium spp., Lactobacillus acidophilus, Lactobacillus casei group, Streptococcus gordonii, Mitis group and Streptococcus mutans by quantitative polymerase chain reaction (qPCR) in dental biofilm from Brazilian children with different stages of early childhood caries (ECC). DESIGN: Seventy-five preschool children were clinically evaluated by ICDAS criteria and divided into groups: caries-free (CF; n = 20), enamel caries lesions (ECL; n = 17) and dentine caries lesions (DCL; n = 38). Plaque samples from all children were collected for detection and quantification of the selected bacteria. RESULTS: L. acidophilus and L. casei group were absent in almost all plaque samples. No differences in relative proportions of A. naeslundii, Mitis group and S. gordonii were observed in any stage of caries. However, S. mutans and Bifidobacterium spp. were present at higher concentrations in the biofilm of children with DCL (p < 0.001). Multivariate analysis showed that S. mutans and Bifidobacterium spp. were strongly associated with biofilm in children with DCL. CONCLUSION: Differences were observed in the proportion of acidogenic and aciduric bacteria with dental caries progression. The data indicate that S. mutans and Bifidobacterium spp. in dental biofilm may be involved in some progression processes for ECC.

POTENTIAL PREVENTIVE EFFECT OF LACTOBACILLUS ACIDOPHILUS AND LACTOBACILLUS PLANTARUM IN PATIENTS WITH POLYPS OR COLORECTAL CÂNCER.

BACKGROUND: Colorectal cancer is one of the major causes of death worldwide. Many studies have been done on the biology of its formation as well as its treatment in recent years. One of the factors involved in the formation or treatment of this malignancy can be attributed to the microbial flora in the intestine. OBJECTIVE: This study investigate the potential preventive effect of Lactobacillus acidophilus and Lactobacillus plantarum in patients with polyps or colorectal cancer (CRC). METHODS: A total of 77 samples were selected in the form of three groups including individuals suffering from CRC, polyps and healthy subjects. Genomic DNA of fecal specimens and standard strains were extracted and amplified employing primers targeting of the 16S rRNA gene for initial detection. Absolute Real Time PCR quantification was used to determine the copy of the bacterial expression per gram of feces. RESULTS: No significant difference were observed between age and gender in the mentioned groups (P=0.06). The average copy number of Lactobacillus acidophilus shows Significant difference between the healthy group and those with polyps (P<0.0001), the healthy group and those with colorectal cancer (P<0.0001), as well as those with polyps and the colorectal cancer patients (P<0.0001). CONCLUSION: These results may indicate that taking Lactobacillus acidophilus in people with a family history of CRC and people with polyps may be a way of preventing, treating or reducing the severity of CRC.

Probiotics modulate gut microbiota and improve insulin sensitivity in DIO mice.

Obesity and type 2 diabetes are characterized by subclinical inflammatory process. Changes in composition or modulation of the gut microbiota may play an important role in the obesity-associated inflammatory process. In the current study, we evaluated the effects of probiotics (Lactobacillus rhamnosus, L. acidophilus and Bifidobacterium bifidumi) on gut microbiota, changes in permeability, and insulin sensitivity and signaling in high-fat diet and control animals. More importantly, we investigated the effects of these gut modulations on hypothalamic control of food intake, and insulin and leptin signaling. Swiss mice were submitted to a high-fat diet (HFD) with probiotics or pair-feeding for 5 weeks. Metagenome analyses were performed on DNA samples from mouse feces. Blood was drawn to determine levels of glucose, insulin, LPS, cytokines and GLP-1. Liver, muscle, ileum and hypothalamus tissue proteins were analyzed by Western blotting and real-time polymerase chain reaction. In addition, liver and adipose tissues were analyzed using histology and immunohistochemistry. The HFD induced huge alterations in gut microbiota accompanied by increased intestinal permeability, LPS translocation and systemic low-grade inflammation, resulting in decreased glucose tolerance and hyperphagic behavior. All these obesity-related features were reversed by changes in the gut microbiota profile induced by probiotics. Probiotics also induced an improvement in hypothalamic insulin and leptin resistance. Our data demonstrate that the intestinal microbiome is a key modulator of inflammatory and metabolic pathways in both peripheral and central tissues. These findings shed light on probiotics as an important tool to prevent and treat patients with obesity and insulin resistance.

Proteolysis in goat "coalho" cheese supplemented with probiotic lactic acid bacteria.

This study aimed to analyse the proteolytic effects of adding isolated and combined probiotic strains to goat "coalho" cheese. The cheeses were: QS - with culture Start, composed by Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris (R704); QLA - with Lactobacillus acidophilus (LA-5); QLP - with Lactobacillus paracasei subsp. paracasei (L. casei 01); QB - with Bifidobacterium animalis subsp. lactis (BB 12); and QC, co-culture with the three probiotic microorganisms. The cheeses were analysed during 28 days of storage at 10°C. The probiotic cell count was higher than 6.5 and 7 log colony-forming units (CFU) g(-1) of cheese at the 1st and 28th days of storage, respectively. The addition of co-culture influenced (p<0.01) proteolysis in the cheese and resulted in a higher content of soluble protein and release of amino acids at the 1st day after processing. However, over all 28 days, the cheese supplemented with Bifidobacterium lactis in its isolated form showed the highest proteolytic activity, particularly in the hydrolysis of the alpha-s2 and kappa-casein fractions.

Effects of Agave tequilana fructans with different degree of polymerization profiles on the body weight, blood lipids and count of fecal Lactobacilli/Bifidobacteria in obese mice.

Fructans are dietary fibers with beneficial effects on the gastrointestinal physiology and offer a promising approach for the treatment of some metabolic disorders associated with obesity. In vitro and in vivo studies were developed to test the safety of fructans obtained from Agave tequilana Weber var. azul. Additionally, an in vivo experiment using a diet-induced obesity model was performed to compare the effect of agave fructans with different degree of polymerization (DP) profiles: agave fructans with DP > 10 (LcF), agave FOS with DP < 10 (ScF), and agave fructans with and without demineralization (dTF, TF) versus commercial chicory fructans (OraftiSynergy1™) on the body weight change, fat, total cholesterol, triglycerides and count of fecal Lactobacillus spp. and Bifidobacterium spp. Results showed that A. tequilana fructans were not mutagenic and were safe even at a dose of 5 g per kg b.w. Obese mice that received ScF showed a significant decrease in body weight gain, fat tissue and total cholesterol without increasing the count of fecal Bifidobacteria. Whereas, obese mice that received LcF and TF showed decreased triglycerides and an increased count of fecal Bifidobacteria. Interestingly, although obese mice that received dTF did not show changes in body weight gain, fat tissue, total cholesterol or triglycerides, they showed an increase in the count of Bifidobacteria. These results demonstrate that both the degree of polymerization and the demineralization process can influence the biological activity of agave fructans.

Queijo minas frescal potencialmente probiótico: avaliação microbiológica e sensorial / Cheese: microbiological and sensory evaluation

Probióticos são definidos como micro-organismos vivos, administrados em quantidades adequadas, que conferem benefícios à saúde do hospedeiro por promoverem balanço da flora microbiana intestinal. E com o aumento da procura por alimentos funcionais os probióticos têm-se mostrado um importante aliado à manutenção de uma alimentação capaz de prevenir doenças, sendo os produtos lácteos como iogurtes, bebidas lácteas fermentadas e queijos os principais vetares desses organismos. Assim, esse trabalho teve como objetivo avaliar microbiologicamente e sensorialmente queijos minas frescal adicionados de lactobacillus acidophilus e Bifidumbacterium bifidus isolados e em co-cultura armazenados por 7 dias em 5ºC e 10ºC. Os resultados demonstraram que os probióticos mantiveram-se viáveis e em valores que permitiram classificar os queijos como alimentos probióticos, além de alcançarem boa aceitação junto aos provadores. (AU)

Probiotic bacteria are defined as living microorganisms, which upon ingestion in adequate amounts, exert health benefits on the host, they beneficially affect the health by promoting balance of the intestinal microbial flora. With the increase of consumers for functional foods, probiotics have been an important one for maintaining a supply capable of preventing diseases, and dairy products like yogurt, cheeses and fermented milk drinks the main vectors of these organisms, so that work aimed to evaluate the microbiological and sensory minas fresh cheese added of Lactobacillus acidophilus and Bifidusbacterium bifidus alone and in co-culture stored for 7days at 5 o C and 10 o C. The results showed that probiotics remained viable at levels that would allow the probiotic cheeses as well as achieving good acceptance among the panelists. (AU)

Antagonistic activity of Lactobacillus acidophilus LA10 against Salmonella enterica serovar Enteritidis SE86 in mice

Salmonella enterica serovar Enteritidis is one of the main pathogens responsible for foodborne illness in Brazil. Probiotic bacteria can play a role in defense and recovery from enteropathogenic -infections. In this study, the ability of Lactobacillus acidophilus LA10 to colonise and exert anta-gonistic effects in the gastrointestinal tract was tested before and during experimental infection in conventional mice contaminated with S. Enteritidis (SE86). A dose of 0.1 mL containing 10(8) viable cells of SE86 and L. acidophilus LA10 was orally administered by gavage to mice. The experiment was divided into groups. As a negative control, Group 1 was administered only sterile saline solution. As a positive control, Group 2 was administered only SE86. Group 3 was first administered SE86, and after 10 days, treated with L. acidophilus LA10. Group 4 was first administered L. acidophilus LA10,and after 10 days, challenged with SE86.The results demonstrated that a significant number of SE86 cells were able to colonize the gastrointestinal tract of mice, specifically in the colon and ileum. L. acidophilus LA10 demonstrated an antagonistic effect against SE86, with better results observed for Group 3 over Group 4. Thus, L. acidophilus LA10 shows potential antagonistic effects against S. Enteritidis SE86, especially if administered after infection.

Sensory acceptance and survival of probiotic bacteria in ice cream produced with different overrun levels.

The effect of different overrun levels on the sensory acceptance and survival of probiotic bacteria in ice cream was investigated. Vanilla ice creams supplemented with Lactobacillus acidophilus were processed with overruns of 45%, 60%, and 90%. Viable probiotic bacterial counts and sensory acceptance were assessed. All the ice creams presented a minimum count of 6 log CFU/g at the end of 60 d of frozen storage. However, higher overrun levels negatively influenced cell viability, being reported a decrease of 2 log CFU/g for the 90% overrun treatment. In addition, it was not reported an influence about acceptability with respect to appearance, aroma, and taste of the ice creams (P > 0.05). Overall, the results suggest that lower overrun levels should be adopted during the manufacture of ice cream in order to maintain its probiotic status through the shelf life.

Use of the checkerboard DNA-DNA hybridisation technique for in vivo detection of cariogenic microorganisms on metallic brackets, with or without use of an antimicrobial agent.

OBJECTIVE: Using checkerboard DNA-DNA hybridisation (CDDH) assay, this randomised clinical study evaluated the contamination of metallic brackets by four cariogenic bacterial strains (Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei and Lactobacillus acidophilus) and the efficacy of 0.12% chlorhexidine gluconate (CHX) mouthwashes in reducing bacterial contamination. METHODS: Thirty-nine 11-33-year-old patients under treatment with fixed orthodontic appliances were enrolled in the study and had 2 new metallic brackets bonded to premolars. Nineteen patients used a 0.12% CHX mouthwash (Periogard) and 20 patients used a placebo mouthwash (control) twice a week. After 30 days, the brackets were removed and samples were obtained for analysis by CDDH. Data were analysed statistically by the Kruskal-Wallis test (α=0.05) using the SAS software. RESULTS: S. mutans, S. sobrinus, L. casei and L. acidophilus were detected in 100% of the samples from both groups. However, brackets of the control group were more heavily contaminated by S. mutans and S. sobrinus (P<0.01). In the experimental group, although all counts decreased after rinsing with the chlorhexidine solution, there was significant difference only for S. mutans (P=0.03). CONCLUSIONS: The use of 0.12% chlorhexidine gluconate mouthwashes can be useful in clinical practice to reduce the levels of cariogenic microorganisms in patients under treatment with fixed orthodontic appliances.

Comparative analysis of two component signal transduction systems of the Lactobacillus acidophilus group

The Lactobacillus acidophilus group is a phylogenetically distinct group of closely related lactobacilli. Members of this group are considered to have probiotic properties and occupy different environmental niches. Bacteria generally sense and respond to environmental changes through two component systems (TCSs) which consist of a histidine protein kinase (HPK) and its cognate response regulator (RR). With the use of in silico techniques, the five completely sequenced L. acidophilus group genomes were scanned in order to predict TCSs. Five to nine putative TCSs encoding genes were detected in individual genomes of the L. acidophilus group. The L. acidophilus group HPKs and RRs were classified into subfamilies using the Grebe and Stock classification method. Putative TCSs were analyzed with respect to conserved domains to predict biological functions. Putative biological functions were predicted for the L. acidophilus group HPKs and RRs by comparing them with those of other microorganisms. Some of TCSs were putatively involved in a wide variety of functions which are related with probiotic ability, including tolerance to acid and bile, production of antimicrobial peptides, resistibility to the glycopeptide antibiotic vancomycin, and oxidative condition.

Lactobacillus acidophilus-derived biosurfactant effect on gtfB and gtfC expression level in Streptococcus mutans biofilm cells

Streptococcus mutans (S. mutans), harboring biofilm formation, considered as a main aetiological factor of dental caries. Gtf genes play an important role in S. mutans biofilm formation. The purpose of this study was to investigate the effect of Lactobacillus acidophilus-derived biosurfactant on S. mutans biofilm formation and gtfB/C expression level (S. mutans standard strain ATCC35668 and isolated S. mutans strain (22) from dental plaque). The Lactobacillus acidophilus (L. acidophilus) DSM 20079 was selected as a probiotic strain to produce biosurfactant. The FTIR analysis of its biosurfactant showed that it appears to have a protein-like component. Due to the release of such biosurfactants, L. acidophilus was able to interfere in the adhesion and biofilm formation of the S. mutans to glass slide. It also could make streptococcal chains shorter. Using realtime RT-PCR quantitation method made it clear that gtfB and gtfC gene expression were decreased in the presence of L. acidophilus-derived biosurfactant fraction. Several properties of S. mutans cells (the surface properties, biofilm formation, adhesion ability and gene expression) were changed after L. acidophilus-derived biosurfactant treatment. It is also concluded that biosurfacant treatment can provide an optional way to control biofilm development. On the basis of our findings, we can suggest that the prepared biosurfactant may interfere with adhesion processes of S. mutans to teeth surfaces, provided additional evaluation produce satisfactory results.

Bacteriocins produced by L fermentum and L acidophilus can inhibit cephalosporin resistant E coli

Reemerging infections occur due to resistant bacteria. Such infections create restrictions for clinicians and microbiologists in drug selection. Such problems demand new strategies for solution. Use of bacteriocins for this purpose may be fruitful. In the present research work, the inhibitory effects of bactericins on cephalosporin resistant Escherichia coli are used as model system for the control of antibiotic resistant pathogenic bacteria. Cephalosporin resistant Escherichia coli strain was isolated from pus by using conventional methodology. For bacteriocin production, Lactobacilli strains were selected by using selective media. Out of seventy two strains isolated from yogurt, fecal materials of human, chick, parrot and cat, only two strains (strain 45 and strain 52) were found to produce bacteriocins having antimicrobial potential against cephalosporin resistant Escherichia coli. Biochemical characterization showed that strain 45 belonged to group of Lactobacillus fermentum and strain 52 to Lactobacillus acidophilus. Both strains showed maximum growth at 25ºC and 35ºC respectively. Suitable pH was 5.5 and 6.0 for Lactobacillus fermentum and Lactobacillus acidophilus respectively. Bacteriocins produced by both strains were found stable at 50, 75 and 100ºC for 60min. Function of bacteriocin was also not disturbed due to change in pH. These findings suggest that bacteriocin produced by Lactobacillus fermentum and Lactobacillus acidophilus can be used for the infection control of cephalosporin resistant Escherichia coli.

Qualidade de leites fermentados funcionais elaborados a partir de bactérias ácido-lácticas isoladas de queijo de coalho / Quality of functional fermented milks produced by the use of lactic acid bacteria isolated from coalho cheese

Leites fermentados foram elaborados a partir de bactérias ácido-lácticas com propriedades funcionais, isoladas de queijo de coalho com e sem a adição de concentrado proteico de soro (CPS). Características físico-químicas, microbiológicas e sensoriais dos produtos elaborados foram analisadas durante 40 dias de estocagem sob refrigeração a 8-10ºC. Todos os leites fermentados elaborados, independentemente da adição de CPS e da cultura utilizada, apresentaram contagens adequadas de bactérias (>10(8)UFC/mL) durante todo o período de avaliação, o que garantiria seu possível potencial funcional. Leites fermentados por Lactobacillus acidophilus apresentaram melhor aceitação (P<0,05) pelos provadores aos 10 dias de estocagem; enquanto, aos 40 dias, o leite fermentado por Weissella confusa sem CPS resultou em pior aceitação (P<0,05). A associação de Lactobacillus acidophilus e Weissella confusa ou somente Lactobacillus acidophilus, independentemente da adição de CPS, seriam recomendados para elaboração industrial de novos leites fermentados potencialmente funcionais a partir de culturas lácticas brasileiras.(AU)

Fermented milks were produced using whey protein concentrate (WPC) and potentially functional lactic acid bacteria, which were isolated from coalho cheese produced in. Physical-chemical, microbiological, and sensorial characteristics of the fermented milks were analyzed during 40 days under refrigeration at 8-10ºC. All products, irrespectively of WPC adding or culture used, showed appropriated bacterial counts (>10(8)CFU/mL) throughout the evaluation time, which would guarantee their functional potential. Lactobacillus acidophilus fermented milks presented better sensorial approval (P<0.05) when evaluated at 10-day storage; while Weissella confusa fermented milks presented lower acceptance (P<0.05) at 40-day storage. The association of Lactobacillus acidophilus and Weissella confusa or Lactobacillus acidophilus isolatedly, irrespectively of WPC adding, should be recommended for the industrial elaboration of novel functional fermented milks using Brazilian lactic cultures as starters.(AU)

Qualidade de leites fermentados funcionais elaborados a partir de bactérias ácido-lácticas isoladas de queijo de coalho / Quality of functional fermented milks produced by the use of lactic acid bacteria isolated from coalho cheese

Leites fermentados foram elaborados a partir de bactérias ácido-lácticas com propriedades funcionais, isoladas de queijo de coalho com e sem a adição de concentrado proteico de soro (CPS). Características físico-químicas, microbiológicas e sensoriais dos produtos elaborados foram analisadas durante 40 dias de estocagem sob refrigeração a 8-10ºC. Todos os leites fermentados elaborados, independentemente da adição de CPS e da cultura utilizada, apresentaram contagens adequadas de bactérias (>10(8)UFC/mL) durante todo o período de avaliação, o que garantiria seu possível potencial funcional. Leites fermentados por Lactobacillus acidophilus apresentaram melhor aceitação (P<0,05) pelos provadores aos 10 dias de estocagem; enquanto, aos 40 dias, o leite fermentado por Weissella confusa sem CPS resultou em pior aceitação (P<0,05). A associação de Lactobacillus acidophilus e Weissella confusa ou somente Lactobacillus acidophilus, independentemente da adição de CPS, seriam recomendados para elaboração industrial de novos leites fermentados potencialmente funcionais a partir de culturas lácticas brasileiras.

Fermented milks were produced using whey protein concentrate (WPC) and potentially functional lactic acid bacteria, which were isolated from coalho cheese produced in. Physical-chemical, microbiological, and sensorial characteristics of the fermented milks were analyzed during 40 days under refrigeration at 8-10ºC. All products, irrespectively of WPC adding or culture used, showed appropriated bacterial counts (>10(8)CFU/mL) throughout the evaluation time, which would guarantee their functional potential. Lactobacillus acidophilus fermented milks presented better sensorial approval (P<0.05) when evaluated at 10-day storage; while Weissella confusa fermented milks presented lower acceptance (P<0.05) at 40-day storage. The association of Lactobacillus acidophilus and Weissella confusa or Lactobacillus acidophilus isolatedly, irrespectively of WPC adding, should be recommended for the industrial elaboration of novel functional fermented milks using Brazilian lactic cultures as starters.

Can Lactobacillus acidophilus influence the adhesion capacity of Candida albicans on the combined contraceptive vaginal ring?

BACKGROUND: This study was conducted to evaluate the influence of Lactobacillus acidophilus on the adhesion capacity of Candida albicans on the combined contraceptive vaginal ring (CCVR). STUDY DESIGN: Two vaginal isolates of C. albicans and an ATCC strain of lactobacilli were used. Isolated and associated yeasts and bacteria (co-aggregated) were employed on the CCVR adherence assays and scanning electron microscopy (SEM). RESULTS: Isolated yeasts and lactobacilli adhered strongly to the CCVR. After the co-aggregation, there were an increase in adhesion capacity of the yeasts (p<.001) and a diminished adhesion of the lactobacilli (p<.001). SEM showed the isolated and co-aggregated microorganisms intimately attached to the irregularities of the CCVR. CONCLUSIONS: If these findings correlated with the conditions in vivo, the use of probiotics based on L. acidophilus or its presence in the vaginal microbiota would not protect against the adhesion of C. albicans to the ring.

Posibilidades de la fluorescencia láser inducida para la detección y cuantificación de la dentina descalcificada: una experiencia "in vitro" / Possibilities of the induced laser fluorescence for the detection and quantification of demineralized dentin: an in vitro experience

En esta experiencia se analizó la influencia del proceso de descalcificación sobre las propiedades de fluorescencia de la dentina. Se utilizaron 22 molares humanos sanos, extraídos por diferentes movitos. De cada uno de ellos se obtuvo una sección horizontal de 2 mm de espesor aproximadamente a 1 mm por debajo de la fosa central, realizándose posteriormente tres marcas sobre una de las superficies planas de la dentina. En una primera etapa (grupo 1) se midió y cuantificó el nivel de calcificación en los tres sitios predeterminados de cada una de las secciones por medio del láser de fluorescencia DIAGNOdent. En una segunda etapa (grupo 2) se repitieron las maniobras de medición, luego que las secciones fueran parcialmente descalcificadas. Por último, en una tercera etapa (grupo 3) las secciones fueron contaminadas con un cultivo puro de Lactobacillus acidophylus, mantenidas en estufa de cultivo a 37ºC durante 72 horas y posteriormente sometidas a los mismos procedimientos de medición que en los grupos anteriores. Los resultados obtenidos revelaron que la dentina perteneciente a los especímenes de los grupos 2 y 3 presenta un nivel de fluorescencia ma