Efeito de dentifrícios com reduzida concentração de fluoreto contendo trimetafosfato de sódio e polióis na erosão inicial do esmalte / Effect of low-fluoride toothpaste containing sodium trimetaphosphate and polyols on initial enamel erosion

Este estudo in vitro avaliou o efeito de dentifrícios contendo fluoreto (F), trimetafosfato de sódio (TMP) e/ou xilitol e eritritol (XE) em inibir ou reparar lesão erosiva inicial do esmalte. Blocos de esmalte bovino (n=120) foram selecionados por dureza de superfície (SH) inicial e divididos em 5 grupos compostos por dentifrícios (24 blocos/grupo): Placebo (sem F, TMP e XE); 1100 ppm F; 16% xilitol + 4% eritritol (XE); 200 ppm F + 0,2% TMP (200 ppm F/TMP); e 200 ppm F + 0,2% TMP + 16% xilitol + 4% eritritol (200 ppm F/TMP/XE). Para a análise do efeito protetor, blocos hígidos (n=60) foram imersos 1x/2 minutos em suspensão de dentifrícios/saliva humana. Em seguida, os blocos foram submetidos a 4 desafios erosivos com ácido cítrico (0,75%, pH 3,5) de 1 minuto cada, sob agitação. A seguir, a SH foi determinada pós-tratamento (t) e após o 1º, 2º, 3º e 4º desafios ácidos erosivos (d) para o cálculo da porcentagem de variação da SH (%SH). Para a análise do efeito reparador, esmalte previamente erodido (n=60) foi tratado e submetido aos mesmos desafios erosivos descritos anteriormente. A %SH de recuperação (R) e %SHt foram calculadas, bem como, a diferença entre a %SHR e %SHd obtendo-se o Δ%SH para cada desafio. Experimento adicional foi realizado para análise da deposição de precipitados por Microscopia Eletrônica de Varredura (MEV) em esmalte hígido e erodido. Os dados foram submetidos à análise de variância de medidas repetidas a dois critérios, seguida pelo teste de Student-Newman-Keuls (p<0,05). Os resultados mostraram que o maior efeito protetor e reparador foi produzido pelo dentifrício 200 ppm F/TMP/XE quando comparado aos demais grupos (p<0,001). Os grupos 1100 ppm F e 200 ppm F/TMP apresentaram similar efeito protetor para o 1º, 2º e 3º desafios (p>0,05), e menor quando comparados ao XE (p<0,001). O efeito protetor e reparador foi: XE>200 ppm F/TMP>1100 ppm F>Placebo (p<0,001). Na MEV observou-se deposição de precipitado no esmalte para todos os grupos, formando uma camada mais espessa e homogênea nos grupos contendo XE e/ou TMP. Concluiu-se que dentifrício contendo 200 ppm F, TMP e polióis apresenta efeito protetor e reparador superior quando comparado a um dentifrício 1100 ppm F em lesões erosivas iniciais no esmalte(AU)

This in vitro study evaluated the effect of toothpaste containing fluoride (F), sodium trimetaphosphate (TMP) and/or xylitol and erythritol (XE) in inhibit or repair initial enamel erosion lesions. Bovine enamel blocks (n=120) were selected by initial surface hardness (SH) and divided into 5 groups of toothpastes (n=24 blocks/group): Placebo (no F, TMP or XE); 1100 ppm F; 16% xylitol + 4% erythritol (XE); 200 ppm F + 0.2% TMP (200 ppm F/TMP); and 200 ppm F + 0.2% TMP + 16% xylitol + 4% erythritol (200 ppm F/TMP/XE). For the analysis of the protective effect, sound blocks (n=60) were immersed in toothpaste slurry in human saliva once for 2 minutes. Hereafter, the blocks were submitted to 4 erosive challenges in citric acid (0.75%, pH 3.5) by 1 minute, under stirring. Then, the SH was determined after treatment (t) and after the 1st, 2nd, 3rd and 4th erosive acid challenges (d) to calculate the percentage of change of the SH (%SH). For the analysis of the repair effect, eroded enamel (n=60) were treated and submitted to erosive challenges as describe previously. The recovery (R) of %SH and %SHt were calculated, as well as the difference between the %SHR and %SHd obtaining the Δ%SH for each challenge. Additional experimental was performed to analysis the deposition of precipitates by Scanning Electronic Microscopy (SEM) on sound and eroded enamel. Variables were submitted to two-way repeated measures analysis of variance followed by StudentNewman-Keuls test (p<0.05). The results showed that the highest protective and repair effect was produced by the 200 ppm F/TMP/XE toothpaste when compared to the other groups (p<0.001). The 1100 ppm F and 200 ppm F/TMP groups had similar protective effect for the 1st, 2nd and 3rd challenges (p>0.05), and lower when compared to XE (p<0.001). The protective and repair effect was: XE>200 ppm F/TMP>1100 ppm F>Placebo (p<0.001). There were deposition of precipitates on enamel for all groups, with a thicker layer and homogeneous for XE and/or TMP groups. It was concluded that toothpaste containing 200 ppm F, TMP and polyols has superior protective and repair effect when compared to 1100 ppm F toothpaste in initial enamel erosive lesions(AU)

Atividade antimicrobiana de Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre bactérias cariogênicas: estudo in vitro / Antimicrobial activity of Stevia rebaudiana Bertoni and non-caloric sweeteners on cariogenic bacteria: in vitro study

Objetivo: avaliar a atividade antimicrobiana in vitro da planta Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre o crescimento de Streptococcus mutanse Lactobacillus casei, micro-organismos cariogênicos presentes na cavidade bucal. Materiais e método: o estudo foi realizado utilizando as cepas padrões de S.mutans (UA159) e L. casei (ATCC7469). Foram avaliados diferentes compostos não calóricos substitutos dasacarose nas concentrações de 1%, 5% e 10%: eritritol(ER), Fit Sucralose® (SU), Stevita® (ST), solução de Steviarebaudiana Bertoni (SSr) e, como controle positivo,digluconato de clorexidina (DC). A análise do efeito inibitório desses compostos no crescimento das bactériasfoi feita por meio da técnica de difusão em ágar. Resultado:observou-se que existe um efeito inibitório decrescimento de ambos os micro-organismos por parte da SSr e do ER, enquanto os demais adoçantes testa dosnão tiveram efeito inibitório sobre esses micro-organismos.Conclusão: os resultados demonstram que SSR eER apresentam efeito inibidor no crescimento das cepastestadas de S. mutans e L. casei. (AU)

Objective: The study evaluated the in vitro antimicrobial activity of the Stevia rebaudiana Bertoni plant and non-caloric sweeteners on the growth of Streptococcus mutans and Lactobacillus casei, which are cariogenic microorganisms present in the oral cavity. Materials and method: The study was conducted using the standard strains of S. mutans (UA159) and L. casei (ATCC7469). Different non-caloric compounds were evaluated at concentrations of 1%, 5%, and 10%: erythritol (ER), Fit Sucralose™ (SU), Stevita™ (ST), Stevia rebaudiana Bertoni solution (SSr), and chlorhexidine digluconate (CD) as positive control. The inhibitory effect of these compounds on the growth of bacteria were analyzed by the agar diffusion technique. Result: There was a growth inhibition effect for both microorganisms by SSr and ER, whereas the other sweeteners tested had no inhibitory effect on the microorganisms. Conclusion: The results showed that SSr and ER present an inhibitory effect on the growth the strains tested of S. mutans and L. casei. (AU)

Clinical and microbiological effects of the supplementary use of an erythritol powder air-polishing device in non-surgical periodontal therapy: a randomized clinical trial

PURPOSE: This study was undertaken to evaluate the clinical and microbiological effects of an erythritol powder air-polishing device (EPAP) as a supplement to scaling and root planing (SRP) therapy in patients with moderate chronic periodontitis. METHODS: Clinical and microbiological evaluations were performed at 21 sites treated with SRP (control) and 21 sites treated with SRP+EPAP (test). All examinations were performed before treatment, 1 month after treatment, and 3 months after treatment. RESULTS: There were no significant clinical differences between the test group and the control group. Microbiological analysis revealed that the relative expression level of Porphyromonas gingivalis was significantly lower in the test group than in the control group at 1 month after treatment. Clinical and microbiological results showed improvements at 1 month compared to baseline; in contrast, the results at 3 months after treatment were worse than those at 1 month after treatment. CONCLUSIONS: In this study, both SRP and SRP+EPAP were clinically and microbiologically effective as non-surgical periodontal treatments. In particular, the SRP+EPAP group showed an antimicrobial effect on P. gingivalis, a keystone bacterium associated with the onset of chronic periodontitis, in a short-term period. Periodic periodontal therapy, at intervals of at least every 3 months, is important for sustaining the microbiological effects of this treatment.

Clinical effects of additional use of erythritol powder air polishing device on non-surgical periodontal treatment in moderate chronic periodontitis

PURPOSE: The purpose of this study was to evaluate the clinical effects of erythritol powder air polishing device (EPAP) in addition to scaling and root planing (SRP) in non-surgical periodontal treatment in moderate chronic periodontitis patients. MATERIALS AND METHODS: Clinical evaluation was performed at 21 sites treated with SRP (control) and 21 sites treated with the addition of SRP+EPAP (test). All examinations were performed before treatment, 1 month after treatment, and 3 months after treatment. Depth of the periodontal pocket, gingival recession, clinical attachment level, plaque index, and bleeding of probing were measured as clinical parameters. RESULTS: In both test and control groups, there was a significant decrease in the depth of the periodontal pocket, plaque index, bleeding of probing, increased gingival recession, and gain of clinical attachment level at 1 month and 3 months after treatment. However, there was no significant clinical difference between the test group and the control group. Clinical result was improved after 1 month compared to the baseline; in contrast, results at 3 months after treatment were worse than at 1 month after treatment. CONCLUSION: In this study, we cannot suggest that SRP + EPAP is clinically more effective than SRP alone as non-surgical periodontal treatments. Periodic periodontal therapy, at intervals of at least every three months, is important for sustaining effects of this treatment.

Strategy of oxygen transfer coefficient control on the L-erythrulose fermentation by newly isolated Gluconobacter kondonii

Background: The effect of diverse oxygen transfer coefficient on the L-erythrulose production from meso-erythritol by a newly isolated strain, Gluconobacter kondonii CGMCC8391 was investigated. In order to elucidate the effects of volumetric mass transfer coefficient (K La) on the fermentations, baffled and unbaffled flask cultures, and fed-batch cultures were developed in present work. Results: With the increase of the K La value in the fed-batch culture, L-erythrulose concentration, productivity and yield were significantly improved, while cell growth was not the best in the high K La. Thus, a two-stage oxygen supply control strategy was proposed, aimed at achieving high concentration and high productivity of L-erythrulose. During the first 12 h, Klawas controlled at 40.28 h-1 to obtain high value for cell growth, subsequently K La was controlled at 86.31 h-1 to allow for high L-erythrulose accumulation. Conclusions: Under optimal conditions, the L-erythrulose concentration, productivity, yield and DCW reached 207.9 ± 7.78 g/L, 6.50 g/L/h, 0.94 g/g, 2.68 ± 0.17 g/L, respectively. At the end of fermentation, the L-erythrulose concentration and productivity were higher than those in the previous similar reports.

Enhanced production of erythritol and mannitol by Yarrowia lipolytica in media containing surfactants

Abstract Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300 g L-1), erythritol production increased by 15% compared to the culture without the surfactant where it reached 142 g L-1 after 5 days, which corresponded to 0.47 g g-1 yield and productivity of 1.1 g L-1 h-1. Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.

Glycemic Effects of Rebaudioside A and Erythritol in People with Glucose Intolerance

BACKGROUND: Rebaudioside A and erythritol are nonnutritive sweeteners. There have been several studies of their glycemic effects, but the outcomes remain controversial. The purpose of this study was to evaluate the glycemic effects of rebaudioside A and erythritol as a sweetener in people with glucose intolerance. METHODS: This trial evaluated the glycemic effect after 2 weeks of consumption of rebaudioside A and erythritol as sweeteners in a pre-diabetic population. The patients were evaluated for fructosamine, fasting plasma glucose, C-peptide, insulin, and 2-hour plasma glucose before and after consumption of sweetener. The primary outcome was a change in fructosamine levels from the baseline to the end of treatment. Secondary outcomes were the changes in levels of fasting plasma glucose and 2-hour plasma glucose. RESULTS: From the baseline to the end of experiment, the changes in fructosamine levels after consumption of rebaudioside A and erythritol, did not differ significantly (244.00±19.57 vs. 241.68±23.39 µmol/L, P=0.366). The change in levels from the baseline to end of the study for rebaudioside A and erythritol were fasting plasma glucose (102.56±10.72 vs. 101.32±9.20 mg/dL), 2-hour plasma glucose (154.92±54.53 vs. 141.92±42.22 mg/dL), insulin (7.56±4.29 vs. 7.20±5.12 IU/mL), and C-peptide (2.92±1.61 vs. 2.73±1.31 ng/mL), respectively, and also did not differ significantly (P>0.05 for all). CONCLUSION: Our study suggests that consumption of rebaudioside A and erythritol does not alter the glucose homeostasis in people with glucose intolerance.

Cloning and expression analysis of 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase gene in Tripterygium wilfordii / 中国中药杂志

To clone the 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (TwMCT) full length cDNA from Tripterygium wilfordii, the specific primers were designed according to the transcriptome data and the LCPCR were carried out. After a series of bioinformatics analysis on the TwMCT, the MeJA induced expression content were investigated by real-time fluorescence quantification polymerase chain reaction (RT-qPCR). The result showed that the full of TwMCTcDNA was 1 318 bp nucleotides encoding 311 amino acids. The molecular weight of the deduced TwMCT protein was about 34.14 kDa and the theoretical isoelectric point was 8.65. Result of the RT-qPCR analysis indicated that the content of TwMCT mRNA expression in T. wilfordii suspension cell was rising after treating with MeJA and reached the maximum in 24 h. Cloning and analyzing TwMCT gene from T. wilfordii provided gene element for studying the function and expression regulation of secondary metabolites.

Effect of Lactobacillus acidophilus on metabolizing lactic acid in formula milk: a quantitative analysis of the effect of erythritol / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the lactic acid productivity of Lactobacillus acidophilus (La) exposed to formula milk containing different concentration of erythritol.</p><p><b>METHODS</b>La was cultured under anaerobic condition (80% N(2), 10% CO(2), 10% H(2)) at 37 °C in five experimental groups (formula milk mixed with different concentrations of erythritol). The five experimental groups contained 1%, 2%, 4%, 6%, and 8% erythritol, respectively (groups 1% E-M, 2% E-M, 4% E-M, 6% E-M, 8% E-M). Formula milk served as control group (group M). The lactic acid was analyzed by high performance liquid chromatography (HPLC) at 4 h intervals during 24 h. The peak-area of lactic acid was recorded and used to calculate the concentration of lactic acid through the equation of a standard curve (y = 590 244x + 67 507). ANOVA and Tukey HDS analysis were used to analyze the data.</p><p><b>RESULTS</b>The concentration of lactic acid at 24 h was group M [(4.693 ± 0.105) g/L], group 1% E-M[(4.114 ± 0.186) g/L], group 2% E-M[(3.720 ± 0.158) g/L], group 4% E-M[(3.045 ± 0.152) g/L], group 6% E-M[(2.971 ± 0.086) g/L], group 8% E-M[(2.789 ± 0.142) g/L]. Statistically significant differences in lactic acid concentrations were found between different time points (P < 0.05) and between different groups (F = 187.448, P < 0.05). Moreover, the concentrations of lactic acid in each experimental group was lower than that in control group (P < 0.05). The difference among groups 4% E-M, 6% E-M, and 8% E-M were not statistically significant (P > 0.05).</p><p><b>CONCLUSIONS</b>Erythritol showed the inhibition potential against La in metabolizing lactic acid in formula milk. The effect of erythritol was concentration depended. The higher concentration of erythritol contained in the milk, the better the inhibition potential against La in metabolizing lactic acid.</p>

Engineering MEP pathway in Escherichia coli for amorphadiene production and optimizing the bioprocess through glucose feeding control / 生物工程学报

The pathway of 2-methyl-D-erythritol-4-phosphate (MEP) is the exclusive isoprenoid precursor biosynthetic pathway in Escherichia coli, with a higher theoretical yield than mevalonate (MVA) pathway. However, due to lack of information about the regulation of MEP pathway, only engineering MEP pathway in E. coli achieved limited improvement of heterologous isoprenoid production. We used exogenous MEP pathway genes to improve MEP pathway in E. coli and optimized the glucose feeding to release the potential of MEP pathway. The results demonstrate that co-expression of dxs2 from Streptomyces avermitilis and idi from Bacillus subtilis can increase amorphadiene production with 12.2-fold compared with the wild-type strain in shake flask fermentation. Then we established a high-cell density fermentation process for the engineered strain, and found that the phase from 24 to 72 h is important for product biosynthesis. The optimization of glucose feeding rate during 24 to 72 h significantly improved product accumulation, which was improved from 2.5 to 4.85 g/L, within the same process time. Considering the attenuation of strain metabolism after 72 h, this study further modulated the glucose feeding rate during exponential phase to control strain growth and the amorphadiene yield eventually reached to 6.1 g/L. These results provided useful information to develop engineered E. coli for isoprenoid production through MEP pathway engineering.

Effects of short-term supplementation of erythritol-salt on urinary electrolyte excretion in rats / 한국영양학회지

PURPOSE: This study was conducted in order to investigate the diuretic effects of Erythritol (ET) salt on urinary electrolyte excretion in Sprague-Dawley Rats. METHODS: Animals were divided into two groups: Salt group (n = 7) and Salt + ET fed group (n = 7). Animals were provided food and water ad libitum. Supplements were administered orally to animals for one week. RESULTS: Body weights were not statistically different between groups either on Day 1 or Day 7. However, water consumption of the Salt + ET group was significantly higher than that of the Salt group on Day 1 and Day 7. Urine volume of the Salt + ET group was approximately 27% and 38% higher than that of the Salt group on Day 1 and Day 7. In addition, we found that the total amounts of urinary electrolytes, such as sodium and potassium, of the Salt + ET group were significantly higher than those of the Salt group on Day 7. We also found that serum electrolyte concentrations did not differ between two groups. These results demonstrated that salt intake with ET was effective in increasing urinary electrolyte excretion, which might be caused by higher water intake and diuretic effect inhibiting reabsorption of water, sodium, and potassium in renal tubules. CONCLUSION: The results suggest that short-term supplementation of ET salt can be a potential diuretic agent by inhibiting sodium and potassium reabsorption and inducing loss of water.

Genotoxicity Assessment of Erythritol by Using Short-term Assay

Erythritol is a sugar alcohol that is widely used as a natural sugar substitute. Thus, the safety of its usage is very important. In the present study, short-term genotoxicity assays were conducted to evaluate the potential genotoxic effects of erythritol. According to the OECD test guidelines, the maximum test dose was 5,000 microg/plate in bacterial reverse mutation tests, 5,000 microg/ml in cell-based assays, and 5,000 mg/kg for in vivo testing. An Ames test did not reveal any positive results. No clastogenicity was observed in a chromosomal aberration test with CHL cells or an in vitro micronucleus test with L5178Y tk +/- cells. Erythritol induced a marginal increase of DNA damage at two high doses by 24 hr of exposure in a comet assay using L5178Y tk +/- cells. Additionally, in vivo micronucleus tests clearly demonstrated that oral administration of erythritol did not induce micronuclei formation of the bone marrow cells of male ICR mice. Taken together, our results indicate that erythritol is not mutagenic to bacterial cells and does not cause chromosomal damage in mammalian cells either in vitro or in vivo.

Study on the mechanism of erythritol effecting on Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of erythritol on cell wall structure of Streptococcus mutans (S. mutans) and explore its potential mechanism.</p><p><b>METHODS</b>Enzyme activities of lactate dehydrogenase (LDH) in bacterial solution were detected under respective condition of sucrose and erythritol. A scanning electron microscope (SEM) was used to investigate the change of S. mutans' cell wall under the condition of sucrose and erythritol.</p><p><b>RESULTS</b>Enzyme activities of LDH in erythritol culture medium were different from that in sucrose, but the difference was slight. SEM observation showed the integrity of cell wall was not destroyed and no content leaked out.</p><p><b>CONCLUSION</b>It's suggested that erythritol has an antibacterial effect on S. mutans through no affecting on the normal structure of the cell wall of S. mutans.</p>

Contrasting study of erythritol and xylitol on Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the inhibitory effect of erythritol by contrast to xylitol on growth and acid production of Streptococcus mutans (S. mutans).</p><p><b>METHODS</b>S. mutans were incubated respectively in 0.5%, 1%, 2%, 4%, 8%, 12%, 16% erythritol or xylitol culture medium under anaerobic conditions. The A and pH value of the mediums were measured at 0, 2, 4, 6, 8, 10, 12, 18, 24 hours, following the profile plots by SPSS.</p><p><b>RESULTS</b>The data of A were higher in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. The data of pH were lower in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while higer in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. It indicated that the growth and acid production of S. mutans were higer in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration.</p><p><b>CONCLUSION</b>Compared with xylitol, erythritol in low concentration has weaker effort on the growth and acid production of S. mutans, while having stronger effort in high concentration.</p>

Effect of fosmidomycin on metabolic and transcript profiles of the methylerythritol phosphate pathway in Plasmodium falciparum

In Plasmodium falciparum, the formation of isopentenyl diphosphate and dimethylallyl diphosphate, central intermediates in the biosynthesis of isoprenoids, occurs via the methylerythritol phosphate (MEP) pathway. Fosmidomycin is a specific inhibitor of the second enzyme of the MEP pathway, 1-deoxy-D-xylulose-5-phosphate reductoisomerase. We analyzed the effect of fosmidomycin on the levels of each intermediate and its metabolic requirement for the isoprenoid biosynthesis, such as dolichols and ubiquinones, throughout the intraerythrocytic cycle of P. falciparum. The steady-state RNA levels of the MEP pathway-associated genes were quantified by real-time polymerase chain reaction and correlated with the related metabolite levels. Our results indicate that MEP pathway metabolite peak precede maximum transcript abundance during the intraerythrocytic cycle. Fosmidomycin-treatment resulted in a decrease of the intermediate levels in the MEP pathway as well as in ubiquinone and dolichol biosynthesis. The MEP pathway associated transcripts were modestly altered by the drug, indicating that the parasite is not strongly responsive at the transcriptional level. This is the first study that compares the effect of fosmidomycin on the metabolic and transcript profiles in P. falciparum, which has only the MEP pathway for isoprenoid biosynthesis.

Tipificación molecular de Brucella abortus cepa 19 y su aplicación al control de biológicos / Molecular characterization of Brucella abortus strain 19 and its application for controlling biologics

Brucella abortus es el agente etiológico de la brucelosis bovina. La cepa 19, utilizada en la elaboración de vacunas, puede ser identificada a través de una deleción en la región eri asociada con la sensibilidad al eritritol. Se optimizó un ensayo de PCR para caracterizar específicamente esta cepa. El método que describimos es un procedimiento rápido para identificar B. abortus y simultáneamente diferenciar la cepa 19 de otras cepas de B. abortus biovar 1. Hemos aplicado este ensayo para la detección de la cepa 19 en vacunas contra la brucelosis bovina elaboradas en Argentina. Los resultados indican que este método podría ser útil para el seguimiento de las cepas madres y semillas utilizadas en la producción industrial de esta vacuna. Esta metodología también contribuiría a la reducción del riesgo de la infección adquirida en el laboratorio y podría aplicarse como prueba de rutina para confirmar la presencia de B. abortus en vacunas no relacionadas.

Brucella abortus is the etiological agent of bovine brucellosis. The strain 19 used in vaccine elaboration can be identified through a deletion in the eri region associated with its susceptibility to erythritol. We optimized a PCR assay for specific characterization of this strain. The method described here is a rapid procedure that enables identification of B. abortus, and simultaneous differentiation of the strain 19 from other B. abortus biovar 1 strains. We applied the assay to detect the strain 19 in vaccines against B. abortus produced in Argentina. The results show this method could be used to follow vaccine seed cultures of this strain. The methodology could also contribute to reduce the risk of a laboratory-acquired infection and could be of great help as a routine test for confirmation of B. abortus in non related vaccines.

An overview of the non-mevalonate pathway for terpenoid biosynthesis in plants.

Terpenoids are known to have many important biological and physiological functions. Some of them are also known for their pharmaceutical significance. In the late nineties after the discovery of a novel non-mevalonate (non-MVA) pathway, the whole concept of terpenoid biosynthesis has changed. In higher plants, the conventional acetate-mevalonate (Ac-MVA) pathway operates mainly in the cytoplasm and mitochondria and synthesizes sterols, sesquiterpenes and ubiquinones predominantly. The plastidic non-MVA pathway however synthesizes hemi-, mono-, sesqui- and di-terpenes, along with carotenoids and phytol chain of chlorophyll. In this paper, recent developments on terpenoids biosynthesis are reviewed with respect to the non-MVA pathway.