Histidine acts as a co-germinant with glycine and taurocholate for Clostridium difficile spores

Aims: It is well established that the bile salt sodium taurocholate acts as a germinant for Clostridium difficile spores and the amino acid glycine acts as a co-germinant. The aim of this study was to determine whether any other amino acids act as co-germinants. Methods and Results: Clostridium difficile spore suspensions were exposed to different germinant solutions comprising taurocholate, glycine and an additional amino acid for 1 h before heating shocking (to kill germinating cells) or chilling on ice. Samples were then re-germinated and cultured to recover remaining viable cells. Only five amino acids out of the 19 common amino acids tested (valine, aspartic acid, arginine, histidine and serine) demonstrated co-germination activity with taurocholate and glycine. Of these, only histidine produced high levels of germination (97·9–99·9%) consistently in four strains of Cl. difficile spores. Some variation in the level of germination produced was observed between different PCR ribotypes, and the optimum concentration of amino acids with taurocholate for the germination of Cl. difficile NCTC 11204 spores was 10–100 mmol l-1. Conclusions: Histidine was found to be a co-germinant for Cl. difficile spores when combined with glycine and taurocholate. Significance and Impact of the Study: The findings of this study enhance current knowledge regarding agents required for germination of Cl. difficile spores which may be utilized in the development of novel applications to prevent the spread of Cl. difficile infection.

Studies on the relative stabilities of Mn(II) and Mn(III) in complexes with N4O2 donor environments:crystal structures of [Mn(pybzhz)2] and [Mn(Ophsal)(imzH)2] ClO4 (pybzhz = N-(benzoyl)-N-(picolinylidene) hydrazine, Ophsal = N,N-o-phenylenebis(salicylideneimine), imzH = imidazole)

Five manganese complexes in an N 4O 2 donor environment have been prepared. Four of the compounds involve aroyl hydrazone as ligands and manganese is in a +2 oxidation state. The fifth compound was prepared using N,Nprime-o-phenylenebis(salicylideneimine) and imidazole as ligands where manganese is present in +3 oxidation state. X-ray crystal structure of one Mn +2 compound and the Mn +3 compound was determined. The relative stabilities of the Mn +2 and Mn +3 oxidation states were analyzed using the structural data and MO calculations. Manganese(II) complexes of four aroyl hydrazone ligands were prepared and characterized by different physicochemical techniques. The complexes are of the type Mn(L) 2, where L stands for the deprotonated hydrazone ligand. One of the compounds, Mn(pybzhz) 2, was also characterized by single crystal structure determination. In all these complexes, the Mn(II) is in an N 4O 2 donor environment and the Mn(II) center cannot be oxidized either chemically or electrochemically. However, when another ligand Ophsal is used to give the compound [Mn(Ophsal)(imzH) 2]ClO 4, which was also characterized by X-ray crystal structure determination, manganese can easily avail the +3 oxidation state. The relative stabilities of the +2 and +3 oxidation states of manganese were analyzed and it was concluded that the extent of distortion from the perfect octahedral geometry is the main controlling factor in these cases. © 2004 Elsevier B.V. All rights reserved.

Quantification of glycine betaine, choline and trimethylamine N-oxide in seawater particulates: Minimisation of seawater associated ion suppression

A liquid chromatography/mass spectrometry (LC/MS, electrospray ionisation) method has been developed for the quantification of nitrogenous osmolytes (N-osmolytes) in the particulate fraction of natural water samples. Full method validation demonstrates the validity of the method for measuring glycine betaine (GBT), choline and trimethylamine N-oxide (TMAO) in particulates from seawater. Limits of detection were calculated as 3.5, 1.2 and 5.9 pg injected onto column (equivalent to 1.5, 0.6 and 3.9 nmol per litre) for GBT, choline and TMAO respectively. Precision of the method was typically 3% for both GBT and choline and 6% for TMAO. Collection of the particulate fraction of natural samples was achieved via in-line filtration. Resulting chromatography and method sensitivity was assessed and compared for the use of both glass fibre and polycarbonate filters during sample collection. Ion suppression was shown to be a significant cause of reduced instrument response to N-osmolytes and was associated with the presence of seawater in the sample matrix

Quantification of glycine betaine, choline and trimethylamine N-oxide in seawater particulates: Minimisation of seawater associated ion suppression

A liquid chromatography/mass spectrometry (LC/MS, electrospray ionisation) method has been developed for the quantification of nitrogenous osmolytes (N-osmolytes) in the particulate fraction of natural water samples. Full method validation demonstrates the validity of the method for measuring glycine betaine (GBT), choline and trimethylamine N-oxide (TMAO) in particulates from seawater. Limits of detection were calculated as 3.5, 1.2 and 5.9 pg injected onto column (equivalent to 1.5, 0.6 and 3.9 nmol per litre) for GBT, choline and TMAO respectively. Precision of the method was typically 3% for both GBT and choline and 6% for TMAO. Collection of the particulate fraction of natural samples was achieved via in-line filtration. Resulting chromatography and method sensitivity was assessed and compared for the use of both glass fibre and polycarbonate filters during sample collection. Ion suppression was shown to be a significant cause of reduced instrument response to N-osmolytes and was associated with the presence of seawater in the sample matrix

Partial molar volumes of glycine and dl-alanine in aqueous ammonium sulfate solutions at 278.15, 288.15, 298.15 and 308.15 K

In this work, the partial molar volumes of glycine and DL-alanine in aqueous solutions of ammonium sulfate at 0.0, 0.1, 0.3, 0.7, and 1.0 mol.kg(-1) are determined between 278.15 and 308.15 K. Transfer volumes were obtained, which are larger for glycine than DL-alanine. On the contrary, the hydration numbers are higher for DL-alanine than glycine, and dehydration of the amino acids is observed with increasing temperature or salt molality. The data suggest that interactions between ion and charged/hydrophilic groups are predominant and, by applying the methodology proposed by Friedman and Krishnan, it was concluded that they are mainly pairwise. A group-contribution scheme has been successfully applied to the pairwise volumetric interaction coefficient. Finally, the dehydration effect on glycine, alanine and serine in the presence of different electrolytes has been rationalized in terms of the charge density and a parameter accounting for the cation's hydration.

Teor de fenólicos totais e crescimento radicular em soja (Glycine max (L.) Merr.) inoculada com as bactérias endofítica e epifítica e sua exposição à ferrugem.

Os compostos fenólicos são formados no metabolismo secundário dos vegetais e estão envolvidos no mecanismo de defesa. O objetivo do trabalho foi avaliar o efeito dos isolados 0G e EN78 na produção de fenólicos totais na soja, frente à exposição à ferrugem da soja (Phakospora pachyrhizi), e no crescimento radicular. O isolado EN78 induziu um aumento no teor de fenólicos totais quando exposto à ferrugem, mesmo antes da manifestação do sintoma. Esse mesmo isolado apresentou eficiência simbiótica com o Biorhizo 10 (Bradyrhizobium elkanii e japonicum), promovendo o desenvolvimento radicular, enquanto que o isolado 0G não influiu no teor de fenólicos totais, mas induziu aumento da biomassa radicular.

Validación de la prueba de tetrazolio como método de vigor para semillas de Glycine max.

El objetivo de este estudio fue demostrar que la Prue- ba de Tetrazolio es un Método de Vigor para Glycine max, repetible dentro de los laboratorios y reproducible entre ellos. Se analizaron tres lotes de semillas de Glycine max, con una germinación de maior ou igual a 80% (lote 1: 92%; lote 2: 89% y lote 3: 80%), empleando la Prueba de Tetrazolio. En la validación participaron 6 laboratorios. Las semillas fueron clasificadas en cuatro categorías: vigor alto, vigor medio, vigor bajo y otras tinciones (semillas viables no vigoro- sas + semillas no viables). La suma de la proporción de las categorías de semillas de vigor alto, medio y bajo se expresó como Vigor-TZ (%). Los valores de Vigor-TZ (%) se encontraron dentro de los niveles de tolerancia esta- blecidos por ISTA. El dato de Vigor-TZ fue analizado sepa- radamente, usando el cálculo del valor z-scores, valores h y valores k. El cálculo de los valores z-scores reveló que los datos de Vigor-TZ no excedieron el valor 2, por lo tanto los resultados son considerados satisfactorios. Los valores h mostraron que cinco laboratorios no sobreesti- maron ni subestimaron los resultados de todos los lotes de semillas. Los valores k mostraron la variabilidad entre las repeticiones de cada uno de los lotes dentro de cada laboratorio. Las repeticiones estuvieron en tolerancia para todos los lotes y todos los laboratorios. La prueba fue re- petible dentro de los laboratorios y reproducible en diferen- tes laboratorios. Concluimos que el dato para Vigor-TZ (%) muestra una variación aceptable y, por lo tanto, la Prueba de Tetrazolio puede ser aplicada como un método de vigor para soja.

Anti-anxiety effect of methanol extract of Pericarpium zanthoxyli using a strychnine-sensitive glycine receptor model

Purpose: To determine if the methanol extract of Pericarpium zanthoxyli exerts anti-anxiety effects and also to explore any probable anti-anxiety mechanism in vivo. Methods: The staircase test, elevated plus maze test, rota-rod treadmill test and convulsions induced by strychnine and picrotoxin on mice were tested to identify potential mechanism of anti-anxiety activity of the plant extract. Results: The plant extract (10 mg/kg, p.o.) significantly reduced rearing numbers in the staircase test while it increased the time spent in the open arms as well as the number of entries to the open arms in the elevated plus maze test, suggesting that it has significant anti-anxiety activity. Furthermore, the extract inhibited strychnine-induced convulsion. However, it had little effect on picrotoxin-induced convulsion, suggesting that its anti-anxiety activity may be linked to strychnine-sensitive glycine receptor and not GABA receptor. Conclusion: These results suggest that the Pericarpium zanthoxyli extract may be beneficial for the control of anxiety.