Extraintestinal Clostridioides difficile infection.

Clostridioides (Clostridium) difficile is the major cause of healthcare antibiotic-associated diarrhoea. However, extra-intestinal manifestations of Clostridioides (Clostridium) difficile infection (CDI) (including bacteremia and tissue infection) are extremely rare. We report a case of extraintestinal CDI after surgery. The isolate of C. difficile was not the PCR ribotype 027. However, this isolate produced toxins A and B. The patient underwent a follow-up examination 30 days after discharge, which showed complete recovery. This case report adds to existing knowledge of CDI.

Effect of temperature on the enantioselectivity of basic analytes using CE with sulfated beta-cyclodextrins.

Twelve basic analytes, including ephedrine and its structurally related compounds, were used to study the influence of capillary temperature on enantioselectivity in CE enantioseparations under reversed polarity mode using sulfated beta-CD (S-beta-CD) as chiral selectors. All of the effective mobility changes of (+)-enantiomers between 35 and 20 degrees C were higher than those of (-)-enantiomers whosoever enantioselectivity increased or decreased with an increase in temperature. However, the unusual temperature effect that enantioselectivity was increased with an increase of temperature was observed for the compounds with hydroxyl substitution on phenyl ring and had relationship with the molecular structures. With performing NMR studies on the selected selector-analyte complexes, the results led to a deeper understanding of the chiral discrimination process. Inspection of the complexation-induced chemical shifts (CICS) of the enantiomers showed that the phenyl ring sits deeply and slantways in the cavity of S-beta-CD and alkyl chain pointed out of the wider rim of S-beta-CD with ion-ion and hydrogen bond interactions between analytes and S-beta-CD.

Temperature effects on the enantioselectivity of basic analytes in capillary EKC using sulfated beta-CDs as chiral selectors.

The thermodynamic processes were investigated to reveal the temperature effects during chiral separation by capillary EKC with reversed polarity mode using sulfated beta-CD (S-beta-CD) as chiral selectors. The temperature effects on enantioselectivities of basic analytes (ephedrine, norephedrine, synephrine, and epinephrine) were investigated in detail over a temperature range of 20-60 degrees C. An increase of the capillary temperature produced the decrease of enantioselectivities for ephedrine and norephedrine, but increase of enantioselectivities for synephrine and epinephrine. The thermodynamic variations showed that the interactions between the basic analytes and chiral selectors were always enthalpy- driven. However, the difference in enthalpy and entropy showed that the enantioseparation was an enthalpy-driven process for ephedrine and norephedrine, but an entropydriven process for synephrine and epinephrine. Just because of the different driving forces, there exist two kinds of temperature effects on enantioselectivities mentioned above.

Study of low-molecular weight organic acids in maize roots under the stress of cadmium using capillary zone electrophoresis.

An indirect CE method was developed for the study of low-molecular weight organic acids (LMWOAs) in maize under the stress of cadmium. The influences of indirect reagents (phthalate, salicylic acid, and benzoic acid), coion concentration, and pH were studied. A buffer composed of 15 mmol/L benzoate and 0.2 mmol/L CTAB (pH 5.7) was used in the organic acid determination. The detection limit ranged between 0.5 and 6 micromol/L. The RSD (n = 14) of the method was found to be in the range of 0.11-0.49% for migration time and 1.25-4.72% for peak area. In the maize roots, obvious increases of LMWOAs were observed when the plants were under the stress of cadmium and/or organic acids. The recovery of standard organic acids added in real samples ranged from 85 to 116%.

Comparison of two capillary electrophoresis online stacking modes by analysis of polycyclic aromatic hydrocarbons in airborne particulates.

Naphthalene, fluorene, pyrene, anthracene, phenanthrene, and chrysene were successfully separated by CD-modified MEKC (CD-MEKC) using 20 mM borate (pH 9.0) containing 90 mM SDS and 75 mM beta-CD. Two online stacking methods, i.e., sweeping and field-enhanced sample injection (FESI), were explored to enhance the detection sensitivity. The influences of some crucial parameters in sweeping and FESI procedures were investigated. For FESI method, a plug of water and low-conductivity sample matrix was used to increase the stacking efficiency. Compared with the sweeping method, FESI can increase the sensitivity in the range of 10-20-fold. The proposed method was used for the analysis of polycyclic aromatic hydrocarbons in airborne particulates.

Simultaneous separation of organomercury species by nonaqueous capillary electrophoresis using methanol containing acetic acid and imidazole.

A simple and rapid nonaqueous capillary electrophoresis method for simultaneous separation of four kinds of mercury species, namely inorganic mercury, methylmercury, ethylmercury, and phenylmercury, is reported. The effective mobilities of organomercury in aqueous and nonaqueous electrolytes were compared. Imidazole was confirmed not only as a co-ion for the separation but also as an online complexing reagent for mercury species. The optimum conditions for separation were achieved by using methanol solvent containing 0.15 M acetic acid and 15 mM imidazole as electrolyte. The sensitive detection of mercury species was accomplished at 191 nm.