Detection of bovine milk adulteration in caprine milk with N-acetyl carbohydrate biomarkers by using 1H nuclear magnetic resonance spectroscopy.

In a return to tradition, the popularity of caprine milk is on the rise. However, particularly in countries with developed dairy industries based on bovine milk, there is the risk of adulteration with bovine milk, which is a cheaper alternative. Thus, a rapid, robust, and simple method for the detection of bovine milk added to caprine milk is necessary, and 1H nuclear magnetic resonance spectroscopy appears to provide a solution. A matrix of 115 pure and artificially adulterated pasteurized milk samples was prepared and used to discover biomarkers of bovine milk that are independent of chemical and biological variation caused by factors such as genetics, diet, or seasonality. Principal component analysis and orthogonal projections to latent structures discriminant analysis of pure bovine milk and pure caprine milk revealed spectral features that were assigned to the resonances of 4 molecules. Of these, the peaks corresponding to protons in the N-acetylglucosamine and N-acetylgalactosamine acetyl moieties showed significant applicability for our method. Receiver operating characteristic curve analysis was used to evaluate the performance of the peak integrals as biomarkers of adulteration. This approach was able to distinguish caprine milk adulterated with 5% of bovine milk with 84.78% accuracy and with 10% of bovine milk an excellent 95.65% accuracy. This study demonstrates that N-acetyl carbohydrates could be used as biomarkers for the detection of bovine milk in caprine milk and could help in protecting caprine milk authenticity.

[In vitro activity of chemotherapeutic agents on the most common bacterial agents causing urinary infections]. / Soucasná aktivita chemoterapeutik in vitro u nejcastejsích bakteriálních agens vyvolávajících mocové infekce.

The authors made an investigation of the contemporary position as regards the effectiveness of chemotherapeutic agents used for treatment of infections of the urinary pathways caused by the most frequently found infectious agents in out-patients, small Prague hospitals and the University hospital in Prague-Motol. The dominating infectious agent causing urinary infections remains E. coli. A serious feature is the increase of enterococcal infections in hospitals. As to the antibacterial effect, a dominant position is held by furantoin, in enterococcal infections in hospitals. high antibacterial activity of fluoroquinolones is, however, also associated with the responsibility to use them rationally.