Search

Copyright of Microbiological Journal / Mikrobiolohichnyi Zhurnal is the property of D.K. Zabolotny Institute of Microbiology & Virology of the National Academy of Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The procedure of the T-2 and НT-2 toxins determination in wheat grain was developed by high performance liquid chromatography according to the following criteria: specificity, linearity, limits of detection (LOD), limits of quantification (LOQ), trueness (recovery), precision, stability. It was found that the correlation coefficient (R²) for T-2 and HT-2 toxin was 0.9999. Mean recoveries from (R, %) for T-2 and HT-2 toxin at the level of 50-150 μg·kg-1 from wheat (sample blank) were 91 and 87 %, respectively. The relative standard deviation (RSD, %) of the measurement results under conditions of repeatability and intra-laboratory precision ranged from 0.23 to 3.93 %. The limits of quantification of the method for T-2 and HT-2 toxin was 2.2 and 1.2 μg·kg-1, respectively. These data are within the range of acceptable minimum levels in accordance with Commission Regulation (EC) No 401/2006. It is confirmed that the standards of T-2, HT2 toxins in solutions can be stored up to 7 days in a freezing chamber, a refrigerator and at room temperature in a tightly closed container without actual loss of concentration. It was found that T-2 and НT-2 in a solution cannot be stored in a lit place, because according to the data obtained, sunlight leads to the destruction of these mycotoxins by 52 % and 59 %, respectively. [ABSTRACT FROM AUTHOR]

The purpose of the work was to investigate the qualitative and quantitative composition of Escherichia coli and Staphylococcus aureus lipids after exposure to disinfectants. Methods. Quantitative and Qualitative composition of total lipids and phospholipids were identified using method of thin layer chromatography. Disinfectants Barez® (active ingredients: essential oils, benzalkonium chloride, nanoparticles of argentum), Biochlor® (sodium hypochlorite), Geocide® (benzalkonium chloride; polyhexamethylene guanide hydrochloride, deltametrin), were used according to manufacturer’s recommendations. For this test, 0.5 ml of disinfectants (0.1 % Barez®, 0.1 % Biochlor®, 0.5 % Geocide®) were added into 3 ml of cell suspension (5×108 cell/ml). Controls were the cells nontreated with disinfectants. Cells suspensions were incubated in standard conditions for 1 hour. Results. The influence of disinfectants on the lipid composition of E. coli and S. aureus after the action of Barez®, Biochlor and Geocide was studied. Changes of quantitative and qualitative composition of the lipids containment were identified. Barez® had the most notable effect on quantitative and qualitative composition of total lipids and phospholipids. It was confirmed that reduction of total quantity of several phospholipids results to increased level of diglycerides. These data allow us to establish the sensitivity of microorganisms to the influence of disinfectants and to determine the optimal concentrations and exposure of disinfectants for high quality disinfection. Conclusions. It has been established that the disinfectants Barez®, Biochlor® and Geocide® cause significant changes in the lipid composition of E. coli and S. aureus cells, which leads to increased fluidity of cell membranes and loss of viability of bacteria. [ABSTRACT FROM AUTHOR]