Preparation of Antimicrobial Agents: From Interpolyelectrolyte Complexes to Silver-Containing Metal-Polymer Complexes and Nanocomposites.

In order to control pathogenic microorganisms, three polymer compositions were prepared and tested. First, a water-soluble positively charged polycomplex was synthesized via the electrostatic binding of anionic polyacrylic acid to an excess of polyethylenimine to enhance the biocidal activity of the polycation. Second, an aqueous solution of AgNO was added to the polycomplex, thus forming a ternary polycation-polyanion-Ag complex with an additional antimicrobial effect.

Additive Nanosecond Laser-Induced Forward Transfer of High Antibacterial Metal Nanoparticle Dose onto Foodborne Bacterial Biofilms.

Additive laser-induced forward transfer (LIFT) of metal bactericidal nanoparticles from a polymer substrate directly onto food bacterial biofilms has demonstrated its unprecedented efficiency in combating pathogenic microorganisms. Here, a comprehensive study of laser fluence, metal (gold, silver and copper) film thickness, and the transfer distance effects on the antibacterial activity regarding biofilms of Gram-negative and Gram-positive food bacteria (, , , , spp.) indicated the optimal operation regimes of the versatile modality.

Microbial Biofilms at Meat-Processing Plant as Possible Places of Bacteria Survival.

Biofilm contamination in food production threatens food quality and safety, and causes bacterial infections. Study of food biofilms (BF) is of great importance. The taxonomic composition and structural organization of five foods BF taken in different workshops of a meat-processing plant (Moscow, RF) were studied.

Evaluation of Antibiotic Resistance of Serotypes and Whole-Genome Sequencing of Multiresistant Strains Isolated from Food Products in Russia.

Food products may be a source of , one of the main causal agents of food poisoning, especially after the emergence of strains resistant to antimicrobial preparations. The present work dealt with investigation of the occurrence of resistance to antimicrobial preparations among strains isolated from food. The isolates belonged to 11 serovars, among which Infantis (28%), Enteritidis (19%), and Typhimurium (13.

Diversity of Strains Isolated from Food Products in the Central European Part of Russia in 2000-2005 and 2019-2020.

Totally, 45 strains isolated from meat, poultry, dairy, and fish products in the Central European part of Russia in 2001-2005 and 2019-2020 were typed using a combined MLST and internalin profile (IP) scheme. Strains belonged to 14 clonal complexes (CCs) of the phylogenetic lineages I and II. Almost half of the strains (20 of 45) belonged to six CCs previously recognized as epidemic clones (ECs).

Spectrally-selective mid-IR laser-induced inactivation of pathogenic bacteria.

Micrometer-thick layers of bacteria were prepared on fluorite substrates and scanned by focused mid-IR femtosecond laser radiation that was spectrally tuned to achieve the selective excitation of either the stretching C-H vibrations (3 μm), or stretching C = O, C-N vibrations (6 μm) of the amide groups in the bacteria. The enhanced biocidal efficiency of the latter selective excitation, compared to the more uniform 3-μm laser excitation, was demonstrated by performing viability assays of laser-treated bacterial layers. The bacterial inactivation by the 6-μm ultrashort laser pulses is attributed to dissociative denaturation of lipids and proteins in the cell membranes and intra-cell nucleic acids.

Antimicrobial Resistance of Strains Isolated from Humans, Animals, and Food Products in Russia in 1950-1980, 2000-2005, and 2018-2021.

Susceptibility of 117 strains isolated during three time periods (1950-1980; 2000-2005, and 2018-2021) to 23 antibiotics was tested by the disk diffusion method. All strains were sensitive to aminoglycosides (gentamicin, kanamycin, neomycin, streptomycin), glycopeptides (vancomycin and teicoplanin), clarithromycin, levofloxacin, amoxicillin/clavulanic acid, and trimethoprim/sulfamethoxazole. Resistance to clindamycin was observed in 35.