Antibiotic resistance in the pathogenic bacteria isolated from environmental samples of the food production facilities

Foodborne pathogens, such as Salmonella spp. and Listeria monocytogenes, may be present at various stages of production. The overuse of antibiotics over the past few decades has led to the emergence of many antibiotic-resistant bacteria, including foodborne pathogens. We investigated the sensitivity of Salmonella spp and Listeria monocytogenes to various antibiotics. Studied strains of L. monocytogenes and Salmonella spp. they showed resistance to tetracycline, which totaled 66.7%. High resistance of strains to ampicillin was also noted (57.14%). All strains were sensitive to amikacin, azithromycin, Meropenem, ciprofloxacin, moxifloxacin, norfloxacin. All strains of Salmonella spp. were resistant to ampicillin and penicillin G. Resistance to streptomycin and trimethoprim/sulfamethoxazole was 91.7%. All strains of L. monocytogenes were resistant to nalidixic acid. 22.2% of the strains showed resistance to tetracycline and cefepime. 11.1% of the strains were resistant to chloramphenicol and trimethoprim/sulfamethoxazole

Studying the Impact of the Genetic Polymorphisms of Chemokines on the Arterial Pressure Level and Kidney Function in Patient with the Chronic Glomerulonephritis

ABSTRACT The associations of polymorphisms of the chemokine genes (+1931А/Т MIP1β, A/G I-TAC (rs4512021), -403A/G RANTES, C/G MCP1 (rs2857657), -801G/A SDF1) with arterial hypertension and renal insufficiency were investigated in 238 patients with chronic glomerulonephritis and 462 individuals of the control group. It has been established that the genetic marker А I-TAC (rs 4512021) is the risk factor for genesis of the severe arterial hypertension at the chronic glomerulonephritis (OR=1,65) and the genotypes АА and AG I-TAC are the risk factors of depression of the kidney function

Ultra-performance liquid chromatography-mass spectrometry for precise fatty acid profiling of oilseed crops

Oilseed crops are one of the most important sources of vegetable oils for food and industry. Nutritional and technical properties of vegetable oil are primarily determined by its fatty acid (FA) composition. The content and composition of FAs in plants are commonly determined using gas chromatography-mass spectrometry (GS-MS) or gas chromatography-flame ionization detection (GC-FID) techniques. In the present work, we applied ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) technique to FA profiling of sunflower and rapeseed seeds and compared this method with the GC-FID technique. GC-FID detected 11 FAs in sunflower and 13 FAs in rapeseed, while UPLC-MS appeared to be more sensitive, detecting about 2.5 times higher numbers of FAs in both plants. In addition to even-chain FAs, UPLC-MS was able to detect odd-chain FAs. The longest FA detected using GC-FID was an FA with 24 carbon atoms, whereas UPLC-MS could reveal the presence of longer FAs with the tails of up to 28 carbon atoms. Based on our results, we may conclude that UPLC-MS has great potential to be used for the assessment of FA profiles of oil crops

Antibiotic resistance in the pathogenic bacteria isolated from environmental samples of the food production facilities

Foodborne pathogens, such as Salmonella spp. and Listeria monocytogenes, may be present at various stages of production. The overuse of antibiotics over the past few decades has led to the emergence of many antibiotic-resistant bacteria, including foodborne pathogens. We investigated the sensitivity of Salmonella spp and Listeria monocytogenes to various antibiotics. Studied strains of L. monocytogenes and Salmonella spp. they showed resistance to tetracycline, which totaled 66.7%. High resistance of strains to ampicillin was also noted (57.14%). All strains were sensitive to amikacin, azithromycin, Meropenem, ciprofloxacin, moxifloxacin, norfloxacin. All strains of Salmonella spp. were resistant to ampicillin and penicillin G. Resistance to streptomycin and trimethoprim/sulfamethoxazole was 91.7%. All strains of L. monocytogenes were resistant to nalidixic acid. 22.2% of the strains showed resistance to tetracycline and cefepime. 11.1% of the strains were resistant to chloramphenicol and trimethoprim/sulfamethoxazole

The role of monitoring production environment facilities to support microbiological safety and food quality in meat processing plants

The results of many studies prove the microbiota of the surfaces of the production environment can be a source of food contamination. Environmental monitoring allows to identify problem areas in the enterprise and take corrective actions to eliminate them. This work is conducted to the analysis of the microbiota of abiotic objects selected in the area of close proximity to food products at a pork processing plant by sequencing the 16S RNA gene. The phylum Proteobacteria (from 37.7 to 73.6%), Firmicutes (from 0.14 to 18.6%), Bacteroidota and Actinobacteriota were the dominant components of the microbial communities of the meat processing enterprise. Bacteria of the genus Pseudomonas were found in all samples, the number of readings of these bacteria ranged from 1.90% to 28.76% of the total number of readings. Bacteria of the genus Brochotrix were found in samples from 0.02% to 2.75%. The identification of this phylum indicates the potential presence of pathogenic microorganisms and spoilage microorganisms at production facilities, which can negatively affect the quality and safety of food products

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. Samples were taken from the surface of technological equipment and premises. Metagenomic analysis showed both similarities in the presented microorganisms dominating in different samples, and unique families prevailing on certain objects were noted. The bacteria found belonged to 11 phyla (no archaea). The dominant ones were Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The greatest diversity was in BFs taken from the cutting table of raw material. Biofilms’ bacteria may be the cause of meat, fish and dairy products spoilage possible representatives include Pseudomonas, Flavobacterium, Arcobacter, Vagococcus, Chryseobacterium, Carnobacterium, etc.). Opportunistic human and animal pathogens (possible representatives include Arcobacter, Corynebacterium, Kocuria, etc.) were also found. Electron-microscopic studies of BF thin sections revealed the following: (1) the diversity of cell morphotypes specific to multispecies BFs; (2) morphological similarity of cells in BFs from different samples, micro-colonial growth; (3) age heterogeneity of cells within the same microcolony (vegetative and autolyzed cells, resting forms); (4) heterogeneity of the polymer matrix chemical nature according to ruthenium red staining

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

Susceptibility of 117 L. monocytogenes 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 35.5% of strains. Resistance to carbapenems, imipenem and meropenem was found in 4% and 5% of strains, respectively. Resistance to erythromycin, penicillin G, trimethoprim, and ciprofloxacin was found in 4%, 3%, 3%, and 2.5% of strains, respectively. Resistance to tylosin, ampicillin, enrofloxacin, linezolid, chloramphenicol, and tetracycline was found in less than 2%. Three strains with multiple antibiotic resistance and 12 strains with resistance to two antibiotics were revealed. Comparison of strains isolated in different time periods showed that the percentage of resistant strains was the lowest among strains isolated before 1980, and no strains with multiple antibiotic resistance were found among them. Statistical analysis demonstrated that the temporal evolution of resistance in L. monocytogenes has an antibiotic-specific character. While resistance to some antibiotics such as ampicillin and penicillin G has gradually decreased in the population, resistance to other antibiotics acquired by particular strains in recent years has not been accompanied by changes in resistance of other strains

Diversity of Listeria monocytogenes Strains Isolated from Food Products in the Central European Part of Russia in 2000–2005 and 2019–2020

Totally, 45 L. monocytogenes 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). ECI and ECV strains were isolated during both studied periods, and ECII, ECIV, ECVI, and ECVII strains were isolated in 2001–2005, but not in 2019–2020. ECI, ECIV, ECV, and ECVII strains were isolated from products of animal origin. ECII and ECVI were isolated from fish. Testing of invasion efficiencies of 10 strains isolated in different years and from different sources and belonging to distinct CCs revealed a statistically significant difference between phylogenetic lineage I and II strains but not between ECs and non-EC CCs or strains differing by year and source of isolation. Strains isolated in 2001–2005 were characterized by higher phylogenetic diversity and greater presentation of ECs and CCs non-typical for natural and anthropogenic environments of the European part of Russia comparatively to isolates obtained in 2019–2020.Closing of the Russian market in 2019–2020 for imported food might be responsible for these differences

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

Food products may be a source of Salmonella, 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 S. enterica strains isolated from food. The isolates belonged to 11 serovars, among which Infantis (28%), Enteritidis (19%), and Typhimurium (13.4%) predominated. The isolates were most commonly resistant to trimethoprim/sulfamethoxazole (n = 19, 59.38%), cefazolin (n = 15, 46.86%), tetracycline (n = 13, 40.63%), and amikacin (n = 9, 28.13%). Most of the strains (68.75%) exhibited multiple resistance to commonly used antibiotics. High-throughput sequencing was used to analyse three multidrug-resistant strains (resistant to six or more antibiotics). Two of them (SZL 30 and SZL 31) belonged to S. Infantis, while one strain belonged to S. Typhimurium (SZL 38). Analysis of the genomes of the sequenced strains revealed the genes responsible for antibiotic resistance. In the genomes of strains SZL 30 and SZL 31 the genes of antibiotic resistance were shown to be localized mostly in integrons within plasmids, while most of the antibiotic resistance genes of strain SZL 38 were localized in a chromosomal island (17,949 nt). Genomes of the Salmonella strains SZL 30, SZL 31, and SZL 38 were shown to contain full-size pathogenicity islands: SPI-1, SPI-2, SPI-4, SPI-5, SPI-9, SPI-11, SPI-13, SPI-14, and CS54. Moreover, the genome of strain SZL 38 was also found to contain the full-size pathogenicity islands SPI-3, SPI-6, SPI-12, and SPI-16. The emergence of multidrug-resistant strains of various Salmonella serovars indicates that further research on the transmission pathways for these genetic determinants and monitoring of the distribution of these microorganisms are necessary

Preparation of Biocidal Nanocomposites in X-ray Irradiated Interpolyelectolyte Complexes of Polyacrylic Acid and Polyethylenimine with Ag-Ions

Due to the presence of cationic units interpolyelectrolyte complexes (IPECs) can be used as a universal basis for preparation of biocidal coatings on different surfaces. Metallopolymer nanocomposites were successfully synthesized in irradiated solutions of polyacrylic acid (PAA) and polyethylenimine (PEI), and dispersions of non-stoichiometric IPECs of PAA–PEI containing silver ions. The data from turbidimetric titration and dynamic light scattering showed that pH 6 is the optimal value for obtaining IPECs. Metal polymer complexes based on IPEC with a PAA/PEI ratio equal to 3/1 and 1/3 were selected for synthesis of nanocomposites due to their aggregative stability. Studies using methods of UV–VIS spectroscopy and TEM have demonstrated that the size and spatial organization of silver nanoparticles depend on the composition of polymer systems. The average sizes of nanoparticles are 5 nm and 20 nm for complexes with a molar ratio of PAA/PEI units equal to 3/1 and 1/3, respectively. The synthesized nanocomposites were applied to the glass surface and exhibited high antibacterial activity against both gram-positive (Staphylococcus aureus) and gram-negative bacteria (Salmonella). It is shown that IPEC-Ag coatings demonstrate significantly more pronounced biocidal activity not only in comparison with macromolecular complexes of PAA–PEI, but also coatings of PEI and PEI based nanocomposites