The aim: To obtain the first estimates data on the occurrence of antibiotic-resistant bacteria in a wide range of fresh vegetables available in the Kyiv city markets. Materials and methods: We performed a multicenter study. Fresh vegetables samples were collected of the six different commodity groups from eleven of retail stores locatedin Kyiv, Ukraine. Samples were tested for up to eight bacteria of concern. The susceptibility to antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing. Results: The antibiotic-resistant bacteria contamination in the fresh vegetables was 24.3%. The contamination among organic produce was significantly higher than in conventionally products. Contamination was found to be higher in leafy vegetables. The predominant contaminated bacteria were: Escherichia coli, Enterobacter spp. And Enterococcus faecalis, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, E. faecium, Staphylococcus aureus and Acinetobacter spp. The overall proportion of extended spectrum beta-lactamase (ESBL) production among Enterobacteriaceae was 36.8% and of methicillin-resistance in S. aureus (MRSA) 10.7%. The prevalence of ESBL production among E. coli isolates was significantly higher than in K. pneumoniae. Vancomycin resistance was observed in 3.1% of isolated enterococci (VRE). Carbapenem resistance was identified in 35.3% of P.aeruginosa isolates and 66.8% of Acinetibacter spp. isolates. Resistance to third-generation cephalosporins was observed in 9.7% K. pneumoniae and E.coli in 14.2% isolates. Conclusions: Research has shown that the majority of fresh vegetables available in Kiev markets is contaminated with antibiotic-resistant bacteria and is a potential vehicle for the transmission of these pathogens to consumers.

One of the modern antibacterial agents that are an alternative to antibiotics are nanoparticles of noble metals, including silver. To reduce their toxicity, cumulative effect and prolong the effect in animals, there is ongoing work on development and improvement of the methods for their synthesis using various carriers, including those based on polymer/inorganic hybrids. In this study, the quality and safety of edible eggs were determined on Hy-Line laying hens using W36 solutions of nanosilver in carriers based on polymer/inorganic hybrids (AgNPs/SPH) in the concentration of 0.0, 1.0 and 2.0 mg/L of water (0.0, 0.2 and 0.4 mg per hen per day) three times with 10 day interval. We determined that one-, two- and three-time feeding of nanosilver in doses of 0.0, 0.2 and 0.4 mg per hen per day did not affect water consumption, feed, egg productivity, as well as dry matter content, crude protein, fat, ash, and calcium and phosphorus in eggs for 30 days. Contamination of the surface of the shell and yolks of eggs with mesophilic aerobic and facultative anaerobic microorganisms (MAFAnM) did not depend on the dose and duration of consumption of the nanosilver drug by laying hens. The nanosilver drug in doses of 0.0, 0.2 and 0.4 mg per hen per day did not affect the contamination of the egg shell surface with microorganisms of genera Citrobacter, Klebsiella, as well as Escherichia coli, Proteus mirabilis, Salmonella spp., Staphylococcus aureus and S. epidermidis. When administered orally, nanosilver in the dose of 0.2 mg per hen per day did not change the number of symbiotic microorganisms of genera Bifidobacterium and Lactobacillus, while and the dose of 0.4 mg per hen daily slightly reduced the number of microorganisms of genus Lactobacillus in the hens’ manure. The obtained data can be used for further research to determine the effective dose and interval of application of nanosilver preparations to poultry for preventive and therapeutic measures, taking into account the preservation of the microbiome of the digestive system of hens.

Cow mastitis is a polyetiological disease involving pathogenic microorganisms. Antibiotics are used to treat sick animals, which contributes to the development of resistant clones of bacteria, and consumption of the corresponding milk leads to the spread of antibiotic-resistant microorganisms. The purpose of the work is to determine strains of antibiotic-resistant bacteria in the milk of cows suffering from subclinical mastitis. Bacteriological studies of mammary gland secretion samples were performed by inoculating the sediment obtained after centrifugation of the examined material on an agarised nutrient medium (with 5% ram erythrocytes). The study of antimicrobial sensitivity was performed by the disk diffusion method. It was established that pathogens with multiple resistance to antibiotics circulate among cows suffering from mastitis on the farm, which indicates their indiscriminate use in animal therapy schemes, in particular mastitis. It was found that the overall level of phenotypic resistance to antimicrobial agents of the examined isolates was within 19-33% (in Staphylococcus spp. – 19.9%, in E. coli – 33.2%, in Enterococcus spp. – 32.5%). The analysis of the results allowed assigning the culture study to the category of multiresistant: 31.6% of cultures of Staphylococcus spp. demonstrated resistance to five groups of antibiotics; 54.5% of Escherichia cultures – up to five groups of antibiotics; 37.5% of cultures of Enterococcus spp. resistant to three groups of antibiotics. It was established that 100% of the studied cultures of Staphylococcus spp. are sensitive to netilmicin, sparfloxacin, gatifloxacin and clarithromycin. Therewith, 100% of the examined cultures of Enterococcus spp. sensitive to gentamicin, norfloxacin, and nitrofurantoin, and 100% of the examined E. coli cultures were sensitive to cephalothin, meropenem, gentamicin, tobramycin, amikacin, nitroxoline, and gatifloxacin. Thus, dairy cows suffering from subclinical mastitis are a source of bacteria with multiple resistance to antibiotics and carry risks for consumers due to the consumption of dairy products contaminated with pathogens of zoonotic diseases, which requires proper control by veterinary service specialists

A significant number of microorganisms in natural and artificial environments exist in a structured formation – biofilm. This formation attaches to a certain surface, particularly the epithelium. The ability to form a similar structure has been observed in Pasteurella multocida, the causative agent of anthropozoonoses that affect domestic and wild animals, birds, companion animals and humans. The spectrum of pathogenetic action of P. multocida is wide and associated with the development of respiratory and multisystemic pathology, bacteraemia and other manifestations. Timely detection of P. multocida and treatment of the diseases it causes in farm and domestic animals is important to limit economic losses and improve social security. The main objective of this study was to determine the pathogenicity of P. multocida, its ability to form a biofilm, its resistance to antibiotics, and to identify the genes responsible for the formation of dermonecrotic toxin and biofilm formation. The paper presents the results of a study of 11 isolates of P. multocida: six isolates (54.5%) from rabbits, two isolates (18.2%) from dogs, two isolates (18.2%) from cats, and one isolate from pigs (9.2%). In all isolates, the gene ptfA was detected. This gene encodes the formation of type 4 fimbriae and participates in the formation of the biofilm, and the studied cultures in vitro formed a biofilm of different densities. The genome of eight isolates (72.7%) included the toxA gene (provides the formation of dermonecrotic toxin), while 45.4% of isolates had a complete set of the studied signs of pathogenicity, both in phenotypic (biofilm formation, mortality for laboratory animals) and genotypic (presence of toxA, ptfA) traits, and three isolates (27.3%) showed signs of multidrug resistance. The virulence of the toxA-negative isolates of P. multocida was lower than in toxA-positive isolates. The culture with the highest virulence (0.5x 101 CFU) and extreme resistance to antibiotics formed a biofilm of the highest density. The association of the gene in the biofilm-producing mechanism needs further evaluation, and further research is needed to identify the relationships between pathogens in Pasteurella multocida isolates from different species of animals and humans.

Today, the most appropriate way of long-term storage of most microorganism strains in collec ons is their lyophiliza on. The rate and quality of the recovery of biological proper es in lyophilized bacterial cultures depend on the quality of culture media used for this purpose. The purpose of this study was to inves gate the effec veness of culture media for the recovery of lyophilized pathogenic bacteria.The strains of Salmonella typhimurium, Pasteurella multocida, Yersinia pseudotuberculosis, and Staphylococcus aureus from the collec on of the