The aim of this study was to investigate the possibility of using essential oils of Thymus vulgaris as an alternative preservative for chromed leather. The differences between the chemical composition of commercial and pure essential oils of thyme were determined. It was observed that these differences have an influence on the antibacterial activity of essential oils. Gram-positive bacteria were found to be more sensitive to the essential oils of thyme than Gram-negative bacteria. The bacteria Pseudomonas aeruginosa had a low sensitivity to the action of the selected essential oils of thyme, but the leather samples treated with the essential oils of thyme remained resistant to the action of these bacteria. As the main result of this study, it was concluded that the essential oil of thyme could be used as a preservation agent in the leather tanning industry. The leather preserved with 2-(thiocyanomethylthio)benzothiazole had weaker protection after four weeks compared to the samples treated with the essential oil of thyme when the amount of the used essential oil was not less than 3% of the wet-blue mass. The essential oil of thyme was the more active component in the mixture of essential oil and synthetic biocide used for the preservation of leather.

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The p-aminobenzoic acid was applied for the synthesis of substituted 1-phenyl-5-oxopyrrolidine derivatives containing benzimidazole, azole, oxadiazole, triazole, dihydrazone, and dithiosemicarbazide moieties in the structure. All the obtained compounds were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, and Pseudomonas aeruginosa by using MIC and MBC assays. This study showed a good bactericidal activity of γ-amino acid and benzimidazoles derivatives. The antimicrobial activity of the most promising compounds was higher than ampicillin. Furthermore, two benzimidazoles demonstrated good antimicrobial activity against L. monocytogenes (MIC 15.62 µg/mL) that was four times more potent than ampicillin (MIC 65 µg/mL). Further studies are needed to better understand the mechanism of the antimicrobial activity as well as to generate antimicrobial compounds based on the 1-phenyl-5-oxopyrrolidine scaffold.

Bovine respiratory disease caused by Mycoplasma bovis is a major health problem of cattle worldwide. It inflicts considerable financial losses on beef herds and is the most common cause of mortality in dairy cattle. Bacteriological examination of 35 nasal cavity samples from calves younger than three months of age identified Mycoplasma bovis in eight (22.9%) samples. These cattle were followed until 17 months of age, and repeated examination of nasal cavity samples before necropsy identified Mycoplasma bovis in four (11.4%) samples. At necropsy and lung samples for bacteriological and histological examination were collected. To identify microorganisms from the Mollicutes class isolated from the nasal cavities of cattle we used the PCR method. Furthermore, Mycoplasma bovis was identified on the grounds of biochemical characteristics and by the disk growth inhibition test. The organism was found in 5.7% of calves younger than three months of age in combination with Pasteurella spp. Mycoplasma bovis in combination with Pasteurella multocida and Mannheimia haemolytica was isolated from 5.7% and 2.9% of cattle at 17 months. However, Pasteurella multocida was common in cattle at 17 months and Mannheimia haemolytica was isolated from both age groups of cattle. Histopathological examination of lung samples revealed broncho-interstitial pneumonia in 14.3% of samples. Mycoplasma bovis was isolated from 60.0% of broncho-insterstitial pneumonia cases. The organism was isolated more frequently from the group of calves rather than from the cattle group (P < 0.05). The most common bacterial agents were Pasteurella multocida and Mannheimia haemolytica.

New N,N-disubstituted β-amino acids and their derivatives with thiazole, aromatic, and heterocyclic substituents were synthesized from N-phenyl-N-thiocarbamoyl-β-alanine by the Hantzsch method; derivatives with hydrazone fragments were also obtained. Some of the synthesized compounds exhibited discrete antimicrobial activity, and 3-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl)(phenyl)amino]propanoic acid was found to promote rapeseed growth and to increase seed yield and oil content.