BACKGROUND: Bovine mastitis is one of the main causes of reduced production in dairy cows. The infection of the mammary gland is mainly caused by the bacterium Staphylococcus aureus, whose resistant strains make the treatment of mastitis with conventional antibiotics very difficult and result in high losses. Therefore, it is important to develop novel therapeutic agents to overcome the resistance of mastitis-causing strains. In this study, novel selenium-tellurium based nanoparticles (SeTeNPs) were synthesized and characterized. Their antibacterial activity and biocompatibility were evaluated both in vitro and in vivo using a bovine model. A total of 10 heifers were divided into experimental and control groups (5 animals each). After intramammary infection with methicillin resistant S. aureus (MRSA) and the development of clinical signs of mastitis, a dose of SeTeNPs was administered to all quarters in the experimental group. RESULTS: Based on in vitro tests, the concentration of 149.70 mg/L and 263.95 mg/L of Se and Te, respectively, was used for application into the mammary gland. Three days after SeTeNPs administration, MRSA counts in the experimental group showed a significant reduction (P < 0.01) compared to the control group. The inhibitory effect observed within the in vitro experiments was thus confirmed, resulting in the suppression of infection in animals. Moreover, the superior biocompatibility of SeTeNPs in the organism was demonstrated, as the nanoparticles did not significantly alter the inflammatory response or histopathology at the site of application, i.e., mammary gland, compared to the control group (P > 0.05). Additionally, the metabolic profile of the blood plasma as well as the histology of the main organs remained unaffected, indicating that the nanoparticles had no adverse effects on the organism. CONCLUSIONS: Our findings suggest that SeTeNPs can be used as a promising treatment for bovine mastitis in the presence of resistant bacteria. However, the current study is limited by its small sample size, making it primarily a proof of the concept for the efficacy of intramammary-applied SeTeNPs. Therefore, further research with a larger sample size is needed to validate these results.

• Klíčová slova
• Antibacterial, Biocompatibility, Heifer, Intramammary, MRSA, Mammary gland, Nanomaterial, Resistance, SeTe,
• Publikační typ
• časopisecké články MeSH

Bacterial skin diseases of livestock could be a serious global threat, especially in association with overcoming bacterial resistance. Combinatory action of antimicrobial agents proves to be an effective strategy to overcome the problem of increasing antibiotic resistance of microorganisms. In this study, the in vitro combined effect of zinc pyrithione with gentamicin against bacterial skin pathogens of livestock (Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae) was evaluated according to the sum of fractional inhibitory concentration indices (FICI) obtained by checkerboard method. The results showed that a combination of zinc pyrithione with gentamicin produced a strong synergistic effect (p < 0.001) against all tested streptococcal strains (with FICI values ranging from 0.20 to 0.42). Compared to that, only three out of eight S. aureus strains were highly susceptible to the combination of antimicrobial agents at single concentration (0.25 µg/mL) of zinc pyrithione with range of FICI 0.35−0.43. These findings suggest that interference between agents tested in this study can be used for the development of future veterinary pharmaceutical preparations for the treatment of bacterial skin infections of livestock.

• Klíčová slova
• antimicrobial interaction, checkerboard microdilution method, fractional inhibitory concentration, gentamicin, zinc pyrithione,
• Publikační typ
• časopisecké články MeSH

The review presents prenylated flavonoids as potential therapeutic agents for the treatment of topical skin infections and wounds, as they can restore the balance in the wound microenvironment. A thorough two-stage search of scientific papers published between 2000 and 2022 was conducted, with independent assessment of results by two reviewers. The main criteria were an MIC (minimum inhibitory concentration) of up to 32 µg/mL, a microdilution/macrodilution broth method according to CLSI (Clinical and Laboratory Standards Institute) or EUCAST (European Committee on Antimicrobial Susceptibility Testing), pathogens responsible for skin infections, and additional antioxidant, anti-inflammatory, and low cytotoxic effects. A total of 127 structurally diverse flavonoids showed promising antimicrobial activity against pathogens affecting wound healing, predominantly Staphylococcus aureus strains, but only artocarpin, diplacone, isobavachalcone, licochalcone A, sophoraflavanone G, and xanthohumol showed multiple activity, including antimicrobial, antioxidant, and anti-inflammatory along with low cytotoxicity important for wound healing. Although prenylated flavonoids appear to be promising in wound therapy of humans, and also animals, their activity was measured only in vitro and in vivo. Future studies are, therefore, needed to establish rational dosing according to MIC and MBC (minimum bactericidal concentration) values, test potential toxicity to human cells, measure healing kinetics, and consider formulation in smart drug release systems and/or delivery technologies to increase their bioavailability.

• Klíčová slova
• MRSA, S. aureus, anti-inflammatory, antibacterial, antioxidant, cytotoxicity, mastitis, nanotechnology, prenylated flavonoids, skin, wound healing,
• MeSH
• antibakteriální látky farmakologie   MeSH
• antiinfekční látky * farmakologie   MeSH
• antioxidancia * farmakologie   MeSH
• flavonoidy farmakologie   MeSH
• hojení ran MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• antiinfekční látky * MeSH
• antioxidancia * MeSH
• flavonoidy MeSH

Staphylococcus aureus is an important pathogen of humans and animals. The aim of this study was to characterize 71 of S. aureus isolates from raw cow milk in southern Xinjiang of China, including molecular typing, distribution of virulence genes, and antimicrobial susceptibility. The isolates belonged to 18 sequence types (STs) (including 11 novel STs) and 6 spa types which were divided into five different clonal complexes (CCs), including CC188, CC352, CC22, CC398, and CC5406. The majority of the strains was grouped into multilocus sequence typing (MLST) CC188 (n = 41), t189 (n = 40), and ST5796 (n = 17). Only 30.9, 12.7, 11.3, and 9.9% of the isolates were resistant to erythromycin, clindamycin/norfloxacin, tetracycline, and gentamicin, respectively. Nine of multidrug resistant (MDR) isolates were observed which was associated with CC398-t2876. The adhesion molecules clfa, clfb, and hlb were most frequently detected with the percentage rate of 98.6% (70/71), 98.6% (70/71), and 90.1% (64/71), respectively. The percentage rates of the staphylococcal enterotoxin genes sea, seb, sec, sed, seg, and sei in S. aureus isolates were 5.6, 19.8, 40.8, 1.4, 49.3, and 30.9%, respectively. The see, seh, and sej genes were not found. This study provides data about the occurrence of S. aureus in raw cow milk, revealing high carriage frequency, drug resistance, and population structure of S. aureus. Furthermore, this study suggests that effective hygienic measures be taken when handling dairy cows, in order to prevent spreading MDR strains to human through direct contact and/or consumption of contaminated food.

• MeSH
• antibakteriální látky farmakologie   MeSH
• antibiotická rezistence MeSH
• enterotoxiny genetika   MeSH
• methicilin rezistentní Staphylococcus aureus * MeSH
• mléko MeSH
• multilokusová sekvenční typizace MeSH
• skot MeSH
• stafylokokové infekce * epidemiologie   veterinární   MeSH
• Staphylococcus aureus MeSH
• virulence genetika   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Čína MeSH
• Názvy látek
• antibakteriální látky MeSH
• enterotoxiny MeSH

Mastitis in dairy cows is generally considered to be the most expensive disease for dairy farmers worldwide. The overuse of antibiotics is a major problem in the treatment of bovine mastitis, and bacteriophage therapy is expected to provide an alternative treatment. The primary aim of this study was to evaluate the efficacy of a phage cocktail against mastitis in a mouse model. First, a Staphylococcus aureus strain was isolated from milk samples taken from mastitis cows from dairy farms in Xinjiang, China, and it was designated as Sau-XJ-21. Next, two phages (designated as vBSM-A1 and vBSP-A2) with strong lytic activity against Sau-XJ-21 were isolated from mixed sewage samples collected from three cattle farms in Xinjiang. Phages vBSM-A1 and vBSP-A2 were identified as members of the Myoviridae and Podoviridae families, respectively. The two phages exhibited a wide range of hosts, especially phage vBSM-A1. To evaluate the effectiveness of the two phages in the treatment against mastitis, female lactating mice were used 10-14 days after giving births. The mice were divided into six groups; one group was kept as healthy control, while the remaining five groups were inoculated with the isolated S. aureus strain to induce mastitis. Four hours after bacterial inoculation, mice in these groups were injected with 25 μL phosphate buffer saline (negative control), ceftiofur sodium (positive control), or phage, either individually or as a cocktail. The mice were sacrificed 20 h later, and the mammary glands were removed and subjected to further analysis, including the quantitation of colony-forming units (CFU), plaque-forming units (PFU), and gross macroscopic as well as histopathology observation. Mice with induced mastitis exhibited significantly improved mastitic pathology and decreased bacterial counts after they had been given phage treatments, with the phage cocktail being more superior than either phage alone. Furthermore, the cocktail treatment also maintained the highest intramammary phage titer without spreading systemically. The effectiveness of the phage cocktail was comparable to that produced by ceftiofur sodium. According to the data obtained for the mouse model of mastitis, phage therapy could be considered as an innovative alternative to antibiotics for the treatment of bovine mastitis.

• MeSH
• bakteriofágy fyziologie   MeSH
• fágová terapie metody   veterinární   MeSH
• mastitida skotu mikrobiologie   terapie   MeSH
• mléko mikrobiologie   MeSH
• Myoviridae fyziologie   MeSH
• myši MeSH
• Podoviridae fyziologie   MeSH
• skot MeSH
• stafylokokové infekce mikrobiologie   veterinární   MeSH
• Staphylococcus aureus fyziologie   virologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Geografické názvy
• Čína MeSH