In the food industry, the increasing antimicrobial resistance of food-borne pathogens to conventional sanitizers poses the risk of food contamination and a decrease in product quality and safety. Therefore, we explored alternative antimicrobials N-Acetyl-l-cysteine (NAC), rhamnolipids (RLs), and usnic acid (UA) as a novel approach to prevent biofilm formation and reduce existing biofilms formed by important food-borne pathogens (three strains of Salmonella enterica and two strains of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus). Their effectiveness was evaluated by determining minimum inhibitory concentrations needed for inhibition of bacterial growth, biofilm formation, metabolic activity, and biofilm reduction. Transmission electron microscopy and confocal scanning laser microscopy followed by image analysis were used to visualize and quantify the impact of tested substances on both planktonic and biofilm-associated cells. The in vitro cytotoxicity of the substances was determined as a half-maximal inhibitory concentration in five different cell lines. The results indicate relatively low cytotoxic effects of NAC in comparison to RLs and UA. In addition, NAC inhibited bacterial growth for all strains, while RLs showed overall lower inhibition and UA inhibited only the growth of Gram-positive bacteria. Even though tested substances did not remove the biofilms, NAC represents a promising tool in biofilm prevention.

• MeSH
• acetylcystein farmakologie   MeSH
• antibakteriální látky farmakologie   MeSH
• antiinfekční látky farmakologie   MeSH
• benzofurany farmakologie   MeSH
• biofilmy účinky léků   MeSH
• buněčné linie MeSH
• Escherichia coli účinky léků   MeSH
• glykolipidy farmakologie   MeSH
• kontaminace potravin prevence a kontrola   MeSH
• lidé MeSH
• Listeria monocytogenes účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• nemoci přenášené potravou farmakoterapie   mikrobiologie   MeSH
• potravinářská mikrobiologie metody   MeSH
• Salmonella enterica účinky léků   MeSH
• Staphylococcus aureus účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Although some metallic nanoparticles (NPs) are commonly used in the food processing plants as nanomaterials for food packaging, or as coatings on the food handling equipment, little is known about antimicrobial properties of palladium (PdNPs) and platinum (PtNPs) nanoparticles and their potential use in the food industry. In this study, common food-borne pathogens Salmonella enterica Infantis, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus were tested. Both NPs reduced viable cells with the log10 CFU reduction of 0.3-2.4 (PdNPs) and 0.8-2.0 (PtNPs), average inhibitory rates of 55.2-99% for PdNPs and of 83.8-99% for PtNPs. However, both NPs seemed to be less effective for biofilm formation and its reduction. The most effective concentrations were evaluated to be 22.25-44.5 mg/L for PdNPs and 50.5-101 mg/L for PtNPs. Furthermore, the interactions of tested NPs with bacterial cell were visualized by transmission electron microscopy (TEM). TEM visualization confirmed that NPs entered bacteria and caused direct damage of the cell walls, which resulted in bacterial disruption. The in vitro cytotoxicity of individual NPs was determined in primary human renal tubular epithelial cells (HRTECs), human keratinocytes (HaCat), human dermal fibroblasts (HDFs), human epithelial kidney cells (HEK 293), and primary human coronary artery endothelial cells (HCAECs). Due to their antimicrobial properties on bacterial cells and no acute cytotoxicity, both types of NPs could potentially fight food-borne pathogens.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• Bacteria klasifikace   účinky léků   růst a vývoj   MeSH
• fibroblasty cytologie   účinky léků   MeSH
• kovové nanočástice aplikace a dávkování   chemie   MeSH
• kultivované buňky MeSH
• ledviny cytologie   účinky léků   MeSH
• lidé MeSH
• nemoci přenášené potravou prevence a kontrola   MeSH
• palladium chemie   MeSH
• platina chemie   MeSH
• potravinářská mikrobiologie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The antimicrobial activity of gold and silver nanoparticles (AuNPs, AgNPs), chitosan (CS) and their combinations was established by determining the minimum inhibitory concentration for planktonic (MICPC80) and biofilm growth (MICBC80), for biofilm formation (MICBF80), metabolic activity (MICBM80) and reduction (MICBR80), and for the metabolic activity of preformed biofilm (MICMPB80). Biofilms were quantified in microtitre plates by crystal violet staining and metabolic activity was evaluated by the MTT assay. Chitosan effectively suppressed biofilm formation (0.31-5 mg ml-1) in all the tested strains, except Salmonella enterica Infantis (0.16-2.5 mg ml-1) where CS and its combination with AgNPs induced biofilm formation. Nanoparticles inhibited biofilm growth only when the highest concentrations were used. Even though AuNPs, AgNPs and CS were not able to remove biofilm mass, they reduced its metabolic activity by at least 80%. The combinations of nanoparticles with CS did not show any significant positive synergistic effect on the tested target properties.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• biofilmy účinky léků   růst a vývoj   MeSH
• chitosan chemie   farmakologie   MeSH
• gramnegativní bakterie účinky léků   MeSH
• grampozitivní bakterie účinky léků   MeSH
• kovové nanočástice chemie   MeSH
• mikrobiální testy citlivosti MeSH
• potravinářská mikrobiologie MeSH
• stříbro chemie   farmakologie   MeSH
• synergismus léků MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zlato chemie   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Odstranění mikrobiálního biofilmu a potlačení jeho tvorby jsou v současné době velkou výzvou, která vyžaduje citlivější a účinnější strategie s ohledem k nárůstu mikrobiálních rezistencí. Nanočástice zaměřené na eradikaci biofilmu vyvolávají v posledních deseti letech zájem kvůli svým vlastnostem. Tyto nanočástice mají široké spektrum biologických účinků a mezi nimiž je významná antibiofilmová aktivita. Daří se jim proniknout do biofilmové matrice, která působí jako bariéra pro mnoho antibiotik a dezinfekčních prostředků.

Eradication of microbial biofilm and prevention of its formation is currently a major challenge that requires more sensitive and effective strategies due to increasing resistence of microorganisms. Nanoparticles targeted on biofilm eradication have gained enormous popularity over the last ten years due to their unique properties. These nanoparticles have a wide range of biological applications, including a significant antibiofilm activity. They are able to penetrate into a biofilm matrix that serves as a barrier against many antibiotics and disinfectants.

• MeSH
• antiinfekční látky farmakologie   izolace a purifikace   MeSH
• biofilmy účinky léků   MeSH
• hořčík MeSH
• matrix extracelulárních polymerních látek mikrobiologie   účinky léků   MeSH
• nanočástice * chemie   terapeutické užití   MeSH
• oxid zinečnatý MeSH
• stříbro MeSH
• železo MeSH
• zlato MeSH
• Publikační typ
• práce podpořená grantem MeSH