Due to the great increase in the non-thermal plasma (NTP) bio-applications, especially thanks to its antimicrobial properties, many types of NTP generating devices have been developed recently. However, a comparison of these devices is difficult due to the differences in the setup of studies testing them, e.g., in species of microorganisms used and sample preparations. In this study, we optimized a robust and reproducible standard protocol using Bacillus subtilis spores and applied it to compare seven different NTP generating devices in terms of technical parameters and sporicidal properties. Inhibition zones determined using the Aurora software and the complete inhibition of bacteria growth induced by the NTP treatment were analyzed to determine both local and overall effects, respectively. The highest sporicidal efficacy of the tested devices was achieved by the volume dielectric barrier discharge from Wroclaw, which inhibited 99.9% of colony forming units after 30 min of exposure. To our knowledge, a comparative study of this extent has not been published to date. The presented protocol is based on an established bacterial method and can therefore serve as a general standard for an effective comparison of NTP sources across laboratories worldwide.

• Klíčová slova
• Bacillus subtilis, Dielectric barrier discharge (DBD), International study, Plasma jet, Reference (standard) protocol, Spores,
• MeSH
• Bacillus subtilis * účinky léků   růst a vývoj   MeSH
• plazmové plyny * farmakologie   MeSH
• spory bakteriální * účinky léků   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• plazmové plyny * MeSH

Antibiotic resistance (ATBR) is increasing every year as the overuse of antibiotics (ATBs) and the lack of newly emerging antimicrobial agents lead to an efficient pathogen escape from ATBs action. This trend is alarming and the World Health Organization warned in 2021 that ATBR could become the leading cause of death worldwide by 2050. The development of novel ATBs is not fast enough considering the situation, and alternative strategies are therefore urgently required. One such alternative may be the use of non-thermal plasma (NTP), a well-established antimicrobial agent actively used in a growing number of medical fields. Despite its efficiency, NTP alone is not always sufficient to completely eliminate pathogens. However, NTP combined with ATBs is more potent and evidence has been emerging over the last few years proving this is a robust and highly effective strategy to fight resistant pathogens. This minireview summarizes experimental research addressing the potential of the NTP-ATBs combination, particularly for inhibiting planktonic and biofilm growth and treating infections in mouse models caused by methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa. The published studies highlight this combination as a promising solution to emerging ATBR, and further research is therefore highly desirable.

• Klíčová slova
• Pseudomonas aeruginosa, antimicrobial resistance (AMR), cold atmospheric plasma (CAP), combinatory therapy, methicillin-resistant Staphylococcus aureus,
• MeSH
• antibakteriální látky * farmakologie   terapeutické užití   MeSH
• antibiotická rezistence MeSH
• bakteriální léková rezistence MeSH
• biofilmy * účinky léků   MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• plazmové plyny * farmakologie   MeSH
• pseudomonádové infekce mikrobiologie   farmakoterapie   MeSH
• Pseudomonas aeruginosa účinky léků   MeSH
• stafylokokové infekce mikrobiologie   farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The increasing risk of antibiotic failure in the treatment of Pseudomonas aeruginosa infections is largely related to the production of a wide range of virulence factors. The use of non-thermal plasma (NTP) is a promising alternative to antimicrobial treatment. Nevertheless, there is still a lack of knowledge about the effects of NTP on the virulence factors production. We evaluated the ability of four NTP-affected P. aeruginosa strains to re-form biofilm and produce Las-B elastase, proteases, lipases, haemolysins, gelatinase or pyocyanin. Highly strains-dependent inhibitory activity of NTP against extracellular virulence factors production was observed. Las-B elastase activity was reduced up to 82% after 15-min NTP treatment, protease activity and pyocyanin production by biofilm cells was completely inhibited after 60 min, in contrast to lipases and gelatinase production, which remained unchanged. However, for all strains tested, a notable reduction in biofilm re-development ability was depicted using spinning disc confocal microscopy. In addition, NTP exposure of mature biofilms caused disruption of biofilm cells and their dispersion into the environment, as shown by transmission electron microscopy. This appears to be a key step that could help overcome the high resistance of P. aeruginosa and its eventual elimination, for example in combination with antibiotics still highly effective against planktonic cells.

• Klíčová slova
• antivirulence factors, biofilm disruption, cold atmospheric plasma (CAP), combined therapy, haemolytic activity,
• MeSH
• antibakteriální látky farmakologie   MeSH
• biofilmy MeSH
• endopeptidasy farmakologie   MeSH
• faktory virulence MeSH
• hemolyziny farmakologie   MeSH
• lidé MeSH
• pankreatická elastasa MeSH
• plankton MeSH
• plazmové plyny * farmakologie   MeSH
• proteasy MeSH
• pseudomonádové infekce * MeSH
• Pseudomonas aeruginosa MeSH
• pyokyanin MeSH
• quorum sensing MeSH
• želatinasy farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• endopeptidasy MeSH
• faktory virulence MeSH
• hemolyziny MeSH
• pankreatická elastasa MeSH
• plazmové plyny * MeSH
• proteasy MeSH
• pyokyanin MeSH
• želatinasy MeSH

Pseudomonas aeruginosa is a gram-negative bacterium capable of forming persistent biofilms that are extremely difficult to eradicate. The species is most infamously known due to complications in cystic fibrosis patients. The high mortality of cystic fibrosis is caused by P. aeruginosa biofilms occurring in pathologically overly mucous lungs, which are the major cause facilitating the organ failure. Due to Pseudomonas biofilm-associated infections, remarkably high doses of antibiotics must be administered, eventually contributing to the development of antibiotic resistance. Nowadays, multidrug resistant P. aeruginosa is one of the most terrible threats in medicine, and the search for novel antimicrobial drugs is of the utmost importance. We have studied the effect of low molecular weight chitosan (LMWCH) on various stages of P. aeruginosa ATCC 10145 biofilm formation and eradication, as well as on production of other virulence factors. LMWCH is a well-known naturally occurring agent with a vast antimicrobial spectrum, which has already found application in various fields of medicine and industry. LMWCH at a concentration of 40 mg/L was able to completely prevent biofilm formation. At a concentration of 60 mg/L, this agent was capable to eradicate already formed biofilm in most studied times of addition (2-12 h of cultivation). LMWCH (50 mg/L) was also able to suppress pyocyanin production when added 2 and 4 h after cultivation. The treatment resulted in reduced formation of cell clusters. LMWCH was proved to be an effective antibiofilm agent worth further clinical research with the potential to become a novel drug for the treatment of P. aeruginosa infections.

• Klíčová slova
• Biofilm, Eradication, Formation, Low molecular weight chitosan, Pseudomonas aeruginosa, Virulence factors,
• MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• biofilmy MeSH
• chitosan * farmakologie   MeSH
• cystická fibróza * MeSH
• faktory virulence MeSH
• lidé MeSH
• pseudomonádové infekce * farmakoterapie   MeSH
• Pseudomonas aeruginosa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• chitosan * MeSH
• faktory virulence MeSH

The current pandemic resulted in a rapidly increasing demand for personal protective equipment (PPE) initially leading to severe shortages of these items. Hence, during an unexpected and fast virus spread, the possibility of reusing highly efficient protective equipment could provide a viable solution for keeping both healthcare professionals and the general public equipped and protected. This requires an efficient decontamination technique that preserves functionality of the sensitive materials used for PPE production. Non-thermal plasma (NTP) is a decontamination technique with documented efficiency against select bacterial and fungal pathogens combined with low damage to exposed materials. We have investigated NTP for decontamination of high-efficiency P3 R filters from viral respiratory pathogens in comparison to other commonly used techniques. We show that NTP treatment completely inactivates SARS-CoV-2 and three other common human respiratory viruses including Influenza A, Rhinovirus and Adenovirus, revealing an efficiency comparable to 90°C dry heat or UVC light. Unlike some of the tested techniques (e.g., autoclaving), NTP neither influenced the filtering efficiency nor the microstructure of the filter. We demonstrate that NTP is a powerful and economic technology for efficient decontamination of protective filters and other sensitive materials from different respiratory pathogens.

• Klíčová slova
• Adenovirus, Pseudomonas aerguinosa, Rhinovirus, cold plasma, human respiratory viruses, influenza A, particle filter, protective equipment,
• Publikační typ
• časopisecké články MeSH

A non-thermal plasma (NTP) is a promising tool against the development of bacterial, viral, and fungal diseases. The recently revealed development of microbial resistance to traditional drugs has increased interest in the use of NTPs. We have studied and compared the physical and microbicidal properties of two types of NTP sources based on a cometary discharge in the point-to-point electrode configuration and a corona discharge in the point-to-ring electrode configuration. The electrical and emission properties of both discharges are reported. The microbicidal effect of NTP sources was tested on three strains of the bacterium Staphylococcus aureus (including the methicillin-resistant strain), the bacterium Pseudomonas aeruginosa, the yeast Candida albicans, and the micromycete Trichophyton interdigitale. In general, the cometary discharge is a less stable source of NTP and mostly forms smaller but more rapidly emerging inhibition zones on agar plates. Due to the point-to-ring electrode configuration, the second type of discharge has higher stability and provides larger affected but often not completely inhibited zones. However, after 60 min of exposure, the NTP sources based on the cometary and point-to-ring discharges showed a similar microbicidal effect for bacteria and an individual effect for microscopic fungi.

• Klíčová slova
• Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus, Trichophyton interdigitale, corona discharge, microbicidal effect,
• Publikační typ
• časopisecké články MeSH