Benzoxonium chloride belongs to the group of quaternary ammonium salts, which have been widely used for decades as disinfectants because of their high efficacy, low toxicity, and thermal stability. In this study, we have prepared the C10-C18 set of benzoxonium-like salts to evaluate the effect of their chemical and biological decontamination capabilities. In particular, biocidal activity against a panel of bacterial strains including Staphylococcus aureus in biofilm form was screened. In addition, the most promising compounds were successfully tested against Francisella tularensis as a representative of potential biological warfare agents. From a point of view of chemical warfare protection, the efficiency of BOC-like compounds to degrade the organophosphate simulant fenitrothion was examined. Notwithstanding that no single compound with universal effectiveness was identified, a mixture of only two compounds from this group would be able to satisfactorily cover the proposed decontamination spectrum. In addition, the compounds were evaluated for their cytotoxicity as a basic safety parameter for potential use in practice. In summary, the dual effect on chemical and biological agents of benzoxonium-like salts offer attractive potential as active components of decontamination mixtures in the case of a terrorist threat or chemical or biological accidents.

• Klíčová slova
• benzoxonium, decontamination, disinfection, micellar catalysis, organophosphates, quaternary ammonium salts,
• Publikační typ
• časopisecké články MeSH

An increasing microbial resistance to known antibiotics raises a demand for new antimicrobials. In this study the antimicrobial properties of a series of new N-Alkylpyridinium quaternary ammonium compounds (QACs) with varying alkyl chain lengths were evaluated for several nosocomial pathogens. The chemical identities of the new QACs were determined by NMR, LC-MS, and HRMS. All the planktonic bacteria tested were susceptible to the new QACs as evaluated by MIC and MBC assays. The antimicrobial effect was most pronounced against Staphylococcus aureus clinical isolates. Live/dead staining CLSM was used to test the effectiveness of the QACs in biofilms. The effectiveness was up to 10-fold lower than in the plankton. When QACs were used as irrigants in Er:YAG - SSP photoacoustic steaming, their effectiveness significantly increased. The combined use of irrigants and photoacoustic streaming increased biofilm removal from the surface and increased the killing rate of the cells remaining on the surface. This may allow for a shorter chemical exposure time and lower dosage of QACs used in applications. The results demonstrate that the new QACs have potential to be applied as antibacterial compounds effective against planktonic and biofilm bacteria as well as irrigants in removal of difficult-to-reach biofilms.

• Klíčová slova
• antimicrobial activity, bacteria, biofilm, photoacoustic irrigation, quaternary ammonium salts,
• Publikační typ
• časopisecké články MeSH

Microbial biofilms are factions of surface-colonized cells encompassed in a matrix of extracellular polymeric substances. Profound application of antibiotics in order to treat infections due to microbial biofilm has led to the emergence of several drug-resistant microbial strains. In this context, a novel type of 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz)-capped silver nanoparticles (TzAgNPs) was synthesized, and efforts were given to test its antimicrobial and antibiofilm activities against Pseudomonas aeruginosa, a widely used biofilm-forming pathogenic organism. The synthesized TzAgNPs showed considerable antimicrobial activity wherein the MIC value of TzAgNPs was found at 40 μg/mL against Pseudomonas aeruginosa. Antibiofilm activity of TzAgNPs was also tested against Pseudomonas aeruginosa by carrying out an array of experiments like microscopic observation, crystal violet assay, and protein count using the sub-MIC doses of TzAgNPs. Since TzAgNPs showed efficient antibiofilm activity, thus, in the present study, efforts were put together to investigate the underlying cause of biofilm attenuation of Pseudomonas aeruginosa by using TzAgNPs. To this end, we discerned that the sub-MIC doses of TzAgNPs increased ROS level considerably in the bacterial cell. The result showed that the ROS level and microbial biofilm formation are inversely proportional. Thus, the attenuation in microbial biofilm could be attributed to the accumulation of ROS level. Furthermore, it was also duly noted that microorganisms upon treatment with TzAgNPs exhibited considerable diminution in virulence factors (protease and pyocyanin) in contrast to the control where the organisms were not treated with TzAgNPs. Thus, the results indicated that TzAgNPs exhibit considerable reduction in the development of biofilms and spreading of virulence factors. Taken together, all the results indicated that TzAgNPs could be deemed to be a promising agent for the prevention of microbial biofilm development that might assist to fight against infections linked to biofilm.

• MeSH
• antibakteriální látky chemická syntéza   farmakologie   MeSH
• biofilmy účinky léků   MeSH
• faktory virulence MeSH
• kovové nanočástice * MeSH
• mikrobiální testy citlivosti MeSH
• mikrobiální viabilita účinky léků   MeSH
• pseudomonádové infekce metabolismus   mikrobiologie   MeSH
• Pseudomonas aeruginosa účinky léků   fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• stříbro * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• faktory virulence MeSH
• reaktivní formy kyslíku MeSH
• stříbro * MeSH

Attachment of bacterial pathogens to the niche tissue in the host is the first step in biofilm formation leading to colonization and establishment of infection in the host. While the most common method used for determining the potential role of a bacterial antigen in biofilm formation has been demonstration of loss of this property using specific knockout mutants, it is an expensive and a laborious procedure. This study describes an alternative immunological assay for identification of attachment antigens of Staphylococcus aureus, potentially important in the development of an effective vaccine against infections caused by this pathogen. The method is based upon the concept of inhibition of attachment of S. aureus to PEGs coated with virulence antigen-specific antibodies. Antibodies used for validation of this assay were specific for ClfA, FnBPA, SdrD, PNAG and α-toxin, accredited biofilm-associated antigens of S. aureus.

• MeSH
• antigeny bakteriální analýza   MeSH
• bakteriální adheze MeSH
• bakteriální adheziny analýza   MeSH
• biofilmy růst a vývoj   MeSH
• imunoanalýza metody   MeSH
• polystyreny MeSH
• protilátky bakteriální metabolismus   MeSH
• Staphylococcus aureus chemie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny bakteriální MeSH
• bakteriální adheziny MeSH
• polystyreny MeSH
• protilátky bakteriální MeSH

Limited treatment options in infectious diseases caused by resistant microorganisms created the need to search new approaches. Several herbal extracts are studied for their enormous therapeutic potential. Silymarin extract, from Silybum marianum (milk thistle), is an old and a new remedy for this goal. The purpose of this study is to evaluate the antibacterial and antiadherent effects of silymarin besides biofilm viability activity on standard bacterial strains. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antiadherent/antibiofilm activity, and effects on biofilm viability of silymarin were evaluated against standard bacterial strains. MIC values were observed between 60 and >241 μg/mL (0.25->1 mmol/L). Gram-positive bacteria were inhibited at concentrations between 60 and 120 μg/mL. Gram-negative bacteria were not inhibited by the silymarin concentrations included in this study. MBC values for Gram-positive bacteria were greater than 241 μg/mL. Adherence/biofilm formations were decreased to 15 μg/mL silymarin concentration when compared with silymarin-untreated group. Silymarin reduced the biofilm viabilities to 13 and 46 % at 1 and 0.5 mmol/L concentrations, respectively. We demonstrated that silymarin shows antibacterial and antiadherent/antibiofilm activity against certain standard bacterial strains which may be beneficial when used as a dietary supplement or a drug.

• MeSH
• antibakteriální látky izolace a purifikace   metabolismus   MeSH
• bakteriální adheze účinky léků   MeSH
• biofilmy účinky léků   MeSH
• gramnegativní bakterie účinky léků   fyziologie   MeSH
• grampozitivní bakterie účinky léků   fyziologie   MeSH
• mikrobiální testy citlivosti MeSH
• mikrobiální viabilita účinky léků   MeSH
• ostropestřec mariánský chemie   MeSH
• silymarin izolace a purifikace   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• silymarin MeSH

Eight antibiotics (aztreonam, ceftazidim, cefoperazon, cefepim, netilmicin, amikacin, ofloxacin and ciprofloxacin) exhibited antimicrobial activity individually and/or in combinations against 20 wild-type biofilm-forming strains of Pseudomonas aeruginosa. The strains were less susceptible in biofilm; in 10 strains antibiotic synergy was observed for the combination of aztreonam and ciprofloxacin. Synergy was also demonstrated in the case of beta-lactams and aminoglycosides, beta-lactams and fluoroquinolones, aminoglycosides and fluoroquinolones, and for monobactams and beta-lactams although the strains were resistant to the individual antibiotics. Synergism or partial synergism was found with one or more antibiotic combinations against 32.4% of isolates.

• MeSH
• antibakteriální látky farmakologie   MeSH
• biofilmy účinky léků   MeSH
• kombinovaná farmakoterapie MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• pseudomonádové infekce farmakoterapie   mikrobiologie   MeSH
• Pseudomonas aeruginosa účinky léků   izolace a purifikace   fyziologie   MeSH
• synergismus léků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• antibakteriální látky MeSH

Based on the ability to attach to polymeric surfaces, the formation of biofilms was determined in 5 wild-type strains (Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanii, Escherichia coli, Staphylococcus warneri). Using modified Christensen method, minimum regrowth concentration (MRC) of piperacillin, piperacillin-tazobactam, cefoperazon, ceftazidim, cefepim, meronem, ciprofloxacin, netilmicin and amikacin for Gram-negative and of ampicillin-sulbactam, chloramphenicol, tetracycline, clindamycin, vancomycin and teicoplanin for Gram-positive bacteria was estimated in trypticase-soy broth medium after a 1-d growth on polystyrene microtiter plates. Adherent bacterial populations exhibited reduced antimicrobial susceptibility, which was not shown in submerged cultures. Our results indicate that MRC can predict therapeutic outcome of antibiotic treatment better than the minimum inhibitory concentration tests commonly used.

• MeSH
• Acinetobacter baumannii účinky léků   růst a vývoj   MeSH
• amikacin farmakologie   MeSH
• antibakteriální látky farmakologie   MeSH
• Bacteria účinky léků   růst a vývoj   MeSH
• bakteriální adheze účinky léků   MeSH
• bakteriální léková rezistence MeSH
• biofilmy účinky léků   růst a vývoj   MeSH
• chloramfenikol farmakologie   MeSH
• ciprofloxacin farmakologie   MeSH
• Escherichia coli účinky léků   růst a vývoj   MeSH
• Klebsiella pneumoniae účinky léků   růst a vývoj   MeSH
• klindamycin farmakologie   MeSH
• laktamy farmakologie   MeSH
• mikrobiální testy citlivosti metody   MeSH
• netilmicin farmakologie   MeSH
• prediktivní hodnota testů MeSH
• Pseudomonas aeruginosa účinky léků   růst a vývoj   MeSH
• Staphylococcus účinky léků   růst a vývoj   MeSH
• teikoplanin farmakologie   MeSH
• tetracyklin farmakologie   MeSH
• vankomycin farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amikacin MeSH
• antibakteriální látky MeSH
• chloramfenikol MeSH
• ciprofloxacin MeSH
• klindamycin MeSH
• laktamy MeSH
• netilmicin MeSH
• teikoplanin MeSH
• tetracyklin MeSH
• vankomycin MeSH