Antibiotic-resistant strains of Staphylococcus aureus pose a significant threat in healthcare, demanding urgent therapeutic solutions. Combining bacteriophages with conventional antibiotics, an innovative approach termed phage-antibiotic synergy, presents a promising treatment avenue. However, to enable new treatment strategies, there is a pressing need for methods to assess their efficacy reliably and rapidly. Here, we introduce a novel approach for real-time monitoring of pathogen lysis dynamics employing the piezoelectric quartz crystal microbalance (QCM) with dissipation (QCM-D) technique. The sensor, a QCM chip modified with the bacterium S. aureus RN4220 ΔtarM, was utilized to monitor the activity of the enzyme lysostaphin and the phage P68 as model lytic agents. Unlike conventional QCM solely measuring resonance frequency changes, our study demonstrates that dissipation monitoring enables differentiation of bacterial growth and lysis caused by cell-attached lytic agents. Compared to reference turbidimetry measurements, our results reveal distinct alterations in the growth curve of the bacteria adhered to the sensor, characterized by a delayed lag phase. Furthermore, the dissipation signal analysis facilitated the precise real-time monitoring of phage-mediated lysis. Finally, the QCM-D biosensor was employed to evaluate the synergistic effect of subinhibitory concentrations of the antibiotic amoxicillin with the bacteriophage P68, enabling monitoring of the lysis of P68-resistant wild-type strain S. aureus RN4220. Our findings suggest that this synergy also impedes the formation of bacterial aggregates, the precursors of biofilm formation. Overall, this method brings new insights into phage-antibiotic synergy, underpinning it as a promising strategy against antibiotic-resistant bacterial strains with broad implications for treatment and prevention.
- Klíčová slova
- Staphylococcus aureus, Antimicrobial treatment, Multidrug-resistant bacteria, Phage therapy, Phage-antibiotic synergy, Piezoelectric biosensor,
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriofágy fyziologie MeSH
- bakteriolýza * účinky léků MeSH
- biosenzitivní techniky * metody přístrojové vybavení MeSH
- lysostafin farmakologie MeSH
- mikrorovnovážné techniky křemenného krystalu * metody MeSH
- Staphylococcus aureus * účinky léků virologie růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antibakteriální látky MeSH
- lysostafin MeSH
The aim of this study was to develop multifunctional magnetic poly(ε-caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three-step approach. Then, a series of PCL-based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow-derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS-2 osteoblast-like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention.
- Klíčová slova
- L‐ascorbic acid, iron oxide nanoparticles, nanocomposites, poly(ε‐caprolactone),
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- Escherichia coli účinky léků MeSH
- kosti a kostní tkáň MeSH
- krysa rodu Rattus MeSH
- kyselina askorbová * chemie farmakologie MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- nádorové buněčné linie MeSH
- nanokompozity chemie MeSH
- osteoblasty metabolismus cytologie MeSH
- osteosarkom patologie MeSH
- polyestery * chemie MeSH
- Staphylococcus aureus * účinky léků růst a vývoj MeSH
- testování materiálů MeSH
- tkáňové inženýrství * MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antibakteriální látky MeSH
- kyselina askorbová * MeSH
- magnetické nanočástice MeSH
- polycaprolactone MeSH Prohlížeč
- polyestery * MeSH
Bacterial cell wall peptidoglycan is essential, maintaining both cellular integrity and morphology, in the face of internal turgor pressure. Peptidoglycan synthesis is important, as it is targeted by cell wall antibiotics, including methicillin and vancomycin. Here, we have used the major human pathogen Staphylococcus aureus to elucidate both the cell wall dynamic processes essential for growth (life) and the bactericidal effects of cell wall antibiotics (death) based on the principle of coordinated peptidoglycan synthesis and hydrolysis. The death of S. aureus due to depletion of the essential, two-component and positive regulatory system for peptidoglycan hydrolase activity (WalKR) is prevented by addition of otherwise bactericidal cell wall antibiotics, resulting in stasis. In contrast, cell wall antibiotics kill via the activity of peptidoglycan hydrolases in the absence of concomitant synthesis. Both methicillin and vancomycin treatment lead to the appearance of perforating holes throughout the cell wall due to peptidoglycan hydrolases. Methicillin alone also results in plasmolysis and misshapen septa with the involvement of the major peptidoglycan hydrolase Atl, a process that is inhibited by vancomycin. The bactericidal effect of vancomycin involves the peptidoglycan hydrolase SagB. In the presence of cell wall antibiotics, the inhibition of peptidoglycan hydrolase activity using the inhibitor complestatin results in reduced killing, while, conversely, the deregulation of hydrolase activity via loss of wall teichoic acids increases the death rate. For S. aureus, the independent regulation of cell wall synthesis and hydrolysis can lead to cell growth, death, or stasis, with implications for the development of new control regimes for this important pathogen.
- Klíčová slova
- antibiotics, cell wall, methicillin, peptidoglycan, vancomycin,
- MeSH
- antibakteriální látky farmakologie MeSH
- antiinfekční látky metabolismus farmakologie MeSH
- bakteriální proteiny metabolismus MeSH
- buněčná stěna metabolismus fyziologie MeSH
- homeostáza MeSH
- kyseliny teichoové metabolismus MeSH
- methicilin farmakologie MeSH
- N-acetylmuramoyl-L-alaninamidasa metabolismus MeSH
- peptidoglykan metabolismus MeSH
- stafylokokové infekce mikrobiologie MeSH
- Staphylococcus aureus růst a vývoj metabolismus MeSH
- vankomycin farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antibakteriální látky MeSH
- antiinfekční látky MeSH
- bakteriální proteiny MeSH
- kyseliny teichoové MeSH
- methicilin MeSH
- N-acetylmuramoyl-L-alaninamidasa MeSH
- peptidoglykan MeSH
- vankomycin MeSH
PURPOSE: Nanomaterials for antimicrobial applications have gained interest in recent years due to the increasing bacteria resistance to conventional antibiotics. Wound sterilization, water treatment and surface decontamination all avail from multifunctional materials that also possess excellent antibacterial properties, eg zinc oxide (ZnO). Here, we assess and compare the effects of synthesized hedgehog-like ZnO structures and commercial ZnO particles with and without mixing on the inactivation of bacteria on surfaces and in liquid environments. METHODS: Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in microbial culture medium were added to reverse spin bioreactors that contained different concentrations of each ZnO type to enable dynamic mixing of the bacteria-ZnO suspensions. Optical density of the bacteria-ZnO suspensions was measured in real-time and the number of viable bacteria after 24 h exposure was determined using standard microbiological techniques. The concentration of zinc ion generated from ZnO dissolution in different liquid types was estimated from the dynamic interaction exposure. Static antibacterial tests without agitation in liquid media and on agar surface were performed for comparison. RESULTS: A correlation between increasing ZnO particle concentration and reduction in viable bacteria was not monotonous. The lowest concentration tested (10 µg/mL) even stimulated bacteria growth. The hedgehog ZnO was significantly more antibacterial than commercial ZnO particles at higher concentrations (up to 1000 µg/mL tested), more against E. coli than S. aureus. Minimum inhibitory concentration in microwell plates was correlated with those results. No inhibition was detected for any ZnO type deposited on agar surface. Zinc ion release was greatly suppressed in cultivation media. Scanning electron microscopy images revealed that ZnO needles can pierce membrane of bacteria whereas the commercial ZnO nanoparticles rather agglomerate on the cell surface. CONCLUSION: The inhibition effects are thus mainly controlled by the interaction dynamics between bacteria and ZnO, where mixing greatly enhances antibacterial efficacy of all ZnO particles. The efficacy is modulated also by ZnO particle shapes, where hedgehog ZnO has superior effect, in particular at lower concentrations. However, at too low concentrations, ZnO can stimulate bacteria growth and must be thus used with caution.
- Klíčová slova
- antibacterial, biotechnology, nanomaterials, zinc oxide,
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- biomimetické materiály chemie farmakologie MeSH
- Escherichia coli účinky léků růst a vývoj MeSH
- ježkovití * MeSH
- mikrobiální testy citlivosti MeSH
- oxid zinečnatý chemie farmakologie MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- oxid zinečnatý MeSH
Targeted and effective therapy of diseases demands utilization of rapid methods of identification of the given markers. Surface enhanced Raman spectroscopy (SERS) in conjunction with streptavidin-biotin complex is a promising alternative to culture or PCR based methods used for such purposes. Many biotinylated antibodies are available on the market and so this system offers a powerful tool for many analytical applications. Here, we present a very fast and easy-to-use procedure for preparation of streptavidin coated magnetic polystyrene-Au (or Ag) nanocomposite particles as efficient substrate for surface SERS purposes. As a precursor for the preparation of SERS active and magnetically separable composite, commercially available streptavidin coated polystyrene (PS) microparticles with a magnetic core were utilized. These composites of PS particles with silver or gold nanoparticles were prepared by reducing Au(III) or Ag(I) ions using ascorbic acid or dopamine. The choice of the reducing agent influences the morphology and the size of the prepared Ag or Au particles (15-100 nm). The prepare composites were also characterized by HR-TEM images, mapping of elements and also magnetization measurements. The content of Au and Ag was determined by AAS analysis. The synthesized composites have a significantly lower density against magnetic composites based on iron oxides, which considerably decreases the tendency to sedimentation. The polystyrene shell on a magnetic iron oxide core also pronouncedly reduces the inclination to particle aggregation. Moreover, the preparation and purification of this SERS substrate takes only a few minutes. The PS composite with thorny Au particles with the size of approximately 100 nm prepared was utilized for specific and selective detection of Staphylococcus aureus infection in joint knee fluid (PJI) and tau protein (marker for Alzheimer disease).
- MeSH
- Alzheimerova nemoc krev diagnóza genetika MeSH
- biologické markery analýza MeSH
- dopamin chemie MeSH
- kyselina askorbová chemie MeSH
- lidé MeSH
- magnetické nanočástice oxidů železa chemie ultrastruktura MeSH
- polystyreny chemie MeSH
- proteiny tau analýza krev genetika MeSH
- Ramanova spektroskopie metody MeSH
- stafylokokové infekce diagnóza mikrobiologie MeSH
- Staphylococcus aureus růst a vývoj patogenita MeSH
- streptavidin chemie MeSH
- stříbro chemie MeSH
- synoviální tekutina mikrobiologie MeSH
- velikost částic MeSH
- zlato chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- dopamin MeSH
- kyselina askorbová MeSH
- MAPT protein, human MeSH Prohlížeč
- polystyreny MeSH
- proteiny tau MeSH
- streptavidin MeSH
- stříbro MeSH
- zlato MeSH
Chronic wounds and their associated bacterial infections are major issues in modern health care systems. Therefore, antimicrobial resistance (AMR), treatment costs, and number of disability-adjusted life-years have gained more interest. Recently, photodynamic therapy emerged as an effective approach against resistant and naïve bacterial strains with a low probability of creating AMR. In this study, needleless electrospinning was used to produce an indocyanine green (ICG) loaded poly(d,l-lactide) nanofibrous mesh as a photoresponsive wound dressing. The non-woven mesh had a homogeneous nanofibrous structure and showed long-term hydrolytic stability at different pH values. The antimicrobial activity was tested against several bacterial strains, namely Staphylococcus saprophyticus subsp. bovis, Escherichia coli DH5 alpha, and Staphylococcus aureus subsp. aureus. Upon irradiation with a laser of a specific wavelength (λ = 810 nm), the bacterial viability was significantly reduced by 99.978% (3.66 log10), 99.699% (2.52 log10), and 99.977% (3.64 log10), respectively. The nanofibrous mesh showed good biocompatibility, which was confirmed by the proliferation of mouse fibroblasts (L929) on the surface and into deeper parts of the mesh. Furthermore, a favorable proangiogenic effect was observed in ovo using the chorioallantoic membrane assay. In general, it can be concluded that ICG loaded nanofibers as an innovative wound dressing represent a promising strategy against chronic wounds associated with skin infections.
- Klíčová slova
- Antimicrobial, Electrospinning, Indocyanine green, Nanofibers, Photodynamic therapy, Wound dressing,
- MeSH
- biokompatibilní materiály chemie farmakologie MeSH
- buněčné linie MeSH
- chorioalantoická membrána krevní zásobení účinky léků MeSH
- Escherichia coli účinky léků růst a vývoj MeSH
- fibroblasty cytologie účinky léků MeSH
- fotochemoterapie MeSH
- indokyanová zeleň chemie farmakologie MeSH
- mikrobiální viabilita účinky léků MeSH
- myši MeSH
- nanovlákna MeSH
- obvazy MeSH
- polyestery chemie MeSH
- proliferace buněk účinky léků MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- Staphylococcus saprophyticus účinky léků růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- indokyanová zeleň MeSH
- poly(lactide) MeSH Prohlížeč
- polyestery MeSH
External fixators of serious fractures could be an attractive substrate on which microorganisms can accumulate. Therefore, this study aimed to develop a suitable method for enabling the simulation of a real situation when osteosynthetic fixation material is open for the potential threat of bacterial attack. Agar-based media represented human tissue, and the metallic pin characterized the screw in the fixation. Various types of agar, supplements, and contamination strategy by Staphylococcus aureus were tested. The influence of the initial bacterial concentration was also examined. Surfaces were observed by scanning electron microscopy (SEM), and all results were compared. Brain Heart Infusion Agar with the Egg Yolk Tellurite Emulsion was established in a transparent test tube as a suitable system for enabling the good interpretability of bacterial contamination in the pin's surroundings. Pin contamination has been found to be an appropriate approach for testing microbial growth, rather than agar surface contamination, which distorted obtained results. A lower initial colony forming units (CFU) provided better clarity of the test. SEM observation of the pin surface was comparable with the visual evaluations in the test tubes. Results were assembled for positive and negative control samples as well. Screening method for the most common bacteria S. aureus has been standardized and developed. This experimental setup could also be a useful tool for surface modification with antibacterial properties testing.
- Klíčová slova
- Antibacterial test, Biofilm, External fixation, Silver, Staphylococcus aureus, Titanium,
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy účinky léků růst a vývoj MeSH
- externí fixátory mikrobiologie MeSH
- kontaminace zdravotnického vybavení * MeSH
- kultivační média MeSH
- lidé MeSH
- mikroskopie elektronová rastrovací MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus účinky léků růst a vývoj ultrastruktura MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- kultivační média MeSH
The antifouling, antimicrobial, elution behavior, skin irritant, and cytotoxicity properties of water-soluble phosphate glass on stainless steel were evaluated. Water-soluble phosphate glass samples with 35% Cu (mol/mol) were prepared by altering the network modifier (Na2O, K2O) and network former (P2O5, B2O3) compositions. The materials were melted at temperatures within the range of 850-950 °C. The melt was then quenched and ground into fine particles using a twin roll mill. The resulting water-soluble glasses were prepared as glass frit (size < 100 μm) using a sieve. The amorphous phase was determined by X-ray diffraction and differential thermal analysis. Water-soluble glasses with a reduced Cu ion elution rate of 1.2 ppm per week were formed because the chemical resistances of the formulated glasses improved as the P2O5 content decreased and the B2O3 content increased. To test its antifouling properties, the glass frit was mixed with paint and coated onto a STS316L sheet. The surface roughness was increased markedly from 1.4 to 19.2 nm, increasing the specific surface area for antimicrobial activity. It was demonstrated that the proposed method was able to form noncytotoxic, nonirritant, water-soluble glasses with 99.9% antimicrobial activity against Staphylococcus aureus. These results suggest that water-soluble phosphate glass on STS316L sheets could be useful in filtration plants.
- Klíčová slova
- Antifouling effect, Antimicrobial activity, Cytotoxicity, Water-soluble glass frit,
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- bioznečištění prevence a kontrola MeSH
- čištění vody přístrojové vybavení MeSH
- difrakce rentgenového záření MeSH
- filtrace přístrojové vybavení MeSH
- fosfáty chemie farmakologie MeSH
- králíci MeSH
- kůže účinky léků MeSH
- sklo chemie MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- fosfáty MeSH
It is generally believed that antibacterial essential oils have the potential to become one of the alternatives in preventing diarrheal diseases of monogastric animals. The disadvantage is their low efficiency per oral due to easy degradation during digestion in the stomach. This study compares the efficacy of chitosan, alginate-chitosan, guar gum-chitosan, xanthan gum-chitosan and pectin-chitosan nanocapsules to the synthesis of pH-responsive biopolymeric nanocapsule for Thymus vulgaris, Rosmarinus officinalis and Syzygium aromaticum essential oils. Using spectrophotometric approach and gas chromatography, release kinetics were determined in pH 3, 5.6 and 7.4. The growth rates of S. aureus and E. coli, as well as minimal inhibition concentration of essential oils were studied. The average encapsulation efficiency was 60%, and the loading efficiency was 70%. The size of the nanocapsules ranged from 100 nm to 500 nm. Results showed that chitosan-guar gum and chitosan-pectin nanocapsules released 30% of essential oils (EOs) at pH 3 and 80% at pH 7.4 during 3 h. Similar release kinetics were confirmed for thymol, eugenol and α-pinene. Minimal inhibition concentrations of Thymus vulgaris and Syzygium aromaticum essential oils ranged from 0.025 to 0.5%. Findings of this study suggest that the suitable pH-responsive nanocapsule for release, low toxicity and antibacterial activity is based on chitosan-guar gum structure.
- Klíčová slova
- E. coli, Rosmarinus officinalis, S. aureus, S. cerevisiae, Syzygium aromaticum, Thymus vulgaris, alginate, chitosan, gastro-intestinal tract, guar gum, pectin, xanthan gum,
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- erytrocyty cytologie účinky léků MeSH
- Escherichia coli účinky léků růst a vývoj MeSH
- hemolýza účinky léků MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- nanokapsle aplikace a dávkování chemie MeSH
- oleje prchavé chemie farmakologie MeSH
- polymery chemie MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- nanokapsle MeSH
- oleje prchavé MeSH
- polymery MeSH
Lactobionic acid (LBA) is a newly identified natural polyhydroxy acid that is widely used in the food industry. In this study, the antibacterial effects and underlying mechanism of action of LBA against Staphylococcus aureus were investigated. LBA exhibited significant antibacterial activity against S. aureus with a determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 15 mg/mL and 50 mg/mL, respectively. The Growth curves indicated that LBA directly inhibited the growth of S. aureus. Moreover, LBA induced the leakage of alkaline phosphatase and nucleotides in the culture medium, indicating damage to the integrity of the S. aureus cell wall membrane, which was confirmed by transmission electron microscopy observations. The relative electric conductivity measurements indicated that LBA changed the cell membrane permeability. The preservation effect of LBA was evaluated by quantifying the total number of colonies, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS). Overall, these results revealed that LBA exerts its antibacterial activity by breaking down the structure of the bacterial cell wall and membrane, thereby releasing the cellular contents as well as inhibiting protein synthesis, which ultimately lead to cell death. The total number of colonies, the TVB-N value, and the TBARS of cold fresh meat treated with preservatives were significantly lower than those of the control group (P < 0.05). With these antibacterial characteristics, LBA has potential to be used as a safe food additive in the food industry.
- MeSH
- antibakteriální látky farmakologie MeSH
- buněčná membrána účinky léků metabolismus MeSH
- buněčná stěna účinky léků metabolismus MeSH
- disacharidy farmakologie MeSH
- dusík analýza MeSH
- konzervace potravin MeSH
- látky reagující s kyselinou thiobarbiturovou analýza MeSH
- mikrobiální testy citlivosti MeSH
- mikrobiální viabilita účinky léků MeSH
- permeabilita buněčné membrány účinky léků MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- disacharidy MeSH
- dusík MeSH
- lactobionic acid MeSH Prohlížeč
- látky reagující s kyselinou thiobarbiturovou MeSH
