Resistance to antibiotics among bacteria of clinical importance, including Staphylococcus aureus, is a serious problem worldwide and the search for alternatives is needed. Some metal complexes have ...antibacterial properties and when combined with antibiotics, they may increase bacterial sensitivity to antimicrobials. In this study, we synthesized the iron complex and tested it in combination with ampicillin (Fe16 + AMP) against S. aureus. An iron complex (Fe16) was synthesized and characterized using spectroscopy methods. Confirmation of the synergistic effect between the iron complex (Fe16) and ampicillin (AMP) was performed using ζ-potential, infrared spectra and FICI index calculated from the minimum inhibitory concentration (MIC) from the checkerboard assay. Cytotoxic properties of combination Fe16 + AMP was evaluated on eukaryotic cell line. Impact of combination Fe16 + AMP on chosen genes of S. aureus were performed by Quantitative Real-Time PCR. The MIC of Fe16 + AMP was significantly lower than that of AMP and Fe16 alone. Furthermore, the infrared spectroscopy revealed the change in the ζ-potential of Fe16 + AMP. We demonstrated the ability of Fe16 + AMP to disrupt the bacterial membrane of S. aureus and that likely allowed for better absorption of AMP. In addition, the change in gene expression of bacterial efflux pumps at the sub-inhibitory concentration of AMP suggests an insufficient import of iron into the bacterial cell. At the same time, Fe16 + AMP did not have any cytotoxic effects on keratinocytes. Combined Fe16 + AMP therapy demonstrated significant synergistic and antimicrobial effects against S. aureus. This study supports the potential of combination therapy and further research.
A long-term exposure of bacteria to zinc oxide and zinc oxide nanoparticles leads to major alterations in bacterial morphology and physiology. These included biochemical and physiological processes ...promoting the emergence of strains with multi-drug resistance and virulence traits. After the removal of zinc pressure, bacterial phenotype reversed back to the original state; however, certain changes at the genomic, transcriptomic, and proteomic level remained. Why is this important? The extensive and intensive use of supplements in animal feed effects the intestinal microbiota of livestock and this may negatively impact the health of animals and people. Therefore, it is crucial to understand and monitor the impact of feed supplements on intestinal microorganisms in order to adequately assess and prevent potential health risks.
For decades, the antimicrobial applications of nanoparticles (NPs) have attracted the attention of scientists as a strategy for controlling the ever‐increasing threat of multidrug‐resistant ...microorganisms. The photo‐induced antimicrobial properties of titanium dioxide (TiO2) NPs by ultraviolet (UV) light are well known. This review elaborates on the modern methods and antimicrobial mechanisms of TiO2 NPs and their modifications to better understand and utilize their potential in various biomedical applications. Additional compounds can be grafted onto TiO2 nanomaterial, leading to hybrid metallic or non‐metallic materials. To improve the antimicrobial properties, many approaches involving TiO2 have been tested. The results of selected studies from the past few years covering the most recent trends in this field are discussed in this review. There is extensive evidence to show that TiO2 NPs can exhibit certain antimicrobial features with disputable roles of UV light. Hence, they are effective in treating bacterial infections, although the majority of these conclusions came from in vitro studies and in the presence of some additional nanomaterials. The methods of evaluation varied depending on the nature of the research while researchers incorporated different techniques, including determining the minimum inhibitory concentration, cell count, and using disk and well diffusion methods, with a noticeable indication that cell count was the most and dominant criterion used to evaluate the antimicrobial activity.
This article is categorized under:
Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Therapeutic Approaches and Drug Discovery > Emerging Technologies
Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease
Application of different types of TiO2 nanoparticles as antimicrobial agents.
Bacterial biofilms are composed of a consortium of bacteria that communicate with each other through quorum sensing. Therefore, bacteria can form an extracellular matrix, which is a mucus composed of ...exopolysaccharides, peptidoglycans, and extracellular DNA, through these communication molecules. The matrix protects the community of bacteria from the adverse effects of the external environment, including antibiotics, biocides, and eradicating agents. Self‐propelled functional microrobots offer great promises in the biomedical field. The self‐propelled microrobots represent an innovative platform in microrobotic research, aiming to have an important role in the biomedical field. One of the potential applications is removal of bacterial biofilms. Herein, the specific design of multifunctional microrobots is demonstrated using antimicrobial‐designed peptides for eradication of methicillin‐resistant Staphylococcus aureus (MRSA)‐produced biofilms. The designed microrobots can perform various tasks, including autonomous navigation toward bacterial cells, mechanical entry into bacterial biofilms, and blockage of the replication of bacterial DNA by indolicidin peptides. The implemented design extends the microrobot applications not only to the removal of biological aggregates but also to the delivery and release of drugs or even target manipulation, demonstrating their great potential for use in biomedical research.
This study demonstrate simultaneous manipulation of microrobots motion and targeted antimicrobial activity. The peptide modified microrobots exhibit excellent selectivity and antimicrobial performance against methicillin‐resistant Staphylococcus aureus (MRSA) biofilm eradication. It shows a general strategy for targeted delivery of microrobots and boosting of antimicrobial effect against resistant MRSA biofilms.
The objective of the study was to assess cytotoxicity (based on the dimethylthiazol–diphenyltetrazolium bromide cell viability assay) and antimicrobial effects of poly(lactictide-co-glycolide) ...nanoparticles with entrapped mupirocin (PLGA/MUP NPs) on
Staphylococcus aureus
and methicillin-resistant
S. aureus
(MRSA) strains using a disk-diffusion method, cryo-scanning electron microscopy (cryo-SEM) and fluorescence microscopy. Based on the evaluation of the growth curve, PLGA/MUP NPs inhibited growth of the both tested strains already at a concentration of 0.29 µg/ml, and their inhibitory effect at concentrations from 0.29 to 1.17 µg/ml was comparable with free MUP using the disk-diffusion method. PLGA/MUP NPs also tended to increase the abundance of the dead cells of MRSA, but not of
S. aureus
, in comparison with free MUP when evaluated by fluorescence microscopy. Further, cryo-SEM evaluation demonstrated an antibacterial-inhibitory effect of PLGA/MUP NPs on
S. aureus
in a dose-dependent manner. On the other hand, PLGA/MUP NPs cytotoxic activity tended to be substantially lower in comparison with both free MUP and empty PLGA NPs. It can be concluded that the excellent biocompatibility and satisfactory antibacterial effects of PLGA/MUP NPs constitute a suitable alternative as far as cutaneous wound healing is concerned.
The objective of the study was to design, synthetize and characterize poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) with entrapped fish oil (FO) for possible application in a cutaneous ...wound healing. Morphology of NPs was evaluated by transmission electron microscopy. Antimicrobial characteristics were tested using the disk diffusion method and plate count method, and cytotoxicity was evaluated by the MTT assay. Fish oil (y) was released from PLGA NPs within the time interval (x) of 96 h according to equation y = 6.2 + 0.914x. PLGA-FO NPs did not affect growth of
Staphylococcus aureus
or methicillin-resistant
S. aureus
(MRSA) strains. No cytotoxic effect of the tested NPs on the keratinocyte cell line was observed for concentration of 1 µg/ml. PLGA-FO NPs represent an interesting alternative for wound healing due to an excellent biocompatibility and unique release profile of FO, despite their lack of antimicrobial efficiency.
This thesis deals with mikrobiology of curd and selected curd products. It describes the microbiological quality and curd products, their unwanted contamination by micro-organisms. Contamination ...occurs most often during production. The most common con-taminating microorganisms are gram – negative bacteria, yeats and fungi. It defines their negative impact on the quality of curd and curd products. It further characterizes other possible contaminants tnat can cause foodborne disease in humans. The thesis also describes technologically important lactic acid bacteria. Part of the thesis is an experi-mental microbiological analysis of curd and curd products during storage. Relatively low numbers of contaminating microorganisms were found. Higher numbers of microor-ganisms showed samples after expiration date and samples of Budapest spread contai-ning flavoring components.
