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dr hab. inż. Piotr Szweda
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- Associate professor at Department of Pharmaceutical Technology and Biochemistry
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total: 81
Catalog Publications
Year 2018
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Investigation of the Antifungal Activity and Mode of Action of Thymus vulgaris, Citrus limonum, Pelargonium graveolens, Cinnamomum cassia, Ocimum basilicum, and Eugenia caryophyllus Essential Oils
PublicationThe antimicrobial activity of plant oils and extracts has been recognized for many years. In this study the activity of Thymus vulgaris, Citrus limonum, Pelargonium graveolens, Cinnamomum cassia, Ocimumbasilicum, and Eugenia caryophyllus essential oils (EOs) distributed by Pollena Aroma (Nowy Dwór Mazowiecki, Poland) was investigated against a group of 183 clinical isolates of C. albicans and 76 isolates of C. glabrata. All of...
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Isolation of Bacteriocin-producing Staphylococcus spp. Strains from Human Skin Wounds, Soft Tissue Infections and Bovine Mastitis
PublicationA collection of 206 Staphylococcus spp. isolates was investigated for their ability to produce compounds exhibiting antistaphylococcal activity. This group included Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus xylosus strains recovered from bovine mastitis (n = 158) and human skin wounds and soft tissues infections (n = 48). Production of substances with antimicrobial activity was observed in six strains. Five...
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Rapid Evaluation of Poultry Meat Shelf Life Using PTR-MS
PublicationThe use of proton transfer reaction mass spectrometry (PTR-MS) for freshness classification of chicken and turkey meat samples was investigated. A number of volatile organic compounds (VOCs) were selected based on the correlation (> 95%) of their concentration during storage at 4 °C over a period of 5 days with the results of the microbial analysis. In order to verify if the selected compounds are not sample-specific, a number...
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Study of the Anti-Staphylococcal Potential of Honeys Produced in Northern Poland
PublicationThe antimicrobial activity of 144 samples of honeys including 95 products from apiaries located in Northern Poland was evaluated. The antibacterial activity of those natural products, their thermal stability, and activity in the presence of catalase was investigated by microdilution assays in titration plates. The MTT assay was performed for the determination of anti-biofilm activity. Spectrophotometric assays were used for the...
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The Antimicrobial Potential of Bacteria Isolated from Honey Samples Produced in the Apiaries Located in Pomeranian Voivodeship in Northern Poland
PublicationThe principal objective of this study was to determine whether the honeys produced in apiaries located in Pomeranian Voivodeship (Northern Poland) contain bacteria producing metabolites with growth inhibition potential against important human and animal pathogens. The pathogens included Staphylococcus aurues, Staphyloccocus epidermidis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Candida albicans. From...
Year 2019
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Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones as a New Class of Antistaphylococcal Agents: Synthesis and Biological Evaluation
PublicationThe development and spread of resistance of human pathogenic bacteria to the action of commonly used antibacterial drugs is one of the key problems in modern medicine. One of the especially dangerous and easily developing antibiotic resistant bacterial species is Staphylococcus aureus. Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones 22–38 have been developed as novel effective antistaphylococcal agents. These compounds have been...
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Gas‐Phase Removal of Indoor Volatile Organic Compounds and Airborne Microorganisms Over Mono‐ and Bimetal‐Modified (Pt, Cu, Ag) Titanium(IV) Oxide Nanocomposites
PublicationThe photocatalytic deactivation of volatile organic compounds and mold fungi using TiO2 modified with mono‐ and bimetallic (Pt, Cu, Ag) particles is reported in this study. The mono‐ and bimetal‐modified (Pt, Cu, Ag) titanium(IV) oxide photocatalysts were prepared by chemical reduction method and characterized using XRD, XPS, DR/UV‐Vis, BET and TEM analysis. The effect of incident light, type and content of mono‐ and bimetallic...
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Method-Dependent Epidemiological Cutoff Values for Detection of Triazole Resistance in Candida and Aspergillus Species for the Sensititre YeastOne Colorimetric Broth and Etest Agar Diffusion Methods
PublicationAlthough the Sensititre Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole, and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method/agent-dependent) 11,171 Candida albicans, 215 C. dubliniensis, 4,418 C. glabrata species complex,...
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The Anti-Staphylococcal Potential of Ethanolic Polish Propolis Extracts
PublicationAbstract: The principal objective of this study was to determine the anti-staphylococcal potential of ethanol extracts of propolis (EEPs). A total of 20 samples of propolis collected from apiaries located in different regions of Poland were used in the study. The two-fold broth microdilution method revealed some important differences in the antimicrobial activity of investigated EEPs. Up to the concentration of 4096 µg/mL no activity...
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Voriconazole-Based Salts Are Active against Multidrug-Resistant Human Pathogenic Yeasts
PublicationVoriconazole (VOR) hydrochloride is unequivocally converted into VOR lactates and valinates upon reaction with silver salts of organic acids. This study found that the anticandidal in vitro activity of these compounds was comparable or slightly better than that of VOR. The Candida albicans clinical isolate overexpressing CaCDR1/CaCDR2 genes, highly resistant to VOR, was apparently more susceptible to VOR salts. On the other hand,...
Year 2020
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Draft genome sequence of antimicrobial producing Paenibacillus alvei strain MP1 reveals putative novel antimicrobials
PublicationA Paenibacillus strain isolated in previous research exhibited antimicrobial activity against relevant human pathogens including Staphylococcus aureus and Listeria monocytogenes. In this study, the genome of the aforementioned strain, designated as MP1, was shotgun sequenced. The draft genome of strain MP1 was subject to multiple genomic analyses to taxonomically characterize it and identify the genes potentially responsible for...
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Effect of Ethanol Extracts of Propolis (EEPs) against Staphylococcal Biofilm—Microscopic Studies
PublicationStaphylococci growing in the form of biofilm exhibit high resistance to a plethora of antibiotics. The aim of the study was to assess the influence of ethanolic extract of propolis (EEPs) on S. epidermidis ATCC 35984 biofilm using fluorescent microscopy. Propidium iodide (PI) and SYTO 9 were used for differentiation of live and dead cells, and calcofluor white was used to stain the extracellular matrix, the self-produced extracellular...
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Influence of Two-Stage Anodization on Properties of the Oxide Coatings on the Ti–13Nb–13Zr Alloy
PublicationThe increasing demand for titanium and its alloys used for implants results in need of such innovative surface treatment that may jointly increase corrosion resistance and biocompatibility, and demonstrate antibacterial protection at no cytotoxicity. The purpose of this research was to characterize the effect of two-stage anodization, performed for 30 min in phosphoric acid, at the presence of hydrofluoric acid in the second stage....
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New Approaches for Escherichia coli Genotyping
PublicationEasy-to-perform, fast, and inexpensive methods of differentiation of Escherichia coli strains beyond the species level are highly required. Herein two new, original tools for genotyping of E. coli isolates are proposed. The first of the developed method, a PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) test uses a highly variable fliC gene, encoding the H antigen as a molecular target. The designing...
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Paenibacillus alvei MP1 as a Producer of the Proteinaceous Compound with Activity against Important Human Pathogens, Including Staphylococcus aureus and Listeria monocytogenes
PublicationAn emerging need for new classes of antibiotics is, on the one hand, evident as antimicrobial resistance continues to rise. On the other hand, the awareness of the pros and cons of chemically synthesized compounds’ extensive use leads to a search for new metabolites in already known reservoirs. Previous research showed that Paenibacillus strain (P. alvei MP1) recovered from a buckwheat honey sample presented a wide spectrum of...
Year 2021
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Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020
PublicationThe aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were...
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Bee Bread Exhibits Higher Antimicrobial Potential Compared to Bee Pollen
PublicationThis study aimed at investigation of the antimicrobial potential of ethanolic extracts of bee bread (BB) and bee pollen (BP) and suspensions of these products in MHB (Mueller Hinton Broth). We covered 30 samples of BP and 19 samples of BB harvested in Polish apiaries. Slightly lower activity was observed against Gram-negative bacteria compared to Gram-positive staphylococci. BB extracts exhibited higher inhibitory potential with...
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Bee Pollen and Bee Bread as a Source of Bacteria Producing Antimicrobials
PublicationThe principal objective of the study was the isolation and identification of bacteria that are present in mature bee bread (BB) and dried (ready for selling and consumption) bee pollen (BP). Obtained isolates were screened for their potential to inhibit select human pathogenic bacteria and their ability to produce enzymes of particular industrial importance. Four and five samples of BP and BB, respectively, were used for the study....
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Honey antibacterial activity: A neglected aspect of honey quality assurance as functional food
PublicationBackground Honey is considered as a functional food with health-promoting properties. Its potent antibacterial and antibiofilm effects are the major attributes of so called ‘medical-grade honey’ which is topically used for the treatment of burns, wounds and skin disorders. Nevertheless, the current set of honey quality parameters adopted in the European Union do not include its biological properties. Furthermore, in light of the...
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Quest for the Molecular Basis of Improved Selective Toxicity of All-Trans Isomers of Aromatic Heptaene Macrolide Antifungal Antibiotics
PublicationThree aromatic heptaene macrolide antifungal antibiotics, Candicidin D, Partricin A (Gedamycin) and Partricin B (Vacidin) were subjected to controlled cis-trans to all trans photochemical isomerization. The obtained all-trans isomers demonstrated substantially improved in vitro selective toxicity in the Candida albicans cells: human erythrocytes model. This effect was mainly due to the diminished hemotoxicity. The molecular modeling...
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Synergistic Effects of Propolis Combined with 2-Phenoxyethanol and Antipyretics on the Growth of Staphylococcus aureus
PublicationThe present investigation aimed to assess the combinational effect of commonly usedantipyretics and antiseptics with ethanolic extracts of propolis (EEPs) on the growth inhibition ofStaphylococcus aureus. The broth microdilution checkerboard assay revealed synergistic interactionsbetween all investigated antipyretics, namely acetylsalicylic acid, ibuprofen, and acetaminophen,with EEPs samples. The values of the fractional inhibitory...
Year 2022
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Glucose oxidase as an important yet overlooked factor determiningthe antibacterial activity of bee pollen and bee bread
PublicationBee pollen (BP) and bee bread (BB) have attracted great attention due to their biological activities including antibacterial activity. However, the mechanism of antibacterial activity is largely unknown. Therefore, we aimed to characterise the antibacterial effect of BP and BB aqueous extracts against bacterial pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Enterococcus faecalis)...
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New Peptide Based Fluconazole Conjugates with Expanded Molecular Targets
PublicationInfections of Candida spp. etiology are frequently treated with azole drugs. Among azoles, the most widely used in the clinical scenario remains fluconazole (FLC). Promising results in treatment of dangerous, systemic Candida infections demonstrate the advantages of combined therapies carried out with combinations of at least two different antifungal agents. Here, we report five conjugates composed of covalently linked FLC and...
Year 2023
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Fatty acids as molecular carriers in cleavable antifungal conjugates
PublicationConjugates composed of C2-18 fatty acid (FA) residues as a molecular carrier and 5-fluorocytosine (5-FC) as an active agent, released upon the action of intracellular esterases on the ester bond between FA and “trimethyl lock” intramolecular linker, demonstrate good in vitro activity against human pathogenic yeasts of Candida spp. The minimal inhibitory concentrations (MIC) values for the most active conjugates containing caprylic...
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Hydrazinolysis Products of Selected Sugar Lactones—Crystal Structure and Microbiological Activity
PublicationCommercially available lactones, as well as those synthesized by us, turned out to be good substrates for the synthesis of sugar hydrazides. The exception was L-ascorbic acid, whose hydrazinolysis led to the formation of a hydrazinium salt, not the hydrazide as expected. The structure of all compounds was confirmed by NMR and X-ray analyses. The lower durability of hydrazinium L-ascorbate was additionally confirmed by thermogravimetric...
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Probiotic potential of Bacillus Isolates from Polish Bee Pollen and Bee Bread
PublicationThe main goal of this study was the evaluation of the probiotic potential of 10 Bacillus spp. strains isolated from 5 bee bread and 3 bee pollen samples. The antagonistic interaction with Staphylococcus aureus and Escherichia coli was a primary criterion for the preliminary selection of the isolates. Three out of ten strains—PY2.3 (isolated from pollen), BP20.15 and BB10.1 (both isolated from bee bread)—were found to be possible...
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Silver(I) complexes with nitrile ligands: New materials with versatile applications
PublicationIn the present study, the structure, thermal stability, conductive properties, and antimicrobial activity of silver(I) complexes with nitrile ligands were investigated. For the construction of the materials, 2-cyanopyridine (2-cpy), 4-cyanopyridine (4-cpy), 1,2-dicyanobenzene (1,2-dcb), and 1,3-dicyanobenzene (1,3-dcb) were used in addition to the silver nitrite and nitrate. Four new compounds were isolated and structurally characterized:...
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Synthesis, Antimicrobial and Mutagenic Activity of a New Class of d-Xylopyranosides
PublicationEight N-[2-(2′,3′,4′-tri-O-acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (1H, 13C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (Candida albicans, Candida glabrata) and bacteria (Staphylococcus aureus, Escherichia...
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Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland
PublicationKlebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended-spectrum beta-lactamases (ESBLs). Metallo-β-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates...
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Whole-genome sequencing and antimicrobial potential of bacteria isolated from Polish honey
PublicationThe aim of this study was the whole-genome analysis and assessment of the antimicrobial potential of bacterial isolates from honey harvested in one geographical location—the north of Poland. In total, 132 strains were derived from three honey samples, and the antimicrobial activity of CFAM (cell-free after-culture medium) was used as a criterion for strain selection and detailed genomic investigation. Two of the tested isolates...
Year 2024
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Oxolane Ammonium Salts (Muscarine-Like)—Synthesis and Microbiological Activity
PublicationCommercially available 2-deoxy-D-ribose was used to synthesize the appropriate oxolane derivative—(2R,3S)-2-(hydroxymethyl)oxolan-3-ol—by reduction and dehydration/cyclization in an acidic aqueous solution. Its monotosyl derivative, as a result of the quaternization reaction, allowed us to obtain eight new muscarine-type derivatives containing a quaternary nitrogen atom and a hydroxyl group linked to the oxolane ring. Their structure...
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