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International journal of molecular sciences 24(9), 8400 (2023). doi:10.3390/ijms24098400 special issue: "Special Issue "Biomaterials and Antimicrobial Materials for Orthopaedic Application" / Special Issue Editors: Dr. Seung Hun Lee, Guest Editor; Prof. Dr. Irena Maliszewska, Guest Editor", Published by Molecular Diversity Preservation International, Basel

Introduction. Extended-spectrum β-lactamase (ESβL)-producing Klebsiella pneumoniae is currently one of the most common causes of nosocomial infections worldwide. The study aimed to characterize antibiotic resistance profile, the prevalence of selected genes encoding ESβLs, virulence, and the genetic relationship in 139 K. pneumoniae isolates identified in John Paul II Specialist Hospital in Southern Poland, collected in 2016. Materials/Methods. Bacterial identification and the preliminary antibiotic susceptibilities was performed using the VI-TEK® 2 Compact automated system. Genes encoding ESβLs were amplified by CTX-Mplex PCR and PCR reactions. The presence of nine genes encoding virulence factors was studied by multiplex PCR. Clonality was investigated by PFGE after digestion with SpeI endonuclease. Results. K. pneumoniae were mostly recovered from the respiratory tract (40.3%), urine (32.4%), wound swabs (19.4%) and blood (5%). In summary, 82.7% of strains were classified as multidrug resistant (MDR). All isolates were confirmed as ESβL producers and carried bla CTX-M-type (85.6%), bla SHV (82%), bla TEM (77.7%), bla CTX-M-9 (75.6%) and bla CTX-M-1 (1.4%) in various combinations. Moreover, triple bla genes were observed in 72% of isolates. The most common virulence-as-sociated genes found among the isolates were entB (91.4%), ybtS (55.4%), iutA (55.4%), magA (53.2%), kfu (14.4%), K2 (11.5%), mrkD (10.1%), rmpA (7.9%) and allS (5%). The PFGE analysis identified 4 major clusters (A–D) comprising 61% of the entire collection. Conclusions. Our results indicate that the presence of a wide variety of MDR K. pneumoniae harbor ESβLs and virulence genes. Studies on molecular epidemiology of ESβL-producing K. pneumoniae isolates are needed, particularly for epidemiological surveillance in the hospital environment.

IntroductionMastitis is a widespread mammary gland disease of dairy cows that causes severe economic losses to dairy farms. Mastitis can be caused by bacteria, fungi, and algae. The most common species isolated from infected milk are, among others, Streptococcus spp., and Escherichia coli. The aim of our study was protein detection based on both in silico and in vitro methods, which allowed the identification of immunoreactive proteins representative of the following species: Streptococcus uberis, Streptococcus agalactiae, and Escherichia coli.MethodsThe study group included 22 milk samples and 13 serum samples obtained from cows with diagnosed mastitis, whereas the control group constituted 12 milk samples and 12 serum samples isolated from healthy animals. Detection of immunoreactive proteins was done by immunoblotting, while amino acid sequences from investigated proteins were determined by MALDI-TOF. Then, bioinformatic analyses were performed on detected species specific proteins in order to investigate their immunoreactivity.ResultsAs a result, we identified 13 proteins: 3 (molybdenum cofactor biosynthesis protein B, aldehyde reductase YahK, outer membrane protein A) for E. coli, 4 (elongation factor Tu, tRNA uridine 5-carboxymethylaminomethyl modification enzyme MnmG, GTPase Obg, glyceraldehyde-3-phosphate dehydrogenase) for S. uberis, and 6 (aspartate carbamoyltransferase, elongation factor Tu, 60 kDa chaperonin, elongation factor G, galactose-6-phosphate isomerase subunit LacA, adenosine deaminase) for S. agalactiae, which demonstrated immunoreactivity to antibodies present in serum from cows with diagnosed mastitis.DiscussionDue to the confirmed immunoreactivity, specificity and localization in the bacterial cell, these proteins can be considered considered potential targets in innovative rapid immunodiagnostic assays for bovine mastitis, however due to the limited number of examined samples, further examination is needed.

The stethoscope remains an indispensable diagnostic tool for medical students. Improper stethoscope hygiene may cause bacterial infections, including hospital-associated infections (HAIs), which challenge the Polish medical system. The study’s main objective was to evaluate the hygiene habits declared by medical students. Moreover, microbiological control with the characteristics of potentially pathogenic microorganisms was performed. The study included 66 medical students from the Faculty of Medicine at the Jagiellonian University Medical College in Cracow, Poland. The participants filled in an anonymous questionnaire. Stethoscope contamination was assessed through isolation, identification, testing of antibiotic resistance, and clonality of the isolates bacterial pathogens. The survey showed that only 30.3% of students cleaned their stethoscopes after each patient, and 1.5% never did this. Of the 66 stethoscopes tested, 100% were positive for bacterial growth. Staphylococcus spp. was the most frequently isolated contaminant (50.5%). The questionnaire results demonstrated the necessity of the validated procedures for cleaning the stethoscopes. Stethoscopes used by medical students are contaminated with numerous bacterial species, including multidrug-resistant organisms. The clonal structure of the MRSA and MRSE populations acquired from stethoscopes has been demonstrated. Our results confirm the possibility that these medical devices mediate the spread of hazardous pathogens in the hospital environment. Practical exercises are essential to forming the correct hygiene habits involving stethoscopes, which enable practicing and checking the correctness of the established skills.

Bone infections are a serious problem to cure, as systemic administration of antibiotics is not very effective due to poor bone vascularization. Therefore, many drug delivery systems are investigated to solve this problem. One of the potential solutions is the delivery of antibiotics from poly(L-actide-co-glycolide) (PLGA) nanoparticles suspended in the gellan gum injectable hydrogel. However, the loading capacity and release kinetics of the system based on hydrophilic drugs (e.g., gentamycin) and hydrophobic polymers (e.g., PLGA) may not always be satisfying. To solve this problem, we decided to use hydrophobized gentamycin obtained by ion-pairing with dioctyl sulfosuccinate sodium salt (AOT). Herein, we present a comparison of the PLGA nanoparticles loaded with hydrophobic or hydrophilic gentamycin and suspended in the hydrogel in terms of physicochemical properties, drug loading capacity, release profiles, cytocompatibility, and antibacterial properties. The results showed that hydrophobic gentamycin may be combined in different formulations with the hydrophilic one and is superior in terms of encapsulation efficiency, drug loading, release, and antibacterial efficacy with no negative effect on the NPs morphology or hydrogel features. However, the cytocompatibility of hydrophobic gentamycin might be lower, consequently more extensive study on its biological properties should be provided to evaluate a safe dose.

In this work, polymeric and bioactive glass (BG)-modified composite films were successfully loaded with polyphenols (PPh) extracted from sage. It was hypothesized that PPh, alone and in combination with BGs particles, would affect physicochemical and biological properties of the films. Furthermore, sol-gel-derived BG particles would serve as an agent for control the release of the polyphenolic compounds, and other important properties related to the presence of PPh. The results showed that polyphenolic compounds significantly modified numerous material properties and also acted as biologically active substances. On the one hand, PPh can be considered as plasticizers for PCL, on the other hand, they can act as coupling agent in composite materials, improving their mechanical performance. The presence of PPh in materials improved their hydrophilicity and apatite-forming ability, and also provided antioxidant activity. What is important is that the aforementioned properties and kinetics of PPh release can be modulated by the use of various concentrations of PPh, and by the modification of PCL matrix with sol-gel-derived BG particles, capable of binding PPh. The films containing the lowest concentration of PPh exhibited cytocompatibility, significantly increased alkaline phosphatase activity and the expression of bone extracellular matrix proteins (osteocalcin and osteopontin) in human normal osteoblasts, while they reduced intracellular reactive oxygen species production in macrophages. Furthermore, materials loaded with PPh showed antibiofilm properties against Gram positive and Gram negative bacteria. The results suggest that obtained materials represent potential multifunctional biomaterials for bone tissue engineering with a wide range of tunable properties., Graphical abstract Image 1, Highlights • PPh-loaded films showed improved hydrophilicity and calcium phosphate-forming ability. • The presence of PPh in the films improved mechanical properties and provided antioxidant activity. • PPh release kinetics can be modulated by the use of sol-gel-derived BG particles as PCL modifier. • Materials enriched with PPh showed antibiofilm properties against Gram‐positive and Gram‐negative bacteria. • Materials enriched with PPh showed anti-inflammatory properties and enhanced osteostimulative activity.

Background: The use of nanotechnology in the production of medical equipment has opened new possibilities to fight bacterial biofilm developing on their surfaces, which can cause infectious complications. In this study, we decided to use gentamicin nanoparticles. An ultrasonic technique was used for their synthesis and immediate deposition onto the surface of tracheostomy tubes, and their effect on bacterial biofilm formation was evaluated. Methods: Polyvinyl chloride was functionalized using oxygen plasma followed by sonochemical formation and the embedment of gentamicin nanoparticles. The resulting surfaces were characterized with the use of AFM, WCA, NTA, FTIR and evaluated for cytotoxicity with the use of A549 cell line and for bacterial adhesion using reference strains of S. aureus (ATCC® 25923™) and E. coli (ATCC® 25922™). Results: The use of gentamicin nanoparticles significantly reduced the adhesion of bacterial colonies on the surface of the tracheostomy tube for S. aureus from 6 × 105 CFU/mL to 5 × 103 CFU/mL and for E. coli from 1.655 × 105 CFU/mL to 2 × 101 CFU/mL, and the functionalized surfaces did not show a cytotoxic effect on A549 cells (ATTC CCL 185). Conclusions: The use of gentamicin nanoparticles on the polyvinyl chloride surface may be an additional supporting method for patients after tracheostomy in order to prevent the colonization of the biomaterial by potentially pathogenic microorganisms.

lt;bgt;Introduction:lt;/bgt; In hospitalized patients, tracheostomy tubes (TTs) are susceptible to colonization by biofilm- producing potentially pathogenic microorganisms (PPMs). Contact with TTs, which are situated in a critical region of the body with enormous microbial exposure, may lead to the emer-gence of resistant respiratory infections.lt;/brgt;lt;/brgt;lt;bgt;Objective:lt;/bgt; Our study aimed to isolate and identify Gram-positive and Gram-negative PPMs, mark their antibiotic resistance and determine the bacteriological pattern of the biofilm colonizing the TTs.lt;/brgt;lt;/brgt;lt;bgt;Methods:lt;/bgt; The study was conducted on 45 tracheostomy tubes obtained from 45 hospitalized adult patients with tracheostomy with intubation periods ranging from 1 to 28 days. Tracheal aspirates (TA) obtained from polyvinyl chloride (PVC) TTs were used for the analysis. Bacteria in biofilms were identified by standard microbiological techniques, tested for antibiotic resistance and phenotypic resistance according to the EUCAST guidelines and visualized by SEM.lt;/brgt;lt;/brgt;lt;bgt;Results:lt;/bgt; Out of 45 TTs, 100% were found to be positive in bacterial cultures with 58 PPM isolates (10 spe-cies) correlating well with the SEM findings. Overall, 72% of isolates were Gram-negative bacilli, followed by Gram-positive cocci (28%). Staphylococcus aureus was the predominant bacterium (identified in 35.5% of patients), followed by Klebsiella pneumoniae (identified in 23.8%). Among the Gram-negative PPMs, 50% of isolates were identified as multidrug-resistant (MDR), 8.6% as extremely drug-resistant (XDR) and 5.2% were pandrug-resistant (PDR).lt;/brgt;lt;/brgt;lt;bgt;Conclusions:lt;/bgt; Our study showed a rapid colonization of the TT surface by biofilm- producing PPMs. Patients with tracheosto- mies, also those with non-infectious conditions, were mainly colonized with highly re-sistant bacteria.

Streptococcus agalactiae (Group B Streptococcus, GBS) is an opportunistic pathogen, which asymptomatically colonizes the gastrointestinal and genitourinary tract of up to one third of healthy adults. Nevertheless, GBS carriage in pregnant women may lead to several health issues in newborns causing life threatening infection, such as sepsis, pneumonia or meningitis. Recommended GBS screening in pregnant women significantly reduced morbidity and mortality in infants. Nevertheless, intrapartum antibiotic prophylaxis, recommended following the detection of carriage or in case of lack of a carriage test result for pregnant women who demonstrate certain risk factors, led to the expansion of the adverse phenomenon of bacterial resistance to antibiotics. In our paper, we reviewed some immunogenic GBS proteins, i.e., Alp family proteins, β protein, Lmb, Sip, BibA, FsbA, ScpB, enolase, elongation factor Tu, IMPDH, and GroEL, which possess features characteristic of good candidates for immunodiagnostic assays for GBS carriage detection, such as immunoreactivity and specificity. We assume that they can be used as an alternative diagnostic method to the presently recommended bacteriological cultivation and MALDI.

The impact of polymer stereoregularity on its interactions with peptides, proteins and bacteria strains was studied for three stereoregular forms of poly(tert-butyl methacrylate) (PtBMA): isotactic (iso), atactic (at) and syndiotactic (syn) PtBMA. Principal component analysis of the time-of-flight secondary ion mass spectrometry data recorded for thin polymer films indicated a different orientation of ester groups, which in the case of iso-PtBMA are exposed away from the surface whereas for at-PtBMA and syn-PtBMA these are located deeper within the film. This arrangement of chemical groups modified the interactions of iso-PtBMA with biomolecules when compared to at-PtBMA and syn-PtBMA. For peptides, the affected interactions were explained by the preferential hydrogen bonding and electrostatic interaction between the exposed polar ester groups of iso-PtBMA and positively charged peptides. In turn, for protein adsorption no impact on the amount of adsorbed proteins was observed. However, the polymer stereoregularity influenced the orientation of immunoglobulin G and induced conformational changes in bovine serum albumin structure. Moreover, the impact of polymer stereoregularity occurred equally for their interactions with Gram-positive bacteria (S. aureus), which absorbed preferentially onto iso-PtBMA films as compared to two other stereoregularities.

Due to growing antimicrobial resistance to antibiotics, novel methods of treatment of infected wounds are being searched for. The aim of this research was to develop a composite wound dressing based on natural polysaccharides, i.e., gellan gum (GG) and a mixture of GG and alginate (GG/Alg), containing lipid nanoparticles loaded with antibacterial peptide—nisin (NSN). NSN-loaded stearic acid-based nanoparticles (NP_NSN) were spherical with an average particle size of around 300 nm and were cytocompatible with L929 fibroblasts for up to 500 µg/mL. GG and GG/Alg sponges containing either free NSN (GG + NSN and GG/Alg + NSN) or NP_NSN (GG + NP_NSN and GG/Alg + NP_NSN) were highly porous with a high swelling capacity (swelling ratio above 2000%). Encapsulation of NSN within lipid nanoparticles significantly slowed down NSN release from GG-based samples for up to 24 h (as compared to GG + NSN). The most effective antimicrobial activity against Gram-positive Streptococcus pyogenes was observed for GG + NP_NSN, while in GG/Alg it was decreased by interactions between NSN and Alg, leading to NSN retention within the hydrogel matrix. All materials, except GG/Alg + NP_NSN, were cytocompatible with L929 fibroblasts and did not cause an observable delay in wound healing. We believe that the developed materials are promising for wound healing application and the treatment of bacterial infections in wounds.

In this work, we automatically distinguish between different clones of the same bacteria species (Klebsiella pneumoniae) based only on microscopic images. It is a challenging task, previously seemed unreachable due to the high clones' similarity. For this purpose, we apply a multi-step algorithm with attention-based deep multiple instance learning, which returns parts of the image crucial to the prediction. Except for obtaining high accuracy, we introduce extensive explainability based on persistence homology, increasing the understandability and trust in the model. Our work opens a plethora of research pathways towards cheaper and faster epidemiological management.

Biofilms are complex structures formed by bacteria, fungi, or even viruses on biotic and abiotic surfaces, and they can be found in almost any part of the human body. The prevalence of biofilm-associated diseases has increased in recent years, mainly because of the frequent use of indwelling medical devices that create opportunities for clinically important bacteria and fungi to form biofilms either on the device or on the neighboring tissues. As a result of their resistance to antibiotics and host immunity factors, biofilms have been associated with the development or persistence of several clinically important diseases. The inability to completely eradicate biofilms drastically increases the burden of disease on both the patient and the healthcare system. Therefore, it is crucial to develop innovative ways to tackle the growth and development of biofilms. This review focuses on dental- and implant-associated biofilm infections, their prevalence in humans, and potential therapeutic intervention strategies, including the recent advances in pharmacology and biomedical engineering. It lists current strategies used to control the formation of clinically important biofilms, including novel antibiotics and their carriers, antiseptics and disinfectants, small molecule anti-biofilm agents, surface treatment strategies, and nanostructure functionalization, as well as multifunctional coatings particularly suitable for providing antibacterial effects to the surface of implants, to treat either dental- or implant-related bacterial infections.

Amorphous silicon oxycarbide (SiOC) based materials are customarily called black glasses. In this work, hermetic layers on the steel substrate based on amorphous SiOC were obtained. The material was modified with cerium ions. Based on the literature, Ce as the modifier is responsible for i.e. enhancement of the corrosion resistance of materials and their antibacterial properties. SiCeOC coatings were produced via ceramization of the polymeric precursors synthesized by the sol-gel method and deposited on the metallic substrates with the use of the dip-coating technique. Numerous structural and microstructural studies were applied for the examination. It was proven that cerium is present in the material in the form of the inclusions and the material might be described as the SiOC/CeO2 composite. The surface properties such as roughness, wettability and surface free energy were also analyzed. Corrosion resistance tests were also conducted to establish the influence of the modification with cerium ions on the characteristics of the basal material. The results illustrated that a limited amount of the modifier enhanced corrosion resistance of black glasses without changes in their structure. However, the modification does not promote Ce ion release and the antibacterial tests showed the materials do not possess antibacterial properties.

(1) Background: Due to the commonness of tracheotomy procedures and the wide use of biomaterials in the form of tracheostomy tubes (TTs), the problem of biomaterial-associated infections (BAIs) is growing. Bacterial colonization of TTs results in the development of biofilms on the surface of biomaterials, which may contribute to the development of invasive infections in tracheostomized patients. (2) Methods: Clinical strains of K. pneumoniae, isolated from TTs, were characterized according to their ability to form biofilms, as well as their resistance to antibiotics, whether they harbored ESβL genes, the presence of selected virulence factors and genetic diversity. (3) Results: From 53 patients, K.&nbsp, pneumoniae were detected in 18 of the TTs examined, which constitued 34% of all analyzed biomaterials. Three of the strains (11%) were ESβL producers and all had genes encoding CTX-M-1, SHV and TEM enzymes. 44.4% of isolates were biofilm formers, SEM demonstrating that K. pneumoniae formed differential biofilms on the surface of polyethylene (PE) and polyvinyl chloride (PVC) TTs in vitro. A large range of variation in the share of fimbrial genes was observed. PFGE revealed sixteen genetically distinct profiles. (4) Conclusions: Proven susceptibility of TT biomaterials to colonization by K. pneumoniae means that the attention of research groups should be focused on achieving a better understanding of the bacterial pathogens that form biofilms on the surfaces of TTs. In addition, research efforts should be directed at the development of new biomaterials or the modification of existing materials, in order to prevent bacterial adhesion to their surfaces.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an important bacterium of nosocomial infections. In this study, CRKP strains, which were mainly isolated from fecal samples of 14 patients in three wards of the hospital in the Silesia Voivodship, rapidly increased from February to August 2018. Therefore, we conducted microbiological and molecular studies of the CRKP isolates analyzed. Colonized patients had critical underlying diseases and comorbidities; one developed bloodstream infection, and five died (33.3%). Antibiotic susceptibilities were determined by the E-test method. A disc synergy test confirmed carbapenemase production. CTX-Mplex PCR evaluated the presence of resistance genes blaCTX-M-type, blaCTX-M-1, blaCTX-M-9, and the genes blaSHV, blaTEM, blaKPC-2, blaNDM-1, blaOXA-48, blaIMP, and blaVIM-1 was detected with the PCR method. Clonality was evaluated by Multi Locus Sequence Typing (MLST) and Pulsed Field Gel Electrophoresis (PFGE). Six (40%) strains were of XDR (Extensively Drug-Resistant) phenotype, and nine (60%) of the isolates exhibited MDR (Multidrug-Resistant) phenotype. The range of carbapenem minimal inhibitory concentrations (MICs, μg/mL) was as follows doripenem (16 to >32), ertapenem (> 32), imipenem (4 to > 32), and meropenem (> 32). PCR and sequencing confirmed the blaCTX-M-15, blaKPC-2, blaOXA-48, and blaVIM-1 genes in all strains. The isolates formed one large PFGE cluster (clone A). MLST assigned them to the emerging high-risk clone of ST147 (CC147) pandemic lineage harboring the blaOXA-48 gene. This study showed that the K. pneumoniae isolates detected in the multi-profile medical centre in Katowice represented a single strain of the microorganism spreading in the hospital environment.

Clostridium difficile (CD) infections are a growing threat due to the strain resistance to antibiotic treatment and the emergence of hypervirulent strains. One solution to this problem is the search for new vaccine antigens, preferably surface-localized that will be recognized by antibodies at an early stage of colonization. The purpose of the study was to assess the usefulness of novel immunoreactive surface proteins (epitopes) as potential vaccine antigens. Such approach might be tough to pursue since pathogens have acquired strategies to subvert adaptive immune response to produce humoral response against non-essential proteins for their survival. In this study CD surface proteins were isolated, immunoreactive proteins identified and mapped to select potential epitopes. The results of the study exclude the use of CD glyceraldehyde 3-phosphate dehydrogenase as a vaccine antigen, especially as a whole protein. Sequences P9 (201AAGNIVPNTTGAAKAI218) and P10 (224KGKLDGAAQRVPVVTG241) recognized by patients sera are conserved and widespread among CD strains. They show cross-reactivity with sera of people suffering from other bacterial infections and are recognized by sera of autoimmune disease patients. Our study documents that special care in analyzing the sequence of new epitope should be taken to avoid side effects prior to consider it as a vaccine antigen.

Background Lactobacilli play an important role in maintaining vaginal health and protection against bacterial infections in the genital tract. The aim of this study is to show the dynamics of changes of the vaginal and rectal Lactobacillus flora during pregnancy by using the Sanger sequencing method. Method The study included 31 healthy pregnant women without clinical signs of genitourinary infections. The material was taken in the three trimesters of pregnancy by vaginal and rectal swabs and grown on the MRS agar quantitatively to estimate the number of Lactobacillus spp. [CFU/ml]. Afterwards, 3 to 8 morphologically different lactobacilli colonies were taken for identification. Bacterial species identification was performed by 16 s rDNA sequence fragment analyses using the Sanger method. Results Among the patients tested, the most common species colonizing the vagina in the first trimester were: L. crispatus 29%, L. gasseri 19.4% and L. rhamnosus 16.1%, in the second trimester: L. crispatus 51.6%, L. gasseri 25.8%, L. rhamnosus 19.4% and L. amylovorus 16.1%, and in the third trimester the most common Lactobacillus species were: L. crispatus 25.8%, L. gasseri 25.8% and L. johnsonii 19.4%. In rectal species, the number decreased in the second and third trimesters in comparison to the first trimester (p = 0.003). An analysis of rectal dynamics showed that in the first trimester, the most common species were: L. johnsonii 19.4%, and L. plantarum 9.7%, in the second trimester: L. crispatus 9.7% and L. mucosae 6.5%, and in the third trimester: L. casei 9.7% and L. rhamnosus 9.7%. Individual dynamics of the Lactobacillus species composition showed variability, characterized by continuous, intermittent, or periodic colonization. The patients examined were mostly colonized by three Lactobacillus species in vagina (32.3%), whereas for the rectum, one Lactobacillus species during the whole pregnancy duration was common (32.3%). Conclusion This study showed that in the examined group of healthy, pregnant Polish women, the vaginal Lactobacillus flora, both qualitative and quantitative, was stable during the three subsequent trimesters. In contrast, the number of rectal Lactobacillus species dramatically decreased after the first trimester.

Introduction: The paper presents the phenotypic and molecular characteristics of the collection of 18 P. aeruginosa clinical isolates used as host indicators to study the lytic range of 12 phages against P. aeruginosa. Methods: The phages host ranges were assayed by spot tests. Phenotypic characteristics of strains was investigated by the API 20NE biochemical fingerprinting, oxidase tests, the production of pyocyanin, fluorescein and L-arginine dihydrolase. Resistance profiles were analyzed. The PCR method and sequencing were used to study the distribution the genes of alkaline protease (aprA), exotoxin A (exoA), elastase B (lasB), exotoxins (exoS/T/U/Y), phenazine modyfing genes (phzM, phzS) and to identify selected β-lactamases (blaGES, blaIMP, blaKPC, blaOXA-2, blaOXA-10, blaPER, blaSPM-1, blaSHV, blaTEM, blaVIM). Additionaly, the genetic diversity was investigated by PFGE.116 M. Brzychczy-Włoch i inni Nr 2-4 Results: Twenteen newly isolated P. aeruginosa phages were found to lyse 100% of the analyzed strains. Phages PAR_3 and PAR_10 exhibited the highest lytic activity against isolates, lysing, 77,8% strains tested. The other phages, PAR_9 and PAR_12, presented generally weaker activity against bacteria, lysing respectively, 50% and 44,4% of tested strains. AprA, exoA, phzM, phzS were presented in all strains; lasB in 77,8%. The most frequentlycombination of egzoenzyme genes S+/T+/U-/Y+ in 78% isolates was remarked. In collection, 18 different resistance profiles were observed and 44% isolates were classified as MDR. The blaGES was the most prevalent gene (44%), followed by blaSPM-1 and blaTEM detected in 17% and 11,1% isolates, respectively. BlaOXA-2 was detected in only 5,5% of all isolates. In PFGE method, 18 singletons (A-S) were identified. No relationship between resistance, virulence and PFGE groups was found. Conclusion: In summarize, all phages infect multiple host species and showed a broad lytic spectrum. All bacteria tested were infected by multiple phages and displayed a wide range of susceptibility. In general, we observed a high degree of genetic diversity and individuality of the studied P. aeruginosa collection, bacteriophage hosts.

This paper reports on the plasma electrolytic oxidation (PEO) of titanium alloy Ti-15Mo in baths containing zinc to obtain biomaterials with bacteriostatic and antibacterial properties. The Ti-15Mo surface was oxidised in a 0.1 M Ca(H

In this work we have investigated the effect of oxygen plasma treatment of graphenic surfaces and the introduction of functional groups on changes in work function, wettability, surface free energy and bacterial adhesion. The plasma parameters were adjusted (generator power:60 W, exposure time:20 min) to limit the modifications to the surface without changing the bulk structure. The parent and modified graphenic surfaces were thoroughly characterized by μRaman spectroscopy, thermogravimetry, scanning electron microscopy, contact angle, X-ray photoelectron spectroscopy, work function and microbiological tests. It was found that even the short time of plasma modification results in a significant increase in work function, surface free energy and hydrophilicity. The changes in surface chemistry stimulate also substantial changes in bacterial adhesion. The strong relationship between work function and adhesion of bacteria was observed for all the investigated strains (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli) whereas the bacterial colonization trend correlates with the bacterial zeta potential. The bacteria-graphenic surface interaction is discussed in terms of total interaction energy. The results point out the work function lowering of the graphenic biomaterial surface as an effective strategy for the infection risk limitation.

The physiological microbiota of the vagina is responsible for providing a protective barrier, but Some factors can disturb the balance in its composition. At that time, the amounts of the genus Lactobacillus decrease, which may lead to the development of infection and severe complications during pregnancy. The aim of the study was the analysis of the bacterial composition of the vagina in 32 Caucasian women at each trimester of pregnancy using the next-generation sequencing method and primers targeting V3-V4 regions. In the studied group, the dominant species were Lactobacillus iners, Lactobacillus gasseri, and Lactobacillusplantarum. Statistically significant differences in the quantitative composition between trimesters were observed in relation to Lactobacillus jensenii,Streptococcus agalactiae, Lactobacillus iners, Gardnerella spp. Out of the 32 patients, 20 demonstrated fluctuations within the genus Lactobacillus, and 9 of them, at different stages of pregnancy, exhibited the presence of potentially pathogenic microbiota, among others: Streptococcus agalactiae, Gardnerella spp., Atopobium vaginae, and Enterococcus faecalis. The composition of the vaginal microbiota during pregnancy was subject to partial changes over trimesters. Although in one-third of the studied patients, both the qualitative and quantitative composition of microbiota was relatively constant, in the remaining patients, physiological and potentially pathogenic fluctuations were distinguished.

This paper reports on the plasma electrolytic oxidation (PEO) of titanium alloy Ti-15Mo in baths containing zinc to obtain biomaterials with bacteriostatic and antibacterial properties. The Ti-15Mo surface was oxidised in a 0.1 M Ca(H2PO2)2 bath containing zinc compound particles: ZnO or Zn3(PO4)2. During the PEO process, the applied voltage was 300 V, and the current density was 150 mA∙cm−2. The surface morphology, roughness and wettability were determined. It has been noted that both roughness and wettability of Ti-15Mo alloy surface increased after PEO. EDX and XPS chemical composition analysis was carried out, and Raman spectroscopy was also performed indicating that Zn has been successfully incorporated into oxide layer. To investigate the antibacterial properties of the PEO oxide coatings, microbial tests were carried out. The bacterial adhesion test was performed using four different bacterial strains: reference Staphylococcus aureus (ATCC 25923), clinical Staphylococcus aureus (MRSA 1030), reference Staphylococcus epidermidis (ATCC 700296) and clinical Staphylococcus epidermidis (15560). Performed zinc-containing oxide coatings did not indicate the bacteria growth inducing effect. Additionally, the cytocompatibility of the formed oxide layers was characterised by MG-63 osteoblast-like live/dead tests. The surface bioactivity and cytocompatibility increased after the PEO process. The zinc was successfully incorporated into the titanium oxide layer. Based on the obtained results of the studies, it can be claimed that zinc-containing PEO layers can be an interesting course of bacteriostatic titanium biomaterials development.

Non-cytotoxic, temperature-responsive and antibacterial poly(di(ethylene glycol)methyl ether methacrylate) – POEGMA188 based nanocomposite coatings attached to a glass surface were successfully prepared using ATRP polymerization. The thickness, morphology and wettability of the resulting coatings were analyzed using ellipsometry, AFM and contact angle measurements, respectively. The strong impact of the thicknesses of the POEGMA188 grafted brush coatings and content of AgNPs on the morphology and temperature-induced wettability changes of the nanocomposite was demonstrated. In addition to the strong temperature-dependent antibacterial activity, the proposed nanocomposite coatings have no significant cytotoxic effect towards normal cells. Moreover, the slight anti-cancer effect of AgNPs may be suggested.

In the present work, deposition of poly(sebacic anhydride) PSBA loaded by amoxicillin, cefazolin, or vancomycin on a previously anodized Ti-15Mo surface is presented. PSBA loaded by the drug was deposited so as not to lose the functionality of the porous oxide layer microstructure. The morphology was evaluated using scanning electron microscopy, surface roughness, and wettability. The drug concentration was evaluated using high-performance liquid chromatography. It was determined that the drugs were loaded into coatings in the range of 35.2-122.87 μg/cm2 of Ti sample. The drugs released more than 16% after 0.5 hr of the hybrid coating immersion in artificial saliva. After 3 days, the PSBA coatings were degraded by 51.3 mol %, and after 7 days by 77.8 mol %, which makes it possible to load the material by different, biologically active substances. An antimicrobial investigation of Staphylococcus aureus (DSM 24167) and Staphylococcus epidermidis (ATCC 700296) confirmed the activity of the hybrid layers against the pathogens. Hybrid layer with vancomycin best inhibits the adhesion of the bacteria, whereas coatings with amoxicillin and cefazolin showed a much better bactericidal activity. In this article, the difference in the obtained results is discussed, as well as the possibility of the application of this functional material in biomedicine.

Most catalysts in use are supported systems where metallic or oxide active phases, usually nanocrystals, are spread over the surface of high-area carriers. Despite dynamic progress, the art and science of catalyst preparation still remain centre stage. Herein, the innovatively prepared catalysts using nonpathogenic bacteria to capture nanoparticles and deposit them on various supports by leveraging the microbial “race for the surface” is presented. It was demonstrated that bacteria are effective biocarriers for the capture, transport, and controlled dispersion of metallic (gold, platinum) and oxide (titania, magnetite) nanoparticles on carbon, alumina, zirconia, and cordierite support surfaces. Next, the bacteria are effectively removed with oxygen plasma or transformed into a carbon film of various compositions and morphologies. The conceptual proposal is substantiated by a feasibility study showing several successful preparations of various supported catalysts via the use of microorganisms, which may be extended to other applications.