Structural and Double Layer Forces between Silica Surfaces in Suspensions of Negatively Charged Nanoparticles.

Direct force measurements between negatively charged silica microparticles are carried out in suspensions of like-charged nanoparticles with atomic force microscopy (AFM). In agreement with previous studies, oscillatory force profiles are observed at larger separation distances. At smaller distances, however, soft and strongly repulsive forces are present. These forces are caused by double layer repulsion between the like-charged surfaces and can be quantitatively interpreted with the Poisson-Boltzmann (PB) model. However, the PB model must be adapted to a strongly asymmetric electrolyte to capture the nonexponential nature of these forces. Thereby, the nanoparticles are modeled as highly charged co-ions, while the counter ions are monovalent. This model permits extraction of the effective charge of the nanoparticles, which is well comparable to the one obtained from electrophoresis. The PB model also explains the presence of a particle-free layer close to the interface.

Oscillatory structural forces between charged interfaces in solutions of oppositely charged polyelectrolytes.

Forces between negatively charged micron-sized silica particles were measured in aqueous solutions of cationic polyelectrolytes with an atomic force microscope (AFM). In these oppositely charged systems, damped oscillatory force profiles were systematically observed in systems at higher polyelectrolyte concentrations, typically around few g L-1. The wavelength of these oscillations is decreasing with increasing concentration. When the wavelength and concentration are normalized with the cross-over concentration, universal power-law dependence is found. Thereby, the corresponding scaling exponent changes from 1/3 in the dilute regime to 1/2 in the semi-dilute regime. This dependence is the same as in the like-charged systems, which were described in the literature earlier. This common behavior suggests that these oscillatory forces are related to the structuring of the polyelectrolyte solutions. The reason that the oppositely charged systems behave similarly to like-charged ones is that the former systems undergo a charge reversal due to the adsorption of the polyelectrolytes to the oppositely charged surface, whereby sufficiently homogeneous adsorbed layers are being formed. The main finding of the present study is that at higher polyelectrolyte concentrations such oscillatory forces are the rule, including the oppositely charged ones.

Structuring of colloidal silica nanoparticle suspensions near water-silica interfaces probed by specular neutron reflectivity.

Structuring of aqueous suspensions of colloidal silica nanoparticles near an isolated planar silica-water interface is studied by specular neutron reflectivity. The reflectivity data clearly show that the suspensions develop a damped, oscillatory concentration profile in the normal direction to the interface. The wavelengths of these oscillations agree well with those independently determined by direct force measurements in the slit-geometry. The reflectivity data further demonstrate that the oscillatory structure persists over several layers and that the first particle layer is separated from the interface by a particle-free region.

Towards control of cellulose biosynthesis by Komagataeibacter using systems-level and strain engineering strategies: current progress and perspectives.

The strains of the Komagataeibacter genus have been shown to be the most efficient bacterial nanocellulose producers. Although exploited for many decades, the studies of these species focused mainly on the optimisation of cellulose synthesis process through modification of culturing conditions in the industrially relevant settings. Molecular physiology of Komagataeibacter was poorly understood and only a few studies explored genetic engineering as a strategy for strain improvement. Only since recently the systemic information of the Komagataeibacter species has been accumulating in the form of omics datasets representing sequenced genomes, transcriptomes, proteomes and metabolomes. Genetic analyses of the mutants generated in the untargeted strain modification studies have drawn attention to other important proteins, beyond those of the core catalytic machinery of the cellulose synthase complex. Recently, modern molecular and synthetic biology tools have been developed which showed the potential for improving targeted strain engineering. Taking the advantage of the gathered knowledge should allow for better understanding of the genotype-phenotype relationship which is necessary for robust modelling of metabolism as well as selection and testing of new molecular engineering targets. In this review, we discuss the current progress in the area of Komagataeibacter systems biology and its impact on the research aimed at scaled-up cellulose synthesis as well as BNC functionalisation. Key points • The accumulated omics datasets advanced the systemic understanding of Komagataeibacter physiology at the molecular level. • Untargeted and targeted strain modification approaches have been applied to improve nanocellulose yield and properties. • The development of modern molecular and synthetic biology tools presents a potential for enhancing targeted strain engineering. • The accumulating omic information should improve modelling of Komagataeibacter's metabolism as well as selection and testing of new molecular engineering targets.

Modifying the Cyanobacterial Metabolism as a Key to Efficient Biopolymer Production in Photosynthetic Microorganisms.

Cyanobacteria are photoautotrophic bacteria commonly found in the natural environment. Due to the ecological benefits associated with the assimilation of carbon dioxide from the atmosphere and utilization of light energy, they are attractive hosts in a growing number of biotechnological processes. Biopolymer production is arguably one of the most critical areas where the transition from fossil-derived chemistry to renewable chemistry is needed. Cyanobacteria can produce several polymeric compounds with high applicability such as glycogen, polyhydroxyalkanoates, or extracellular polymeric substances. These important biopolymers are synthesized using precursors derived from central carbon metabolism, including the tricarboxylic acid cycle. Due to their unique metabolic properties, i.e., light harvesting and carbon fixation, the molecular and genetic aspects of polymer biosynthesis and their relationship with central carbon metabolism are somehow different from those found in heterotrophic microorganisms. A greater understanding of the processes involved in cyanobacterial metabolism is still required to produce these molecules more efficiently. This review presents the current state of the art in the engineering of cyanobacterial metabolism for the efficient production of these biopolymers.

Questing Ixodes ricinus ticks (Acari, Ixodidae) as a vector of Borrelia burgdorferi sensu lato and Borrelia miyamotoi in an urban area of north-eastern Poland.

Green areas located within large cities, as natural ecotypes, are a convenient habitat for ticks and their use as recreational areas is associated with the potential risk of acquiring tick-borne diseases. This study estimated the I. ricinus tick density, prevalence of infection with Borrelia species and the diversity of these bacteria in a green urban area (Olsztyn) of north-eastern Poland, an endemic region of tick-borne diseases. The ticks were collected during spring and autumn of 2015, at sites differing in the degree of human pressure and habitat. Borrelia species detection, typing and a molecular phylogenetic analysis were carried out based on the sequenced flaB gene. The overall mean abundance of I. ricinus was 2.0 ± 1.55 ticks per 100 m2. The density of I. ricinus did not vary significantly between sites. According to semi-qualitative tick abundance categories, the collection sites were classified as 'very low' and 'low' tick abundance category. The overall infection rate of I. ricinus with Borrelia spirochaetes was 27.4%. The infection rate of adult ticks (42.0%) was three times higher than with nymphs (14.3%). Based on the restriction patterns and sequencing, B. afzelii (93.1%; 27/29), B. valaisiana 3.5% (1/29) and B. miyamotoi (3.5%; 1/29), related to the relapsing fever (RF) spirochaetes, were detected. No co-infections were found. Borrelia miyamotoi, detected for the first time in ticks in the north-eastern urban areas of Poland, was identical to isolates described as European-type. The Borrelia spirochaete infection rate of I. ricinus ticks in an urban area indicated a high risk of LB. Physicians should also be aware of B. miyamotoi infections among patients with a history of tick-bites in north-eastern Poland.

Dermacentor reticulatus ticks (Acari: Ixodidae) distribution in north-eastern Poland: an endemic area of tick-borne diseases.

Dermacentor reticulatus is the second most important tick species in Poland. Although the north-eastern region of Poland is considered typical for D. reticulatus and is treated as a contiguous area of Eastern populations of the meadow ticks, the occurrence of this tick species in this region to date has been recorded as separate foci. The present report supplements data on the geographical distribution of D. reticulatus in urban and natural biotopes of north-eastern Poland (Warmia and Mazury province). In 2015-2017 (during the springtime activity of ticks) adult questing D. reticulatus were found in 13 of 25 monitored localities. Six sites are located in urbanized areas, within the administrative borders of the city of Olsztyn and seven sites are in natural biotopes in the central part of Warmia and Mazury. A total of 398 adult D. reticulatus ticks, including 257 females and 141 males, were collected. A comparison of data grouped according to urban and natural type of area revealed no statistical differences between them. Taking into account the habitat type, the mean tick density was the highest in open landscapes. The identification of new foci D. reticulatus in the endemic areas of Lyme borreliosis, tick-borne encephalitis and canine babesiosis is crucial for determining the risk of diseases transmitted by ticks and taking proper preventive measures.

Helminths of European smelt Osmerus eperlanus (Linnaeus, 1758) in Lake Hancza and the Vistula Lagoon, with special regard to their zoonotic threats.

Reports published in recent years on the increased risk in the Baltic Sea of fish infection with larvae of nematodes potentially pathogenic to humans have prompted a study of European smelt Osmerus eperlanus with respect to the presence of these parasites in the Vistula Lagoon. Additionally, samples of this fish from Lake Hancza were comparatively considered. The body cavity, the surface of internal organs, the alimentary tract and the swimbladder of fish from two environmentally different water bodies were taken into account in the analysis. Only the tapeworm Proteocephalus longicollis was found in the alimentary tract of the fish from Lake Hancza. Depending on the period of study, the prevalence ranged from 60% to 100%, and the mean intensity from 11.5 to 42.0. The helminth fauna of smelt from the Vistula Lagoon was more diverse: Cystidicola farionis occurred with a prevalence from 25.9 to 75.0% and a mean intensity of infection from 2.7 to 66.0%, Proteocephalus longicollis and cystacanths of Corynosoma with a prevalence ranging in different years from 12.0 to 44.0% and from 14.8 to 50.0%, respectively. Zoonotic parasites, such as nematode larvae of the Anisakidae family (Contracaecum sp., Anisakis simplex), occurred in the intestine with a prevalence of 31%, 72% and 22% in consecutive years of the study.

[Watching dance of the molecules - CARS microscopy]. / Obserwujac tanczace molekuly - mikroskopia CARS.

CARS (Coherent Anti-Stokes Raman Scattering) microscopy is an imaging method for living cells visualization as well as for food or cosmetics material analysis without the need for staining. The near infrared laser source generates the CARS signal - the characteristic intrinsic vibrational contrast of the molecules in a sample which is no longer caused by staining, but by the molecules themselves. It provides the benefit of a non-toxic, non-destructive and almost noninvasive method for sample imaging. CARS can easily be combined with fluorescence confocal microscopy so it is an excellent complementary imaging method. In this article we showed some of the applications for this technology: imaging of lipid droplets inside human HaCaT cells and analysis of the composition of cosmetic products. Moreover we believe, that soon new fields of application become accessible for this rapidly developing branch of microscopy.

The prevalence of Trichomonas vaginalis infections in the population of Warminsko-Mazurskie voivodeship (North-Eastern Poland)

INTRODUCTION: Trichomonas vaginalis is considered to be the most common non-viral sexually transmitted infection. Trichomoniasis is not a reportable disease and due to this fact only estimates can be made about its incidence AIM OF THE STUDY: The aim of the study was to determine the prevalence of T. vaginalis in the female population of north-eastern Poland as well as to conduct an epidemiological analysis on the basis of the data from the years of 2009 ­ 2015 derived from the registers of the National Health Fund MATERIALS AND METHODS: In this study 300 women aged 19 ­ 50 were examined. Two vaginal swabs were taken from each patient. The first swab was used to prepare microscope slides, and stained with Giemsa stain. The second swab was used for a diagnostic immunochromatographic rapid test (OSOM Trichomonasis test). Each woman was also asked to complete a questionnaire. Additionally, on the basis of the data from the National Health Fund, epidemiological analysis was conducted. Statistical analysis was performed with SPSS Statistics ver. 24 using Fisher test RESULTS: T. vaginalis infection was confirmed in two women. The diagnosis of trichomoniasis was confirmed as a result of T.vaginalis antigen detection with the use of immunochromatographic diagnostic test (OSOM Trichomonas test). The data from the National Health Fund show that 160 cases of trichomoniasis were reported, of which women accounted for 135 (84%), and men for 25 (16%). The highest infection rate was found in women aged 50 ­ 59 and those over 60 years old CONCLUSIONS: Our results show that the prevalence of T. vaginalis infection remains low, the infection occurs mainly in elderly women. However, one should pay attention to the differences in the detection of T. vaginalis connected with a particular method used. Conducting screen tests on a larger scale using more advanced tests would allow a more accurate assessment of the scale of the problem in our country

Kinetics of silver nanoparticle deposition at PAH monolayers: reference QCM results.

The deposition kinetics of silver nanoparticles on Au/SiO2 /PAH substrate was studied under in situ conditions using the QCM method and the ex situ SEM imaging. Because of low dissipation, the Sauerbrey equation was used for calculating the mass per unit area (coverage). Measurements were done for various bulk suspension concentrations, flow rates, and ionic strengths. It was shown that particle deposition for the low coverage regime is governed by the bulk mass transfer step that results in a linear increase of the coverage with the time. A comparison of QCM and SEM results showed that the hydration of the silver monolayers was negligible. This allowed one to derive a universal kinetic equation that describes the mass transfer rates in the cell as a function of the bulk concentration, flow rate, and diffusion coefficient. Measurements were also performed for longer times and for various ionic strengths where the deposition kinetics and the maximum coverage of particles were determined. The experimental data confirmed a significant increase in the maximum coverage with ionic strength. This was interpreted as due to the decreasing range of the electrostatic interactions among deposited particles. These results were adequately interpreted in terms of the extended random sequential adsorption (eRSA) model. Additionally, it was shown that the QCM data matched the ex situ SEM results, indicating that the monolayer hydration was also negligible for higher coverage range. These results derived for the model silver nanoparticle system can be exploited as reference data for the interpretation of protein adsorption kinetics where the dry mass is needed in order to assess the extent of hydration.

The prevalence of intestinal parasites in children in preschools and orphanages in the Warmia-Masuria province (North-Eastern Poland).

OBJECTIVE: A comparison of the prevalence of intestinal parasites (IP) in preschoolers and orphans in the Warmia-Masuria province (Poland). MATERIAL AND METHODS: Between 2003-2006 fecal samples and perianal swabs from 1052 preschoolers and 859 orphans were tested on the basis of direct saline and iodine mount, decantation test and the adhesive cellophane tape method. RESULTS: 10.8% of preschoolers and 46,3% of orphans were infected with IP. Among the six detected IP species the E. vermicularis was the most common. Infections of E. vermicularis were diagnosed in 9.5% of preschoolers and 36,7% of orphans. There were statistically significant differences in the distribution of IP between males and females in preschools. IP infections were the most frequent among 7-year-old children, 19.1% in preschools and 65.7% in orphanages, respectively. In preschools, the prevalence of IP was higher among preschoolers from the rural area (17.3%) than from the urban area (10.3%). CONCLUSION: Orphans and children from rural areas, especially at the age of 7, should be covered by systematic screening with parasitic tests throughout all of Poland. In this group of children, enterobiasis is the main health problem. The promotion of the awareness of IP infections and their prevention among parents and educational staff is required.

Tick-Borne pathogens and defensin genes expression: A closer look at Ixodes ricinus and Dermacentor reticulatus.

The immune system of ticks, along with that of other invertebrates, is comparatively simpler than that of vertebrates, relying solely on innate immune responses. Direct antimicrobial defence is provided by the synthesis of antimicrobial peptides (AMPs), including defensins. The aim of this study was to investigate the differences in defensin genes expression between questing and engorged Ixodes ricinus (def1 and def2) and Dermacentor reticulatus (defDr) ticks, in the presence of selected pathogens: Borrelia spp., Rickettsia spp., Babesia spp., Anaplasma phagocytophilum, and Neoehrlichia mikurensis in the natural environment. After pathogen screening by PCR/qPCR, the expression of defensin genes in pathogen positive ticks and ticks without any of the tested pathogens, was analysed by reverse transcription qPCR. The results showed an increased expression of defensin genes in I. ricinus ticks after blood feeding and I. ricinus and D. reticulatus ticks during in cases of co-infection. In particular, the expression of defensins genes was higher in questing D. reticulatus than in questing and engorged I. ricinus ticks, when borreliae were detected. This study contributes to uncovering the expression patterns of defensin genes in the presence of several known tick pathogens, the occurrence of these pathogens and possible regulatory mechanisms of defensins in tick vector competence.

Main sources and predictive factors of folate intake in female university students.

OBJECTIVE: The study aimed to identify the main folate sources and examine socio-demographic and lifestyle determinants influencing folate intake among 1410 women aged 18 to 39. METHODS: Data were collected using a self-administered health and lifestyle questionnaire and a 5-d dietary record method. To assess folate intake in relation to the dietary reference intakes, the probability approach was used. Folate intake determinants were identified using multivariate-adjusted logistic regression models; odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: The average total folate intake among women was 311 ± 144 µg/day dietary folate equivalents. Vegetables (30.7%) and cereals (22.6%) were the most important folate sources. Foods fortified with folic acid were consumed by 20.6% of women, dietary supplements by 7.2%. More than half of the participants (55%) had a high probability of inadequate folate intake. The predictors of being in the highest tertile of folate intake (>303 versus <225 µg) were: physical activity (high versus low; OR: 2.97, 95% CI: 1.77-4.97), nutritional knowledge (high versus low; OR: 5.32, 95% CI: 2.82-10.1), following a vegetarian diet (yes versus no; OR: 6.13; 95% CI: 2.79-13.5), daily number of meals (≥5 versus ≤3; OR: 4.17, 95% CI: 2.38-7.32), excluding/including some foods (yes versus no; OR: 2.47; 95% CI: 1.41-4.31) and energy intake (3rd versus 1st tertile; OR:17.4, 95% CI: 11.1-27.4). CONCLUSION: Identifying factors associated with a higher intake of folate may be helpful in shaping public health nutrition policy. It allows the design of effective nutrition education programs to promote increased intake of folate in subgroups at risk of deficiency.

Visualising and quantifying the usefulness of new predictors stratified by outcome class: The U-smile method.

Binary classification methods encompass various algorithms to categorize data points into two distinct classes. Binary prediction, in contrast, estimates the likelihood of a binary event occurring. We introduce a novel graphical and quantitative approach, the U-smile method, for assessing prediction improvement stratified by binary outcome class. The U-smile method utilizes a smile-like plot and novel coefficients to measure the relative and absolute change in prediction compared with the reference method. The likelihood-ratio test was used to assess the significance of the change in prediction. Logistic regression models using the Heart Disease dataset and generated random variables were employed to validate the U-smile method. The receiver operating characteristic (ROC) curve was used to compare the results of the U-smile method. The likelihood-ratio test demonstrated that the proposed coefficients consistently generated smile-shaped U-smile plots for the most informative predictors. The U-smile plot proved more effective than the ROC curve in comparing the effects of adding new predictors to the reference method. It effectively highlighted differences in model performance for both non-events and events. Visual analysis of the U-smile plots provided an immediate impression of the usefulness of different predictors at a glance. The U-smile method can guide the selection of the most valuable predictors. It can also be helpful in applications beyond prediction.

Tick-borne pathogens in questing adults Dermacentor reticulatus from the Eastern European population (north-eastern Poland).

Dermacentor reticulatus is tick species with an expanding geographical range in Europe, which creates the possibility of spreading microorganisms of significant veterinary and medical importance. The study aimed to investigate the prevalence and genetic diversity of Rickettsia spp., Babesia spp., Borrelia spp. and Anaplasma phagocytophilum in adult D. reticulatus ticks from the Eastern European population in the urban and the natural biotopes of north-eastern Poland. Microorganisms were detected by PCR and identified by DNA sequencing. The overall infection rate of at least one of the pathogens was 29.6%. The predominantly was Rickettsia spp. (27.1%) (with R. raoultii-9.1%) followed by Babesia spp. (2.4%) with B. canis (1.5%) as the most frequent. Based on 18S rRNA gene sequence, three B. canis genotypes were revealed. The prevalence of R. raoultii and B. canis was significantly higher in ticks from natural biotopes. The infection rates of B. afzelii and A. phagocytophilum were determined at 0.9% and 0.3%, respectively. Co-infections were detected in 3.8% of infected ticks. In diagnosing tick-borne diseases in humans, tick-borne lymphadenopathy should not be excluded. The prevalence of different genotypes of B. canis suggests differences in the clinical picture of canine babesiosis in the area.

Experimental Calibration of a Homogeneous Substitute Material Model for Reinforced High-Performance Concrete Modeling.

The purpose of this work was to develop a substitute material model for the analysis of reinforced concrete structures. This paper presents proposals to solve the problem of limited calculation time, both to perform simulation models and to perform effective numerical or analytical analyses of structural elements in order to achieve results consistent with experimental results. Achieving this aim is conditional upon the determination of the material model parameters, taking into account the type of structure, the system of reinforcement, and the static strength-deformation parameters of the component materials. A universal procedure is proposed for determining the parameters of the substitute material model on the basis of the homogenization function, in which the homogenization coefficient is assumed as being equal to the effective reinforcement ratio of real reinforced concrete structural elements. In addition, the introduction of a new concrete constraint coefficient to this procedure, which corresponds to the proportionality coefficient of biaxial to uniaxial compressive strength, is proposed. On the basis of the conducted comparative analyses, the possibility of using the hypothetical substitute material model for the design of building elements and structures was confirmed. The average values of the obtained results for individual research series did not differ from the experimental results by more than 8.5%, for both the numerical and analytical models.

Do Dietary Supplements Affect Inflammation, Oxidative Stress, and Antioxidant Status in Adults with Hypothyroidism or Hashimoto's Disease?-A Systematic Review of Controlled Trials.

This systematic review aims to summarise the results of controlled trials on dietary supplements (DS) usage and inflammation, oxidative stress, antioxidant status, and thyroid parameter improvement in hypothyroidism (HT)/Hashimoto's thyroiditis (AIT) patients. The study protocol was registered with PROSPERO (no. CRD42022365149). A comprehensive search of the PubMed, Scopus, and Web of Science databases resulted in the identification of nineteen randomised controlled trials and three non-randomised studies for the review; three studies examined the effect of supplementation with vitamin D, twelve studies-with selenium, and seven studies-with other DS. Based on very limited evidence, the lack of influence of vitamin D supplementation on inflammatory parameters was found, while no studies have examined oxidative stress and antioxidant status parameters, and only one provided results for a single thyroid parameter after an intervention. Some evidence was found proving that selenium supplementation may decrease inflammation and improve thyroid parameters, but reaching a conclusion about its influence on oxidative stress and antioxidant status is not possible because of the insufficient number of studies. Additionally, due to examining other DS (e.g., multicomponent, Nigella sativa, and genistein) only in single studies, conclusions cannot be drawn. Further long-term, high-quality randomised controlled trials are necessary to better understand the influence of DS on inflammation, oxidative stress, and antioxidant status, as well as their potential to improve thyroid gland function in HT/AIT patients.

Neoehrlichia mikurensis-A New Emerging Tick-Borne Pathogen in North-Eastern Poland?

Neoehrlichia mikurensis is a new emerging tick-borne Gram-negative bacterium, belonging to the family Anaplasmataceae, the main vector of which in Europe is the tick Ixodes ricinus. N. mikurensis is responsible for neoehrlichiosis, occurring mostly in patients with underlying diseases. In the present study, a total of 348 I. ricinus and Dermacentor reticulatus ticks collected in north-eastern Poland were analyzed for the prevalence of N. mikurensis. A total of 140 questing ticks (124 of I. ricinus ticks and 16 D. reticulatus) collected with the flagging method and 208 ticks (105 and 103 I. ricinus and D. reticulatus, respectively) removed from dogs were selected for the study. cDNA (questing ticks) and total DNA (questing and feeding ticks) were analyzed by qPCR targeting the 16S rRNA gene of N. mikurensis. Positive samples were further analyzed by nested PCR and sequencing. The prevalence differed between ticks collected from vegetation (19.3%; 27/140) and ticks removed from dogs (6.7%; 14/208). The presence of the pathogen in questing and feeding D. reticulatus ticks was proven in Poland for the first time. In summary, our research showed that infections of ticks of both the most common tick species I. ricinus and D. reticulatus in north-eastern Poland are present and ticks collected from urban areas were more often infected than ticks from suburban and natural areas. The detection of N. mikurensis in I. ricinus and D. reticulatus ticks from north-eastern Poland indicates potential transmission risk for tick-bitten humans at this latitude.

Abundance of Ixodes ricinus Ticks (Acari: Ixodidae) and the Diversity of Borrelia Species in Northeastern Poland.

Monitoring the abundance of ticks and the prevalence of pathogens in ticks is an important activity in assessing the risk of tick-borne diseases and helps to develop preventive measures. This study aimed to estimate the density of Ixodes ricinus, the prevalence of Borrelia species, and their diversity in northeastern Poland. The overall mean I. ricinus density was 9.7 ticks/100 m2. There were no differences between years, subregions, or habitats of study. The Borrelia infection rate was higher in females (22.6%) and males (14.3%) than in nymphs 5.5% (MIR). The most infected ticks came from the eastern subregion (10.1%) where the incidence of borreliosis among the inhabitants was over 20% higher than in the other subregions. In the infected ticks, B. afzelii (38.3%) and B. garinii (34.5%) were predominant. B. bavariensis was confirmed in I. ricinus in Poland for the first time. The most polymorphic was B. garinii. B. miyamotoi (belonged to the European type) was identified as a mono-infection in 0.9% of ticks and in 1.5% as a co-infection with B. afzelii and with B. garinii. Besides the risk of borreliosis and co-infections with different Borrelia species, physicians should also be aware of B. miyamotoi infections among patients.