Мандельштам и Гераклит

The article proves that the ontological poetics of Osip Mandelstam and one of his sources of the concept of the word lie in the doctrine of the Logos of Heraclitus of Ephesus, which is set in the surviving fragments of his treatise On Nature. The author comments on the explicit and hidden references of Mandelstam to Heraclitus and shows the specifics of the functional refraction of Heraclitic allusions in different periods of the Acmeist poet’s work.It is noted that Mandelstam received from Heraclitus the material-being and sensually perceived the integral and hypostatic idea of the Logos as a kind of cosmic law, and at the same time as an ordinary human word, the form of which can nevertheless conceal an analogy with the laws of the world order.Like Heraclitus, Mandelstam assumes that the universe (cosmos) has different stages of formation, controlled by the Logos. According to Heraclitus, the primary basis of the world, its material root is fire. The idea of the changing state of natural substances, their mutual transitions and transformations caused by the “world fire,” which goes back to Heraclitus, permeates a number of the poet’s works written in the era of social upheavals. In the “post-revolutionary” period, Mandelstam develops the idea of the unity of the world and aeonic time, based on Heraclitus. Heraclitic overtones are discerned in a number of Mandelstam’s poems of the 1920s and 30s, including one of his final works – Poems about the Unknown Soldier.In light of the discovered references, Mandelstam, with the sayings of Heraclitus, clarified a number of aesthetic ideas and tropic moves of the poet – for example, the idea of the correlation of how sound envelops speech and its meaning; the motive is the “fluidity” of the world and at the same time its structural unity; the method of the “reversible metaphor of,” marking the identity or paradoxical union of different and sometimes antinomic phenomena.В статье доказывается, что одним из источников концепции слова и онтологической поэтики Осипа Мандельштама является учение о Логосе Гераклита Эфесского, изложенное в сохранившихся фрагментах его трактата «О природе». Прокомментированы явные и выявлены скрытые отсылки Мандельштама к Гераклиту и показана специфика функционального преломления гераклитовских аллюзий в разных периодах творчества поэта-акмеиста. Отмечается, что Мандельштам воспринял от Гераклита свойственное ему материально-бытийственное и чувственно воспринимаемое, целостное и в то же время ипостазированное представление о Логосе как о некоем космическом законе, и одновременно об обычном человеческом слове, форма которого тем не менее может таить в себе аналогию с законами мироустройства. Как и Гераклит, Мандельштам предполагает, что мироздание (космос) имеет разные стадии формообразования, управляемые Логосом. По Гераклиту, первоосновой мира, его материальным первотолчком является огонь. Восходящая к Гераклиту идея изменчивого состояния природных субстанций, их взаимопереходов и превращений, вызванных «мировым пожаром», пронизывает целый ряд произведений поэта, написанных в эпоху социальных потрясений. В «постреволюционный» период Мандельштам разрабатывает идею единства мира и эонического времени с опорой на Гераклита. Гераклитовские подтексты угадываются в ряде стихотворений Мандельштама 1920–30-х гг., в том числе и в одном из его итоговых произведений – «Стихах о неизвестном солдате». В свете обнаруженных перекличек Мандельштама с изречениями Гераклита проясняется ряд эстетических идей и тропеических ходов поэта, например, идея соотнесенности звуковой оболочки слова и его смысла; мотив «текучести» мира и одновременно его структурного единства; прием «обратимой метафоры», знаменующей тождество или парадоксальное объединение различных, и порою антиномичных явлений

Effect of daptomycin and vancomycin on Staphylococcus epidermidis biofilms: An in vitro assessment using fluorescence in situ hybridization

Colonization of in-dwelling catheters by microbial biofilms is a major concern in patient health eventually leading to catheter-related blood stream infections. Biofilms are less susceptible to standard antibiotic therapies that are effective against planktonic bacteria. Standard procedure for the detection of microorganisms on the catheter tip is culture. However, viable but non-culturable cells (VBNCs) may be missed. The aim of this study was to evaluate the use of fluorescence in situ hybridization (FISH) as an indicator to visualize and quantify the effect of the antibiotics daptomycin and vancomycin on biofilms in situ. We established an in vitro catheter biofilm model of Staphylococcus epidermidis biofilms on polyurethane catheters. Biofilm activity was measured by FISH and correlated to colony forming units (CFU) data. Digital image analysis was used for quantification of total biofilm mass and the area of the FISH positive biofilm cells. FISH showed a pronounced effect of both antibiotics on the biofilms, with daptomycin having a significantly stronger effect in terms of both reduction of biofilm mass and number of FISH-positive cells. This supports the anti-biofilm capacity of daptomycin. Interestingly, neither antibiotic was able to eradicate all of the FISH-positive cells. In summary, FISH succeeded in visualization, quantification, and localization of antibiotic activity on biofilms. This technique adds a new tool to the arsenal of test systems for anti-biofilm compounds. FISH is a valuable complementary technique to CFU since it can be highly standardized and provides information on biofilm architecture and quantity and localization of survivor cells

From Conception to Text: Paradoxes of Incompleteness

Three unfinished texts by Akhmatova ("Poem without a Hero", sketches of a ballet libretto for "A Poem without a Hero" and "Prose about a Poem") became the object of the paper.В статье рассматриваются три незавершенных текста А. Ахматовой ("Поэма без героя", наброски балетного либретто к "Поэме без героя" и "Проза о поэме")

A short artificial antimicrobial peptide shows potential to prevent or treat bone infections.

Infection of bone is a severe complication due to the variety of bacteria causing it, their resistance against classical antibiotics, the formation of a biofilm and the difficulty to eradicate it. Antimicrobial peptides (AMPs) are naturally occurring peptides and promising candidates for treatment of joint infections. This study aimed to analyze the effect of short artificial peptides derived from an optimized library regarding (1) antimicrobial effect on different bacterial species, (2) efficacy on biofilms, and (3) effect on osteoblast‑like cells. Culturing the AMP-modifications with Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus (including clinical isolates of MRSA and MSSA) and Staphylococcus epidermidis identified one candidate that was most effective against all bacteria. This AMP was also able to reduce biofilm as demonstrated by FISH and microcalorimetry. Osteoblast viability and differentiation were not negatively affected by the AMP. A cation concentration comparable to that physiologically occurring in blood had almost no negative effect on AMP activity and even with 10% serum bacterial growth was inhibited. Bacteria internalized into osteoblasts were reduced by the AMP. Taken together the results demonstrate a high antimicrobial activity of the AMP even against bacteria incorporated in a biofilm or internalized into cells without harming human osteoblasts

J.W. Goethe’s “Faust” code in A. Akhmstova’s poem “Without a hero”

A new aspect of intertextuality research of Anna Akhmatova’s “Poem without a hero” is suggested in this article. Authors identify quotational and reminiscent layers of the J.W. Goethe’s tragedy “Faust”. They also show that each of the many references to Goethe is a structure-forming principle towards the poem’s text. It structures the poem on different layers starting from motives and images ending in its composition. Artistic functions of Faust and Mephistopheles images who were intentionally included in the poem are considered. Interconnection with “Faust” opening plot is also presented. The situation when infernal powers come to the character who summoned them by the means of magic ritual (fortunetelling) is analyzed. The motives of devil carnival in “Poem without a hero” (with its references to “Night Brocken”) are compared with the motives of “Walpurgis night” in “Faust”. Leitmotivs of “poisoned wine”, “Golden Age”, “Dark Crime”, “pangs of conscience” in Akhmatova’s poem are conformable to the main story lines in Goethe’s tragedy. It is proved that Akhmatova’s appeals to Goethe were based not only on the original text but also on the translation by N.A. Kholodkovsky

Effect of Quorum Sensing Molecule Farnesol on Mixed Biofilms of Candida albicans and Staphylococcus aureus

This article belongs to the Special Issue Microbial Biofilms, Antimicrobials, and Virulence Determinants.The natural bioactive molecule farnesol (FAR) is widely studied mainly for its antibiofilm and antimicrobial properties. In addition, it increases the effectiveness of some antimicrobial substances, which makes it interesting for the development of combined therapy. In the present work, the effect of FAR either alone or in combination with oxacillin (OXA) on mixed biofilms formed by clinically relevant pathogens, Candida albicans and Staphylococcus aureus, was studied. S. aureus isolates used for biofilm formation originated from blood cultures and central venous catheters (CVC) were characterized in terms of antimicrobial resistance. The minimal biofilm inhibitory concentration (MBIC50) for FAR of 48 h mixed biofilms formed by the C. albicans and methicillin-sensitive S. aureus (MSSA) was determined to be 125 M, and for the mixed biofilms with methicillin-resistant S. aureus (MRSA) was determined to be 250 M. Treatment of mixed biofilms with OXA (2 mg/mL) showed 4% inhibition; however, the combination of OXA (2 mg/mL) and FAR (300 M) resulted in 80% inhibition of biofilms. In addition, planktonic cells of S. aureus exhibited an increased susceptibility to OXA, cefoxitin and kanamycin in the presence of FAR (150 and 300 M). Scanning electron microscopy (SEM) micrographs confirmed patchy biofilm and lack of candidal hyphae in the samples treated with FAR and FAR/OXA in comparison to control and mixed biofilms treated only with OXA. Intriguingly, in a pilot experiment using fluorescence in situ hybridization (FISH), considerable differences in activity (as indicated by ribosome content) of staphylococcal cells were detected. While the activity rate of the staphylococci in mixed biofilms treated with FAR was high, no FISH-positive signal for staphylococcal cells was found in the biofilm treated with FAR/OXA.This research was funded by the Slovak Research and Development Agency under contracts of SK-PT-18-0006 as part of the Bilateral Cooperation Program (2019–2022), APVV-21-0302 and APVV-18-0075. This work was also supported by the EU Grant number 952398—CEMBO, Call: H2020-WIDESPREAD-05-2020—Twinning.info:eu-repo/semantics/publishedVersio

Activity of daptomycin- and vancomycin-loaded poly-epsilon-caprolactone microparticles against mature staphylococcal biofilms.

The aim of the present study was to develop novel daptomycin-loaded poly-epsilon-caprolactone (PCL) microparticles with enhanced antibiofilm activity against mature biofilms of clinically relevant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and polysaccharide intercellular adhesin-positive Staphylococcus epidermidis. Daptomycin was encapsulated into PCL microparticles by a double emulsion-solvent evaporation method. For comparison purposes, formulations containing vancomycin were also prepared. Particle morphology, size distribution, encapsulation efficiency, surface charge, thermal behavior, and in vitro release were assessed. All formulations exhibited a spherical morphology, micrometer size, and negative surface charge. From a very early time stage, the released concentrations of daptomycin and vancomycin were higher than the minimal inhibitory concentration and continued so up to 72 hours. Daptomycin presented a sustained release profile with increasing concentrations of the drug being released up to 72 hours, whereas the release of vancomycin stabilized at 24 hours. The antibacterial activity of the microparticles was assessed by isothermal microcalorimetry against planktonic and sessile MRSA and S. epidermidis. Regarding planktonic bacteria, daptomycin-loaded PCL microparticles presented the highest antibacterial activity against both strains. Isothermal microcalorimetry also revealed that lower concentrations of daptomycin-loaded microparticles were required to completely inhibit the recovery of mature MRSA and S. epidermidis biofilms. Further characterization of the effect of daptomycin-loaded PCL microparticles on mature biofilms was performed by fluorescence in situ hybridization. Fluorescence in situ hybridization showed an important reduction in MRSA biofilm, whereas S. epidermidis biofilms, although inhibited, were not eradicated. In addition, an important attachment of the microparticles to MRSA and S. epidermidis biofilms was observed. Finally, all formulations proved to be biocompatible with both ISO compliant L929 fibroblasts and human MG63 osteoblast-like cells

Aerococcus urinae – A potent biofilm builder in endocarditis

The diagnosis of infective endocarditis (IE) remains a challenge. One of the rare bacterial species recently associated with biofilms and negative cultures in infective endocarditis is Aerococcus urinae. Whether the low number of reported cases might be due to lack of awareness and misidentification, mainly as streptococci, is currently being discussed. To verify the relevance and biofilm potential of Aerococcus in endocarditis, we used fluorescence in situ hybridization to visualize the microorganisms within the heart valve tissue. We designed and optimized a specific FISH probe (AURI) for in situ visualization and identification of A. urinae in sections of heart valves from two IE patients whose 16S rRNA gene sequencing had deteced A. urinae. Both patients had a history of urinary tract infections. FISH visualized impressive in vivo grown biofilms in IE, thus confirming the potential of A. urinae as a biofilm pathogen. In both cases, FISH/PCR was the only method to unequivocally identify A. urinae as the only causative pathogen for IE. The specific FISH assay for A. urinae is now available for further application in research and diagnostics. A. urinae should be considered in endocarditis patients with a history of urinary tract infections. These findings support the biofilm potential of A. urinae as a virulence factor and are meant to raise the awareness of this pathogen

Limiting Factors in Treatment Success of Biofilm-Forming Streptococci in the Case of Canine Infective Endocarditis Caused by Streptococcus canis

An 8-year-old male Rhodesian Ridgeback was presented with fever and severe thrombocytopenia. Clinical and laboratory examination, echocardiography, blood culture, and pathohistology revealed evidence of infective endocarditis, ischemic renal infarcts, and septic encephalitis. Treatment was started immediately but the dog’s condition worsened, and the dog had to be euthanized. The causative Streptococcus canis strain was detected by blood culture and MALDI-TOF MS and analyzed using whole-genome sequencing and multilocus sequence typing. Antibiotic susceptibility testing did not detect any resistance. The affected heart valve was analyzed using FISH imaging, which showed a streptococcal biofilm on the heart valve. Bacteria in biofilms are recalcitrant to antibiotic treatment. Early diagnosis could be beneficial to treatment outcome. Treatment of endocarditis could be improved by researching the optimal dosage of antibiotics in conjunction with the use of biofilm-active drugs