RESUMEN

This study investigates the state of inclusivity in Ukrainian universities, focusing on the perceptions of university staff amid the country's ongoing sociopolitical transformations. Here we report on the perceptions of 820 staff members from various professional roles, including academic, management, and support positions, this research explored inclusivity through diverse lenses, encompassing work experience, interactions with students with disabilities, and self-identification with vulnerable groups. Most respondents assessed a moderate to high level of inclusivity, indicating a positive overall outlook on inclusive practices within these institutions. Notably, perceptions of inclusivity vary slightly across different professional roles, with academic staff expressing a marginally lower level of perceived inclusivity than their counterparts. However, these variations are not statistically significant, suggesting a uniform perception across staff categories. Furthermore, the study revealed that personal experience in working with students with disabilities does not substantially alter staff perceptions of inclusivity. Similarly, self-identification with vulnerable groups only marginally influences these perceptions. This suggests that while individual experiences and identities are factors in inclusivity perceptions, their impact is not profoundly different. This research contributes to understanding inclusivity in higher education, particularly within environments undergoing significant social and political changes.

Asunto(s)

RESUMEN

The genus Acinetobacter comprises both environmental and clinically relevant species associated with hospital-acquired infections. Among them, Acinetobacter baumannii is a critical priority bacterial pathogen, for which the research and development of new strategies for antimicrobial treatment are urgently needed. Acinetobacter spp. produce a variety of structurally diverse capsular polysaccharides (CPSs), which surround the bacterial cells with a thick protective layer. These surface structures are primary receptors for capsule-specific bacteriophages, that is, phages carrying tailspikes with CPS-depolymerizing/modifying activities. Phage tailspike proteins (TSPs) exhibit hydrolase, lyase, or esterase activities toward the corresponding CPSs of a certain structure. In this study, the data on all lytic capsule-specific phages infecting Acinetobacter spp. with genomes deposited in the NCBI GenBank database by January 2024 were summarized. Among the 149 identified TSPs encoded in the genomes of 143 phages, the capsular specificity (K specificity) of 46 proteins has been experimentally determined or predicted previously. The specificity of 63 TSPs toward CPSs, produced by various Acinetobacter K types, was predicted in this study using a bioinformatic analysis. A comprehensive phylogenetic analysis confirmed the prediction and revealed the possibility of the genetic exchange of gene regions corresponding to the CPS-recognizing/degrading parts of different TSPs between morphologically and taxonomically distant groups of capsule-specific Acinetobacter phages.

Asunto(s)

RESUMEN

Two novel virulent phages of the genus Obolenskvirus infecting Acinetobacter baumannii, a significant nosocomial pathogen, have been isolated and studied. Phages Brutus and Scipio were able to infect A. baumannii strains belonging to the K116 and K82 capsular types, respectively. The biological properties and genomic organization of the phages were characterized. Comparative genomic, phylogenetic, and pangenomic analyses were performed to investigate the relationship of Brutus and Scipio to other bacterial viruses and to trace the possible origin and evolutionary history of these phages and other representatives of the genus Obolenskvirus. The investigation of enzymatic activity of the tailspike depolymerase encoded in the genome of phage Scipio, the first reported virus infecting A. baumannii of the K82 capsular type, was performed. The study of new representatives of the genus Obolenskvirus and mechanisms of action of depolymerases encoded in their genomes expands knowledge about the diversity of viruses within this taxonomic group and strategies of Obolenskvirus-host bacteria interaction.

Asunto(s)

RESUMEN

This study examined burnout dynamics among Ukrainian academic staff during the full-scale war. A cross-sectional study was conducted twice: the first wave in July 2022 and the second in January 2023. To assess the burnout syndrome as the final outcome, the self-reported Maslach Burnout Inventory-Human Services adapted for socioeconomic professions by Vodopyanova was used and correlated with different characteristics. The results showed a significant positive trend in emotional exhaustion among Ukrainian academic staff, with females being more sensitive to war-related factors. The results demonstrate that prolonged stressful situations associated with the ongoing war and constant changes in professional conditions lead to significant depersonalization dynamics among academic staff of both sexes. For male academic staff, factors such as age and academic position become less significant for depersonalization. However, university relocation and migration processes were significant factors affecting female academic staff's' perception of effectiveness and accomplishment in their professional activities. The alarming dynamic of burnout levels detected among Ukrainian academic staff urges the national and institutional levels to take prompt actions to enhance the academic staff's mental health in the workplace for preserving not only the quality of higher education, but also human capital in war times for postwar recovery in Ukraine.

Asunto(s)

RESUMEN

Acinetobacter baumannii is a critical priority nosocomial pathogen that produces a variety of capsular polysaccharides (CPSs), the primary receptors for specific depolymerase-carrying phages. In this study, the tailspike depolymerases (TSDs) encoded in genomes of six novel Friunaviruses, APK09, APK14, APK16, APK86, APK127v, APK128, and one previously described Friunavirus phage, APK37.1, were characterized. For all TSDs, the mechanism of specific cleavage of corresponding A. baumannii capsular polysaccharides (CPSs) was established. The structures of oligosaccharide fragments derived from K9, K14, K16, K37/K3-v1, K86, K127, and K128 CPSs degradation by the recombinant depolymerases have been determined. The crystal structures of three of the studied TSDs were obtained. A significant reduction in mortality of Galleria mellonella larvae infected with A. baumannii of K9 capsular type was shown in the example of recombinant TSD APK09_gp48. The data obtained will provide a better understanding of the interaction of phage-bacterial host systems and will contribute to the formation of principles of rational usage of lytic phages and phage-derived enzymes as antibacterial agents.

Asunto(s)

RESUMEN

We report the genome sequence of bacteriophage KpS110, which infects Klebsiella pneumoniae, a multidrug-resistant encapsulated bacterium that causes severe community-acquired and hospital-acquired infections. The phage genome is 156,801 bp, with 201 open reading frames. KpS110 is most closely related to phages of the family Ackermannviridae at the genome and proteome levels.

RESUMEN

The polysaccharide capsule surrounding bacterial cell plays an important role in pathogenesis of infections caused by the opportunistic pathogen Acinetobacter baumannii by providing protection from external factors. The structures of the capsular polysaccharide (CPS) produced by A. baumannii isolates and the corresponding CPS biosynthesis gene clusters are highly diverse, although many of them are related. Many types of A. baumannii CPSs contain isomers of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid (DTNA). Three of these isomers, namely acinetaminic acid (l-glycero-l-altro isomer), 8-epiacinetaminic acid (d-glycero-l-altro isomer), and 8-epipseudaminic acid (d-glycero-l-manno isomer), have not been found so far in naturally occurring carbohydrates from other species. In A. baumannii CPSs, DTNAs carry N-acyl substituents at positions 5 and 7; in some CPSs, both N-acetyl and N-(3-hydroxybutanoyl) groups are present. Remarkably, pseudaminic acid carries the (R)-isomer and legionaminic acid carries the (S)-isomer of the 3-hydroxybutanoyl group. The review addresses the structure and genetics of biosynthesis of A. baumannii CPSs containing di-N-acyl derivatives of DTNA.

Asunto(s)

RESUMEN

Curtobacterium is a genus of Gram-positive bacteria within the order Actinomycetales. Some Curtobacterium species (C. flaccumfaciens, C. plantarum) are harmful pathogens of agricultural crops such as soybean, dry beans, peas, sugar beet and beetroot, which occur throughout the world. Bacteriophages (bacterial viruses) are considered to be potential curative agents to control the spread of harmful bacteria. Temperate bacteriophages integrate their genomes into bacterial chromosomes (prophages), sometimes substantially influencing bacterial lifestyle and pathogenicity. About 200 publicly available genomes of Curtobacterium species, including environmental metagenomic sequences, were inspected for the presence of sequences of possible prophage origin using bioinformatic methods. The comparison of the search results with several ubiquitous bacterial groups showed the relatively low level of the presence of prophage traces in Curtobacterium genomes. Genomic and phylogenetic analyses were undertaken for the evaluation of the evolutionary and taxonomic positioning of predicted prophages. The analyses indicated the relatedness of Curtobacterium prophage-derived sequences with temperate actinophages of siphoviral morphology. In most cases, the predicted prophages can represent novel phage taxa not described previously. One of the predicted temperate phages was induced from the Curtobacterium genome. Bioinformatic analysis of the modelled proteins encoded in prophage-derived regions led to the discovery of some 100 putative glycopolymer-degrading enzymes that contained enzymatic domains with predicted cell-wall- and cell-envelope-degrading activity; these included glycosidases and peptidases. These proteins can be considered for the experimental design of new antibacterials against Curtobacterium phytopathogens.

Asunto(s)

RESUMEN

A structurally diverse capsular polysaccharide (CPS) in the outer cell envelope plays an important role in the virulence of the important bacterial pathogen, Acinetobacter baumannii. More than 75 different CPS structures have been determined for the species to date, and many CPSs include isomers of a higher sugar, namely 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid. Recently, a novel isomer having the d-glycero-l-manno configuration (5,7-di-N-acetyl-8-epipseudaminic acid; 8ePse5Ac7Ac) has been identified in the CPS from A. baumannii clinical isolate RES-546 [Carbohydr. Res. 513 (2022) 108,531]. Here, the complete chemical structure of this CPS, designated K135, was elucidated. The CPS was found to have a branched tetrasaccharide K unit and to include the higher sugar as part of a 8ePse5Ac7Ac-(2 â†’ 6)-α-Gal disaccharide branching from a →3)-α-D-GlcpNAc-(1 â†’ 3)-ß-D-GlcpNAc-(1→ main chain. Assignment of glycosyltransferases encoded by the CPS biosynthesis gene cluster in the RES-546 genome enabled the first sugar of the K unit, and hence the topology of the K135 CPS, to be determined.

Asunto(s)

RESUMEN

In this study, several different depolymerases encoded in the prophage regions of Acinetobacter baumannii genomes have been bioinformatically predicted and recombinantly produced. The identified depolymerases possessed multi-domain structures and were identical or closely homologous to various proteins encoded in other A. baumannii genomes. This means that prophage-derived depolymerases are widespread, and different bacterial genomes can be the source of proteins with polysaccharide-degrading activities. For two depolymerases, the specificity to capsular polysaccharides (CPSs) of A. baumannii belonging to K1 and K92 capsular types (K types) was determined. The data obtained showed that the prophage-derived depolymerases were glycosidases that cleaved the A. baumannii CPSs by the hydrolytic mechanism to yield monomers and oligomers of the K units. The recombinant proteins with established enzymatic activity significantly reduced the mortality of Galleria mellonella larvae infected with A. baumannii of K1 and K92 capsular types. Therefore, these enzymes can be considered as suitable candidates for the development of new antibacterials against corresponding A. baumannii K types.

Asunto(s)

RESUMEN

PURPOSE: The pathological, clinical, and therapeutic features of colorectal cancer (CRC) depend on its anatomical localization. We investigated possible associations between the red blood cell distribution width (RDW) and CRC localization. METHODS: Two-hundred eighty-eight consecutive patients with CRC were retrospectively studied. Demographic, clinical, pathological and laboratory data were retrieved from clinical records and reports. RESULTS: Median RDW values were significantly higher in patients with right-sided CRC when compared to those with CRC in other localizations (16.2, IQR: 14.5-20.0 vs 13.8, IQR: 13.0-16.1, p < 0.0001). Anisocytosis was statistically associated to haemoglobin (Hb), mean haemoglobin concentration (MHC), and mean corpuscular volume (MCV) values in all the patient groups examined. A cut-off value of 14.3% was associated with right-sided localization with sensitivity and specificity of 76.3% and 64.2%, respectively (AUC 0.71). CONCLUSION: Median RDW values were significantly higher in right-sided CRC when compared to other tumour locations, and may represent an additional marker for differential diagnosis.

Asunto(s)

RESUMEN

The control of far-from-equilibrium physical systems, including active materials, requires advanced control strategies due to the non-linear dynamics and long-range interactions between particles, preventing explicit solutions to optimal control problems. In such situations, Reinforcement Learning (RL) has emerged as an approach to derive suitable control strategies. However, for active matter systems, it is an important open question how the mathematical structure and the physical properties determine the tractability of RL. In this paper, we demonstrate that RL can only find good mixing strategies for active matter systems that combine attractive and repulsive interactions. Using analytic results from dynamical systems theory, we show that combining both interaction types is indeed necessary for the existence of mixing-inducing hyperbolic dynamics and therefore the ability of RL to find homogeneous mixing strategies. In particular, we show that for drag-dominated translational-invariant particle systems, mixing relies on combined attractive and repulsive interactions. Therefore, our work demonstrates which experimental developments need to be made to make protein-based active matter applicable, and it provides some classification of microscopic interactions based on macroscopic behavior.

Asunto(s)

RESUMEN

High-pressure electron paramagnetic resonance (EPR) was used to measure translational diffusion coefficients (Dtr) of a TEMPONE spin probe in poly(D,L-lactide) (PDLLA) and swollen in supercritical CO2. Dtr was measured on two scales: macroscopic scale (>1 µm), by measuring spin probe uptake by the sample; and microscopic scale (<10 nm), by using concentration-dependent spectrum broadening. Both methods yield similar translational diffusion coefficients (in the range 5-10 × 10-12 m2/s at 40-60 °C and 8-10 MPa). Swollen PDLLA was found to be homogeneous on the nanometer scale, although the TEMPONE spin probe in the polymer exhibited higher rotational mobility (τcorr = 6 × 10-11 s) than expected, based on its Dtr. To measure distribution coefficients of the solute between the swollen polymer and the supercritical medium, supercritical chromatography with sampling directly from the high-pressure vessel was used. A distinct difference between powder and bulk polymer samples was only observed at the start of the impregnation process.

RESUMEN

Acinetobacter baumannii appears to be one of the most crucial nosocomial pathogens. A possible component of antimicrobial therapy for infections caused by extremely drug-resistant A. baumannii strains may be specific lytic bacteriophages or phage-derived enzymes. In the present study, we observe the biological features, genomic organization, and phage-host interaction strategy of novel virulent bacteriophage Aristophanes isolated on A. baumannii strain having K26 capsular polysaccharide structure. According to phylogenetic analysis phage Aristophanes can be classified as a representative of a new distinct genus of the subfamily Beijerinckvirinae of the family Autographiviridae. This is the first reported A. baumannii phage carrying tailspike deacetylase, which caused O-acetylation of one of the K26 sugar residues.

Asunto(s)

RESUMEN

Antibiotic resistance is a major public health concern in many countries worldwide. The rapid spread of multidrug-resistant (MDR) bacteria is the main driving force for the development of novel non-antibiotic antimicrobials as a therapeutic alternative. Here, we isolated and characterized three virulent bacteriophages that specifically infect and lyse MDR Klebsiella pneumoniae with K23 capsule type. The phages belonged to the Autographiviridae (vB_KpnP_Dlv622) and Myoviridae (vB_KpnM_Seu621, KpS8) families and contained highly similar receptor-binding proteins (RBPs) with polysaccharide depolymerase enzymatic activity. Based on phylogenetic analysis, a similar pattern was also noted for five other groups of depolymerases, specific against capsule types K1, K30/K69, K57, K63, and KN2. The resulting recombinant depolymerases Dep622 (phage vB_KpnP_Dlv622) and DepS8 (phage KpS8) demonstrated narrow specificity against K. pneumoniae with capsule type K23 and were able to protect Galleria mellonella larvae in a model infection with a K. pneumoniae multidrug-resistant strain. These findings expand our knowledge of the diversity of phage depolymerases and provide further evidence that bacteriophages and phage polysaccharide depolymerases represent a promising tool for antimicrobial therapy.

RESUMEN

Acinetobacter baumannii, one of the most significant nosocomial pathogens, is capable of producing structurally diverse capsular polysaccharides (CPSs) which are the primary receptors for A. baumannii bacteriophages encoding polysaccharide-degrading enzymes. To date, bacterial viruses specifically infecting A. baumannii strains belonging to more than ten various capsular types (K types) were isolated and characterized. In the present study, we investigate the biological properties, genomic organization, and virus-bacterial host interaction strategy of novel myovirus TaPaz isolated on the bacterial lawn of A. baumannii strain with a K47 capsular polysaccharide structure. The phage linear double-stranded DNA genome of 93,703 bp contains 178 open reading frames. Genes encoding two different tailspike depolymerases (TSDs) were identified in the phage genome. Recombinant TSDs were purified and tested against the collection of A. baumannii strains belonging to 56 different K types. One of the TSDs was demonstrated to be a specific glycosidase that cleaves the K47 CPS by the hydrolytic mechanism.

Asunto(s)

RESUMEN

Acinetobacter myovirus BS46 was isolated from sewage by J. S. Soothill in 1991. We have sequenced the genome of BS46 and found it to be almost unique. BS46 contains double-stranded DNA with a genome size of 94,068 bp and 176 predicted open reading frames. The gene encoding the tailspike that presumably possesses depolymerase activity toward the capsular polysaccharides of the bacterial host was identified.

RESUMEN

The K17 capsular polysaccharide (CPS) produced by Acinetobacter baumannii G7, which carries the KL17 configuration at the capsule biosynthesis locus, was isolated and studied by chemical methods along with one- and two-dimensional 1H and 13C NMR spectroscopy. Selective cleavage of the glycosidic linkage of a 2,4-diacetamido-2,4,6-trideoxy-d-glucose (d-QuiNAc4NAc) residue by (i) trifluoroacetic acid solvolysis or (ii) alkaline ß-elimination (NaOH-NaBH4) of the 4-linked D-alanine amide of a 2-acetamido-2-deoxy-d-galacturonic acid residue (d-GalNAcA6DAla) yielded trisaccharides that were isolated by Fractogel TSK HW-40 gel-permeation chromatography and identified by using NMR spectroscopy and high-resolution electrospray ionization mass spectrometry. The following structure was established for the trisaccharide repeat (K unit) of the CPS: →4)-α-d-GalpNAcA6dAla-(1→4)-α-d-GalpNAcA-(1→3)-ß-d-QuipNAc4NAc-(1→ . The presence of the itrA1 gene coding for the initial glycosylphosphotransferase in the KL17 gene cluster established the first sugar of the K unit as d-QuipNAc4NAc. KL17 includes genes for three transferases that had been annotated previously as glycosyltransferases (Gtrs). As only two Gtrs are required for the K17 structure and one d-GalpNAcA residue is modified by a d-alanine amide, these assignments were re-assessed. One transferase was found to belong to the ATPgrasp_TupA protein family that includes d-alanine-d-alanine ligases, and thus was renamed Alt1 (alanine transferase). Alt1 represents a novel family that amidate the carboxyl group of d-GalpNAcA or d-GalpA.

Asunto(s)

RESUMEN

In the present study, we investigate the biological properties and genomic organization of virulent bacteriophage AM24, which specifically infects multidrug-resistant clinical Acinetobacter baumannii strains with a K9 capsular polysaccharide structure. The phage was identified as a member of the family Myoviridae by transmission electron microscopy. The AM24 linear double-stranded DNA genome of 97,177 bp contains 167 open reading frames. Putative functions were assigned for products of 40 predicted genes, including proteins involved in nucleotide metabolism and DNA replication, packaging of DNA into the capsid, phage assembly and structural proteins, and bacterial cell lysis. The gene encoding the tailspike, which possesses depolymerase activity towards the corresponding capsular polysaccharides, is situated in the phage genome outside of the structural module, upstream of the genes responsible for packaging of DNA into the capsid. The data on characterization of depolymerase-carrying phage AM24 contributes to our knowledge of the diversity of viruses infecting different capsular types of A. baumannii.

Asunto(s)

RESUMEN

A new capsular polysaccharide (CPS) biosynthesis gene cluster, KL16, was found in the genome sequence of a clinical Acinetobacter baumannii ST25 isolate, D4. The variable part of KL16 contains a module of genes for synthesis of 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (5,7-di-N-acetylpseudaminic acid, Pse5Ac7Ac), a gene encoding ItrA3 that initiates the CPS synthesis with d-GlcpNAc, and two glycosyltransferase (Gtr) genes. The K16 CPS was studied by sugar analysis and Smith degradation along with 1D and 2D 1H and 13C NMR spectroscopy, and shown to be built up of linear trisaccharide repeats containing d-galactose (d-Gal), N-acetyl-d-glucosamine (d-GlcNAc), and Pse5Ac7Ac. The d-Galp residue is linked to the d-GlcpNAc initiating sugar via a ß-(1 → 3) linkage evidently formed by a Gtr5 variant, Gtr5K16, encoded in KL16. This reveals an altered or relaxed substrate specificity of this variant as the majority of Gtr5-type glycosyltransferases have previously been shown to form a ß-d-Galp-(1 → 3)-d-GalpNAc linkage. The ß-Psep5Ac7Ac-(2 → 4)-d-Galp linkage is predicted to be formed by the other glycosyltransferase, Gtr37, which does not match members of any known glycosyltransferase family.

Asunto(s)