Insights into respiratory microbiome composition and systemic inflammatory biomarkers of bronchiectasis patients.

Unlabelled: The human microbiomes, including the ones present in the respiratory tract, are described and characterized in an increasing number of studies. However, the composition and the impact of the healthy and/or impaired microbiome on pulmonary health and its interaction with the host tissues remain enigmatic. In chronic airway diseases, bronchiectasis stands out as a progressive condition characterized by microbial colonization and infection.

Human nasal microbiota shifts in healthy and chronic respiratory disease conditions.

Background: An increasing number of studies investigate various human microbiotas and their roles in the development of diseases, maintenance of health states, and balanced signaling towards the brain. Current data demonstrate that the nasal microbiota contains a unique and highly variable array of commensal bacteria and opportunistic pathogens. However, we need to understand how to harness current knowledge, enrich nasal microbiota with beneficial microorganisms, and prevent pathogenic developments.

Immunogenicity of novel vB_EcoS_NBD2 bacteriophage-originated nanotubes as a carrier for peptide-based vaccines.

Non-infectious virus-like nanoparticles mimic native virus structures and can be modified by inserting foreign protein fragments, making them immunogenic tools for antigen presentation. This study investigated, for the first time, the immunogenicity of long and flexible polytubes formed by yeast-expressed tail tube protein gp39 of bacteriophage vB_EcoS_NBD2 and evaluated their ability to elicit an immune response against the inserted protein fragments. Protein gp39-based polytubes induced humoral immune response in mice, even without the use of adjuvant.

Air pollution-associated shifts in the human airway microbiome and exposure-associated molecular events.

Publications addressing air pollution-induced human respiratory microbiome shifts are reviewed in this article. The healthy respiratory microbiota is characterized by a low density of bacteria, fungi and viruses with high diversity, and usually consists of Bacteroidetes, Firmicutes, Proteobacteria, Actinobacteria, Fusobacteria, viruses and fungi. The air's microbiome is highly dependent on air pollution levels and is directly reflected within the human respiratory microbiome.

A polyamine acetyltransferase regulates the motility and biofilm formation of Acinetobacter baumannii.

Acinetobacter baumannii is a nosocomial pathogen highly resistant to environmental changes and antimicrobial treatments. Regulation of cellular motility and biofilm formation is important for its virulence, although it is poorly described at the molecular level. It has been previously reported that Acinetobacter genus specifically produces a small positively charged metabolite, polyamine 1,3-diaminopropane, that has been associated with cell motility and virulence.

Novel Antibiotic Resistance Genes Identified by Functional Gene Library Screening in and spp. Bacteria of Soil Origin.

As one of the most diverse habitats of microorganisms, soil has been recognised as a reservoir of both antibiotics and the antibiotic resistance genes (ARGs). Bacteria naturally inhabiting soil or water often possess innate ARGs to counteract the chemical compounds produced by competitors living in the same environment. When such bacteria are able to cause infections in immunocompromised patients, their strong innate antibiotic resistance mechanisms make treatment difficult.

The Impact of Intensive Fish Farming on Pond Sediment Microbiome and Antibiotic Resistance Gene Composition.

Aquaculture is a fast-growing animal food sector, and freshwater fish farming is particularly common in Central and Eastern Europe. As the biodiversity of fishery ponds is changed toward fulfilling the industrial needs, precautions should be taken to keep the system sustainable and protect the adjacent environment from possible damage. Due to risk of infectious diseases, antibiotics are used in aquaculture production systems.

Microbial and Antimicrobial Resistance Profiles of Microbiota in Common Carps () from Aquacultured and Wild Fish Populations.

In this study we analyzed differences in microbial composition and antimicrobial resistance profiles in common carp living in two different environments: fish ponds, where carp have been kept under the same growing conditions over the last 50 years, and from the wild. The results demonstrated that wild fish carry a great variety of bacterial species (448 species with a prevalence of at least 0.01% from the total number of reads).

The Toxin-Antitoxin Systems of the Opportunistic Pathogen of Environmental and Clinical Origin.

is a ubiquitous environmental bacterium that has recently emerged as a multidrug-resistant opportunistic pathogen causing bloodstream, respiratory, and urinary tract infections. The connection between the commensal environmental and the opportunistic pathogen strains is still under investigation. Bacterial toxin-antitoxin (TA) systems have been previously associated with pathogenic traits, such as biofilm formation and resistance to antibiotics, which are important in clinical settings.

Capsule Protects From Inter-Bacterial Competition Mediated by CdiA Toxin.

Currently, is considered as one of the most important infectious agents causing hospital acquired infections worldwide. It has been observed that many clinically important pathogens express contact-dependent growth inhibition (CDI) phenomenon, which modulates cell-cell and cell-environment interactions, potentially allowing bacteria to adapt to ever-changing conditions. Mainly, these systems are used for the inhibition of the growth of genetically different individuals within the same species.

Blp1 protein shows virulence-associated features and elicits protective immunity to Acinetobacter baumannii infection.

Background: Multidrug resistant Acinetobacter baumannii is one of the major infection agents causing nosocomial pneumonia. Therefore, new therapeutic approaches against this bacterium are needed. Surface-exposed proteins from bacterial pathogens are implicated in a variety of virulence-related traits and are considered as promising candidates for vaccine development.

The role of Acinetobacter baumannii response regulator BfmR in pellicle formation and competitiveness via contact-dependent inhibition system.

Background: Acinetobacter baumannii is one of the most important opportunistic pathogens responsible for hospital acquired infections. It displays multi-drug resistance profile and has the ability to colonize surfaces and persist under harsh conditions. A.

Microbial Diversity and Antimicrobial Resistance Profile in Microbiota From Soils of Conventional and Organic Farming Systems.

Soil is one of the biggest reservoirs of microbial diversity, yet the processes that define the community dynamics are not fully understood. Apart from soil management being vital for agricultural purposes, it is also considered a favorable environment for the evolution and development of antimicrobial resistance, which is due to its high complexity and ongoing competition between the microorganisms. Different approaches to agricultural production might have specific outcomes for soil microbial community composition and antibiotic resistance phenotype.

Surface-Related Features and Virulence Among Clinical Isolates Belonging to International Clones I and II.

currently represents one of the most important nosocomial infection agent due to its multidrug-resistance and a propensity for the epidemic spread. The strains belonging to the international clonal lineages I (IC I) and II (IC II) are associated with the hospital outbreaks and a high virulence. However, the intra and inter lineage-specific features of strains belonging to these most worldwide spread clones are not thoroughly explored.

The Toxin-Antitoxin Module From the Opportunistic Pathogen - Regulation, Activity, and Evolution.

is one of the major causes of hard to treat multidrug-resistant hospital infections. features contributing to its spread and persistence in clinical environment are only beginning to be explored. Bacterial toxin-antitoxin (TA) systems are genetic loci shown to be involved in plasmid maintenance and proposed to function as components of stress response networks.

Another Brick in the Wall: a Rhamnan Polysaccharide Trapped inside Peptidoglycan of .

Polysaccharides are ubiquitous components of the Gram-positive bacterial cell wall. In , a polysaccharide pellicle (PSP) forms a layer at the cell surface. The PSP structure varies among lactococcal strains; in MG1363, the PSP is composed of repeating hexasaccharide phosphate units.

Regulation of Cell Wall Plasticity by Nucleotide Metabolism in Lactococcus lactis.

To ensure optimal cell growth and separation and to adapt to environmental parameters, bacteria have to maintain a balance between cell wall (CW) rigidity and flexibility. This can be achieved by a concerted action of peptidoglycan (PG) hydrolases and PG-synthesizing/modifying enzymes. In a search for new regulatory mechanisms responsible for the maintenance of this equilibrium in Lactococcus lactis, we isolated mutants that are resistant to the PG hydrolase lysozyme.

Purification and characterization of a new β-lactamase OXA-205 from Pseudomonas aeruginosa.

Background: We have identified a novel class 1 integron (1503 bp), named In671 in a clinical Pseudomonas aeruginosa isolate. Integron sequence analysis revealed two gene cassettes, one coding for a new OXA-type β-lactamase designated as OXA-205 and the other coding for the aadB gene that is responsible for aminoglycoside resistance. The 266 amino acid sequence of OXA-205 revealed that this β-lactamase belongs to the Ambler class D showing highest sequence homology to the OXA-2 sub-lineage.

Surface proteome analysis of a natural isolate of Lactococcus lactis reveals the presence of pili able to bind human intestinal epithelial cells.

Surface proteins of Gram-positive bacteria play crucial roles in bacterial adhesion to host tissues. Regarding commensal or probiotic bacteria, adhesion to intestinal mucosa may promote their persistence in the gastro-intestinal tract and their beneficial effects to the host. In this study, seven Lactococcus lactis strains exhibiting variable surface physico-chemical properties were compared for their adhesion to Caco-2 intestinal epithelial cells.

Characterization of Escherichia coli dinJ-yafQ toxin-antitoxin system using insights from mutagenesis data.

Escherichia coli dinJ-yafQ operon codes for a functional toxin-antitoxin (TA) system. YafQ toxin is an RNase which, upon overproduction, specifically inhibits the translation process by cleaving cellular mRNA at specific sequences. DinJ is an antitoxin and counteracts YafQ-mediated toxicity by forming a strong protein complex.

Detection of methicillin-resistant Staphylococcus aureus using double duplex real-time PCR and dye Syto 9.

A screening method for methicillin-resistant Staphylococcus aureus (MRSA) using real-time polymerase chain reaction (PCR) and dye Syto 9 was developed and evaluated. The assay was based on the two duplex reactions run simultaneously. The detection reaction amplified staphylococcal cassette chromosome mec (SCCmec) right extremity sequences and S.

Tigecycline - how powerful is it in the fight against antibiotic-resistant bacteria?

Tigecycline is a semisynthetic analogue of earlier tetracyclines and represents the first member of a novel class of antimicrobials - glycylcyclines - recently approved for clinical use. It is active against a broad range of gram-negative and gram-positive bacterial species including clinically important multidrug-resistant nosocomial and community-acquired bacterial pathogens. The exact molecular basis of tigecycline action is not clear at present, although similarly to the tetracyclines, it has been shown to inhibit the translation elongation step by binding to the ribosome 30S subunit and preventing aminoacylated tRNAs to accommodate in the ribosomal A site.

An Escherichia coli asr mutant has decreased fitness during colonization in a mouse model.

The Escherichia coli asr gene, like its homologues in other enterobacteria, is strongly induced by low external pH. The E. coli asr mutant shows weakened ability to adapt to acidic pH.

Escherichia coli dinJ-yafQ genes act as a toxin-antitoxin module.

Bacterial toxin-antitoxin (TA) systems are operons that code for a stable toxic protein and a labile antitoxin. TA modules are widespread on the chromosomes of free-living Bacteria and Archaea, where they presumably act as stress response elements. The chromosome of Escherichia coli K-12 encodes four known TA pairs, as well as the dinJ-yafQ operon, which is hypothesized to be a TA module based on operon organization similar to known TA genes.