Fate of cultured populations when exposed to moxifloxacin.

Given the current need for predictive persisting model for , we adopted a classical assay to study drug-tolerant bacterial persisters, focusing on the behavior of a small antibiotic-insensitive subpopulation during prolonged exposure to moxifloxacin. Our study showed a wide-ranging response of , depending on antibiotic concentration, growth stage of mycobacterial cultures, and the availability of potassium ions in the medium. Mid-logarithmic cultures, initially grown in either balanced or K-free medium, contained small sup-populations capable of prolonged and stable survival in the presence of moxifloxacin.

Bioaccumulation of molybdate ions by alkanotrophic Rhodococcus leads to significant alterations in cellular ultrastructure and physiology.

Alkanotrophic Rhodococcus strains from the Regional Specialised Collection of Alkanotrophic Microorganisms (acronym IEGM, www.iegmcol.ru) were screened for accumulation and sorption of MoO ions.

Phenotypic and metabolic adaptations of strain IEGM 1243 to separate and combined effects of diclofenac and ibuprofen.

Introduction: The increasing use of non-steroidal anti-inflammatory drugs (NSAIDs) has raised concerns regarding their environmental impact. To address this, understanding the effects of NSAIDs on bacteria is crucial for bioremediation efforts in pharmaceutical-contaminated environments. The primary challenge in breaking down persistent compounds lies not in the biochemical pathways but in capacity of bacteria to surmount stressors.

Distinct Effects of Moxifloxacin and Bedaquiline on Growing and 'Non-Culturable' .

has recently emerged as the cause of an increasing number of human infections worldwide. Unfortunately, it is highly resistant to existing drugs, and new specific agents to combat have not yet been found. The discovery of antibiotics that are effective not only against replicating but also against dormant and often recalcitrant cells is a daunting challenge.

Highly purified DNA-containing cell envelopes from fungi for direct use in PCR.

Efficient DNA sample preparation from fungi with the rigid cell walls is still critical for successful polymerase chain reaction (PCR), one of the basic platforms in molecular diagnostics of fungi, especially in medical mycology. Common methods that involve different chaotropes to yield DNA samples have found a limited application for fungi. Here we describe a novel procedure for efficient production of permeable fungal cell envelopes with DNA inside as suitable templates for PCR.

Biotransformation of (-)-Isopulegol by .

The ability of actinobacteria of the genus to biotransform the monoterpenoid (-)-isopulegol has been established for the first time. . strain IEGM 1362 was selected as a bacterium capable of metabolizing (-)-isopulegol to form new, previously unknown, 10-hydroxy () and 10-carboxy () derivatives, which may presumably have antitumor activity and act as respiratory stimulants and cancer prevention agents.

sp. nov., isolated from a thawing ancient ice wedge.

A novel actinobacterium, strain K3-2, was isolated in pure culture from a thawing ancient ice wedge at Mammoth Mountain (Eastern Siberia, Russia). Colonies of strain K3-2 were yellowish orange; cells had the fine structure typical of Gram-positive bacteria, were non-motile short rods and were non-spore-forming. Strain K3-2 was mesophilic (optimum growth at 28 °С), but capable of growing at 4 °С.

Prokaryotic community in Pleistocene ice wedges of Mammoth Mountain.

Ice wedges differ from other types of surface and underground glacial bodies and are widely spread in perennially frozen sub-Arctic regions, but the bacterial and archaeal diversity in these permafrost features remains poorly studied. Here, we compared the prokaryotic community composition in the active layer and ancient, 13-19 kyr BP and ~ 40 kyr BP, ice wedge horizons from the same exposure profile of the Mammoth Mountain, using pyrosequencing 16S rRNA gene. The most abundant OTUs in the active layer were affiliated with Acidobacteria (31.

Ribonucleic acid (RNA) condensation by thermal cycling with metal cations: yield of nanoparticles and their applicability for transfection.

To the present, different efficient but expensive, multistage, and time-consuming technologies have been developed to deliver ribonucleic acids (RNA) into eukaryotic cells. Here, we report a simple and feasible solution to design RNA nanocarriers based on nucleic acid condensation by bi- and trivalent metal ions during thermal cycling. Efficient RNA conversion to nanoparticles with small size (10-50 nm) suitable for transfection was achieved using cations Ni, Co or Cu alone or in combination with Ca at the specially selected concentrations (2.

Structural variability of DNA-containing Mg-pyrophosphate microparticles: optimized conditions to produce particles with desired size and morphology.

Our previous studies demonstrated the formation of structurally diverse DNA-containing microparticles (DNA MPs) in PCR with Mg-pyrophosphate (MgPPi) as the structure-forming component. These DNA MPs were referred to major structural types: microdisks (2D MPs) with nanometer thickness and 3D MPs with sophisticated morphology and constructed from intersecting disks and their segments. Little is known about factors that influence both the morphology and size of DNA MPs, and the present study was aimed at fulfilling this gap.

The response of soil Arthrobacter agilis lush13 to changing conditions: Transition between vegetative and dormant state.

This work was aimed at studying the response of soil non-spore-forming actinobacterial strain Arthrobacter agilis Lush 13 to changing natural conditions, such as nutrient availability and the presence of degradable and recalcitrant aliphatic and aromatic substrates. The A. agilis strain Lush13 was able to degrade octane, nonane, hexadecane, benzoate, phenol, and 2,3-, 2,4-, 2,5-, 2,6-dichlorophenols, but not grew on 3,4-dichlorophenol, 2,3,4-, 2,4,5-, 2,4,6-trichlorophenol (TCP), pentachlorophenol (PCP), 2-chlorobenzoate, 3-chlorobenzoate, 3,5-dichlorobenzoate, 2,4-dichlorobenzoate.

Bacterial community in ancient permafrost alluvium at the Mammoth Mountain (Eastern Siberia).

Permanently frozen (approx. 3.5Ma) alluvial Neogene sediments exposed in the Aldan river valley at the Mammoth Mountain (Eastern Siberia) are unique, ancient, and poorly studied permafrost environments.

New insight into formation of DNA-containing microparticles during PCR: the scaffolding role of magnesium pyrophosphate crystals.

This work aims to study molecular mechanisms involved in the formation of DNA-containing microparticles and nanoparticles during PCR. Both pyrophosphate and Mg(2+) ions proved to play an important role in the generation of DNA microparticles (MPs) with a unique and sophisticated structure in PCR with Taq polymerase. Thus, the addition of Tli thermostable pyrophosphatase to a PCR mixture inhibited this process and caused the destruction of synthesized DNA MPs.

Drotaverine hydrochloride degradation using cyst-like dormant cells of Rhodococcus ruber.

This work has a focus on adaptive capabilities of the actinobacterium Rhodococcus ruber IEGM 326 to cope with drotaverine hydrochloride (DH), a known pharmaceutical pollutant. Cultivation of R. ruber in a nitrogen-limited medium with incubation at the ambient temperature resulted in the formation of cyst-like dormant cells (CLDCs).

The structural peculiarities of condensed DNA micro- and nanoparticles formed in PCR.

Studies of DNA condensation have opened new perspectives in biotechnology and medicine. DNA condensation induced by polyamines or trivalent metal ions in vitro at room temperature has been investigated in detail. Our recent studies have demonstrated Mg(2+)-mediated formation of DNA condensates during the PCR.

Dormant ovoid cells of Mycobacterium tuberculosis are formed in response to gradual external acidification.

It is believed that latent tuberculosis is associated with the persistence of Mycobacterium tuberculosis (MTB) in a dormant-like state. Dormant cells of MTB with coccoid morphology were produced in some in vivo studies, but similar forms were not produced in the known in vitro models in sufficient amounts to permit their characterization. This work demonstrates the efficient formation of phase-dark ovoid cells in MTB cultures within 150 days after the onset of stationary phase.

The role of histone-like protein, Hlp, in Mycobacterium smegmatis dormancy.

The role of histone-like protein (Hlp) in the development of a dormant state in long-incubated stationary-phase Mycobacterium smegmatis cells was studied in two models: (1) adoption of 'nonculturable' (NC) state, which is reversible due to resuscitation with proteinaceous resuscitation-promoting factor (Rpf) and (2) the formation of morphologically distinct, ovoid resting forms. In the first model, inactivation of the hlp gene resulted in prolongation of culturability of starved cells followed by irreversible nonculturability when mycobacterial cells were unresponsive to resuscitation with Rpf. In the second model, M.

Dormant forms of Mycobacterium smegmatis with distinct morphology.

Cultivation of Mycobacterium smegmatis cells in a nitrogen-limited minimal medium (SR-1) followed by prolonged storage at room temperature without shaking resulted in the gradual accumulation of morphologically distinct ovoid forms characterized by (i) low metabolic activity; (ii) elevated resistance to antibiotics and to heat treatment; and (iii) inability to produce colonies on standard agar plates (non-platable cells). Detailed microscopic examination confirmed that ovoid cells possessed an intact cell envelope, specific fine structure and large electron-transparent bodies in the cytoplasm. Cell staining with Nile red and analysis of the lipid content by TLC revealed the presence of significant amounts of apolar lipids in these bodies.

Nature of DNA-bound fatty acids in Pseudomonas aurantiaca.

The existence of Pseudomonas aurantiaca DNA-bound fatty acids and lipids is presented in this work. The isolation of DNA was carried out by two different procedures, namely, phenol and detergent-based phenol isolation in order to prove the presence of DNA-bound lipids. The lipid content of DNA is expressed in terms of fatty acid profile.

Hematogenous infection of the human temporomandibular joint.

Objective This study was designed to discover the relationship between bacteremia and the presence of specific bacterial species in the synovial fluid of the human temporomandibular joint (TMJ). Study design Sixteen volunteers (female to male, 1:2.2; average age, 30.