Genetic Alternatives for Experimental Adaptation to Colistin in Three Lineages.

is characterized by a high adaptive potential, developing resistance in response to antimicrobial pressure. We employed a spatiotemporal evolution model to disclose the pathways of adaptation to colistin, a last-resort polymyxin antimicrobial, among three unrelated lineages. The ATCC-27833 reference strain (), an environmental isolate (), and a clinical isolate with multiple drug resistance () were grown over an increasing 5-step colistin concentration gradient from 0 to 400 mg/L.

virulence: a current view.

is an opportunistic pathogen intrinsically resistant to multiple and broad-spectrum antibiotics. Although the bacterium is considered a low-virulence pathogen, it can cause various severe diseases and contributes significantly to the pathogenesis of multibacterial infections. During the COVID-19 pandemic, has been recognized as one of the most common causative agents of respiratory co-infections and bacteremia in critically ill COVID-19 patients.

Analysis of Isolates from Patients with Cystic Fibrosis Revealed Novel Groups of Filamentous Bacteriophages.

is an opportunistic pathogen that can cause infections in humans, especially in hospital patients with compromised host defence mechanisms, including patients with cystic fibrosis. Filamentous bacteriophages represent a group of single-stranded DNA viruses infecting different bacteria, including and other human and animal pathogens; many of them can replicate when integrated into the bacterial chromosome. Filamentous bacteriophages can contribute to the virulence of and influence the course of the disease.

Clonal diversity, antimicrobial resistance, and genome features among nonfermenting gram-negative bacteria isolated from patients with cystic fibrosis in Russia.

Nonfermenting gram-negative (NFGN) bacteria were isolated from cystic fibrosis (CF) patients and subjected to susceptibility testing and whole-genome sequencing. Among 170 enrolled CF patients, 112 (65.9%) were colonized with at least 1 key NFGN species.

Application of Dimethicone to Prevent Culture Media from Drying in Microbiological Diagnostics.

Unlabelled: The search for novel modifications of culture media aimed at culture prolongation is a prerequisite for microbiological diagnostic progress. was to assess the possibilities of applying dimethicone (polymethylsiloxane) as a barrier between the agar surface and atmosphere to prevent drying of solid and semisolid culture medium providing the retention of its useful properties.

Materials And Methods: We studied the dynamics of water (volume) loss of culture media used in microbiology, and the effect of dimethicone on the process.

The structure of Klebsiella pneumoniae K108 capsular polysaccharide is similar to Escherichia coli colanic acid.

The clinical isolate of Klebsiella pneumoniae 1333/P225 was revealed as containing a KL108 K. pneumoniae K locus for capsule biosynthesis. The gene cluster demonstrated a high level of sequence and arrangement similarity with that of the E.

A case of localized paranasal sinusitis associated with ST 1880 in a cystic fibrosis patient.

complex (Bcc) bacteria are considered to be very dangerous players in cystic fibrosis (CF) pathogenesis and are a criterion for negative prognosis in CF cases. In this report, a pediatric case of paranasal sinusitis caused by in a CF patient is described. This is an unusual case, since the paranasal sinuses were the only colonization locus of in this patient for 5 years (2015-2020).

Characteristics of Stenotrophomonas maltophilia isolates from cystic fibrosis patients in Russia.

Stenotrophomonas maltophilia is a common opportunistic microorganism and an important respiratory pathogen in cystic fibrosis (CF). The aim of this study was to determine antimicrobial resistance phenotypes, sequence-types (ST) and genetic determinants of antibiotic resistance in S. maltophilia strains recovered from CF patients in Russia.

Mobile Colistin Resistance Genetic Determinants of Non-Typhoid Isolates from Russia.

Polymyxin resistance, determined by genes located on plasmid DNA, currently poses a high epidemiological threat. Non-typhoid (NTS) are one of the key pathogens causing diarrheal diseases. Here, we report the isolation and whole genome sequencing of multidrug colistin-resistant/susceptible isolates of non-typhoid serovars carrying genes.

Genetic determinants of virulence and antibiotic resistance are common for Pseudomonas aeruginosa ST235 isolates from cystic fibrosis patients from various geographical regions.

The dissemination of multiple-drug resistant high virulent strains of P. aeruginosa in patients with cystic fibrosis is of concern worldwide. Herein, we describe genomic characteristics of ST235 isolates recovered from cystic fibrosis patients in Russia.

Genome features and antibiotic resistance of Pseudomonas aeruginosa strains isolated in patients with cystic fibrosis in the Russian Federation.

Cystic fibrosis (CF) is a common genetic disease, manifested by airway obstruction and chronic respiratory infection. The most prevalent infectious agent in airways of CF patients is Pseudomonas aeruginosa. This study aimed to determine sequence-types, antimicrobial resistance phenotypes and genes defining adaptive antibiotic resistance in P.

Life-On-Hold: Lanthanoids Rapidly Induce a Reversible Ametabolic State in Mammalian Cells.

Until now, the ability to reversibly halt cellular processes has been limited to cryopreservation and several forms of anabiosis observed in living organisms. In this paper we show that incubation of living cells with a solution containing ~50 mM neodymium induces a rapid shutdown of intracellular organelle movement and all other evidence of active metabolism. We have named this state REEbernation (derived from the terms REE (rare earth elements) and hibernation) and found that the process involves a rapid replacement of calcium with neodymium in membranes and organelles of a cell, allowing it to maintain its shape and membrane integrity under extreme conditions, such as low pressure.

The classification of bacterial survival strategies in the presence of antimicrobials.

The survival of bacteria under antibiotic therapy varies in nature and is based on the bacterial ability to employ a wide range of fundamentally different resistance mechanisms. This great diversity requires a disambiguation of the term 'resistance' and the development of a more precise classification of bacterial survival strategies during contact with antibiotics. The absence of a unified definition for the terms 'resistance', 'tolerance' and 'persistence' further aggravates the imperfections of the current classification system.

Computer Program for Detection and Analyzing the Porin-Mediated Antibiotic Resistance of Bacteria.

Unlabelled: was to develop a new software tool for identifying gene mutations that determine the porin-mediated resistance to antibiotics in gram-negative bacteria and to demonstrate the functionality of this program by detecting porin-mediated resistance to carbapenems in clinical isolates of .

Materials And Methods: The proposed algorithm is based on searching for a correspondence between the reference and the studied genes. When the sought nucleotide sequence is found in the analyzed genome, it is compared with the reference one and analyzed.

[Bacteria survival strategies in contact with antibiotics.].

Bacteria survival in the conditions of antimicrobial therapy is the global problem of health care. This review highlights the complexity and diversity of mechanisms used by bacteria to neutralize antibiotics. To analyze the problem, the search was made using PubMed database, Russian scientific electronic library eLIBRARY, search system of World Health Organization and European Society of Clinical Microbiology and Infectious Diseases (ESCMID).

Genotypes, carbapenemase carriage, integron diversity and oprD alterations among carbapenem-resistant Pseudomonas aeruginosa from Russia.

Pseudomonas aeruginosa is a serious opportunistic pathogen demonstrating a high level of resistance to many groups of antibiotics, including carbapenems. This study aimed to characterise the molecular epidemiology and prevalence of mobile genetic elements associated with resistance to carbapenems among P. aeruginosa (CRPA) clinical isolates.

[Integron diversity in bla-carrying carbapenem-resistant clinical Pseudomonas aeruginosa isolates].

The growing prevalence of metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa in nosocomial pathogen populations has been attributed to their clonal spread, and/or horizontal transfer of MBL determinants in mobile genetic elements, including integrons. To characterize the genetic background of the beta-lactamase VIM-2 encoding gene in the population of carbapenemresistant (Carba-R) P. aeruginosa clinical isolates.

A rapid method of whole cell sample preparation for scanning electron microscopy using neodymium chloride.

The quality of electron microscopy (EM) visualization of biological objects is constantly improving, primarily with the usage of more complex technologies, such as serial block-face scanning electron microscopy (SEM), focused ion beam scanning electron microscopy, and array tomography. Here we suggest a new rapid method of whole cell sample preparation for scanning EM using neodymium chloride treatment followed by staining with lead acetate. This variant of sample preparation does not require separate fixation, complete dehydration, and metal sputtering.

Exogenous contaminating DNA in Taq polymerases: A method to avoid false-positive results when detecting the bla gene.

In the course of developing an assay to identify genes responsible for antibiotic resistance in gram-negative bacteria, it has been found that standard (not DNA-free) Taq DNA polymerases were contaminated with bla gene fragments that varied in length and quantities. The complete bla gene sequence was either absent or was detected in infinitesimal amounts. We developed an approach to avoid false-positive findings caused by contaminating bla gene sequences in conventional polymerases.

[The comparison of methods for determination of colistin susceptibility in carbapenem-resistant Klebsiella pneumoniae.].

In recent years, because of carbapenemase spreading in Klebsiella pneumoniae strains, the antibiotic of reserve group, colistin, is increasingly prescribed. In vitro testing of colistin susceptibility in everyday practice has a number of difficulties due to the cationic properties of molecule and weak diffusion into agar. Therefore it is recommended to use the reference Broth Microdilution Method (BMD) for determination of the Minimum Inhibitory Concentration (MIC) for colistin.

Inactivation of the oprD porin gene by a novel insertion sequence ISPa195 associated with large deletion in a carbapenem-resistant Pseudomonas aeruginosa clinical isolate.

Objectives: Alteration of the porin-encoding gene oprD by insertion sequences (ISs) is one mechanism conferring carbapenem resistance in Pseudomonas aeruginosa. Here we describe a carbapenem-resistant clinical P. aeruginosa isolate 36-989 harbouring a novel IS (ISPa195) in oprD.

[The mass-spectrometric evaluation of сarbapenemase activity of Pseudomonas aeruginosa.].

The Pseudomonas aeruginosa is among number of leading opportunistic pathogens. The evaluation of sensitivity of hospital isolates of P. aeruginosa to antibiotics is an important stage in the struggle with Pseudomonas sepsis pathology.

Emergence of the Uncommon Clone ST944/ST78 Carrying bla and bla Genes Among Carbapenem-Nonsusceptible Acinetobacter baumannii in Moscow, Russia.

Carbapenem-nonsusceptible (Carba-NS) Acinetobacter baumannii has emerged as an important cause of nosocomial infections. In the present study, we characterized 91 Carba-NS A. baumannii isolates collected from patients of surgical departments and intensive care units at three hospitals in Moscow in 2012-2015.

[The possibilities, problems and perspectives of mass-spectrometry in medical microbiology: publications review].

The publications review deals with analysis of possibilities, shortcomings and perspectives of mass-spectrometry - important applied technology that is headlong introduced in medical microbiology. The main achievement of mass-spectrometry is fast and valid identification of most species of microbes actual for medicine both in pure growths and biologic samples. There are only single taxonomic which representatives are identified unreliably in case of using of mass-spectrometry.