New Flexible Analogues of 8-Aza-7-deazapurine Nucleosides as Potential Antibacterial Agents.

A variety of ribo-, 2'-deoxyribo-, and 5'-norcarbocyclic derivatives of the 8-aza-7-deazahypoxanthine fleximer scaffolds were designed, synthesized, and screened for antibacterial activity. Both chemical and chemoenzymatic methods of synthesis for the 8-aza-7-deazainosine fleximers were compared. In the case of the 8-aza-7-deazahypoxanthine fleximer, the transglycosylation reaction proceeded with the formation of side products.

Motility provides specific adhesion patterns and improves Listeria monocytogenes invasion into human HEp-2 cells.

Listeria monocytogenes is motile at 22°C and non-motile at 37°C. In contrast, expression of L. monocytogenes virulence factors is low at 22°C and up-regulated at 37°C.

[Identification of Clinical Isolates of the Bacillus cereus Group and Their Characterization by Mass Spectrometry and Electron Microscopy].

Bacillus cereus is a spore-forming bacterium found in the environment mainly in soil. Bacillus spores are known to be extremely resistant not only to environmental factors, but also to various sanitation regimes. This leads to spore contamination of toxin-producing strains in hospital and food equipment and, therefore, poses a great threat to human health.

A novel antivirulent compound fluorothiazinone inhibits Klebsiella pneumoniae biofilm in vitro and suppresses model pneumonia.

The problematic treatment of infections caused by multiple-resistant Klebsiella, especially in ICU, is the leading cause of prolonged hospitalization and high mortality rates. The use of antibiotics for the prevention of infections is considered unreasonable as it may contribute to the selection of resistant bacteria. In this regard, the development of drugs that will be effective in preventing infection during various invasive procedures is extremely necessary.

PLGA Carriers for Controlled Release of Levofloxacin in Anti-Tuberculosis Therapy.

Levofloxacin (LFX) is a highly effective anti-tuberculosis drug with a pronounced bactericidal activity against (). In this work, an "organic solvent-free" approach has been used for the development of polylactic-co-glycolic acid (PLGA) microparticles and scaffolds containing LFX at a therapeutically significant concentration, providing for its sustained release. To achieve the target, both nonpolar supercritical carbon dioxide and polar supercritical trifluoromethane have been used.

Evaluation of a new assay for nontuberculous mycobacteria species identification in diagnostic material and cultures.

The purpose of the present study was to evaluate a real-time PCR system for 12 nontuberculous mycobacteria (NTM) species identification developed by Central Tuberculosis Research Institute (CTRI; Moscow, Russia) in cooperation with Syntol LLC (Moscow, Russia). NTM cultures (210 strains, 19 species), Mycobacterium tuberculosis complex (MTBC) cultures (21 strains, 2 species), non-mycobacterial microorganisms (18 strains, 13 species) were used for the first stage of the assay evaluation. Clinical samples (sputum, N = 973) positive for smear microscopy and MTBC/NTM DNA by a PCR-based screening assay collected from 819 patients were used for specificity and sensitivity evaluation.

Interaction of 5-substituted pyrimidine nucleoside analogues and M.Tuberculosis: A view through an electron microscope.

The data of transmission electron microscopy (TEM) on morphology of M. tuberculosis H37Rv bacterial cells treated with four analogues of pyrimidine nucleosides with different substituents at 5 position of base are presented. We showed that the growth of M.

Microcolonies: a novel morphological form of pathogenic spp.

The class unites cell wall lacking bacteria many of which are membrane parasites and opportunistic bacteria.. This study describes a novel morphological form found in the five species belonging to the bacterial class Mollicutes, and referred to as microcolonies (MCs).

Investigation of 5'-Norcarbocyclic Nucleoside Analogues as Antiprotozoal and Antibacterial Agents.

Carbocyclic nucleosides have long played a role in antiviral, antiparasitic, and antibacterial therapies. Recent results from our laboratories from two structurally related scaffolds have shown promising activity against both and several parasitic strains. As a result, a small structure activity relationship study was designed to further probe their activity and potential.

New assay to diagnose and differentiate between Mycobacterium tuberculosis complex and nontuberculous mycobacteria.

The purpose of the present study was to create a real-time PCR test system allowing simultaneous detection of nontuberculous mycobacteria (NTM) and Mycobacterium tuberculosis complex (MTBC) both in culture and sputum. NTM cultures (18 strains, 18 species), MTBC cultures (16 strains, 2 species) and non-mycobacterial microorganisms from the collection of the Central Research TB Institute (CTRI) were used for the preliminary evaluation of the test system. 301 NTM cultures from patients with mycobacteriosis were used to assess the sensitivity of the developed test system.

Novel 5'-Norcarbocyclic Pyrimidine Derivatives as Antibacterial Agents.

A series of novel 5'-norcarbocyclic derivatives of 5-alkoxymethyl or 5-alkyltriazolyl-methyl uracil were synthesized and the activity of the compounds evaluated against both Gram-positive and Gram-negative bacteria. The growth of was completely inhibited by the most active compounds at a MIC of 67 μg/mL (mc²155) and a MIC of 6.7⁻67 μg/mL (VKPM Ac 1339).

Optical and Electron Microscopic Study of the Morphology and Ultrastructure of Biofilms Formed by Streptococcus pyogenes.

Our study confirmed the capacity of S. pyogenes strains to form biofilms on abiotic surfaces. Chains of streptococci surrounded by bluish film were seen under a microscope after alcian blue staining of the preparations grown on slides.

Draft Genome Sequence of a Mycobacterium heckeshornense Clinical Isolate.

We report here the draft genome sequence of , isolated from the sputum of a patient admitted to a tuberculosis hospital with suspected pulmonary tuberculosis.

[The Spectrum of Mutations in Genes Associated with Resistance to Rifampicin, Isoniazid, and Fluoroquinolones in the Clinical Strains of M. tuberculosis Reflects the Transmissibility of Mutant Clones].

To study the transmissibility of drug resistant mutant clones, M. tuberculosis samples were isolated from the patients of the clinical department and the polyclinic of the Central TB Research Institute (n = 1455) for 2011-2014. A number of clones were phenotypically resistant to rifampicin (n = 829), isoniazid (n = 968), and fluoroquinolones (n = 220).

Dual-targeted anti-TB/anti-HIV heterodimers.

HIV and M. tuberculosis are two intersecting epidemics making the search for new dual action drugs against both pathogens extremely important. Here, we report on the synthesis and suppressive activities of five dual-targeted HIV/TB compounds.

Antigen-Specific IFN- Responses Correlate with the Activity of Infection but Are Not Associated with the Severity of Tuberculosis Disease.

IFN- is a key cytokine in antituberculosis (TB) defense. However, how the levels of its secretion affect () infection is not clear. We have analyzed associations between IFN- responses measured in QuantiFERON®-TB Gold In-tube (QFT) assay, TB disease severity, and infection activity.

First Draft Genome Sequence of a Mycobacterium gordonae Clinical Isolate.

Here, we report the first draft genome sequence of the clinically relevant species Mycobacterium gordonae The clinical isolate Mycobacterium gordonae 14-8773 was obtained from the sputum of a patient with mycobacteriosis.

Antibacterial Effects of Liposomes Containing Phospholipid Cardiolipin and Fluoroquinolone Levofloxacin on Mycobacterium tuberculosis with Extensive Drug Resistance.

The effects of liposomes containing phospholipid cardiolipin without antibiotic and loaded with levofloxacin on the growth of Mycobacterium tuberculosis with extensive drug resistance were studied in vitro. Liposomes consisting of cardiolipin alone in a concentration of 335 μM completely suppressed the growth of M. tuberculosis.

Mycobacterium tuberculosis Type II Toxin-Antitoxin Systems: Genetic Polymorphisms and Functional Properties and the Possibility of Their Use for Genotyping.

Various genetic markers such as IS-elements, DR-elements, variable number tandem repeats (VNTR), single nucleotide polymorphisms (SNPs) in housekeeping genes and other groups of genes are being used for genotyping. We propose a different approach. We suggest the type II toxin-antitoxin (TA) systems, which play a significant role in the formation of pathogenicity, tolerance and persistence phenotypes, and thus in the survival of Mycobacterium tuberculosis in the host organism at various developmental stages (colonization, infection of macrophages, etc.

Multidrug-Resistant Tuberculosis Treatment Outcomes in Relation to Treatment and Initial Versus Acquired Second-Line Drug Resistance.

Background: Resistance to second-line drugs develops during treatment of multidrug-resistant (MDR) tuberculosis, but the impact on treatment outcome has not been determined.

Methods: Patients with MDR tuberculosis starting second-line drug treatment were enrolled in a prospective cohort study. Sputum cultures were analyzed at a central reference laboratory.

Resistance to pyrazinamide in Russian Mycobacterium tuberculosis isolates: pncA sequencing versus Bactec MGIT 960.

Resistance to pyrazinamide (PZA) may impact clinical outcome of anti-tuberculosis chemotherapy. PZA susceptibility testing using MGIT 960 is not reliable and little information is available on the prevalence of PZA resistance in Russia. A collection of 64 clinical isolates of Mycobacterium tuberculosis, including 35 multidrug resistant and extensively drug-resistant (MDR/XDR), was analyzed for PZA resistance using MGIT 960, Wayne test, and sequencing of PZA resistance genes pncA, rpsA and panD.

5-Arylaminouracil Derivatives: New Inhibitors of Mycobacterium tuberculosis.

Three series of 5-arylaminouracil derivatives, including 5-(phenylamino)uracils, 1-(4'-hydroxy-2'-cyclopenten-1'-yl)-5-(phenylamino)uracils, and 1,3-di-(4'-hydroxy-2'-cyclopenten-1'-yl)-5-(phenylamino)uracils, were synthesized and screened for potential antimicrobial activity. Most of compounds had a negative effect on the growth of the Mycobacterium tuberculosis H37Rv strain, with 100% inhibition observed at concentrations between 5 and 40 μg/mL. Of those, 1-(4'-hydroxy-2'-cyclopenten-1'-yl)-3-(4‴-hydroxy-2‴-cyclopenten-1‴-yl)-5-(4″-butyloxyphenylamino)uracil proved to be the most active among tested compounds against the M.

Inhibition of Mycobacterium tuberculosis strains H37Rv and MDR MS-115 by a new set of C5 modified pyrimidine nucleosides.

Two sets of pyrimidine nucleoside derivatives bearing extended alkyloxymethyl or alkyltriazolidomethyl substituents at position 5 of the nucleobase were synthesized and evaluated as potential antituberculosis agents. The impact of modifications at 3'- and 5'-positions of the carbohydrate moiety on the antimycobacterial activity and cytotoxicity was studied. The highest effect was shown for 5-dodecyloxymethyl-2'-deoxyuridine, 5-decyltriazolidomethyl-2'-deoxyuridine, and 5-dodecyltriazolidomethyl-2'-deoxycytidine.

Carbocyclic analogues of inosine-5'-monophosphate: synthesis and biological activity.

9-(4'-Phosphonomethoxy-2'-cyclopenten-1'-yl)hypoxanthine and 9-(4'-phosphonomethoxy-2',3'-dihydroxycyclopenten-1'-yl)hypoxanthine were synthesized as isosteric carbocyclic analogues of inosine-5'-monophosphate. The synthesized compounds were shown to be capable of inhibiting the activity of human type II inosine-5'-monophosphate dehydrogenase (IMPDH II) (IC(50 )= 500 µM) and to have no significant effects on the growth ofMycobacterium tuberculosis.

Performance of Cepheid ® Xpert MTB/RIF ® and TB-Biochip ® MDR in two regions of Russia with a high prevalence of drug-resistant tuberculosis.

The purpose of this study was to assess the performance of Cepheid® Xpert MTB/RIF® ("Xpert") and TB-Biochip® MDR ("TB-Biochip"). Sputum specimens from adults with presumptive tuberculosis (TB) were homogenized and split for: (1) direct Xpert and microscopy, and (2) concentration for Xpert, microscopy, culture [Lowenstein-Jensen (LJ) solid media and Mycobacteria Growth Indicator Tube® (MGIT)], indirect drug susceptibility testing (DST) using the absolute concentration method and MGIT, and TB-Biochip. In total, 109 of 238 (45.