Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 14 de 14
Filter
1.
Int J Mol Sci ; 24(18)2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37762396

ABSTRACT

This paper illustrates how the size and type of substituent R in the phosphinate group of ferrocenyl bisphosphinic acids can affect conformational possibilities and coordination packing. It also demonstrates that H-phosphinate plays a key role in variational mobility, while Me- or Ph- substituents of the phosphinate group can only lead to 0D complexes or 1D coordination polymer. Overall, this paper provides valuable insights into the design and construction of coordination polymers based on ferrocene-contained linkers. It sheds light on how different reaction conditions and substituents can affect conformational possibilities and coordination packing, which could have significant implications for developing new polymers with unique properties.


Subject(s)
Metal-Organic Frameworks , Polymers , Bandages , Molecular Conformation
2.
Int J Mol Sci ; 23(24)2022 Dec 08.
Article in English | MEDLINE | ID: mdl-36555177

ABSTRACT

Herein, the synthesis of ferrocene-containing salts is presented. Acylation of ferrocene (Fc) according to the Friedel-Crafts method led to ω-bromoacyl ferrocenes. The ω-bromoacyl ferrocenes were subsequently introduced to quaternization reaction with tri-tert-butyl phosphine, which resulted in phosphonium salts. Obtained phosphonium salts were characterized by physical methods. The electrochemical properties of phosphonium salts were studied by cyclic voltammetry (CV). It was found that the replacement of n-butyl fragments at the phosphorus atom by tert-butyl leads to a more anodic potential shift. In contrast to isolobal structures Fc-C(O)(CH2)nP+(n-Bu)3X- and Fc-(CH2)n+1P+(n-Bu)3X-, the CV curves of Fc-C(O)(CH2)nP+(t-Bu)3X- and Fc-(CH2)n+1P+(t-Bu)3X- did not show a large discrepancy between forward and reverse currents. The transformation of the C=O groups to CH2 fragments had a significant effect on the electrochemical properties of ferrocene salts, the oxidation potential of which is close to that of pure ferrocene.


Subject(s)
Ionic Liquids , Metallocenes , Ionic Liquids/chemistry , Salts/chemistry , Oxidation-Reduction
3.
Microb Drug Resist ; 28(1): 39-47, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34357824

ABSTRACT

The pneumococcal population structure and drug resistance patterns are constantly changing worldwide. In this study, we described serotypes and antimicrobial susceptibility among 478 multiple-drug resistant (MDR) pediatric nasopharyngeal pneumococci recovered in 2010-2017. The majority of isolates (89.3%; n = 427) carried pneumococcal conjugate vaccine (PCV)13 serotypes, predominantly 6A/B, 14, 19A/F, and 23F. A non-PCV13 serotype capsule was detected in 44 (9.2%) MDR pneumococci, including serotypes 23A (n = 8), 13 (n = 7), 28F (n = 6), 11A (n = 5), and serogroup 35 (n = 10) isolates. The remaining seven (1.5%) MDR isolates were nontypeable. The majority of non-PCV13-serotype isolates were resistant to tetracycline, erythromycin, and clindamycin; most harbored both the ermB and mef genes. Among the 44 serotyped MDR non-PCV13 isolates, multilocus sequence typing analysis revealed 24 different sequence types (STs). ST2754 was the most abundant lineage demonstrating an unusual association with serotypes 13 (n = 7) and 9N (n = 1). The whole-genome sequencing-based analysis demonstrated that the serotype 13/ST2754 lineage was closely related to the serotype 13/ST2754 isolate recovered in Africa (Malawi) in 2013, possessed a Tn6002-like transposon carrying the erm(B) and tet(M) genes, and harbored additional virulence determinants, including arginine metabolism genes and a putative bacteriocin locus. Such a favorable genetic background may provide competitive advantages and potential for spreading and expansion of this clone among pneumococci. These data warrant further molecular monitoring of the genetic composition of the changing pneumococcal population.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/genetics , Adolescent , Female , Genes, Bacterial , Humans , Male , Microbial Sensitivity Tests , Multilocus Sequence Typing , Nasopharyngeal Diseases/microbiology , Retrospective Studies , Russia/epidemiology , Serotyping , Streptococcal Infections/microbiology , Young Adult
4.
Int J Antimicrob Agents ; 55(4): 105899, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31931151

ABSTRACT

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. Among 145 carbapenem-resistant P. aeruginosa isolates, 34 different sequence types (STs) were detected; the six most common STs were ST654 (24%), ST235 (24%), ST111 (8%), ST446 (6%), ST357 (5%) and ST2592 (a novel single-locus variant of ST357) (4%). A carbapenemase gene was found in 94 isolates (64.8%). The blaVIM-2 gene was harboured by 64 isolates (44.1%) restricted to ST111, ST235 and ST654, and the blaGES-type and blaOXA-10 group genes were each detected in 15 isolates (10.3%); none of other tested carbapenemase genes, including blaIMP, blaNDM and blaGIM, were detected. Among the blaVIM-2-positive isolates, five types of blaVIM-2-containing integrons were discovered, including In56, In559, In59-like, In59 and In249. The oprD gene was disrupted by an insertion sequence (IS) in 15.9% of isolates. Overall, five types of IS elements were found (ISPsme1, ISPa1328, ISPa26, ISPst2 and ISPa195). Observed rearrangements within variable regions of blaVIM-2-carrying integrons in conjunction with the discovery of a novel type of oprD-disrupting IS element illustrate the ongoing evolution of CRPA a, which warrants further investigation.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Carbapenems/pharmacology , Integrons/genetics , Porins/genetics , Pseudomonas aeruginosa/drug effects , beta-Lactamases/genetics , Drug Resistance, Multiple, Bacterial/genetics , Genetic Variation/genetics , Humans , Microbial Sensitivity Tests , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Russia
5.
Diagn Microbiol Infect Dis ; 94(4): 385-390, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30871743

ABSTRACT

Serotype distribution and antimicrobial resistance were analyzed in 632 nasopharyngeal pneumococcal isolates collected at a single pediatric center in 2010-2017 before and following the introduction of the 13-valent pneumococcal conjugated vaccine (PCV13) in Russia in 2014. The mean prevalence of PCV13 serotypes was 77.7% in 2010-2015 with a significant decline to 58.5% in 2017, which was accompanied by an elevation in serotype 15B/C prevalence (15.1% in 2017), 66% and 26% of 15B/C-pneumococci related to ST1025 and ST1262, respectively. The rate of oxacillin, erythromycin, and clindamycin resistance has increased by 15-20 percentage points from 2010 to 2016, approaching a 40-45% prevalence in 2016. The resistance rates significantly increased over time only in a group of PCV13 serotypes. The growing resistance among serotype 14 pneumococci was associated with expansion of a multidrug-resistant clone of ST143. These results emphasize the need for close monitoring of the constantly changing pneumococcal population.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Nasopharynx/microbiology , Streptococcus pneumoniae/drug effects , Bacterial Typing Techniques , Carrier State/epidemiology , Carrier State/microbiology , Child, Preschool , Humans , Infant , Microbial Sensitivity Tests , Moscow/epidemiology , Multilocus Sequence Typing , Prevalence , Retrospective Studies , Serogroup , Streptococcus pneumoniae/classification
6.
Pract Lab Med ; 12: e00106, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30090845

ABSTRACT

OBJECTIVES: Specialized analyzers are used to automate the diagnosis of bacteriuria in laboratory practice. They are based on analysis of microorganisms concentration in urine samples or recording the growth of urine microflora. Coherent fluctuation nephelometry (CFN) has high sensitivity and allows analyzing both parameters simultaneously. The aim of the study is to compare the effectiveness of CFN-based and flow cytometry based analyzers. DESIGN AND METHODS: Total 117 urine samples from children were studied in parallel using the CFN-analyzer and UF-1000i (Sysmex), the results were confirmed by conventional microbiological methods. RESULTS: In 21 urine samples (18%), significant bacteriuria was determined (≥104 CFU/ml). The best diagnostic indicators were obtained while testing urine samples using the CFN-analyzer. The most efficient bacteriuria diagnosis is achieved by simultaneous analyses of microorganisms concentration in urine and growth of urine microflora (sensitivity - 95.2%, specificity - 96.9%, positive predictive value - 87%, negative predictive value - 98.9%, diagnostic odds ratio - 81.7, positive likelihood ratio - 30.5, negative likelihood ratio- 0.049, area under curve in ROC-analysis - 0.987). The CFN-analyzer allows the preliminary selection of negative urine samples, which do not require further analysis by conventional microbiological methods, thereby decreasing the number of cultures by 80.3%. CONCLUSIONS: This study suggests that the CFN-analyzer is the effective tool for bacteriuria screening in children.

7.
Microb Drug Resist ; 23(7): 864-870, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28437227

ABSTRACT

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. Multilocus sequence typing (MLST) using the Oxford (Oxf) scheme identified 16 sequence types (STs) of three clonal complexes (CCs), including CC92Oxf (67%), CC109Oxf (1%), CC944Oxf (29%), and the singleton ST1100Oxf (3%). CC944Oxf was composed of ST944Oxf (n = 16) and two of its newly described single locus variants ST1103Oxf (n = 3) and ST1104Oxf (n = 7); all the three STs were identical to the Pasteur (Pas) MLST scheme ST78. All CC944Oxf/ST78Pas isolates were blaOXA-40-like positive and all but one isolate harbored a blaCTX-M-like gene. ST944Oxf was the only ST found in each of the three study hospitals. Biofilm growth capacity was similar among Carba-NS and nonclonal carbapenem-susceptible isolates. Our data demonstrate the predominance of two clonal lineages among Carba-NS A. baumannii. One of these, the uncommon blaOXA-40-like/blaCTX-M-like-positive clone of CC944Oxf/ST78Pas, seems to be endemic in Russia.


Subject(s)
Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Biofilms/growth & development , Drug Resistance, Multiple, Bacterial/genetics , beta-Lactamases/genetics , Acinetobacter Infections/drug therapy , Acinetobacter Infections/microbiology , Acinetobacter baumannii/classification , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/isolation & purification , Adult , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Carbapenems/pharmacology , Child , Clone Cells , Gene Expression , Hospitals , Humans , Microbial Sensitivity Tests , Molecular Epidemiology , Moscow/epidemiology , Multilocus Sequence Typing , Phylogeny , beta-Lactamases/metabolism
8.
Diagn Microbiol Infect Dis ; 85(1): 125-30, 2016 May.
Article in English | MEDLINE | ID: mdl-26971180

ABSTRACT

We conducted a series of polymerase chain reactions (PCRs) in order to detect bacteria (7 species) and viruses (17 species) in middle ear fluid (MEF) and nasopharynx (Nph) of children with acute otitis media (AOM; n=179). Bacterial and viral nucleic acids were detected in MEF of 78.8% and 14.5% patients, respectively. The prevalence was as follows: Streptococcus pneumoniae, 70.4%; Haemophilus influenzae, 17.9%; Staphylococcus aureus, 16.8%; Streptococcus pyogenes, 12.3%; Moraxella catarrhalis, 9.5%; rhinovirus, 9.5%; and adenovirus, 3.4%. The overall rate of PCR-positive specimens for bacterial pathogens was 2.6 times higher, compared to culture results. The rate of PCR-positive results and the distribution of pathogens in the Nph were similar to those in the MEF. Nph PCR results had variable positive predictive values and high negative predictive values in predicting MEF findings. Our results indicate that Nph PCR could be a practical tool for examining respiratory pathogens in children with acute infections.


Subject(s)
Ear, Middle/microbiology , Ear, Middle/virology , Nasopharynx/microbiology , Nasopharynx/virology , Otitis Media/diagnosis , Otitis Media/etiology , Polymerase Chain Reaction , Acute Disease , Child, Preschool , Female , Genes, Bacterial , Genes, Viral , Humans , Infant , Infant, Newborn , Male , Otitis Media/epidemiology , Prevalence , Retrospective Studies
9.
Pediatr Infect Dis J ; 34(3): 255-60, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25232779

ABSTRACT

BACKGROUND: We aimed to describe bacterial etiology of acute otitis media (AOM) and characterize resistance, serotypes and genotype profiles of AOM-causing pneumococci recovered in Moscow children. METHODS: Children with AOM and an available middle ear fluid specimen were prospectively enrolled in this study. Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and Moraxella catarrhalis were considered as true otopathogens. All pneumococcal isolates were serotyped using the Quellung reaction; multidrug-resistant (MDR) pneumococci underwent multilocus sequence typing. RESULTS: In 172 of 541 enrolled AOM patients (32%) at least 1 otopathogen was recovered, with S. pneumoniae having the highest rate of 63% (109/172). When adjusted for antibiotic treatment before sampling, in untreated patients the rate of culture-positive AOM was 35% (124/352), S. pneumoniae had a prevalence of 69% (86/124), S. pyogenes 19% (24/124), H. influenzae 13% (16/124) and M. catarrhalis 9% (11/124). Among 107 examined pneumococci, 45% were penicillin-nonsusceptible, 34 and 30% were resistant to erythromycin and clindamycin, respectively; 30% had an MDR phenotype, but no amoxicillin-resistant isolates were found. Ten of 32 (31%) MDR pneumococci related to clonal complex 320, the remaining isolates belonged to 7 different clonal complex. Six leading serotypes were 19F (27%), 3 (12%), 6B (11%), 14 (11%), 19A (9%) and 23F (8%); overall polysaccharide conjugate vaccine13 coverage was 93%. CONCLUSIONS: S. pneumoniae, the leading bacterial AOM pathogen in Moscow children, is characterized by a substantial rate of antibiotic nonsusceptibility and clonality. A polysaccharide conjugate vaccine with expanded coverage seems to fit the current AOM pneumococcal serotype distribution in Russia better.


Subject(s)
Cross Infection , Genotype , Otitis Media/epidemiology , Otitis Media/microbiology , Serogroup , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/genetics , Acute Disease , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Child , Child, Preschool , Drug Resistance, Bacterial , Female , Hospitals, Pediatric , Humans , Male , Microbial Sensitivity Tests , Moscow/epidemiology , Multilocus Sequence Typing , Otitis Media/prevention & control , Pneumococcal Vaccines/immunology , Prospective Studies , Streptococcus pneumoniae/drug effects
10.
Int J Infect Dis ; 20: 58-62, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24462930

ABSTRACT

BACKGROUND: Pneumococcal infections remain a major medical problem associated with high morbidity and mortality. Moreover, the resistance of Streptococcus pneumoniae to conventional antibiotics is constantly growing. The implementation of pneumococcal conjugate vaccines (PCVs) in the last decade has dramatically reduced the incidence of the vaccine type-associated invasive pneumococcal diseases in many countries. However, information on the seroepidemiology of S. pneumoniae in Russia is limited. METHODS: We report the results of serotyping and antibiotic susceptibility testing performed on 863 non-invasive pneumococcal isolates collected prospectively in 2009-2013 from children (median age 3.5 years) who sought medical care at five pediatric hospitals in Moscow. The isolates were recovered from the nasopharynx (71.2%), middle ear fluid (14.3%), and lower respiratory tract specimens (13.6%). RESULTS: In total, we identified 45 different serotypes. The six leading serotypes (prevalence >5%) included 19F (21.7%), 6B (12.8%), 23F (10.1%), 14 (9.0%), 6A (8.4%), and 3 (7.5%). Serotype 19A isolates had a prevalence of 2.3%. The proportion of PCV-13 serotypes was 78%; the coverage by PCV-7 was 58.2% and was similar to that of PCV-10 (59.8%). The rate of multidrug-resistant pneumococci (i.e., resistant to ≥3 antimicrobials) was 22%. The majority of the multidrug-resistant isolates were serotype 6B, 14, 19A, and 19F. Penicillin non-susceptibility was displayed by 28% of the isolates. The resistance rate to erythromycin was 26%. Among the examined erythromycin-resistant strains, 54% had the erm(B) gene and 13% had the mef gene as a single resistance determinant, whereas both determinants were found in 31% of these strains. CONCLUSIONS: Our data predict a good coverage of the circulating S. pneumoniae by the PCVs and could be useful for evaluating the serotype distribution in support of the introduction of PCV in Russia. In addition, the antimicrobial resistance rate of S. pneumoniae in Russia is substantial, and the emergence of pneumococcal strains with a dual macrolide resistance mechanism is alarming.


Subject(s)
Drug Resistance, Multiple, Bacterial , Pneumococcal Infections/epidemiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Child, Preschool , Erythromycin/therapeutic use , Hospitals, Pediatric , Humans , Incidence , Macrolides , Moscow/epidemiology , Nasopharynx/microbiology , Penicillins/therapeutic use , Pneumococcal Infections/microbiology , Prospective Studies , Seroepidemiologic Studies , Serotyping , Specimen Handling , Streptococcus pneumoniae/classification , Vaccines, Conjugate/therapeutic use
11.
J Org Chem ; 76(2): 471-83, 2011 Jan 21.
Article in English | MEDLINE | ID: mdl-21192652

ABSTRACT

The palladium-catalyzed direct arylation of indoles, pyrroles, and furans by aryl chlorides has been demonstrated. The method employs a palladium acetate catalyst, 2-(dicyclohexylphosphino)-biphenyl ligand, and an inorganic base. Electron-rich and electron-poor aryl chlorides as well as chloropyridine coupling partners can be used, and arylated heterocycles are obtained in moderate to good yields. Optimization of base, ligand, and solvent is required for achieving best results.


Subject(s)
Furans/chemistry , Furans/chemical synthesis , Hydrocarbons, Chlorinated/chemistry , Indoles/chemistry , Indoles/chemical synthesis , Palladium/chemistry , Pyrroles/chemistry , Pyrroles/chemical synthesis , Solvents/chemistry , Catalysis , Ligands , Magnetic Resonance Spectroscopy , Molecular Structure
12.
Proc Natl Acad Sci U S A ; 107(6): 2544-9, 2010 Feb 09.
Article in English | MEDLINE | ID: mdl-20133786

ABSTRACT

The circadian clock controls many circadian outputs. Although a large number of transcripts are affected by the circadian oscillator, very little is known about their regulation and function. We show here that the Drosophila takeout gene, one of the output genes of the circadian oscillator, is regulated similarly to the circadian clock genes Clock (Clk) and cry. takeout RNA levels are at constant high levels in Clk(JRK) mutants. The circadian transcription factor PAR domain protein 1 (Pdp1epsilon) is a transcription factor that had previously been postulated to control clock output genes, particularly genes regulated similarly to Clk. In agreement with this, we show here that Pdp1epsilon is a regulator of takeout. Takeout levels are low in flies with reduced Pdp1epsilon and high in flies with increased amounts of Pdp1epsilon. Furthermore, flies with reduced or elevated Pdp1epsilon levels in the fat body display courtship defects, identifying Pdp1epsilon as an important transcriptional regulator in that tissue.


Subject(s)
Basic-Leucine Zipper Transcription Factors/genetics , Circadian Rhythm/genetics , Drosophila Proteins/genetics , Drosophila melanogaster/genetics , Animals , Animals, Genetically Modified , Basic-Leucine Zipper Transcription Factors/metabolism , Blotting, Northern , Blotting, Western , CLOCK Proteins/genetics , CLOCK Proteins/metabolism , Courtship , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Drosophila melanogaster/physiology , Fat Body/metabolism , Female , Gene Expression Regulation , Male , Mutation , Period Circadian Proteins/genetics , Period Circadian Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sexual Behavior, Animal/physiology
13.
PLoS Genet ; 3(1): e16, 2007 Jan 26.
Article in English | MEDLINE | ID: mdl-17257054

ABSTRACT

Mating behavior in Drosophila depends critically on the sexual identity of specific regions in the brain, but several studies have identified courtship genes that express products only outside the nervous system. Although these genes are each active in a variety of non-neuronal cell types, they are all prominently expressed in the adult fat body, suggesting an important role for this tissue in behavior. To test its role in male courtship, fat body was feminized using the highly specific Larval serum protein promoter. We report here that the specific feminization of this tissue strongly reduces the competence of males to perform courtship. This effect is limited to the fat body of sexually mature adults as the feminization of larval fat body that normally persists in young adults does not affect mating. We propose that feminization of fat body affects the synthesis of male-specific secreted circulating proteins that influence the central nervous system. In support of this idea, we demonstrate that Takeout, a protein known to influence mating, is present in the hemolymph of adult males but not females and acts as a secreted protein.


Subject(s)
Behavior, Animal , Drosophila melanogaster/physiology , Fat Body/physiology , Animals , Animals, Genetically Modified , Base Sequence , Chromatography, Affinity , DNA Primers , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Female , Male , Reverse Transcriptase Polymerase Chain Reaction , Sexual Maturation
14.
Org Lett ; 8(23): 5211-3, 2006 Nov 09.
Article in English | MEDLINE | ID: mdl-17078680

ABSTRACT

[Structure: see text] Unsubstituted benzylamines and N-methylbenzylamine can be ortho-arylated under palladium catalysis at 130 degrees C. The reactions require the presence of trifluoroacetic acid and silver acetate.

SELECTION OF CITATIONS
SEARCH DETAIL
...