Homogeneous electrochemical analysis of β-glycosidase and pathogenic bacteria in clinical sample assisted by click chemistry and enzyme-free catalytic hairpin assembly

2021 ◽  
pp. 130628
Author(s):  
Piaopiao Chen ◽  
Chengli Zhang ◽  
Xiaolong Guo ◽  
Yanming Meng ◽  
Fuqiang Shao ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Pathogenic Bacteria ◽  
Clinical Sample ◽  
Electrochemical Analysis ◽  
Catalytic Hairpin Assembly

Electrochemical biosensor for detection of pathogenic bacteria based on dual signal amplification of Cu3(PO4)2-mediated click chemistry and DNAzyme

The Analyst ◽  
2021 ◽  
Author(s):  
Hongguo Wei ◽  
Jiayu Wan ◽  
Shengjun Bu ◽  
Wenguang Zhang ◽  
Ma Li ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Magnetic Separation ◽  
Concanavalin A ◽  
Signal Amplification ◽  
Pathogenic Bacteria ◽  
Electrochemical Biosensor ◽  
Inorganic Hybrid ◽  
Highly Sensitive ◽  
Antibody Conjugates ◽  
Dual Signal Amplification

A novel electrochemical biosensor for detecting pathogenic bacteria was designed based on specific magnetic separation and highly sensitive click chemistry. Instead of enzyme-antibody conjugates, organic-inorganic hybrid nanoflowers (Concanavalin A (Con...

scholarly journals K1 Antigen Is Associated with Different AST Profile in Escherichia coli: A One-Month-Long Pilot Study

2021 ◽  
Vol 9 (9) ◽  
pp. 1884
Author(s):  
Maelys Proquot ◽  
Lovasoa Najaraly Jamal ◽  
Chloe Plouzeau-Jayle ◽  
Anthony Michaud ◽  
Lauranne Broutin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Clinical Sample ◽  
University Hospital ◽  
Clinical Samples ◽  
Bacterial Surface ◽  
E Coli ◽  
Negative Results ◽  
Resistant Strains ◽  
K Antigen

Escherichia coli is responsible for diseases of varying severity. The “K” antigen designates the capsular polysaccharides on the bacterial surface, which are mostly similar to those of highly pathogenic bacteria. The K1 antigen is often found in pathogenic E. coli. Aim: While the published studies on the AST profile of K1-positive E. coli have focused on pregnant women or newborns, this study aimed to characterize the AST profile of K1-positive E. coli independently of the clinical sample of isolation. Over a 4-week-long period, all patients hospitalized/consulting at the Poitiers University Hospital presenting a determined AST on E. coli were prospectively included to define their K1-status (Pastorex Meningitis) and to collect the clinical (age/sex) or biological metadata (AST/MIC). Among the 296 included samples, no differential representation was observed between K1 results regarding sample nature. K1-negative results were associated with multiple antibiotic-resistance (12.3% vs. 33.0%; p < 0.01). AST phenotypes differed between these groups, with a higher proportion of K1-negativity among resistant strains, especially on β-lactams (ureidopenicillin, 25.8% vs. 14.9%; and ampicillin/inhibitor, 50.0% vs. 26.8%; p < 0.05) or quinolone (19.8% vs. 7.0%) and sulfamethoxazole-trimethoprim (30.2% vs. 12.3%) (p < 0.01). This study analyzed E. coli ASTs in clinical samples of all types, regarding their K1-antigen status.

scholarly journals A Three Component Synthetic Vaccine Containing a β-Mannan T-Cell Peptide Epitope and a β-Glucan Dendritic Cell Ligand

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1961 ◽  
Author(s):  
David Bundle ◽  
Eugenia Paszkiewicz ◽  
Hassan Elsaidi ◽  
Satadru Mandal ◽  
Susmita Sarkar
Keyword(s):  
T Cell ◽  
Dendritic Cell ◽  
Click Chemistry ◽  
Conjugate Vaccine ◽  
Pathogenic Bacteria ◽  
Capsular Polysaccharide ◽  
Cell Epitope ◽  
Quarter Century ◽  
Peptide Epitope ◽  
Conjugate Vaccines

Glycoconjugates prepared from the capsular polysaccharide of several pathogenic bacteria and carrier proteins, such as CRM 197 or tetanus toxoid, have been one of the most successful public health measures to be implemented in the last quarter century. A crucial element in the success of conjugate vaccines has been the recruitment of T-cell help and systematic induction of a secondary immune response. The seminal discovery, that degraded polysaccharide fragments with attached peptide are presented to the T-cell receptor of carbohydrate specific T-cells by MHC-II molecules that bind to the peptide component of degraded vaccine, suggests potentially novel designs for conjugate vaccines. A fully synthetic conjugate vaccine was constructed from a 1,2-linked β-mannose trisaccharide conjugated to a T-cell peptide, previously shown to afford protection against Candida albicans. This combined B- and T-cell epitope was synthesized with a C-terminal azidolysine residue for subsequent conjugation by click chemistry. Four copies of a β-1,3 linked hexaglucan dendritic cell epitope were conjugated to an asymmetric dendrimer bearing an alkyne terminated tether. Click chemistry of these two components created a conjugate vaccine that induced antibodies to all three epitopes of the fully synthetic construct.

Real-Time Recombinase Polymerase Amplification (RPA) Detection of Pseudomonas aeruginosa Using Magnetic Nano-Beads for DNA Extraction

2021 ◽  
Vol 13 (9) ◽  
pp. 1657-1665
Author(s):  
Yun Xu ◽  
Yanqi Wu ◽  
Ling Liang ◽  
Pingping Huang ◽  
Rui Chen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Nosocomial Infection ◽  
Real Time ◽  
Dna Extraction ◽  
Pathogenic Bacteria ◽  
Magnetic Beads ◽  
Clinical Sample ◽  
Recombinase Polymerase Amplification ◽  
Clinical Samples ◽  
Time Saving

Pseudomonas aeruginosa (P. aeruginosa) is a ubiquitous nonfermentative gram-negative bacillus, residing in nature widely as a conditional pathogen that is commonly isolated from nosocomial infection cases, having a larger genome (5.5–7 Mbp). P. aeruginosa possesses great environmental adaptability and higher mutation rates, which accounts for its ability to resist antibiotics. Furthermore, multi-antibiotics-resistant P. aeruginosa has recently been established to be responsible for increased nosocomial infection incidence. Therefore, to detect, diagnose, and treat this life-threatening infection early enough, we introduced a real-time recombinase polymerase amplification (RPA) method of rapid P. aeruginosa detection, which is time-saving, convenient, highly sensitive, and more specific than the traditional bacterial culture method. System effectiveness and efficiency were then determined by a series of experiments, where specific RPA primers and probes accurately distinguished P. aeruginosa from other common pathogenic bacteria with optimal RPA reaction procedures set at 39 °C for 20 min. Additionally, specific primers and probes were designed based on the oprF gene sequence of P. aeruginosa. Subsequently, a real-time RPA system was used to analyze 20 cases of different clinical samples for P. aeruginosa detection in blood, open wound swab, and sputum. Results indicated that this system was suitable for bacterial analysis of common clinical sample types. The DNA extraction method used in this study was based on the magnetic beads method. In conclusion, this study established that the real-time RPA system was a rapid, specific, and sensitive method for clinical P. aeruginosa detection, which can be integrated into automatic high-throughput detection machines.

Probiotic Displaces Pathogenic Bacteria

2006 ◽  
Vol 37 (7) ◽  
pp. 48
Author(s):  
ERIK GOLDMAN
Keyword(s):  
Pathogenic Bacteria

Iron and Malaria: Absorption, Efficacy and Safety

2010 ◽  
Vol 80 (45) ◽  
pp. 279-292 ◽  
Author(s):  
Richard Hurrell
Keyword(s):  
Pathogenic Bacteria ◽  
Intestinal Barrier ◽  
Systemic Circulation ◽  
Malarial Parasite ◽  
Asymptomatic Malaria ◽  
Iron Supplements ◽  
Fortified Food ◽  
Care Giving ◽  
Single Meal ◽  
Women And Children

Febrile malaria and asymptomatic malaria parasitemia substantially decrease iron absorption in single-meal, stable isotope studies in women and children, but to date there is no evidence of decreased efficacy of iron-fortified foods in malaria-endemic regions. Without inadequate malarial surveillance or health care, giving iron supplements to children in areas of high transmission could increase morbidity and mortality. The most likely explanation is the appearance of non-transferrin-bound iron (NTBI) in the plasma. NTBI forms when the rate of iron influx into the plasma exceeds the rate of iron binding to transferrin. Two studies in women have reported substantially increased NTBI with the ingestion of iron supplements. Our studies confirm this, but found no significant increase in NTBI on consumption of iron-fortified food. It seems likely that the malarial parasite in hepatocytes can utilize NTBI, but it cannot do so in infected erythrocytes. NTBI however may increase the sequestration of parasite-infected erythrocytes in capillaries. Bacteremia is common in children with severe malaria and sequestration in villi capillaries could lead to a breaching of the intestinal barrier, allowing the passage of pathogenic bacteria into the systemic circulation. This is especially important as frequent high iron doses increase the number of pathogens in the intestine at the expense of the barrier bacteria.

Adolescents’ self-mutilation - Relationship with dependent behaviour

2003 ◽  
Vol 62 (4) ◽  
pp. 241-249 ◽  
Author(s):  
M. Bolognini ◽  
B. Plancherel ◽  
J. Laget ◽  
P. Stéphan ◽  
O. Halfon
Keyword(s):  
Suicide Attempts ◽  
Clinical Sample ◽  
Control Sample ◽  
Clinical Population ◽  
Control Group ◽  
Clinical Group ◽  
Self Mutilation ◽  
Self Harm ◽  
Partial Overlap ◽  
The Relationship

The aim of this study, which was carried out in the French-speacking part of Switzerland, was to examine the relationship between suicide attempts and self-mutilation by adolescents and young adults. The population, aged 14-25 years (N = 308), included a clinical sample of dependent subjects (drug abuse and eating disorders) compared to a control sample. On the basis of the Mini Neuropsychiatric Interview ( Sheehan et al., 1998 ), DSM-IV criteria were used for the inclusion of the clinical population. The results concerning the occurrence of suicide attempts as well as on self-mutilation confirm most of the hypotheses postulated: suicidal attempts and self-mutilation were more common in the clinical group compared to the control group, and there was a correlation between suicide attempts and self-mutilation. However, there was only a partial overlap, attesting that suicide and self-harm might correspond to two different types of behaviour.

Test-Retest Reliability of a Self-Report Questionnaire for DSM-IV and ICD-10 Personality Disorders

2000 ◽  
Vol 16 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Hans Ottosson ◽  
Martin Grann ◽  
Gunnar Kullgren
Keyword(s):  
Personality Disorder ◽  
Anxiety Disorders ◽  
Personality Disorders ◽  
Clinical Sample ◽  
Self Report ◽  
Anxiety State ◽  
Short Term ◽  
Retest Reliability ◽  
Axis I ◽  
Test Retest Reliability

Summary: Short-term stability or test-retest reliability of self-reported personality traits is likely to be biased if the respondent is affected by a depressive or anxiety state. However, in some studies, DSM-oriented self-reported instruments have proved to be reasonably stable in the short term, regardless of co-occurring depressive or anxiety disorders. In the present study, we examined the short-term test-retest reliability of a new self-report questionnaire for personality disorder diagnosis (DIP-Q) on a clinical sample of 30 individuals, having either a depressive, an anxiety, or no axis-I disorder. Test-retest scorings from subjects with depressive disorders were mostly unstable, with a significant change in fulfilled criteria between entry and retest for three out of ten personality disorders: borderline, avoidant and obsessive-compulsive personality disorder. Scorings from subjects with anxiety disorders were unstable only for cluster C and dependent personality disorder items. In the absence of co-morbid depressive or anxiety disorders, mean dimensional scores of DIP-Q showed no significant differences between entry and retest. Overall, the effect from state on trait scorings was moderate, and it is concluded that test-retest reliability for DIP-Q is acceptable.

Structuring Assessments of Psychopathology

2006 ◽  
Vol 27 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Willem K.B. Hofstee ◽  
Dick P.H. Barelds ◽  
Jos M.F. Ten Berge
Keyword(s):  
Principal Components ◽  
Personality Assessment ◽  
Clinical Sample ◽  
Principal Component ◽  
Normal Sample ◽  
Normative Sample ◽  
Assessment Data ◽  
Obsessive Compulsive ◽  
Oblique Rotation ◽  
Two Samples

Hofstee and Ten Berge (2004a) have proposed a new look at personality assessment data, based on a bipolar proportional (-1, .. . 0, .. . +1) scale, a corresponding coefficient of raw-scores likeness L = ΢XY/N, and raw-scores principal component analysis. In a normal sample, the approach resulted in a structure dominated by a first principal component, according to which most people are faintly to mildly socially desirable. We hypothesized that a more differentiated structure would arise in a clinical sample. We analyzed the scores of 775 psychiatric clients on the 132 items of the Dutch Personality Questionnaire (NPV). In comparison to a normative sample (N = 3140), the eigenvalue for the first principal component appeared to be 1.7 times as small, indicating that such clients have less personality (social desirability) in common. Still, the match between the structures in the two samples was excellent after oblique rotation of the loadings. We applied the abridged m-dimensional circumplex design, by which persons are typed by their two highest scores on the principal components, to the scores on the first four principal components. We identified five types: Indignant (1-), Resilient (1-2+), Nervous (1-2-), Obsessive-Compulsive (1-3-), and Introverted (1-4-), covering 40% of the psychiatric sample. Some 26% of the individuals had negligible scores on all type vectors. We discuss the potential and the limitations of our approach in a clinical context.

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