scholarly journals Coherent fluctuation nephelometry in clinical microbiology

2019 ◽  
Vol 9 (2) ◽  
pp. 385-392
Author(s):  
A. S. Gur’ev ◽  
O. Yu. Shalatova ◽  
E. V. Rusanova ◽  
I. V. Vasilenko ◽  
A. Yu. Volkov
Keyword(s):  
Antibiotic Susceptibility ◽  
Clinical Microbiology ◽  
Urine Analysis ◽  
Growth Curves ◽  
High Sensitivity ◽  
Pure Cultures ◽  
Susceptibility Tests ◽  
Express Methods ◽  
Coherent Fluctuation

In this article data concerning coherent fluctuation nephelometry (CFN) use in clinical microbiology is presented. CFN-analyzer allows to solve two important problems – fast urine screening for bacteriuria within 2-4 hours and antibiotic susceptibility testing within 3-6 hours. Altogether more than 650 urine samples were tested, and the effectivity of CFN-analyzer for preliminary selection of samples for further analysis was shown. Method allows to detect negative samples, reducing the number of urine analyses by 70-80%. Simultaneous analysis of growth curves and concentration of microorganisms shows high sensitivity and specificity (95.2% и 96.9%). Also more than 250 antibiotic susceptibility tests were performed using CFN-analyzer to show its effectiveness for determination of resistant properties of both pure cultures and urine microflora without isolation of bacteria. The agreement with traditional methods was from 84% to 88%. The use of CFN-analyzer with express methods of identification of microorganisms (chromogenic nutrient broths or mass-spectrometry) allows to make full urine analysis within 1-2 days. In the future CFN-analyzer gives an opportunity to screen different human biological liquids, and finds an application for other microbiological tasks, including standardization and speeding-up in sanitary bacteriology.

scholarly journals The Calgary Biofilm Device: New Technology for Rapid Determination of Antibiotic Susceptibilities of Bacterial Biofilms

1999 ◽  
Vol 37 (6) ◽  
pp. 1771-1776 ◽  
Author(s):  
H. Ceri ◽  
M. E. Olson ◽  
C. Stremick ◽  
R. R. Read ◽  
D. Morck ◽  
...  
Keyword(s):  
Antibiotic Susceptibility ◽  
Clinical Laboratory ◽  
Rapid Determination ◽  
New Technology ◽  
Growth Curves ◽  
National Committee ◽  
Standard Group ◽  
Antibiotic Susceptibilities ◽  
Significant Difference

Determination of the MIC, based on the activities of antibiotics against planktonic bacteria, is the standard assay for antibiotic susceptibility testing. Adherent bacterial populations (biofilms) present with an innate lack of antibiotic susceptibility not seen in the same bacteria grown as planktonic populations. The Calgary Biofilm Device (CBD) is described as a new technology for the rapid and reproducible assay of biofilm susceptibilities to antibiotics. The CBD produces 96 equivalent biofilms for the assay of antibiotic susceptibilities by the standard 96-well technology. Biofilm formation was followed by quantitative microbiology and scanning electron microscopy. Susceptibility to a standard group of antibiotics was determined for National Committee for Clinical Laboratory Standards (NCCLS) reference strains: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, andStaphylococcus aureus ATCC 29213. Growth curves demonstrated that biofilms of a predetermined size could be formed on the CBD at specific time points and, furthermore, that no significant difference (P > 0.1) was seen between biofilms formed on each of the 96 pegs. The antibiotic susceptibilities for planktonic populations obtained by the NCCLS method or from the CBD were similar. Minimal biofilm eradication concentrations, derived by using the CBD, demonstrated that for biofilms of the same organisms, 100 to 1,000 times the concentration of a certain antibiotic were often required for the antibiotic to be effective, while other antibiotics were found to be effective at the MICs. The CBD offers a new technology for the rational selection of antibiotics effective against microbial biofilms and for the screening of new effective antibiotic compounds.

scholarly journals An alternative for urine cultures: Direct identification of uropathogens from urine by MALDI-TOF MS

2020 ◽  
Author(s):  
Arzu Akşit İlki ◽  
Sevim Özsoy ◽  
Gulşen Gelmez ◽  
Burak Aksu ◽  
Güner Söyletir
Keyword(s):  
Flow Cytometry ◽  
Antibiotic Susceptibility ◽  
Clinical Microbiology ◽  
Urine Samples ◽  
Clinical Microbiology Laboratory ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Susceptibility Tests ◽  
Tract Infections ◽  
Tof Ms

AbstractUrinary tract infections are one of the most common bacterial infections and rapid diagnosis of the infection is essential for appropriate antibiotic therapy. The goal of our study was to identify urinary pathogens directly by MALDI-TOF MS and to perform antibiotic susceptibility tests in order to shorten the period spent for culturing.Urine samples submitted for culture to the Clinical Microbiology Laboratory were enrolled in this study. Urine samples were screened for leukocyte and bacteria amount by flow cytometry. Samples with bacterial load of 106–107/mL were tested directly by MALDI-TOF MS and antibiotic susceptibility tests (AST) were performed.In total, 538 positive urine samples were evaluated in our study. MALDI-TOF MS identified the microorganism directly from the urine sample in 91.8% of these samples and the concordance rate of conventional identification and direct detection was 95.8% for Gram-negatives at the genus and species level. Escherichia coli (n:401) was the most frequently isolated microorganism, followed by Klebsiella pneumoniae (n:57). AST results were generated for 111 of these urine samples and the concordance was 90% and 87% for E. coli and K. pneumoniae, respectively.Our results showed that screening of urine samples with flow cytometry to detect positive samples and identification of uropathogens directly by MALDI-TOF MS with an accuracy of over 90% can be a suitable method particularly for Gram-negative bacteria in clinical microbiology laboratories.

Extraction and Phytochemicals Determination of Traditional Medicinal Plants for Anti-microbial Susceptibility Test

2020 ◽  
Vol 2020 ◽  
Author(s):  
Firew Admasu
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plants ◽  
Traditional Medicine ◽  
Crude Extract ◽  
Susceptibility Test ◽  
Plant Sample ◽  
Traditional Medicinal Plants ◽  
Traditional Health Care ◽  
Susceptibility Tests

Abstract: The study were conducted at Dilla University, College of Natural Sciences, Biological Sciences laboratories. Background: Ethiopia is a country with many ethnic groups, cultures and beliefs which in turn have contributed to the high diversity of traditional health care knowledge and practices of traditional medicine from local growth plants, animals and minerals for various physical and mental disorders of human and livestock population that passed from generation to generation for centuries. Medicinal plants contributors to pharmaceutical, agricultural and food industries in the world. The use of medicinal plants in the industrialized societies has been traced to extraction and development of several drugs used in order to heel some diseases having inhibiting effect against pathogenic microorganism. Objective: The main objective of this study was Extraction and Phytochemicals determination of traditional medicinal plants for anti microbial susceptibility test. Methodology: The extraction and identification of some phytochemicals crude compound which used for antimicrobial susceptibility test from plant sample such as Ocimum lamiifolium (OL), Croton maerosth (Cm) and Ruta chalepesis (RC) were conducted. Plant samples are collected, powdered using mortal and pistil and extracted using ethanol and some susceptibility tests were performed to identify some phytochemicals compound. Result: The main result of Antimicrobial activity test showed that the crude extract of OL has the highest zone of inhibition. The highest yield of crude extract (38.21%) was obtained from Croton maerosth (CM) which followed by Ruta chalepesis (RC) (32.43%). However, the lowest yield (28.37%) was obtained from Oscpmum lamifolium (OL). Conclusion: Traditional Medicine is used by many people to managing numerous conditions; it’s accessible and effective on antimicrobial activity. Therefore, it plays a significant role by reducing life-threatening ailments of people and other animals.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural
Keyword(s):  
High Performance ◽  
Phthalate Esters ◽  
High Sensitivity ◽  
Hplc Method ◽  
Cosmetic Products ◽  
Limit Of Quantification ◽  
Nail Polish ◽  
Accuracy And Precision ◽  
Butyl Phthalate

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

Urinary gonadotropin measurements by enhanced luminometric assays (LIA) for the evaluation of pubertal development

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
And Demir ◽  
Adem Aydın ◽  
Atilla Büyükgebiz ◽  
Ulf-Håkan Stenman ◽  
Matti Hero
Keyword(s):  
Healthy Subjects ◽  
Reliable Method ◽  
Pubertal Development ◽  
High Sensitivity ◽  
Tanner Stage ◽  
Time Resolved ◽  
Stage 1 ◽  
Sensitive Detection Technique ◽  
Serum And Urine

Abstract Objectives Determination of LH in urine has proved to be a reliable method for evaluation of pubertal development. The human LH assay based on time-resolved immunofluorometric (IFMA) technology (AutoDELFIA, PerkinElmer, Wallac) has been found to be suitable for this purpose thanks to its high sensitivity but other assays have not been evaluated. We have analyzed our data obtained by another potentially sensitive detection technique, enhanced luminometric assay (LIA) with the objective of finding a viable alternative to IFMA since these may not be available in the future. Methods LIA was used to measure LH and FSH in serum and urine samples from 100 healthy subjects of each Tanner stage and both genders, whose pubertal development has been determined. Results Urinary gonodotropin concentrations measured by LIA correlated well with Tanner stage [(r=0.93 for girls, r=0.81 for boys; p<0.01 for LH) and (r=0.81 for girls, r=0.73 for boys; p<0.01 for FSH)]. LIA determinations revealed the increase in U-LH concentrations during the transition from Tanner stage 1–2 in both girls and boys (p<0.001), whereas U-FSH and S-LH were able to detect the increase from Tanner stage 1–2 only in boys or girls, respectively (both p<0.001). Conclusions Measurement of urinary gonadotropin concentrations by LIA may be useful for the evaluation of overall pubertal development and also in the detection of transition from prepuberty to puberty.

scholarly journals Fluorescent Probes for Live Cell Thiol Detection

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3575
Author(s):  
Shenggang Wang ◽  
Yue Huang ◽  
Xiangming Guan
Keyword(s):  
Fluorescent Probes ◽  
Biological System ◽  
High Sensitivity ◽  
Intracellular Distribution ◽  
Live Cell ◽  
Live Cells ◽  
High Demand ◽  
Non Invasive

Thiols play vital and irreplaceable roles in the biological system. Abnormality of thiol levels has been linked with various diseases and biological disorders. Thiols are known to distribute unevenly and change dynamically in the biological system. Methods that can determine thiols’ concentration and distribution in live cells are in high demand. In the last two decades, fluorescent probes have emerged as a powerful tool for achieving that goal for the simplicity, high sensitivity, and capability of visualizing the analytes in live cells in a non-invasive way. They also enable the determination of intracellular distribution and dynamitic movement of thiols in the intact native environments. This review focuses on some of the major strategies/mechanisms being used for detecting GSH, Cys/Hcy, and other thiols in live cells via fluorescent probes, and how they are applied at the cellular and subcellular levels. The sensing mechanisms (for GSH and Cys/Hcy) and bio-applications of the probes are illustrated followed by a summary of probes for selectively detecting cellular and subcellular thiols.

scholarly journals The Double Face of Ketamine—The Possibility of Its Identification in Blood and Beverages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 813
Author(s):  
Magdalena Świądro ◽  
Paweł Stelmaszczyk ◽  
Irena Lenart ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Date Rape ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Heroin Addiction ◽  
Assisted Extraction ◽  
Low Concentrations ◽  
High Concentrations ◽  
Rosé Wine ◽  
Tof Ms

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

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