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Safety is the core of the quality of Chinese materia medica products， and microbial pollution caused by medicinal materials， decoction pieces， intermediate products and others can bring certain impact on the quality and safety of Chinese materia medica products. The reasons for this are not only the problems of medicinal materials themselves， but also the exogenous pollution introduced in the production process. How to effectively use microbial detection technology and establish an appropriate microbial quality control strategy in the whole process of Chinese materia medica production is of great significance to improve the quality of Chinese materia medica products. Therefore， the authors put forward a microbial quality control strategy in the whole process of Chinese materia medica production based on the guidance of quality by design （QbD） concept， emphasizing the scientific linkage between the internal and external microbial quality control systems to jointly ensure the quality of products in all aspects. Among them， the internal microbial quality control system includes the control of the whole chain of Chinese materia medica-decoction pieces-intermediate products-excipitents-packaging materials-final products， which should be carried out by stages and characteristics， while the external microbial quality control system includes the control of personnel-equipment and facilities-pharmaceutical water-environment， emphasizing the principle of quality risk management and the development of monitoring programs， aiming to closely integrate microbial quality risk management with the production process of Chinese materia medica products， and to classify and develop microbial control strategies in order to minimize the impact of contaminating microorganisms and effectively guarantee the quality of Chinese materia medica products.
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Objective:To explore the clinical value of urine semi-quantitative colorimetry by sodium dithionite reduction method in the diagnosis and treatment of diquat poisoning.Methods:The data of 49 patients with acute diquat poisoning treated in the First Affiliated Hospital of Nanjing Medical University from December 3, 2020 to November 23, 2022 were retrospectively analyzed, the correlation between urine colorimetric results and plasma diquat concentration was observed, and the predictive value of urine colorimetric results for target organ damage and prognosis were evaluated.Results:There was a significant correlation between urine colorimetric results and plasma diquat concentration, the correlation coefficient was r=0.89, P <0.01. The cut-off value of urine colorimetry for the predicting the damage of gastrointestinal tract, liver, kidney, and central nervous system injury were 2.5, 3.5, 3.5, 5.5, respectively; in which the urine colorimetric results showed the highest sensitivity in predicting digestive tract injury [ AUC 0.93 (95% CI:0.89-1.00)]. The cut-off value of urine colorimetry for the prognosis of death was 4.5, the positive predictive value was 64.2%, and the negative predictive value was 95.2%. Conclusions:The urine semi-quantitative method can be used for rapid prediction of the plasma diquat concentration range on admission. The urine colorimetry results can also effectively predict the occurrence of organ injury and clinical outcome related to diquat poisoning, which provides evidence for the clinical diagnosis and therapy.
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Aiming at the hysteresis and destructiveness of off-line static detection of critical quality attribute of the moisture content of the raw material unit of the traditional Chinese medicine manufacturing process, honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis were used as the research carriers, and the drying method was used to measure the moisture content as a reference value. The moving stage was used to simulate the movement process of samples on the conveyor belt in the actual on-site production process, and near-infrared (NIR) spectra were collected, combined with machine learning, to establish NIR on-site dynamic detection model of moisture content in multi-variety honey-processed Chinese herbal slice. The results show that the second derivative method is used to preprocess the spectrum. The number of decision trees (ntree), the number of random features (max feature), and the minimum number of samples for generating leaf nodes (node size) are selected: 46, 76, and 8, respectively. The quantitative analysis model of moisture content has the best effect. The prediction coefficient of determination (the prediction coefficient of determination, R2pre) and the root mean square error of prediction (root mean square error of prediction, RMSEP) of the model were 0.903 2 and 0.330 2, respectively. The NIR quantitative model for the moisture content of multi-variety honey-processed Chinese herbal slice established in this study has good predictive performance, and can achieve rapid, accurate and non-destructive quantitative analysis of the moisture content of honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis at the same time, and provides a method for determining the moisture content of honey-processed Chinese herbal slice of the raw material unit of the traditional Chinese medicine manufacturing process.
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Objective:To analyze the clinical characteristics and pathogenic distribution of severe pneumonia in adults in order to provide basis for clinical diagnosis and treatment.Methods:From June 2021 to April 2022, 145 patients with pneumonia admitted to the Department of Respiratory and Critical Care Medicine of the Second People's Hospital of Guangdong Province. According to whether they meet the diagnostic criteria for severe pneumonia, they were divided into severe ( n=63) and mild ( n=82) groups, and the clinical features between the two groups were compared. At the same time, the role of FilmArray detection in severe pneumonia was discussed. The measurement data were tested using independent sample t test or Mann-Whitney U test, and the counting data were tested using Chi-square test or Fisher exact probability method. Results:The age of the patients in the severe group was (72.67±1.71) years, male patients accounted for 84.1%, and the median hospitalization time was 16 days. Nine patients died in hospital; most of them had fever, shortness of breath, and change of consciousness, accompanied by hypertension, diabetes, cerebrovascular disease, chronic kidney disease, and tumor history. Compared with the mild group, the total number of leukocytes, neutrophil ratio, procalcitonin, and C-reactive protein were higher in the severe group, but the CD3 +, CD4 +, and CD8 + cell counts were lower ( P<0.05). The positive rate of FilmArray detection in the severe group was 81%, and the mixed infection of multiple bacteria accounted for 50%, which was higher than that of traditional culture ( P<0.05). The top four pathogens in severe group were Pseudomonas aeruginosa, Acinetobacter baumannii complex, Klebsiella pneumoniae, and Staphylococcus aureus, which were significantly higher than that in the mild group ( P<0.05). Resistance genes were detected in patients with severe disease, which was significantly higher than that in patients with mild disease (70.7% vs. 17.5%, P<0.05). Conclusions:Severe pneumonia is more common in elderly men, with more basic diseases and poor immunity. FilmArray has a high positive rate and can detect multiple pathogens, which may have a role in the rapid diagnosis of severe pneumonia.
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OBJECTIVE@#In order to grasp the quality status of the first-aid ventilator in pre-hospital and field environment in time, the quality control and detection items of invasive ventilator were optimized to form a rapid detection operation process of first-aid ventilator and ensure the safety of patient treatment.@*METHODS@#Based on the quality control detection data of invasive ventilator in hospital in recent years, methods such as narrowing the range of qualified criteria and analyzing confidence interval were adopted to extract indicators prone to deviation and verify their correlation with similar indicators, so as to form an optimized rapid detection portfolio.@*RESULTS@#Compared with the original quality control detection procedures, the detection indicators of the rapid detection procedures were reduced from 5 categories of 24 indicators to 3 categories of 7 indicators. The detection time was shortened by 56.1% and the coincidence rate of the detection results was 100% after the actual measurement and verification.@*CONCLUSIONS@#Under the premise of ensuring the testing quality, the operating procedure for rapid detection of emergency ventilator can greatly reduce the detection time, and realize the rapid and high frequency quality control detection, so as to ensure the quality and safety of the equipment.
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Humans , Home Care Services , Quality Control , Ventilators, MechanicalABSTRACT
As a multiplex PCR pathogen detection system, Filmarray has the characteristics of high flux and high positive rate.This paper evaluates the pathogen detection performance, clinical value and economic value of Filmarray in children with community acquired pneumonia.Bronchoalveolar lavage fluid is a good respiratory sample type for Filmarray in pathogen detection.Filmarray respiratory panel(FARP)can be used as one of the supplementary detection methods for pathogens in CAP when the conventional ways is negative.Not only it can provide more pathogenic information of children with severe CAP, but also provide early pathogen warning signals for severe CAP.Furthermore, it may be more suitable for severe CAP or children with severe CAP transformation tendency.Filmarray pneumonia panel(FAPP)provides rapid respiratory pathogen results and drug-resistant gene results to assist in the targeted use of antibiotics in the early stage of severe CAP or when the condition worsens, which is expected to play a certain antibiotic management potential.The results of FARP and FAPP need to be interpreted by doctor based on the clinical characteristics of the children.Confounding factors need to be strictly controlled in the evaluation of different clinical indicators and economic value of the two detection systems.
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The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.
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Aflatoxin B1/analysis , China , Chromatography, Liquid , Enzyme-Linked Immunosorbent Assay , Tandem Mass SpectrometryABSTRACT
The medicinal plants with roots and rhizomes as the medicinal parts account for about 1/3 of Chinese medicinal herbs. Root and rhizome medicinal materials are widely used in clinical practice, whereas their wild resource reserves are insufficient to meet the market demand. With the expansion of planting areas, the formation of large-scale production areas, and the increase in planting years, diseases and insect pests of these medicinal plants, which are diverse and have broad transmission routes, strong concealment, and heavy damage, have become more and more serious. The prevention and control of these diseases and insect pests is characterized by multiple ways of pesticide application, large consumption of pesticides, susceptibility to soil barrier, difficulty in the control, and unstable control efficiency. Organophosphorus pesticides(OPPs) are widely used in the cultivation of Chinese medicinal plants because of their diverse varieties, broad-spectrum, good efficacy, and low residues, and have a positive effect on the yield and quality of Chinese medicinal materials. However, the abuse of OPPs not only increases the planting cost, but also affects the quality and safety of Chinese medicinal plants, the safety of clinical use of Chinese medicine, and the ecological safety of production areas. This paper reviewed the research and development progress of OPPs, the registration status of OPPs used in root and rhizome medicinal materials, residue limit standards, residue status, and rapid detection technology progress of OPPs. This review aims to provide research ideas and references for standardizing the use of OPPs in root and rhizome medicinal materials, reducing OPP residues, and establishing a fast, efficient, accurate, and reliable method for the detection of OPP residues in Chinese herbal medicine.
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Organophosphorus Compounds , Pesticide Residues/analysis , Pesticides/analysis , Plants, Medicinal , Rhizome/chemistryABSTRACT
Chinese medicinal material is the foundation of traditional Chinese medicine(TCM) industry. Its quality is not only closely related to the health of residents but also the key to the development of the TCM industry. Pesticide residues, heavy metals and mycotoxins are the major pollutants of Chinese medicinal materials. In recent years, quite a number of rapid detection methods for pollutants have been constructed. Among them, surface-enhanced Raman scattering(SERS), which has been widely used in food chemistry, environmental analysis, and other fields because of its speediness and non-destructiveness, shows its great potential in the pollutant detection in Chinese medicinal material. This paper firstly reviews the application of SERS for the detection of common pollutants in Chinese medicinal material. We then discussed the characteristics and advantages of SERS technique for pesticide detection, including the principle, SERS substrate design, specific recognition, etc. Finally, simultaneous detection of multiple pesticide residues in Chinese medicinal material was explored.
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China , Environmental Pollutants , Medicine, Chinese Traditional , Pesticide Residues/analysis , Spectrum Analysis, RamanABSTRACT
Objective To establish a scientific and objective evaluation model of the comprehensive performance of immunocolloidal gold qualitative rapid detection kits, and to provide a reference for the overall evaluation of similar products. Methods Based on the various factors affecting the performance of qualitative rapid detection kits, a comprehensive performance evaluation index system consisting of 4 first-level indicators and 18 second-level indicators was constructed.The analytic hierarchy process (AHP) and the fuzzy comprehensive evaluation (FCE) method were combined to determine the weights for the evaluation indicators and graded thresholds.The model was then used to evaluate the performance level of 6 brands of furazolidone metabolite rapid test kits. Results According to maximum membership degree principle, the evaluation of brand A, B, C, D, E and F were graded as good, excellent, middle, excellent, middle and excellent, respectively.Then the scores of 6 brands were calculated according to the hundred-mark system, and brand B had the highest score.This was consistent with the actual use experience. Conclusion The application of this model can make the evaluation results more comprehensive and accurate, providing reference for rational evaluation and selection of qualitative rapid detection kits.
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Dao-di herbs, which are widely recognized as medicinal materials with a high quality and good efficacy in clinic, are now facing the dilemma of absence of standard. This study focused on a pivotal scientific problem of design and application of quality standard of Dao-di herbs, and systematically illustrated the general rules for the quality standard of Dao-di herbs involving "four rules, six core contents, and three key methods". The quality standard of Dao-di herbs shall be fully based on literatures as well as habitat, planting/breeding, processing, characters, chemical-pharmacological/toxic data. The common requirements for the quality standard of Dao-di herbs contain "clear source, explicit origin, rational indicator, gradable quality, and multiple detection methods". Notably, traditional experiences and modern techniques, quality tracing management system, "quality determination by distinguishing characters" method, rapid detection technology, effective/toxic substances control method, were comprehensively applied in this standard to purse the objectification, automation, and intellectualization of detection technology. Appearance characters, chemical components, and bioactive parameters, unified effective/toxic indicators, quality markers, and pharmacopeial control indicators and reasonable ranges were included in rigorous quality standards for Dao-di herbs. Besides, simple grading method shall be developed to guide the implementation of "high quality-high price" policy. Eventually, the new quality standards for Dao-di herbs will lead international standards and promote the high-quality development of Dao-di herbs.
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Drugs, Chinese Herbal , Medicine, Chinese Traditional , Plants, Medicinal , Reference Standards , TechnologyABSTRACT
OBJECTIVE: To optimize DNA extraction methods and PCR reaction parameters, and develop an excellent and accurate rapid detection reagent for Fetus Cervi. METHODS: The DNA of Fetus Cervi was extracted by the modified salting method, modified SDS method A and modified SDS method B. Four DNA polymerase were chosen from the market and compared with each other. The annealing temperature and annealing time were optimized by classical control variable method and intersected experiment. A rapid detection reagent of Fetus Cervi was developed and then evaluated. RESULTS: The A260 /A280 ratio of the DNA extracted by modified SDS method B was (1.74 ± 0.05), and the mass concentration was (0.250 ± 0.005) μg•L -1. With high fidelity Taq DNA polymerase, the PCR product concentration could reach (0.185 ± 0.005) μg•L-1. Through these experiments, the annealing temperature was set at 58 ℃ and the annealing time was 30 s. The rapid detection reagent course was established to quickly and accurately identify Fetus Cervi and their artefacts, with one clear and bright band at 563 bp. CONCLUSION: The rapid detection reagent of Fetus Cervi combines the optimal DNA extraction method and the optimal PCR reaction parameters, and can accomplish the identification of Fetus Cervi and its pseudo-products with high accuracy and specificity.
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Objective@#To establish the loop-mediated isothermal amplification (LAMP) method for detection of variola virus.@*Methods@#One set of primers were designed for recognizing 5 distinct sequences on variola virus-specific gene HA. To optimize the reaction temperature and primers screening, and the sensitivity and specificity of this method for variola virus (VARV) detection were evaluated.@*Results@#Rapid detection of variola virus by LAMP assay was completed within 60 min at 63 ℃. The sensitivity of LAMP with detection limits of 1 pg/μl was 10 times higher than that of PCR, that is, the LAMP sensitivity was 3.37×105 copies/μl, and the PCR sensitivity was 3.37×106 copies/μl. and the result of 2 kinds of other virus were negative, showing that it had a good specificity.@*Conclusions@#The method reported here demonstrates a potential and valuable means for detection of VARV. The LAMP assay is suitable for wide-area sample screening and on-site detection of variola virus in grassroots units, for on-site and primary quarantine, medical units for rapid diagnosis.
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Aflatoxin B1 (AFB1) is a toxic secondary metabolite produced by toxigenic Aspergillus spp. (such as A. flavus and A. parasiticus) with carcinogenic,teratogenic and mutagenic effects. Studies have shown that AFB1 is widely found in crops,food,feed and traditional Chinese medicine,which poses a serious safety hazards to humans healthy. The establishment of a rapid detection technique that is suitable for AFB1 in different matrices has a great significance in preventing contamination,controlling food and medicines safety and ensuring human health. With the continuous improvement of small-molecule immune technology,various rapid immunoassays of AFB1 have been developed and utilized in recent years. This review systematically summarized current relevant standards for the detection of AFB1 in China and the maximum recommended levels for the application of aflatoxins in Chinese herbal medicines in some regions and countries. These standards are mainly applicable for aflatoxins in food,feed and some easily contaminated samples of Chinese herbal medicines. Some studies have shown that except the Chinese herbal medicines specified with the maximum recommended levels,some medicinal herbs and their products were also contaminated by aflatoxins. In addition,this paper reviewed the preparation technology of antigen and antibody for AFB1,and the rapid detection methods based on the specific recognition ability between antigen and antibody, including enzyme-linked immunosorbent assay,immunochromatographic assay,fluorescence immunoassay,chemiluminescence immunoassay,and novel immunosensor method, were also summarized and compared. This review aims to provide the reference for rapid,accurate,and sensitive technical standards for the detection of AFB1 in traditional Chinese medicine during the agricultural planting,distribution, trade and quality supervision and for the market, pharmacies and hospitals,so as to ensure the quality and safety of the traditional Chinese medicines.
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Objective@#To explore the preliminary application effect of real-time fluorescence recombinase polymerase amplification (RPA) in the detection of Candida albicans.@*Methods@#(1) Candida albicans standard strain and negative control bacteria of Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Candida glabrata standard strains of respectively 1 mL were collected and their DNA were extracted by yeast/bacterial genomic kit. The specificity of polymerase chain reaction (PCR), real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. (2) One Candida albicans standard strain and one negative control bacteria of Candida glabrata standard strain were collected, resuscitated, and counted. Candida albicans was diluted 10 times to 1×107 to 1×101 colony-forming unit (CFU)/mL. The DNA of the two bacteria were extracted as experiment (1). The sensitivity of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. The number of cycles for amplification curve to reach the threshold in real-time fluorescent quantitative PCR, and time of appearance of specific amplification curve in real-time fluorescence RPA were recorded and compared with the results in PCR. The detection limit and rate of the above-mentioned 3 methods in detecting Candida albicans were analyzed, and the correlation between concentration of Candida albicans in real-time fluorescence RPA and detection time was analyzed. (3) One standard strain of Candida albicans was collected, and the DNA was extracted as experiment (1) and detected by PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA. The total detection time of the above-mentioned 3 methods was recorded, respectively. (4) The DNA of 31 clinical samples of suspected Candida albicans infection and 1 clinical sample of Candida albicans collected from cotton swab were extracted, PCR and real-time fluorescence RPA were carried out, and the positive detection rates of the above-mentioned methods were calculated. The DNA of the clinical samples with positive results in both PCR and real-time fluorescence RPA were extracted by yeast/bacterial genomic kit, chelex-100 boiling method, and repeatedly freeze-thawing with liquid nitrogen method, and real-time fluorescence RPA and PCR were carried out. The negative control bacteria was Candida glabrata in real-time fluorescence RPA, while negative control bacteria in PCR were the same as experiment (1). The positive results in PCR and real-time fluorescence RPA were observed and time for amplification curve to reach the fluorescence threshold in real-time fluorescence RPA was recorded, respectively. Data were processed with linear correlation analysis and t test.@*Results@#(1) Three methods showed positive results in detecting standard strain of Candida albicans, and none of the 5 negative control bacteria showed positive results. (2) As the concentration of bacterial solution of Candida albicans decreased, the number of cycles for the amplification curve to reach the threshold increased in real-time fluorescent quantitative PCR, the time for appearance of specific amplification curve prolonged in real-time fluorescence RPA, and brightness of the gel strip weakened in PCR. None of the negative control bacteria in the above-mentioned 3 detection methods showed corresponding positive results. The detection limit of Candida albicans in real-time fluorescence RPA, PCR, and real-time fluorescent quantitative PCR was 1×101 CFU/mL. There was a significant negative correlation between the concentration of Candida albicans and the detection time in real-time fluorescence RPA (r=-0.95, P<0.01). The positive detection rates of PCR and real-time fluorescent quantitative PCR for Candida albicans of 1×101 to 1×107 CFU/mL were 100%. The positive detection rate of real-time fluorescence RPA for Candida albicans of 1×101 CFU/mL was 78%, and the positive detection rate of real-time fluorescence RPA for Candida albicans of 1×102 to 1×107 CFU/mL was 100%. (3) The total time of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA detection for Candida albicans was 133, 93, and 35 min, respectively. (4) The positive detection rate of real-time fluorescence RPA for 31 clinical samples of suspected Candida albicans infection was 32.26% (10/31), which was slightly lower than 35.48% (11/31) of PCR. Eleven clinical samples showed positive results both in real-time fluorescence RPA and PCR detection. No positive result was observed in the negative control bacteria detected both by real-time fluorescence RPA and PCR. The DNA was extracted by yeast/bacterial genomic extraction kit and chelex-100 boiling method for real-time fluorescence RPA detection. The time for the amplification curve to reach the threshold was (438±13) and (462±12) s, respectively, which was close (t=1.32, P>0.05). The DNA was extracted by repeatedly freeze-thawing with liquid nitrogen method for real-time fluorescence RPA, and the time for the amplification curve to reach the threshold in real-time fluorescence RPA was (584±15) s, which was significantly longer than that in the other 2 methods (t=7.55, 6.39, P<0.01).@*Conclusions@#Real-time fluorescence RPA has advantages of rapid detection, simple operation, high sensitivity, and good specificity in detecting Candida albicans, which is worthy of clinical application.
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Objective To establish a real-time quantitative PCR (RT-PCR) preliminary screening method for rapid detection of Brucella.Methods Based on the nucleotide sequence encoding Brucella's outer membrane proteins omp10 and omp31,four primers and probes of omp10,omp10-1,omp31 and omp31-1 were designed.The primers and probes were used to detect 19 strains of 6 categories of Brucella DNA of known organisms,10 strains of Brucella DNA that were isolated from Yuxi of Yunnan.And 224 negative Brucella DNA,including 35 strains of Bartonella DNA,103 strains of the Lord Komori enterocolitis DNA (including 4 parts of O ∶ 3 and 9 parts of O ∶ 9) and 86 samples of hybrids bacteria DNA.Then the specificity of primers and probes were evaluated based on the test results.Results The DNA of 19 standard Brucella strains could be amplified by omp10 and omp10-1,and the peak time and amplification curve of omp10 is better than omp10-1,and the DNA of negative control strains could not be amplified by omp10.The DNA of 16 standard Brucella strains could be amplified by omp31-1.The DNA of standard Brucella strains could not be amplified by omp31.The average Ct values of 10 strains of Brucella DNA which were isolated from Yuxi of Yunnan that were detected by omp10,omp10-1 and omp31-1 respectively were 19.87,19.14 and 17.52.Conclusion Omp10 has strong specificity and only specific for Brucella,so it can be used for rapid detection of Brucella.
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Objective@#To establish an optimized method of recombinase polymerase amplification (RPA) to rapidly detect Pseudomonas aeruginosa in clinic.@*Methods@#(1) The DNA templates of one standard Pseudomonas aeruginosa strain was extracted and detected by polymerase chain reaction (PCR), real-time fluorescence quantitative PCR and RPA. Time of sample loading, time of amplification, and time of detection of the three methods were recorded. (2) One standard Pseudomonas aeruginosa strain was diluted in 7 concentrations of 1×107, 1×106, 1×105, 1×104, 1×103, 1×102, and 1×101 colony forming unit (CFU)/mL after recovery and cultivation. The DNA templates of Pseudomonas aeruginosa and negative control strain Pseudomonas putida were extracted and detected by PCR, real-time fluorescence quantitative PCR, and RPA separately. The sensitivity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (3) The DNA templates of one standard Pseudomonas aeruginosa strain and four negative control strains (Staphylococcus aureus, Acinetobacter baumanii, Candida albicans, and Pseudomonas putida) were extracted separately, and then they were detected by PCR, real-time fluorescence quantitative PCR, and RPA. The specificity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (4) The DNA templates of 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin, 1 clinical strain of which was taken by cotton swab, and negative control strain Pseudomonas putida were extracted separately, and then they were detected by RPA. Positive amplification signals of the clinical strains were observed, and the detection rate was calculated. All experiments were repeated for 3 times. Sensitivity results were analyzed by GraphPad Prism 5.01 statistical software.@*Results@#(1) The loading time of RPA, PCR, and real-time fluorescence quantitative PCR for detecting Pseudomonas aeruginosa were all 20 minutes. In PCR, time of amplification was 98 minutes, time of gel detection was 20 minutes, and the total time was 138 minutes. In real-time fluorescence quantitative PCR, amplification and detection could be completed simultaneously, which took 90 minutes, and the total time was 110 minutes. In RPA, amplification and detection could also be completed simultaneously, which took 15 minutes, and the total time was 35 minutes. (2) Pseudomonas putida did not show positive amplification signals or gel positive results in any of the three detection methods. The detection limit of Pseudomonas aeruginosa in real-time fluorescence quantitative PCR and PCR was 1×101 CFU/mL, and that of Pseudomonas aeruginosa in RPA was 1×102 CFU/mL. In RPA and real-time fluorescence quantitative PCR, the higher the concentration of Pseudomonas aeruginosa, the shorter threshold time and smaller the number of cycles, namely shorter time for detecting the positive amplified signal. In real-time fluorescence quantitative PCR, all positive amplification signal could be detected when the concentration of Pseudomonas aeruginosa was 1×101-1×107 CFU/mL. In RPA, the detection rate of positive amplification signal was 0 when the concentration of Pseudomonas aeruginosa was 1×101 CFU/mL, while the detection rate of positive amplification signal was 67% when the concentration of Pseudomonas aeruginosa was 1×102 CFU/mL, and the detection rate of positive amplification signal was 100% when the concentration of Pseudomonas aeruginosa was 1×103-1×107 CFU/mL. (3) In RPA, PCR, and real-time fluorescence quantitative PCR, Pseudomonas aeruginosa showed positive amplification signals and gel positive results, but there were no positive amplification signals or gel positive results in four negative control strains of Acinetobacter baumannii, Staphylococcus aureus, Candida albicans, and Pseudomonas putida. (4) In RPA, 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin and 1 clinical strain of Pseudomonas aeruginosa taken by cotton swab showed positive amplification signals, while Pseudomonas putida did not show positive amplification signal. The detection rate of positive amplification signal of 29 clinical strains of Pseudomonas aeruginosa in RPA was 100%.@*Conclusions@#The established optimized RPA technology for fast detection of Pseudomonas aeruginosa requires shorter time, with high sensitivity and specificity. It was of great value in fast detection of Pseudomonas aeruginosa infection in clinic.
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With the rapid development of instrument technology , Raman spectrometer has become one of the fastest growing type of instrument in the molecular spectroscopy . In recent years , Raman spectrometer gradually emerging in the application in the domain of biology and medicine , Raman spectroscopy technology appears new development constantly in the rapid identification and classification of microorganisms because of its rapid , efficient, sensitive, noninvasive, repeatability and other unique advantages.This article describes its application in the rapid detection of bacteria , viruses and other microorganisms , and also prospects for the application of Raman spectroscopy in future clinical work .
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A novel immunochromatographic assay was developed, which could provide visual evidence of triazophos in agro products, and also could directly identify the safety status by setting visual cut-off limit of detection in maximal residual limit ( MRL) value. Three test lines ( T1, T2, T3) were applied to the nitrocellulose membrane with different concentrations of Triazophos-OVA, and one control line (C) was settled with goat anti mouse IgG antibody. Thereafter, by combining with conjugate pad which immobilized monoclonal antibody labeled with 20 nm Colloidal gold particles, absorbent pad and PVC plate, a chromatographic test strip was assembled. With optimization of sample extraction and solvents selection, the test strips were employed for the determination of triazophos in rice, cabbage and apple. The results revealed that the cut-off limit of detection could reach 0. 005, 0. 01 and 0. 02 μg / mL represented by test line T3, T2 and T1, respectively. After modification, the cut-off limit of detection was resettled to 0. 05, 0. 1 and 0. 2 μg / mL according to the MRL values which enforced by the national standard of GB2763. Using acetonitrile for the sample extraction, the extracts were diluted 10 times or solvent exchanged with equivalent volume by PBS solution, and then tested by strips descripted above mentioned. The two test strips could precisely identified the safety status of agro product with MRL as threshold within 8-12 min. Furthermore, the residues value of triazophos could be quantified by the multiple quantitative test lines. Parallel GC data indicated that the strip had no false negative. This MRL-based multiple quantitative triazophos detection strip would provide a simple, direct, accurate and the most intuitionistic performance for the evaluation of agro product safety.
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Objective To establish a accurate and rapid method of loop-mediated isothermal amplification(LAMP) for detecting Legionella Pneumophila(LP) .Methods The strains of LP ,Staphylococcus aureus ,Pseudomonas aeruginosa ,Escherichia coli ,Enterobacter sakazakii ,Listeria monocytogenes ,Salmonella typhimurium ,shigella flexneri and Vibrio parahaemolyticus were selected . According to six special domains of toxicity-related mip gene on LP ,the LAMP primers(mip-1 ,mip-2 ,mip-3) were designed by using the Primer Explorer Version 4 .0 .The genomic DNA was extracted for conducting LAMP .Then its specificity ,lowest detectable limit and stability were evaluated .Results The screened primer mip-3 appeared the peak after amplification for about 10 min in the LAMP reaction system for detecting LP ,moreover the peak value was higher ;while the strains of non-LP had no amplification reaction ;the LAMP detection limit could reach 100 fg/μL .The primer mip-3 appeared the peak almost at the same time in 20 times of duplicated detection ,and its stability was good .Conclusion The established LAMP detection method has the advantages of strong specificity and high stability ,can rapidly and accurately detect LP and has large prospect of promotion and application .