Comparison of Microdilution Method with Agar Dilution Method for Antibiotic Susceptibility Test of Neisseria gonorrhoeae.

INTRODUCTION: Antimicrobial resistance (AMR) of Neisseria gonorrhoeae (N. gonorrhoeae) becomes a grave public health problem in the world. A strengthened Antimicrobial Resistance Surveillance Program is needed to track the trend of AMR development. However, the lack of a proper antimicrobial susceptibility test (AST) method is a barrier to expand the AMR surveillance in China. Traditional agar dilution (AD) method is laborious and E-test strips have no approval license for clinical use. Herein, a Chinese group modified the microdilution (MD) method for clinical ASTs. The objective of this study is to compare the MD method with the AD method for N. gonorrhoeae AST. MATERIALS AND METHODS: A total of 166 clinical isolates were tested for antimicrobial susceptibility of ceftriaxone, spectinomycin, azithromycin, ciprofloxacin, tetracycline, and penicillin using MD and AD method simultaneously. Results of MD method were read manually or automatically. Rates of essential agreement (EA), category agreement (CA), minor error, and very major error were compared. RESULTS: The total EAs (compared with results read manually) of penicillin, tetracycline, ciprofloxacin, spectinomycin, ceftriaxone, and azithromycin were 90.4%, 97.0%, 85.5%, 100.0%, 94%, and 72.3%; and CAs were 82.5%, 94.0%, 100%, 100%, 95.2%, and 94%, respectively. CONCLUSION: We conclude that the MD method might be an alternative for clinical AST of N. gonorrhoeae in China. In particular, MD method has the potency of accurate differentiation of isolates resistant to ceftriaxone or azithromycin, which were empirically recommended for gonococcal treatment, but its quality remained suboptimal, and further improvement is needed for clinical use.

Different structures of berberine and five other protoberberine alkaloids that affect P-glycoprotein-mediated efflux capacity.

Berberine, berberrubine, thalifendine, demethyleneberberine, jatrorrhizine, and columbamine are six natural protoberberine alkaloid (PA) compounds that display extensive pharmacological properties and share the same protoberberine molecular skeleton with only slight substitution differences. The oral delivery of most PAs is hindered by their poor bioavailability, which is largely caused by P-glycoprotein (P-gp)-mediated drug efflux. Meanwhile, P-gp undergoes large-scale conformational changes (from an inward-facing to an outward-facing state) when transporting substrates, and these changes might strongly affect the P-gp-binding specificity. To confirm whether these six compounds are substrates of P-gp, to investigate the differences in efflux capacity caused by their trivial structural differences and to reveal the key to increasing their binding affinity to P-gp, we conducted a series of in vivo, in vitro, and in silico assays. Here, we first confirmed that all six compounds were substrates of P-gp by comparing the drug concentrations in wild-type and P-gp-knockout mice in vivo. The efflux capacity (net efflux) ranked as berberrubine > berberine > columbamine ~ jatrorrhizine > thalifendine > demethyleneberberine based on in vitro transport studies in Caco-2 monolayers. Using molecular dynamics simulation and molecular docking techniques, we determined the transport pathways of the six compounds and their binding affinities to P-gp. The results suggested that at the early binding stage, different hydrophobic and electrostatic interactions collectively differentiate the binding affinities of the compounds to P-gp, whereas electrostatic interactions are the main determinant at the late release stage. In addition to hydrophobic interactions, hydrogen bonds play an important role in discriminating the binding affinities.

[Research of pollution-free and precision cultivation system of Chinese herbal medicines].

The issues of disordering production and non-standard pesticide application are common in the production of Chinese herbal medicines. Aimed to above problems, research groups built the pollution-free and precision cultivation system of medicinal plants. This system mainly included the precise site selection of medicinal plants based on the GIS technology, modern omics-assisted breeding, metagenomics guiding the soil complex improvement, and the precise field management based on rational application of fertilizer and comprehensive control of disease. At present, the production and distribution of medicinal plants were performed in the many poor counties of the whole nation. The breeding platform of resistant varieties was built, and certificates of new and well-bred varieties were received, in the base of genetic backgrounds of the original species of medicinal plants. The disease incidences were declined after application of these resistant varieties. Additionally, chemical pesticide consumption of medicinal plants (such as Panax ginseng, P. notoginseng, Salvia miltiorrhiza, P. quinquefolium, Schisandra chinensis, Platycodon grandiflorum and P. grandiflorus etc.) reduced by 20%-80% based on the genetic testing technologies of plant diseases and insect pests and safety evaluation of pollution-free pesticides. The application of pollution-free and precision cultivation system of Chinese herbal medicines achieve significantly social, economic and ecological benefits.

[DNA marker-assisted selection of medicinal plants (â ) .Breeding research of disease-resistant cultivars of Panax notoginseng].

DNA marker-assisted selection of medicinal plants is based on the DNA polymorphism, selects the DNA sequences related to the phenotypes such as high yields, superior quality, stress-resistance and so on according to the technologies of molecular hybridization, polymerase chain reaction and high-throughput sequencing, and assists the breeding of new cultivars. This study bred the first disease-resistant cultivar of notoginseng "Miaoxiang Kangqi 1" using the technology of DNA marker-assisted selection of medicinal plants and systematic breeding. The disease-resistant cultivar of notoginseng contained 12 special SNPs based on the analysis of Restriction-site Associated DNA Sequencing (RAD-Seq). Among the SNP (record_519688) was related to the root rot-resistant characteristics, which indicated this SNP could serve as genetic markers of disease-resistant cultivars and assist the systematic breeding. Compared to the conventional cultivated cultivars, the incidence rate of root-rot and rust-rot in notoginseng seedlings decreased by 83.6% and 71.8%, respectively. The incidence rate of root-rot respectively declined by 43.6% and 62.9% in notoginseng cultivation for 2 and 3 years compared with those of the conventional cultivated cultivars. Additionally, the potential disease-resistant groups were screened based on the relative SNP, and this model enlarged the target groups and advanced the breeding efficiency. DNA marker-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry.

[DNA marker-assisted selection of medicinal plants (â ¢)Evaluation of disease resistance of "Miaoxiang Kangqi 1" --a new cultivar of Panax notoginseng].

DNA marked-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry. The first disease-resistant cultivar of notoginseng, namely "Miaoxiang Kangqi 1", served as the object of study. We evaluated the Kangqi's resistance of seeds, seedlings and root against the pathological bacteria (Fusarum oxysporum) of root rot. Compared to the traditional cultivars, the disease index of notoginseng seeds declined by 52.0% after inoculation for seven days; the death rate of seedlings and disease index of root respectively decreased by 72.1% and 62.4% after inoculation for 25 days. Additionally, the growth inhibition ratio of notoginseng seeds and seedlings declined after inoculation. The seeds, seedlings and roots of "Miaoxiang Kangqi 1" showed significantly resistant to root rot. The evaluation of disease-resistance of Kangqi provided the basis for the popularization of new cultivar and guaranteed the favoring conduct of notoginseng pollution-free cultivation.

Stability-increasing effects of anthocyanin glycosyl acylation.

This review comprehensively summarizes the existing knowledge regarding the chemical implications of anthocyanin glycosyl acylation, the effects of acylation on the stability of acylated anthocyanins and the corresponding mechanisms. Anthocyanin glycosyl acylation commonly refers to the phenomenon in which the hydroxyl groups of anthocyanin glycosyls are esterified by aliphatic or aromatic acids, which is synthetically represented by the acylation sites as well as the types and numbers of acyl groups. Generally, glycosyl acylation increases the in vitro and in vivo chemical stability of acylated anthocyanins, and the mechanisms primarily involve physicochemical, stereochemical, photochemical, biochemical or environmental aspects under specific conditions. Additionally, the acylation sites as well as the types and numbers of acyl groups influence the stability of acylated anthocyanins to different degrees. This review could provide insight into the optimization of the stability of anthocyanins as well as the application of suitable anthocyanins in food, pharmaceutical and cosmetic industries.

[Contents and the Correlations of the Total Anthocyanins and Saponins of the Vegetative Organs of Panax notoginseng with Purple and Green Aerial Stems at Different Growth Stages].

Objective: To study the accumulation characteristics of total anthocyanins and saponins in the vegetative organ of Panax notoginseng with purple and green aerial stems at different growth stages. Methods: The contents of the total anthocyanins and saponins of the leaves, aerial stems, rhizomes and the adventitious roots of one-, two- and three-year-old Panax notoginseng with purple and green aerial stems were determined by spectrophotometry. Results: From one-year-old to three-year-old Panax notoginseng, the total anthocyanin contents (TACs) of the leaves, aerial stems and all vegetative organs and the percentages of the aerial stems TACs to those of all vegetative organs of purple aerial stemmed Panax notoginseng plants, the percentages of the total saponin contents (TSCs) of the leaves and aerial stems to those of all vegetative organs of the purple and green aerial stemmed plants and the percentages of the leaves TACs to those of vegetative organs of the green aerial stemmed plants all decreased. The TACs of the leaves and all vegetative organs of the green aerial stemmed plants, the TACs of the rhizomes and their adventitious roots, the vegetative organ TSCs and the percentages of the TSCs of the rhizomes and their adventitious roots to those of all vegetative organs of the purple and green aerial stemmed plants, and the percentages of the TACs of the rhizomes and their adventitious roots to those of all vegetative organs of the purple aerial stemmed plants were increased. The increasing rates of the TACs of the aerial stems and all vegetative organs and the TSCs of the aerial stems, rhizomes and their adventitious roots and all vegetative organs of the purple aerial stemmed plants were always higher than those of the green aeria stemmed plants, but the increasing rates of the leaves TSCs were lower than those of the green aerial stemmed plants, and the content changes of the vegetative organ TACs and TSCs of the purple and green aerial stemmed plants exhibited different correlations. Additionally, the three-years-old plants, the TSCs of the vegetative organs of the purple aerial stemmed plants were all higher than those of the green aerial stemmed plants, but the TACs of the leaves and rhizomes and their adventitious roots were lower than those of the green aerial stemmed plants. Conclusion: The saponin-accumulating capacity of the vegetative organs of purple aerial stemmed Panax notoginseng plants is stronger than that of green aerial stemmed Panax notoginseng.

[Analysis of global ecology of Panax notoginseng in suitability and quality].

In this study, the Geographic Information System for Global Medicinal Plants(GMPGIS) was used to assess the global production and ecological adaptation of Panax notoginseng. Based on climate factors and soil types of P. notoginseng from 326 sampling sites, which cover both traditional and current major producing regions, as well as on the results of the ecological similarity computing analysis, we obtained the maximum ecological similarity areas for P. notoginseng worldwide. The results indicated that China was the most suitable ecological and cultivated area globally for P. notoginseng, accounting for more than 70% of the total cultivated area in the world. The United States, Brazil, Portugal, and other 22 countries also had a small amount of potential suitable producing area. China has eight potential suitable producing provinces, including Yunnan, Fujian, Guangxi, Guizhou, etc. The prediction is consistent with the new district of P. notoginseng reported in recent years, which verifies the accuracy of the prediction of GMPGIS. We conducted a literature analysis on resource regeneration and quality ecology on P. notoginseng, and summarized the cultivation, wild tending models, and effects of environmental factors on the quality of P. notoginseng. The results provide scientific basis for selection of P. notoginseng, as well as the introduction, cultivation, and production of P. notoginseng worldwide.

Gold nanoparticle-based immunoassay by using non-stripping chemiluminescence detection.

A novel microplate-compatible chemiluminescence (CL) immunoassay has been developed for the determination of human immunoglobulin G (IgG) based on the luminol-AgNO(3)-gold nanoparticles CL system. Polystyrene microtiter plates were used for both immunoreactions and CL measurements. The primary antibody, goat-anti-human IgG, was first immobilized on polystyrene microwells. Then the antigen (human IgG) and the gold-labeled second antibody were connected to the microwells successively to form a sandwich-type immunocomplex. The gold label could trigger the reaction between luminol and AgNO(3), accompanied by light emission. Under the optimized conditions, the CL intensity of the system was linear with the logarithm of the concentration of human IgG in the range from 25 to 5000 ng mL(-1), with a detection limit of 12.8 ng mL(-1) ( approximately 80 pM) at a signal to noise ratio of three (S/N = 3). Compared with other reported CL immunoassay method based on gold labels, the proposed CL protocol avoids a strict stripping procedure or difficult to control synthesis processes, making the method more simple, time-saving and easily automated. The present CL method is promising for the determination of clinically important bioactive analytes.