[Sensitivity Comparison Experiment of Four Testing Methods for Helicobacter pylori].

Objective: To measure with standard microbiology methods the sensitivity of 4 commonly used testing methods for Helicobacter pylori (Hp) and to conduct a comparative study of the correlations and differences across the 4 methods. Methods: With the Hp standard strain (SS1) as the reference, colony forming units (CFU) as the units of quantitative analysis for detection performance, and gradient dilution of SS1 suspension as the simulation sample, we measured the sensitivity of 4 Hp testing methods, including bacterial culture, rapid urease test, antigen test, and quantitative fluorescent PCR. CFU values at different concentrations corresponding to the 4 commonly used Hp testing methods were documented and the correlations and differences were analyzed accordingly. Results: The sensitivity of Hp bacterial culture, rapid urease test, antigen test and quantitative fluorescent PCR was 2.0×10 CFU/mL, 2.0×10 5 CFU/mL, 2.0×10 5 CFU/mL, and 2.0×10 2 CFU/mL, respectively. Conclusion: The testing turnover time and sensitivity of different laboratory methods for Hp testing varied significantly. The quantitative fluorescent PCR and bacterial culture both showed relatively high sensitivity, but bacterial culture has complicated operation procedures and is too time-consuming. The rapid urease test and antigen test both were simple and quick to perform, but showed low sensitivity. For clinical and laboratory testing of Hp, appropriate testing method that can identify the corresponding changes of Hp should be selected according to the actual testing purpose.

[Preparation and Release Properties of Helicobacter pylori Recombinant Protein PLGA Microspheres and PLGA-Chitosan Microspheres].

OBJECTIVE: To preparethe poly lactic-co-glycolic acid (PLGA) microspheres and PLGA-chitosan microspheres containing Helicobacter pylori recombinant protein, namely the BIB protein, and to explore their optimal preparation parameters and in vitro release performance in gastric and intestinal fluids. METHODS: Double emulsions (water-in-oil-in-water, or W1/O/W2) solvent evaporation method was used to prepare the BIB-PLGA microspheres and the BIB-PLGA-chitosan microspheres. Univariate analysis was done to study the impact of the water-to-oil ratio (W1/O), PLGA mass fraction and PVA concentration on the morphology, particle size, polydispersity index (PDI), encapsulation efficiency (EE), and drug loading (DL) so as to identify the optimal parameters. Bicinchoninic acid (BCA) assay was used to determine the protein concentration and the release efficiency of BIB. RESULTS: The optimal preparation parameters identified in the study were as follows: W1/O at 1∶2, PLGA mass fraction at 5%, and PVA mass fraction at 0.2%. The BIB-PLGA microspheres were found to be (2.11±0.08) µm in particle size, 0.35±0.18 in PDI, (78.20±1.73)% in EE and (10.58±0.23)% in DL. The BIB-PLGA-chitosan microspheres were (2.28±0.52) µm in particle size, 0.39±0.54 in PDI, and (78.87±1.30)% and (15.50±0.25)% in EE and DL, respectively. Both BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres showed slow-release property in gastric and intestinal fluids in vitro, with BIB-PLGA-chitosan microspheres showing better slow-release performance. CONCLUSION: The BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres prepared with the double emulsions solvent evaporation method showed high DL and EE, controllable particle sizes, dispersive appearance, and slow-release property in gastric and intestinal fluids in vitro.

Anti-bacterial and anti-viral effects of Fengreqing oral liquid () in vitro and in vivo.

OBJECTIVE: To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid (, FRQ) in vitro and in vivo. METHODS: The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans, Peptostreptococcus anaerobius, Hemolytic streptococcus, Streptococcus pneumoniae, Klebsiella pneumoniae), seven gram-negative bacteria (Escherichia coli, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Haemophilus influenzae, Helicobacter pylori, Pseudomonas aeruginosa, Gardnerella vaginalis) and Candida albicans were detected by the paper disc diffusion method. The inhibition rate of A/PuertoRico/8/34(H1N1) (PR8) influenza virus in different concentrations of Fengreqing oral solution was detected by chicken embryo method. CCK8 method was used to detect the half-cell infection of RSV, VSV and CVB3. The effect of FRQ on the survival curve of mice was detected by using co-infection model of Streptococcus pneumoniae and influenza virus. RESULTS: In vitro, FRQ can inhibit Actinobacillus actinomycetemcomitans, Helicobacter pylori, Gardnerella vaginalis, Staphylococcus aureus, Streptococcus mutans and Streptococcus pneumoniae and has an antiviral effect on the envelope virus H1N1. In vivo, Fengreqing oral solution had therapeutic effect on influenza-Streptococcus pneumoniae co-infection in mice, significantly improving the survival rate of mice. The medium dose and low dose FRQ significantly prolonged the survival time of mice. CONCLUSION: FRQ has good anti-bacterial and anti-viral effectsin vivo and in vitro.