[Comparison on discriminatory power of different variable number tandem repeats locus-set on genotyping of mycobacterium tuberculosis isolated in China].

Objective: To evaluate the application of different variable number tandem repeats (VNTR) locus in genotyping of Mycobacterium tuberculosis (M.tuberculosis) strains isolated from eight provinces in China, and to find the suitable locus-set of VNTR for epidemical strains in China.

Methods: All 140 M.

[The influence of lysogenic phage on biofilm formation of Pseudomonas aeruginosa].

Objective: To investigate the effect of the lysogenic phage Ppa3094 on the biofilm formation of PA3094.

Methods: The modified plate culture method was used to established the biofilm model in vitro. The viable counts of bacteria in biofilm were detected by MTT method; The real-time RT-PCR was applied to measure the expression level of algC and algD during the biofilm formtion of PA3094 and PA3094-L.

[Quantification of class 1 integrase gene expression of Pseudomonas aeruginosa in biofilm].

Objective: To study the molecular mechanism of integron related gene transfer in biofilm and aqueous culture of P. aeruginosa by investigating the expression level of intI1 mRNA in class 1 integron positive strains.

Methods: A competitive reverse transcription-PCR (cRT-PCR) method was designed to quantify class 1 integrase mRNA production in two clinical P.

[Analysis of class I integrons in metalloenzyme-producing Pseudomonas aeruginosa].

Objective: To investigate class I integrons and integrated gene cassettes in metalloenzyme-producing Pseudomonas aeruginosa.

Methods: A total of 68 isolated clinical strains of Pseudomonas aeruginosa were subjected to PCR analysis with primers specific for bla(IMP-1) and bla(VIM). The positive strains then underwent examination for class I integrons and integrated gene cassettes with PCR with primers specific to class I integrase ((IntI)1) and integrated gene cassettes, followed by sequence analysis for some of the positive strains.

[Establishing a real-time PCR assay for anatid herpesvirus 1].

Objectives: To develop a real-time quantitative PCR assay to detect duck plague virus (DPV) for the rapid diagnosis of DPV infection, the investigation of its nosogenesis and the screening of effective antiviral drugs.

Methods: The primer and probe were designed according to the gene sequence of DPV DNA polymerase gene. To establish a standard curve, a plasmid containing 125 bp PCR product was constructed and severed as a positive control.

[Quantification for biofilm formation of pseudomonas aeruginosa isolates and their genotypic analysis].

Objective: To probe the correlation between the ability of biofilm formation of Pseudomonas aeruginosa isolates and their genotypes.

Methods: Forty-eight Pseudomonas aeruginosa isolates were tested for their biofilm formation with a modified microtiter test and were analyzed by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The percent similarity between their genetic fingerprints and cluster analysis was performed and worked out using computer software.

[The cloning and expression of rhlR, a quorum sensing gene in Pseudomonas aeruginosa PAO1, and a study of its effect on bacterial clearance rate in mouse lung].

Objective: To inquire about the molecular characteristics of rhlR, a Quorum Sensing gene in Pseudomonas aeruginosa (P. aeruginosa) PAO1, and to explore the immunogenicity of RhlR protein in mouse.

Methods: The rhlR gene of PAO1 was amplified by PCR and cloned into pGEX4T-1 plasmid.

[Protective effect of vitamin C on protein activity in plasma during virus inactivation].

To determine whether addition of vitamin C (Vit C) to single-unit plasma could influence the efficacy of inactivating viruses and could maintain the activity of plasma proteins by methylene blue (MB)-light treatment. Vesicular stomatitis virus (VSV) Indiana strain was used as the indicating virus. Human plasma containing VSV was added with different concentrations of Vit C and final concentration 1 micromol/L MB and irradiated by fluorescence at an intensity of 40,000 lx, samples were collected at different times for detection.

Evaluation of the biofilm-forming ability and genetic typing for clinical isolates of Pseudomonas aeruginosa by enterobacterial repetitive intergenic consensus-based PCR.

Biofilm formation is an important phenotype associated with chronic Pseudomonas aeruginosa infections. In the present study, a total of 48 P. aeruginosa strains isolated from clinical specimens were examined for their biofilm-forming ability using a microtiter plate method.

Development of quantitative real-time polymerase chain reaction for duck enteritis virus DNA.

Duck enteritis virus (DEV) is a herpesvirus that causes an acute, contagious, and fatal disease. In the present article, we introduce a quantitative real-time polymerase chain reaction (PCR) assay for DEV DNA using TaqMan technology and a two-step protocol. It was confirmed to be rapid, sensitive, and specific for DEV detection.

The action of Pseudomonas aeruginosa biofilms in intrinsic drug resistance.

Background: There is a growing interest in studying the relationship between intrinsic resistance and biofilms resistance to drugs. However, the relationship still remains unclear in the macroscopic bacterial growth. Our study is to illuminate the change of bacterial drug resistance of gyrA mutant and active efflux pump during the development of Pseudomonas aeruginosa (P.

[Experimental study on the antiviral mechanism of Ceratostigma willmattianum against herpes simplex virus type 1 in vitro].

Objective: To study the antiviral effect and mechanisms of the liquid extract from Ceratostigma willmattianum against herpes simplex virus type 1 (HSV-1) in vitro.

Method: C. willmattianum in various concentration was applied to different steps of HSV-1 replication cycle.

[Preparation and transfection of GFP plasmid DNA/cationic liposome complex].

Objective: This work was directed at obtaining a better gene carrier to improve the effects of gene delivery.

Methods: Cationic liposomes made from cholesterol, lecithin and Eighteenth Amic by reverse evaporation technique were used for encapsulating plasmid DNA containing gfp gene. The DNA/liposome complexes differed in quantity of plasmid DNA.