Objective:To investigate the levels of the specific antibody in the serum of convalescent SARS patients.Methods:The specific antibody in the serum of convalescent SARS patients were detected by indirect ELISA and double antigen sandwich method.Results:The levels of the specific IgG antibody in the serum of convalescent SARS patients is up to the maximum in the fifth week, the levels of the specific IgM is up to the maximum in the third week. The levels of the specific IgG in the serum of convalescent SARS patients is 1-7 times than that of the specific IgM. The positive detection rate of the specific antibody during 5-7 weeks in the serum of convalescent SARS patients is up to 100%.Conclusion:The levels of the specific antibody in the serum of convalescent SARS patients is up to the maximum in the fifth week, and the positive detection rate of the specific antibody is 100%.

The results of drug activity of singe drug and multidrug combination susceptibility tests showed the coincidence rate between the two kinds of tests was above 95% . The results also indicated that the chemotherapy program consisted of resistant drugs exhibited an inhibitory effects to different extents on the growth of 40% strains in vitro. Using two resistant drugs and one susceptible drug in the susceptibility test of three drug combination assay the pathogenic strain was still susceptible. It is proved that the extents of susceptibility of pathogenic strains to chemotherapy programs could be accurately calculated by the time of initial growth , the colony count and the colony size in multidrug combination susceptibility test. The results suggested Kuang′s agar medium should be adapted in the drug susceptibility test and the multidrug combination susceptibility test should be carried out for multidrug resistant strains of Mycobacterium tuberculosis.

Objective To investigate the drug tolerance of Acinetobacter baumanni and Stenotrophomonas maltophilia . Methods The antimicrobial susceptibility tests for 275 isolates of Acinetobacter baumanni and 107 isolates of Stenotrophomonas maltophilia from 2000 to 2004 were measured by MicroScan WarkAway 96 The chemotherapeutic effects of 18 cases of sequent infection with Acinetobacter baumanni and Stenotrophomonas maltophilia was analyzed. Results The resistance of the two species of bacteria to twelve antibiotics increased obviously during the last five years, especially from 2000 to 2001. The resistant rate of Acinetobacter baumanni to Cefepime、Cefotaxime、Ceftazidime and Ceftriaxonewas was 20~50% in 2000, but raised to 70%~81% in 2004. For Acinetobacter baumanni to Amikacin、Amp/sulbac、Ciprofloxacin、Gentamicin、Tobramycin and Trimeth/Sulfa, the resistant rate was 20%~40% in 2000, while 63~86% in 2004. The lowest resistant rate was to Imipenem, only 7% or so. The resistant rate of Stenotrophomonas maltophilia to Ciprofloxacin、Ceftazidime、ceftriaxone and Tobramycin was 25%、50%、0% and 0%, respectively, in 2000, but in 2004 year, was 76%、76%、95% and 95%, respectively. Stenotrophomonas maltophilia showed a high drug tolerance to other antibiotics. Conclusion To strengthen the monitoring of the antibiotic resistance of Acinetobacter baumanni and Stenotrophomonas maltophilia and the monitoring of sequential infection in Acinetobacter baumanni and Stenotrophomonas maltophilia is very important for clinic so as to choose antibiotic rationally and improve curative effect

Objective To investigate the feasibility of multiplex PCR for rapid identification of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria. Methods According to MTP40 gene sequence of Mycobacterium tuberculosis, 32kD gene sequence of Mycobacterium and IS6110 insertion sequence gene sequence of Mycobacterium tuberculosis complex, three specific pairs of primers (PT1-PT2, MT1-MT2 and IS5-IS6) for Mycobacterium were designed, and the target DNA for MTP40, 32kD and IS6110 was 396bp, 506bp and 984bp, respectively. The genome of 92 Mycobacterium tuberculosis clinically isolated strains and 5 non-tuberculosis Mycobacteria clinical strains were amplified in the same system, and the results were compared with reference strains. Results Among 92 clinical strains of Mycobacterium tuberculosis, the DNA fragments of 396bp, 506bp and 984bp were found in 90 Mycobacterium tuberculosis clinical strains, as well as in the reference strain H37Rv; the sensitivity of multiplex PCR for Mycobacterium tuberculosis was 97.8%, and the specificity was 100.0%. The DNA fragments of 506bp were all found in 5 non-tuberculosis Mycobacteria clinical strains, the sensitivity and specificity for non-tuberculosis Mycobacterium were both 100.0%. Conclusion The multiplex PCR is a rapid, sensitive and specific method for identification of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria, and it may provide an effective way for clinical diagnosis of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria, therefore useful in clinical application.

Objective To investigate the isoniazid-dependence of clinical isolated strains of M.tuberculosis.Methods The double-phase Kuang's agar medium was employed to isolate M.tuberculosis from the patient's sputum,and its drug-resistance and drug-dependence were determined.Results 184 clinical isolates of isoniazid-dependent M.tuberculosis were grouped as follows.Type A:the strains grew faster and more vigorous in drug tubes than in control tubes,and there were 12 strains(6.5%)which grew more colonies in high concentration tubes than in low concentration tubes;Type B:the strains grew faster and more vigorous in drug tubes than in control tubes,and there were 10 strains(5.4%)which grew more colonies in low concentration tubes than in high concentration tubes;Type C:the strains grew faster and more vigorous in low concentration tubes than in control tubes,and there were 15 strains(8.15%)which grew less colonies in high concentration tubes than in control tubes;Type D:the strains grew faster and more vigorous in high concentration tubes than in control tubes,and there were 4 strains(2.2%)which grew less colonies in low concentration tubes than in control tubes.The isoniazid-dependent strains covered 22.3%(41/184)of the total clinical isolates.Conclusion The isoniazid-dependent strains did exist in the clinical isolates of M.tuberculosis,and different features of dependence have been detected.

Objective To analyze the dielectrophoresis patterns of the proteome of the Rifampin-dependent and-resistant stains of Mycobacterium tuberculosis,to search and identify the differently expressed proteins,and to provide the proteomic basis for researching the mechanism of anti-tuberculosis drug dependence of M.tuberculosis.Methods The whole somatic proteins were extracted from two strains of M.tuberculosis.The first dimensional ampholine electrophoresis was performed on immobilized pH gradient(IPG) rod gels(pH 4-7).Then the proteins on IPG strips were separated using SDS-PAGE.The stained gels were scanned with image scanner and the images were analyzed by Imagemaster 2D software.The differentially expressed proteins were detected by matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS).Results Seven hundred and fifty-three spots were detected in Rifampin-dependent strain of M.tuberculosis,while 584 spots were detected in Rifampin-resistant strain,including 404 match spots(the match rate: 61.5%).As to the expression in Rifampin-dependent strain,7 spots significantly up-regulated and 35 spots down-regulated,6 spots were absent in expression,and 5 spots expressed separately,most of the spots were small molecular proteins.Ten spots were selected to run MS analysis.Nine spots were identified as representing 7 proteins.Conclusion The Rifampin-dependent strain of M.tuberculosis is characterized by a rapid and vigorous growth mainly by means of the differential expression of enzymes related to energy metabolism and fatty acid biosynthesis.