ABSTRACT
Background & objectives: Emergence and spread of drug resistant Mycobacterium tuberculosis is a serious threat to tuberculosis (TB) control programme. Therefore, the objective of this study was to genotype drug-resistant M. tuberculosis strains isolated from patients in Sichuan, China, using Mycobacterial Interspersed Repetitive Units (MIRU) for epidemiological analysis. Methods: Drug-resistance testing of M. tuberculosis isolates from pulmonary TB patients was confirmed by proportion method. Twelve MIRU loci were analyzed on 80 drug-resistant and 9 susceptible isolates by polymerase chain reaction and agarose gel electrophoresis. Hunter-Gaston discriminatory index (HGI) values were determined for each 12 MIRU loci for the evaluation of their discrimination power. Results: Among 12 MIRU loci examined, polymorphic bands could be generated on 11 loci. Sixty five isolates had distinct MIRU patterns, while other 24 belonged to 8 clusters and resistant to at least one anti-TB drug tested. The association between the MIRU patterns and the mutation patterns of drug-resistance relevant target genes was not significant among the drug-resistant isolates. Interpretation & conclusions: The results showed that with a satisfactory discrimination power exhibited, the 12 loci based MIRU typing could be a valuable tool for epidemiological studies in M. tuberculosis isolates from Sichuan.
Subject(s)
Bacterial Typing Techniques/methods , China/epidemiology , Electrophoresis, Agar Gel , Gene Frequency , Genetic Loci/genetics , Humans , Interspersed Repetitive Sequences/genetics , Mycobacterium tuberculosis/classification , Mycobacterium tuberculosis/genetics , Polymerase Chain Reaction , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/genetics , Tuberculosis, Multidrug-Resistant/microbiologyABSTRACT
The chemical constituents of fistular onion stalk obtained by supercritical CO2 extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained.On the basis of the spectral data,they were structurally identified as(+)-catechin,(-)-epicatechin,astragalin,and 3-O-β-D(2-O-β-D-glucopyranosyl)-glucopyranosides of kaempferol.