Mycobacterium Tuberculosis Clinical Isolates Genotyping And Drug Resistance Detection

To find out the distribution of22clinical isolates of Mycobacterium tuberculosisgenotyping， explore the best methods to identificate Mycobacterium tuberculosisBeijing genotype. To analyze the correlation between different genotypes and drugresistance. Discovery the relationship between MTB drug resistance andresistance-related gene to explore the rapid way to detect drug-resistantMycobacterium tuberculosis. Methods22clinical isolates of Mycobacteriumtuberculosis which were collected from Jilin Province were identified with RD105detection method，use absolute concentration method to test drug sensitive of theseisolates to six kind of anti-TB drugs including isoniazid, rifampin, streptomycin,kanamycin, ofloxacin, and para sodium aminosalicylate， finally， analyze thesusceptibility results and genotyping results. Use gene sequencing method to sequencekatG gene, rpoB gene, rpsl gene, rrs gene, gyrA gene, thyA gene of resistantstrains,then detect the presence or absence of drug resistance gene mutation anddetermine the type of mutation. Results There are10drug-resistant strains in22clinical isolates of Mycobacterium tuberculosis， accounted for45.5%. six strainsresistant to rifampin， accounted for27.3%. four strains resistant to isoniazid，accounted for18.0%. two strains resistant to streptomycin，accounted for9.0%. fourstrains resistant to kanamycin， accounted for18.0%.three strains resistant toofloxacin，accounted for13.6%..a strain resistant to para sodium aminosalicylate，accounted for4.5%. Beijing genotype strains accounted for77.3%(17/22).there arenine strains are sensitivite to six kinds of anti-TB drug in17Beijing family ofMycobacterium tuberculosis clinical isolates, accounted for52.9%(9/17),47.1%(8/17) showed resistance.60%of non-Beijing family (3/5) showed sensitivity and40%(2/5) showed resistance.by test,the difference was not statistically significant.,there is a strains katG gene mutation has not occurred in4isoniazid-resistant strains,the other three katG gene mutation occurred in the315point, from the AGC (Ser) mutated to ACC (Thr).there are four strains in6rifampin-resistant strains occurred531rpoB gene mutation, from TCG (Ser) mutation into TTG (Leu).2strains occurred526rpoB gene mutation, from CAC (His) mutated into GAC (Asp).2streptomycinresistant strains both occurred rpsl gene mutation in43point, from AAG (Lys)mutation into AGG (Arg). there is a strains rrs gene is not mutated in4strainsKanamycin resistant isolates,,the other three rrs gene11point mutation occurred,GGT (Gly) was mutated to GTT (Val).3ofloxacin-resistant strains all have occurred94point gyrA gene mutation, GAC (Asp) was mutated into GCC (Gly). One parasodium aminosalicylate resistant strains thyA gene has occurred C nucleotide deletionat355point, CTG (Leu) was mutated to GTC (Val). Conclusion RD105deletiondetection method is a simple and effective way to identify Beijing genotype. Beijinggenotype is the main type of the MTB strains in this study. No significant difference isobserved in drug resistance between Beijing genotype and non-Beijing genotypestrains. Mycobacterium tuberculosis resistant to anti-TB drug resistance is closelyrelated with the resistance gene mutation.