Abstract:

Objective In order to detect the phenotypic pyrazinamide (PZA) resistance and the genotypic distribution of MDR Mycobacterium tuberculosis (MTB) isolates from Fujian Province, and analyze the correlation between PZA resistance and genotype.Methods A total of 119 MDR-MTB strains were collected from the drug resistant surveillance sites in Fujian Province among 2007-2008 and 2010-2011. The drug susceptibility test (DST) of PZA recommended by WHO was conducted. Genotyping was performed by using Spoligotyping, and the results were uploaded to SpolDB 4.0 database for cluster analysis.Results The PZA resistant rate of 119 MDR-MTB strains was 36.97% (44/119). The streptomycin (Sm) resistant rate of PZA resistant strains (70.45%, 31/44) was higher than that of PZA sensitive strains (50.67%, 38/75), and the difference was statistically significant (χ ²=4.45, P=0.035). The ethambutol (EMB) resistant rate of PZA resistant strains (81.82%, 36/44) was higher than that of PZA sensitive strains (52.00%, 39/75), and the difference was statistically significant (χ ²=1.58, P=0.001). Beijing genotype strains accounted for 67.23% (80/119). Non Beijing genotype strains (32.77%, 39/119) had 16 genotypes including 8 new genotypes, the most common genotypes of which were H family containing H and H3 and T family containing T1, T2, T3 and T5. The PZA resistant rate of Beijing genotypic strains was 38.75% (31/80), and that of non Beijing genotypic strains was 33.33% (13/39); there was no significant difference in PZA resistant rate (χ ²=0.33, P=0.566). Conclusion We should pay attention to the problem about PZA resistance of MDR-MTB strains in Fujian Province. The resistance to PZA is related to the resistance to Sm and EMB. Beijing genotype is mainly prevalent in Fujian Province, and there is no significant difference in the PZA rate between Beijing genotypic strains and non Beijng genotypic strains.

Key words: Mycobacterium tuberculosis, Tuberculosis, multidrug-resistant, Pyrazinamide, Genotype