[Multiple resistance of neisseria gonorrhoeae and mutations in the inverted sequence within the mtrR promoter region].

ABSTRACT

OBJECTIVE: To evaluate the correlation between multiple resistance of Neisseria gonorrhoeae and mutations in the inverted sequence within the mtrR promoter region. METHODS: The susceptibilities of 56 Neisseria gonorrhoeae to 5 antibiotic agents were tested by disc diffusion method. 13 bp inverted sequences positioned within the mtrR promoter region were amplified by PCR and examined by single strand conformation polymorphism technology. According to the results of SSCP, 12 strains were selected and were directly sequenced, and their nucleotide sequences were compared with those of susceptible strain ATCC19 424. RESULTS: In the 56 strains of Neisseria gonorrhea, 5 strains were susceptible to all antibiotics and 22 strains were resistant to one antibiotic agent. In the 19 strains that were resistant to 2 antibiotic agents, 2 had mutations in a 13 bp inverted sequence positioned within the mtrR promoter region. Another 7, 2 and 1 strain which was resistant to 3,4 and 5 antibiotic agents respectively all had mutations in a 13 bp inverted sequence positioned within the mtrR promoter region. All of the 12 strains which contained the same mutation exhibited a single base pair deletion in a 13 bp inverted sequence positioned within the mtrR promoter region. CONCLUSION: Deletions in the 13 bp inverted sequence positioned within the mtrR promoter region mediate multiple resistances in Neisseria gonorrhoeae. A single base pair deletion in a 13 bp inverted sequence positioned within the mtrR promoter region is associated with multiple resistance.