ABSTRACT
Objective To evaluate the relationship between spectinomycin resistance in Neisseria gonorrhoeae and mutations in the rpsE gene.Methods Genomic DNA was extracted from 4 clinical isolates of Neisseria gonorrhoeae with different levels of spectinomycin resistance.Then,PCR was performed to amplify the entire rpsE gene and the spectinomycin resistance-determining region (SRDR) in the 16S rRNA gene followed by direct sequencing.Two spectinomycin-sensitive Neisseria gonorrhoeae strains were transformed with the genomic DNA containing the mutant rpsE gene.Subsequently,the susceptibility of the transformants to spectinomycin was determined,and PCR was performed to amplify the rpsE and 16S rRNA genes in the transformants followed by sequencing.Results All the 4 spectinomycin-resistant Neisseria gonorrhoeae strains harbored an A70C transversion in the rpsE gene,but no abnormality in the SRDR of the 16S rRNA gene.No mutations were detected in the spectinomycin-sensitive Neisseria gonorrhoeae strains.The A70C transversion in the rpsE gene was also detected in the two Neisseria gonorrhoeae transformants with spectinomycin resistance.Conclusion The A70C point mutation within the rpsE gene is associated with spectinomycin resistance in Neisseria gonorrhoeae.