Objective To understand the mtrR gene mutation of Neisseria gonorrhoeae in Shunde area and to explore the connection between its gene mutation and ceftriaxone hyposensitivity.Methods In this study,146 gonococcal strains were collected by isolating and culturing gonococci from clinical specimens.The drug susceptibility of six drugs(including ceftriaxone,ciprofloxacin,norfloxacin,penicillin,tetracycline and spectinomycin)was detected by K-B method(disk diffusion method);ceftriaxone was determined by agar dilution method according to the MIC value,gonococci were divided into ceftriaxone-sensitive group and ceftriaxone-hyposensitive group.We extracted the whole genome nucleic acid of Neisseria gonorrhoeae from the ceftriaxone-sensitive group and the low-sensitivity group,amplified the mtrR gene,isolated and purified it,and sequenced it to compare the mtrR gene mutations of the two groups of gonococci.The correlation between gene mutations and ceftriaxone hyposensitivity was also analyzed.We explored its resistance mechanism.Results In this study,the antibiotic resistance rates of gonococci in this study were penicillin 72％,ciprofloxacin 92％,tetracycline 78％,norfloxacin 75％,and no resistant strains were detected to ceftriaxone and spectinomycin.According to the MIC results,there were 12 strains with low sensitivity to ceftriaxone,accounting for 8％,and 134 strains with high sensitivity to ceftriaxone,accounting for 92％.Gene sequencing shows that there are three main types of mutations in the gonococcal mtrR gene in Shunde:A39T,G45D,and H105Y.There are two or more gene mutation sites in the mtrR gene of 12 strains of gonococci in the ceftriaxone hyposensitive group.Conclusion Neisseria gonorrhoeae in this area are highly sensitive to ceftriaxone and spectinomycin,which can be used as the first-choice drugs for treatment.The mtrR gene mutations of gonorrhea in Shunde are mainly A39T,G45D,and H105Y genotypes.Two or more gene mutations exist in ceftriaxone-low-susceptible gonococci at the same time.Gonorrhea screening and drug resistance monitoring need to be expanded for better prevention and control of gonorrhea.
维普
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