淋病奈瑟菌对头孢曲松耐药性及penA基因的分子特征分析

Molecular Characterization Analysis of Ceftriaxone Resistance and the penA Gene in Neisseria Gonorrhoeae

摘要: 目的：分析合肥部分地区淋病奈瑟菌对头孢曲松、阿奇霉素、环丙沙星、青霉素和四环素的耐药率，并探讨头孢曲松耐药菌株的penA基因型分布。方法：收集2024年6月至2025年6月期间98株临床分离株，采用琼脂稀释法测定头孢曲松及另外四种抗生素的最小抑菌浓度(MIC)。对头孢曲松耐药菌株(MIC ≥ 0.5 μg/mL)进行penA基因测序及等位基因分型。结果：头孢曲松、阿奇霉素、环丙沙星、青霉素和四环素的耐药率分别为22.4%、14.3%、99.0%、100%和99.0%。其中，90.9% (20/22)的头孢曲松耐药菌株携带嵌合型penA60.001等位基因，其余两株分别携带penA41.001和penA34.001。结论：头孢曲松耐药菌株中镶嵌型penA等位基因的优势表明高度耐药菌株在合肥地区的克隆扩增，可能威胁广谱头孢菌素类药物的长期疗效，强调持续分子监测的重要性。

Abstract: Purpose: This study aimed to analysis the antimicrobial resistance rates of Neisseria gonorrhoeae to ceftriaxone, azithromycin, ciprofloxacin, penicillin, and tetracycline in selected areas of Hefei, and to further characterize the distribution of penA genotypes among ceftriaxone-resistant isolates. Methods: A total of 98 non-duplicated clinical isolates collected between June 2024 and June 2025 were subjected to agar dilution to determine MICs for ceftriaxone and four additional antibiotics. Isolates exhibiting reduced susceptibility to ceftriaxone (MIC ≥ 0.5 μg/mL) underwent full-length sequencing of the penA gene, followed by allele typing. Results: Resistance rates to ceftriaxone, azithromycin, ciprofloxacin, penicillin and tetracycline were 22.4%, 14.3%, 99.0%, 100% and 99.0%. Notably, 90.9% (20/22) of resistant isolates harbored the mosaic penA 60.001 allele, while the remaining two isolates carried penA41.001 and penA34.001. Conclusion: The predominance of mosaic penA alleles among ceftriaxone-resistant isolates indicates clonal expansion of highly resistant lineages in Hefei, which may compromise the long-term efficacy of extended-spectrum cephalosporins and warrants continuous molecular surveillance.