Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Diagn Microbiol Infect Dis. 2021 Sep;101(1):115423. doi: 10.1016/j.diagmicrobio.2021.115423. Epub 2021 May 11.
Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibility to extended-spectrum cephalosporins in India is deficient. In this study, we have sequenced penA, porB, mtrR and ponA and bla genes in 70 clinical isolates of NG with varying ceftriaxone MICs. Amongst these, 22 (31.4%) were PPNG. Additionally, N. gonorrheae Multiantigen Sequence Typing was performed. Fisher exact and χ were used to evaluate significance of mutations with MICs. A total of six non-mosaic penA (Penicillin binding protein 2 [PBP2]) amino acid patterns were seen (II, IV, IX, XII, XIX, XXII) of which, pattern IX was significantly associated with decreased susceptibility to ceftriaxone. Other significant associations were noted in porB & mtrR genes. There were no mutations in bla gene. ST6069 was significantly associated with decreased susceptibility to ceftriaxone. To conclude, development of decreased susceptibility to ceftriaxone in gonococci involves cumulation of different mutations in the four chromosomal genes investigated.
印度缺乏对表现出对扩展谱头孢菌素类药物敏感性降低的淋病奈瑟菌分离株的遗传特征数据。在这项研究中，我们对 70 株具有不同头孢曲松 MIC 的淋病奈瑟菌临床分离株进行了 penA、porB、mtrR 和 ponA 以及 bla 基因测序。其中，22 株（31.4%）为 PPNG。此外，还进行了淋病奈瑟菌多抗原序列分型。Fisher 确切检验和 χ 检验用于评估 MIC 与突变之间的显著性。总共观察到六种非镶嵌 penA（青霉素结合蛋白 2 [PBP2]）氨基酸模式（II、IV、IX、XII、XIX、XXII），其中模式 IX 与头孢曲松敏感性降低显著相关。在 porB 和 mtrR 基因中也观察到了其他显著的相关性。bla 基因无突变。ST6069 与头孢曲松敏感性降低显著相关。总之，淋病奈瑟菌对头孢曲松敏感性降低的发展涉及在所研究的四个染色体基因中累积不同的突变。
