Virulence (Dec 2022)

MALDI-TOF MS for rapid detection and differentiation between Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant Gram-negative bacteria

  • Zi-Jian Zheng,
  • Ze-Hua Cui,
  • Qiu-Yue Diao,
  • Xin-Qing Ye,
  • Zi-Xing Zhong,
  • Tian Tang,
  • Shuai-Bin Wu,
  • Hui-Ling He,
  • Xin-Lei Lian,
  • Liang-Xing Fang,
  • Xi-Ran Wang,
  • Li-Jie Liang,
  • Ya-Hong Liu,
  • Xiao-Ping Liao,
  • Jian Sun

DOI
https://doi.org/10.1080/21505594.2021.2018768
Journal volume & issue
Vol. 13, no. 1
pp. 77 – 88

Abstract

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The extensive use of tetracycline antibiotics has led to the widespread presence of tetracycline-resistance genes in Gram-negative bacteria and this poses serious threats to human and animal health. In our previous study, we reported a method for rapid detection of Tet(X)-producers using MALDI-TOF MS. However, there have been multiple machineries involved in tetracycline resistance including efflux pump, and ribosomal protection protein. Our previous demonstrated the limitation in probing the non-Tet(X)-producing tetracycline-resistant strains. In this regard, we further developed a MALDI-TOF MS method to detect and differentiate Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant strains. Test strains were incubated with tigecycline and oxytetracycline in separate tubes for 3 h and then analyzed spectral peaks of tigecycline, oxytetracycline, and their metabolite. Strains were distinguished using MS ratio for [metabolite/(metabolite+ tigecycline or oxytetracycline)]. Four control strains and 319 test strains were analyzed and the sensitivity was 98.90% and specificity was 98.34%. This was consistent with the results obtained from LC-MS/MS analysis. Interestingly, we also found that the reactive oxygen species (ROS) produced by tetracycline-susceptible strains were able to promote the degradation of oxytetracycline. Overall, the MALDITet(X)-plus test represents a rapid and reliable method to detect Tet(X)-producers, non-Tet(X)-producing tetracycline-resistant strains, and tetracycline-susceptible strains.

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