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

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

  • Virulence. 2022 Dec;13(1):77-88. doi: 10.1080/21505594.2021.2018768.
Zi-Jian Zheng 1 2 3,  Ze-Hua Cui 1 2 3,  Qiu-Yue Diao 1 2 3,  Xin-Qing Ye 1 2 3,  Zi-Xing Zhong 1 2 3,  Tian Tang 1 2 3,  Shuai-Bin Wu 1 2 3,  Hui-Ling He 1 2 3,  Xin-Lei Lian 1 2 3,  Liang-Xing Fang 1 2 3,  Xi-Ran Wang 1 2 3,  Li-Jie Liang 1 2 3,  Ya-Hong Liu 1 2 3 4,  Xiao-Ping Liao 1 2 3,  Jian Sun 1 2 3
Affiliations

Affiliations

  • 1 National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.
  • 2 Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.
  • 3 Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
  • 4 Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou, China.
PMID: 34951562 DOI: 10.1080/21505594.2021.2018768
Abstract

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.

Keywords

MALDI-TOF MS; Rapid detection; Tet(X)-producers; non-Tet(X)-producers; phenotypic detection; tetracycline resistance.

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