Molecular Analysis and Antimicrobial Resistance Pattern of Tigecycline-Non-Susceptible K. pneumoniae Isolated from a Tertiary Care Hospital of East Asia

Infect Drug Resist. 2021 Oct 7:14:4147-4155. doi: 10.2147/IDR.S334098. eCollection 2021.

Abstract

Introduction: Tigecycline is one of the last resorts for carbapenem-resistant K. pneumoniae (CRKP) infections. Indeed, tigecycline-non-susceptible K. pneumoniae (TNSKP) strains are increasingly treated with the use of tigecycline. In this study, we attempted to better understand their epidemiological trends and characteristics. K. pneumoniae were collected from 2017 to 2020 at the First Affiliated Hospital of Nanchang University.

Methods: Thirty-four TNSKP strains were selected during the study period, all of which were analyzed using antimicrobial susceptibility testing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). PCR and DNA sequencing were performed for the detection of β-lactamase genes and carbapenemase genes, and the mutation analysis of tet(A), tet(X), tet(L), tet(M), rpsJ, ramR, and oqxR, which are related to tigecycline resistance. Virulence gene and capsular genotype testing were conducted to identify whether the TNSKP strains were hypervirulent Klebsiella pneumoniae.

Results: An epidemiology analysis showed that Klebsiella pneumoniae carbapenemase-2 (KPC-2) was the predominant carbapenemase in tigecycline non-susceptible carbapenem-resistant K. pneumoniae (TNSCRKP) (96.7%), and the dominant clone type was ST11-K14K64 (82.4%). Among them, 55.9% (19/34) of strains were from each department of ICU, particularly EICU and neurosurgery ICU. In order to further understand the molecular mechanisms of the TNSKP, a polymerase chain reaction of the resistant determinants was carried out. The results detected many tigecycline-resistant genes, such as tet(A) (97.1%), tet(X) (17.6%), rpsJ (97.1%), and ramR (8.8%).

Conclusion: As the results of this study reveal, we should take effective measures to control the increase in TNSKP.

Keywords: Klebsiella pneumoniae; carbapenem-resistant; tigecycline-non-susceptible.

Grants and funding

This work was supported by the National Natural Science Foundation of China (32060040 and 31760261), the National Science Foundation of Jiangxi province (20202BABL216084 and 20192ACBL21042), and the Science and Technology Plan Projects of Health and Family Planning Commission of Jiangxi province (20203692).