Distribution and drug resistance characteristics of carbapenem-resistant Enterobacterales in Nanchang area from 2021 to 2022
- Author:
YU Feng
;
JIANG Qinwen
;
HU Longhua
- Publication Type:Journal Article
- Keywords:
Carbapenem-resistant Enterobacteriaceae;
enzyme inhibitor enhancement test;
ceftazidime/avibactam;
blaKPC-33
- From:
China Tropical Medicine
2024;24(12):1439-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the sensitivity of carbapenem-resistant Enterobacteriaceae (CRE) producing different carbapenemases to antibacterial drugs, compare various detection methods of carbapenemases, and provide a technical basis for the clinical anti-infective treatment of CRE. Methods A total of 88 CRE strains isolated from clinical samples in a hospital in Nanchang, Jiangxi Province, from January 2021 to August 2022 were collected. MALDI-TOF MS was used for strain identification and Vitek 2-compact was used to detect their susceptibility to commonly used antibacterial drugs. The susceptibility of ceftazidime/avibactam and polymyxin B to CRE was detected by the broth microdilution method. The carbapenemase inhibitor enhancement test (EDTA-APB) was employed to screen for carbapenemase phenotypes, while polymerase chain reaction (PCR) method was used to detect five carbapenemase resistance genes: Klebsiella pneumoniae carbapenemases (blaKPC), New Delhi metallo-beta-lactamase-1 (blaNDM), Imipenem hydrolyzing β-lactamase (blaIMP), Metal β-lactamase of Verona integron (blaVIM), and Oxacillin-hydrolyzing carbapenemase (blaOXA-48-like). The consistency between carbapenemase phenotypes and gene results was compared. Results CRE infection was predominantly found in males (58 cases), with an average age of (63.4±14.2) years, mainly distributed in neurosurgery (26.1%, 23/88), the intensive care unit (17.0%, 15/88), and the rehabilitation department (15.9%, 14/88). The main sources of positive specimens were respiratory secretions (60.2%, 53/88), urine (21.6%, 19/88), and blood (5.7%, 5/88). The results of the drug susceptibility test showed that CRE had the highest resistance rate to cephalosporins and piperacillin/tazobactam, exceeding 95%, and the lowest resistance rate to tigecycline and polymyxin B, at 4.5% (4/88) and 1.1% (1/88), respectively. The results of the carbapenemase phenotype detection showed that the strains producing class A serine enzymes, class B metalloenzymes, and both class A and B carbapenemases accounted for 69.4% (61/88), 28.4% (25/88), and 1.1% (1/88), respectively. The results of PCR amplification of carbapenemase genes showed that the strains carrying class A resistance gene blaKPC, class B resistance gene blaNDM or blaIMP, and both blaKPC+NDM accounted for 70.5% (62/88), 28.4% (25/88), and 1.1% (1/88), respectively, with high consistency with enzyme phenotype results. The susceptibility rate of the strains carrying only blaKPC to ceftazidime/avibactam was 91.9% (57/62), while those carrying blaNDM or blaIMP were all highly resistant to ceftazidime/avibactam, accounting for 83.3% (25/30) of ceftazidime/avibactam-resistant strains. Conclusions The resistance mechanism of CRE strains to ceftazidime/avibactam is primarily due to the production of NDM-type metalloenzymes, while strains producing only KPC-type show higher sensitivity. Some ceftazidime/avibactam-resistant strains producing only KPC enzymes are caused by blaKPC-2 mutations. In addition, enzyme phenotype inhibition enhancement test and in vitro drug susceptibility test of ceftazidime/avibactam are recommended clinically to provide a basis for the rational selection of antibacterial drugs.
- Full text:2025111315062317052.Distribution and drug resistance characteristics of carbapenem-resistant Enterobacterales in Nanchang area from 2021 to 2022.pdf
