Study on plasmid-mediated blaNDM-1 gene in carbapenem-resistant Citrobacter freundii
10.16718/j.1009-7708.2018.06.008
- VernacularTitle:碳青霉烯类耐药弗劳地枸橼酸杆菌中质粒介导blaNDM-1基因的研究
- Author:
Na DU
1
;
Yun LIN
;
Shumin LIU
;
Min NIU
;
Yabo LI
;
Xiongfei SHI
;
Fang ZHOU
;
Jing YAO
;
Mengshuang ZHANG
;
Yan DU
Author Information
1. 云南省中医医院检验科
- Keywords:
blaNDM-1 gene;
plasmid;
Citrobacter freundii;
mechanism of transmission
- From:
Chinese Journal of Infection and Chemotherapy
2018;18(6):604-607
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the transmission of blaNDM-1 gene in carbapenem-resistant Citrobacter freundii. Methods A total of 18 strains of NDM-1-producing C. freundii were collected from the First Affiliated Hospital of Kunming Medical University during the period from June 2012 to October 2014. The isolates were identified and subjected to antimicrobial susceptibility testing with VITEK 2 System. Conjugation experiments, pulsed-field gel electrophoresis (PFGE) and Southern blot hybridization were performed to determine the transferability of plasmids. Results The antibiotic susceptibility results showed that all the NDM-1-producing C. freundii isolates were resistant to penicillins, cephalosporins and carbapenems. All isolates exhibited different level resistance to other antibiotics. Conjugation experiments revealed that the plasmids harboring blaNDM-1 in 13 strains were transformed into E. coli 600, and exhibited carbapenem resistance. PFGE and Southern blot hybridization found that blaNDM-1 was located on a 33.3 kb plasmid in 16 isolates and on 33.3-54.7 kb plasmid in 2 isolates. Conclusions Our findings suggest that plasmids contribute to the horizontal dissemination of blaNDM-1 gene in carbapenemresistant C. freundii.
