Detection of integrons and ISCR1 in and genotyping of NDM-1-producing Citrobacter freundii
10.16718/j.1009-7708.2017.05.007
- VernacularTitle:产NDM-1弗劳地枸橼酸杆菌整合子和插入序列共同区1检测及分型
- Author:
Na DU
1
;
Jian MAO
;
Shumin LIU
;
Min NIU
;
Jing YAO
;
Mengshuang ZHANG
;
Yan DU
Author Information
1. 昆明医科大学第一附属医院检验科
- Keywords:
integron;
insertion sequence common region-1;
NDM-1-producing Citrobacter freundii;
clonal dissemination
- From:
Chinese Journal of Infection and Chemotherapy
2017;17(5):523-526
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the distribution of integrons and ISCR1 elements in NDM-l-producing Citrobacterfreundii isolates,and analyze the genotypes of these strains to understand their homology.Methods A total of 18 strains of NDM-1-producing Citrobacterfreundii were collected from the First Affiliated Hospital of Kunming Medical University during the period from June 2012 and October 2014.The isolates were identified and subjected to antimicrobial susceptibility testing with VITEK 2 System.Class Ⅰ,Ⅱ,and 1Ⅲ integrons and ISCR1 elements were detected by PCR.Clonal relatedness was assessed by pulsed field gel electrophoresis (PFGE).Results Most (77.8％,14/18) strains were positive for class Ⅰ integron conserved region,27.8％ (5/18) isolates were positive for ISCR1 conserved region.No class Ⅱ or Ⅲ integron was detected.Most (72.2％,13/18) isolates were positive for class Ⅰ integron variable region.None of the strains harbored class Ⅱ integron or ISCR1 variable region.Integron variable regions included gene cassette encoding resistance to aminoglycosides (aadA1,aadA5,aac(6')-Ib-cr) and trimethoprim-sulfamethoxazole (dfrA,dfrA15,dfrA17).PFGE revealed 17 clusters among 18 NDM-l-producing Citrobacter freundii isolates.Conclusions The clonal dissemination of NDM-l-producing Citrobacterfreundii isolates is not significant.Class I integron is prevalent in NDM-l-producing Citrobacter freundii.The presence of ISCR1 is relatively rare.The two mobile elements are not related to the spread of NDM-1 gene in this hospital.
