Preliminary study on carbapenem resistance mechanism of clinical isolate of Raoultella planticola
10.3760/cma.j.issn.1009-9158.2014.06.015
- VernacularTitle:植生拉乌尔菌对碳青霉烯类抗生素耐药机制的初探
- Author:
Chunbao XIE
;
Hua YU
;
Daiwen XIAO
;
Yongchang YANG
;
Wei JIANG
;
Hua LIU
;
Wenfang HUANG
- Publication Type:Journal Article
- Keywords:
Enterobacteriaceae;
Carbapenems;
beta-Lactamases
- From:
Chinese Journal of Laboratory Medicine
2014;(6):459-462
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanism of one carbapenems resistant Raoultella planticola( R.planticola) isolate.Methods This is an experimental study.R.planticola was isolated from a patient′s drainage fluid from orthopedic department in November 2010 in Sichuan Provincial People′s Hospital.Minimum inhibitory concentration of R.planticola to 13 antibiotics was determined by using the agar dilution method.Modified Hodge test was used to detect carbapenemase .EDTA synergistic test was performed to research metallo-beta-lactamase.The genes coded the β-lactamase were amplified by polymerase chain reaction ( PCR ) , including class A carbapenemase ( KPC ) , class B carbapenemases (NDM, IMP, VIM, SIM), extended spectrum beta-lactamases[ESBL(CTX, TEM, SHV)], and AmpCβ-lactamases ( FOX, EBC, ACC, DHA, CIT, MOX).Results The susceptibility test showed that R.planticola was resistant to 9 antibiotics.MIC value of meropenem for R.planticola was up to 32 mg/L.R.planticola kept intermediary to imipenem , whereas it was susceptible to cefepime , amikacin and polymyxin B.Modified Hodge test and EDTA synergistic test were positive in R.planticola.Class B carbapenemase (IMP) gene and two extended spectrum β-lactamases(CTX, SHV) genes were positive by PCR.The genes were conformed as IMP-4, CTX-M3 and SHV-12 by sequencing and compared with GenBank.Other resistant genes were negative.Conclusion IMP-4 was identified in R.planticola, the combined produce IMP-4 and ESBLs might be the main mechanism of R.planticola resistant to carbapenems.
