OBJECTIVE T o establish a simple,rapid,highly sensitive and highly specific visualized detection meth-od for Klebsiella pneumoniae based on recombinase polymerase amplification(RPA)technique combined with the lateral flow dipstick(LFD)technique.METHODS The specific primers targeting the khe gene of K.pneumoniae were designed for RPA,the reaction temperature and reaction time for RPA were optimized,the optimal experi-mental conditions for the LFD were determined based on the colorimetric results.The sensitivity,stability,speci-ficity and clinical practicability of RPA-LFD in detection of the K.pneumoniae were evaluated.RESULTS RPA could achieved the optimal detection result for simplification of K.pneumoniae at 34 ℃ for 10 min.The LFD showed the best color development when Milipore HF 135s was used as the nitrocellulose membrane,phosphate buffered saline containing Tween-20(PBST)was used as the sample developing solution,and the concentrations of streptavidin and secondary antibody were 0.8 mg/ml and 0.1 mg/ml,respectively.The detection limit of the RPA-LFD was 5 CFU/ml for detection of K.pneumoniae,the relative standard deviation of the band color inten-sity was less than 5％in six parallel experiments,and there was no cross reactions with other bacterial strains.In addition,the sensitivity of the RPA-LFD in detection of K.pneumoniae was not affected by the serum compo-nents such as proteins and lipids.CONCLUSION The rapid detection method for K.pneumoniae that is established based RPA-LFD is characterized by the simple operation,high sensitivity and high specificity,and it does not need complicated equipment or strict technical requirement for operators and provides a new technique for early diagno-sis and epidemiological survey of the K.pneumoniae.

OBJECTIVE T o establish a simple,rapid,highly sensitive and highly specific visualized detection meth-od for Klebsiella pneumoniae based on recombinase polymerase amplification(RPA)technique combined with the lateral flow dipstick(LFD)technique.METHODS The specific primers targeting the khe gene of K.pneumoniae were designed for RPA,the reaction temperature and reaction time for RPA were optimized,the optimal experi-mental conditions for the LFD were determined based on the colorimetric results.The sensitivity,stability,speci-ficity and clinical practicability of RPA-LFD in detection of the K.pneumoniae were evaluated.RESULTS RPA could achieved the optimal detection result for simplification of K.pneumoniae at 34 ℃ for 10 min.The LFD showed the best color development when Milipore HF 135s was used as the nitrocellulose membrane,phosphate buffered saline containing Tween-20(PBST)was used as the sample developing solution,and the concentrations of streptavidin and secondary antibody were 0.8 mg/ml and 0.1 mg/ml,respectively.The detection limit of the RPA-LFD was 5 CFU/ml for detection of K.pneumoniae,the relative standard deviation of the band color inten-sity was less than 5％in six parallel experiments,and there was no cross reactions with other bacterial strains.In addition,the sensitivity of the RPA-LFD in detection of K.pneumoniae was not affected by the serum compo-nents such as proteins and lipids.CONCLUSION The rapid detection method for K.pneumoniae that is established based RPA-LFD is characterized by the simple operation,high sensitivity and high specificity,and it does not need complicated equipment or strict technical requirement for operators and provides a new technique for early diagno-sis and epidemiological survey of the K.pneumoniae.

AIM:To investigate the expression of transmembrane protein 16A(TMEM16A) in Fischer rat thy-roid follicular epithelial ( FRT) cells and its electrophysiologic properties .METHODS: The eukaryotic expression vector of pUB6/V5-TMEM16A was constructed and transfected into FRT cells by liposome-mediated transfection .In order to ob-tain the high efficiency of gene transfection and expression , the quantity and ratio of lipid/DNA complexes were optimized . The FRT cells stably expressing TMEM16A were gained by the selection with blasticidin and confirmed by the techniques of RT-PCR and immunofluorescence .The expression and location of TMEM 16A in the FRT cells were observed under an in-verted fluorescence microscope .TMEM16A protein was associated with calcium-dependent chloride current , as measured with halide-sensitive fluorescent protein and patch-clamp technique .RESULTS: The results of double digestion and se-quencing indicated that TMEM16A was cloned into pUB6/V5.The results of RT-PCR and immunofluorescence confirmed that TMEM16A was expressed in the FRT cells after transfection with TMEM16A.The classical calcium-activated chloride channel currents were recorded in the FRT cells stably expressing TMEM 16A by the technique of patch-clamp and halide-sensitive fluorescent protein YFP-H148Q/I152L.CONCLUSION:The protein expression of TMEM16A in the FRT cells was observed.TMEM16A is the molecular identity of calcium-activated chloride channels .