To establish the microarray technique with 16S rRNA probe for the rapid detection of pathogenic bacteria in cerebrospinal fluid, a set of Digoxin labelling universal primers were designed, and used to amplify the 16S ...To establish the microarray technique with 16S rRNA probe for the rapid detection of pathogenic bacteria in cerebrospinal fluid, a set of Digoxin labelling universal primers were designed, and used to amplify the 16S rRNA gene, and 2 specific probes for each bacterium designed were spotted onto nylon membrane to make a microarray, followed by hybridization to PCR products of bacteria, which set up a microarray technique for parallel detection of bacteria in cerebrospinal fluid (CSF). Twenty-nine CSF specimens from 16 patients that were proved to be positive by bacterial cultures and by using Vitek AMA-32 automated system were examined in the present investigation. It was found that positive fragment with length of 168?bp were amplified from 45 strains of 20 bacterial species, and amplifications also detected in 29 CSF specimens. The method of universal PCR could detect as few as 1 pg of bacterial DNA, and this microarray could identify all the bacterial species in CSF except Mycobacterium tuberculosis and Proteus mirabilis , satisfying the direct detection of bacteria in CSF specimens including a case of mixed bacterial infection. The positive and negative predictive value as well as the diagnostic index of this microarray were 100%, 94.67%, and 180.88 respectively, and the time of performance spent only for 5?h. It was concluded the method described in the present investigation can be used to detect and identify the pathogenic bacteria in CSF.展开更多
Background: The rapid diagnosis of mycobacterial infections is essential to implement the adequate antimicrobial therapy. This study evaluates the performance of the BacT/ALERT 3D system for isolates and identificatio...Background: The rapid diagnosis of mycobacterial infections is essential to implement the adequate antimicrobial therapy. This study evaluates the performance of the BacT/ALERT 3D system for isolates and identification of mycobacteria from clinical samples. Methods: 1011 clinical specimens from nonsterile and sterile body sites were studied from August 2010 to December 2012 at the National Reference Laboratory of Tuberculosis, IPK, Cuba. The results obtained were compared with respect to time detection of mycobacteria and contamination rates, and performance indicators of BacT/ALERT 3D were calculated. Results: The time detection of growth (TDG) for Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM) by BacT/ALERT 3D was 16,435 and 10,956, respectively;by LJ the TDG was 33.577 for Mtb and 35.952 for NTM. By culture method used the TDG for LJ was 33,577 and 6.435 by BacT/ALERT 3D, this difference being statistically significant. The overall contamination rate (CR) for BacT/ALERT 3D was 4.6% and 7.8% for LJ. Conclusions: BacT/ALERT 3D were a suitable method for recovering mycobacteria from clinical samples. It demonstrated a shorter time to detection of mycobacteria growth;it was very useful to provide faster treatment and a better prognosis in patients AFB smear negative with HIV. The use of LJ culture and BacT/ALERT 3D System was useful to assure a total mycobacterial recovery.展开更多
文摘To establish the microarray technique with 16S rRNA probe for the rapid detection of pathogenic bacteria in cerebrospinal fluid, a set of Digoxin labelling universal primers were designed, and used to amplify the 16S rRNA gene, and 2 specific probes for each bacterium designed were spotted onto nylon membrane to make a microarray, followed by hybridization to PCR products of bacteria, which set up a microarray technique for parallel detection of bacteria in cerebrospinal fluid (CSF). Twenty-nine CSF specimens from 16 patients that were proved to be positive by bacterial cultures and by using Vitek AMA-32 automated system were examined in the present investigation. It was found that positive fragment with length of 168?bp were amplified from 45 strains of 20 bacterial species, and amplifications also detected in 29 CSF specimens. The method of universal PCR could detect as few as 1 pg of bacterial DNA, and this microarray could identify all the bacterial species in CSF except Mycobacterium tuberculosis and Proteus mirabilis , satisfying the direct detection of bacteria in CSF specimens including a case of mixed bacterial infection. The positive and negative predictive value as well as the diagnostic index of this microarray were 100%, 94.67%, and 180.88 respectively, and the time of performance spent only for 5?h. It was concluded the method described in the present investigation can be used to detect and identify the pathogenic bacteria in CSF.
文摘Background: The rapid diagnosis of mycobacterial infections is essential to implement the adequate antimicrobial therapy. This study evaluates the performance of the BacT/ALERT 3D system for isolates and identification of mycobacteria from clinical samples. Methods: 1011 clinical specimens from nonsterile and sterile body sites were studied from August 2010 to December 2012 at the National Reference Laboratory of Tuberculosis, IPK, Cuba. The results obtained were compared with respect to time detection of mycobacteria and contamination rates, and performance indicators of BacT/ALERT 3D were calculated. Results: The time detection of growth (TDG) for Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM) by BacT/ALERT 3D was 16,435 and 10,956, respectively;by LJ the TDG was 33.577 for Mtb and 35.952 for NTM. By culture method used the TDG for LJ was 33,577 and 6.435 by BacT/ALERT 3D, this difference being statistically significant. The overall contamination rate (CR) for BacT/ALERT 3D was 4.6% and 7.8% for LJ. Conclusions: BacT/ALERT 3D were a suitable method for recovering mycobacteria from clinical samples. It demonstrated a shorter time to detection of mycobacteria growth;it was very useful to provide faster treatment and a better prognosis in patients AFB smear negative with HIV. The use of LJ culture and BacT/ALERT 3D System was useful to assure a total mycobacterial recovery.
