Objective To optimize the performance of Pulsed-Field Gel Electrophoresis （PFGE） for the comparison of inter-laboratory results and information exchange of Borrelia burgdorferi subtypingo Methods A panel of 34 strai...Objective To optimize the performance of Pulsed-Field Gel Electrophoresis （PFGE） for the comparison of inter-laboratory results and information exchange of Borrelia burgdorferi subtypingo Methods A panel of 34 strains of B. burgdorferi were used to optimize PFGE for subtyping. In order to optimize the electrophoretic parameters （EPs）, all 34 strains of B. burgdorferi were analyzed using four EPs, yielding different Simpson diversity index （D） values and the epidemiological concordance was also evaluated. Results The EP of a switch time of l s to 25 s for13 h and l s to10 s for 6 h produced the highest D value and was declared to be optimal for Mlul and 5mal PFGE of B. burgdorferi. Mlul and Smal were selected as the first and second restriction enzymes for PFGE subtyping of B. burgdorferi according to discrimination and consistency with epidemiological data. Conclusion PFGE can be used as a valuable test for routine genospecies identification of B burgdorferi.展开更多
We show that by scanning the frequency of a single mode infrared （IR） optical parametric oscillator （IR- OPO） laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet （VU...We show that by scanning the frequency of a single mode infrared （IR） optical parametric oscillator （IR- OPO） laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet （VUV） laser to photoionize the IR excited species, high-resolution IR spectra of polyatomic neutrals can be obtained with high sensitivity. The fact that this IR-VUV-photoion （IR-VUV-PI） method is based on VUV photoionization probe, and thus, allows the identification of the neutral IR absorber, makes it applicable for IR spectroscopy measurements of isotopemers, radicals, and clusters, which usually exist as impure samples. The highly resolved IR-VUV-PI measurements achieved using the single mode IR-OPO laser have made possible the selection of single rovibrational states of CH3X （X=Br and I）, C2H4, and C3H4 for VUV-pulsed field ionization-photoelectron （VUV-PFI-PE） measurements, resulting in rovibrationally resolved photoelectron spectra for these polyatomic molecules. These experiments show that the signal- to-noise ratios of the IR-VUV-PI and IR-VUV-PFI-PE spectra obtained by employing the high-resolution IR-OPO laser are significantly higher than those observed in previous IR-VUV-PI and IR-VUV-PFI-PE studies using a low-resolution IR-OPO laser. Further improvement in sensitivity of IR-VUV-PI and IR- VUV-PFI-PE measurements by using the collinear arrangement of IR-VUV lasers and molecular beam is discussed.展开更多
Background: We aimed at determining whether the pathogenic bacteria at the onset of disease are genetically different and whether this affects future choice of the therapeutic methods against group A β-hemolytic stre...Background: We aimed at determining whether the pathogenic bacteria at the onset of disease are genetically different and whether this affects future choice of the therapeutic methods against group A β-hemolytic streptococcal acute pharyngitis/tonsillitis. Methods: A pharynx swab was collected from pediatric patients who visited our hospital. The swab was cultured, and hemolytic streptococcus was detected 230 times. We isolated pathogenic bacteria of patients infected more than once and examined the bacteria using pulse-field gel electrophoresis. Results: Based on gene search results, we found that if the period of developing relapse was within 1 month from the first infection, all patients had the same gene. However, all patients in whom reinfection occurred after 6 months or later had different pertinent genes. Conclusions: The number of relapse/reinfection is significant for this disease, and considerably caution is essential for its treatment. No changes to antibacterial drug administration may be necessary for the second administration unless more than 6 months have passed since the first infection.展开更多
基金supported by the National Natural Science Foundation of China (NSFC)(31100105)the 12th Five-Year Major National Science and Technology Projects of China(No.2012ZX10004219-007)
文摘Objective To optimize the performance of Pulsed-Field Gel Electrophoresis （PFGE） for the comparison of inter-laboratory results and information exchange of Borrelia burgdorferi subtypingo Methods A panel of 34 strains of B. burgdorferi were used to optimize PFGE for subtyping. In order to optimize the electrophoretic parameters （EPs）, all 34 strains of B. burgdorferi were analyzed using four EPs, yielding different Simpson diversity index （D） values and the epidemiological concordance was also evaluated. Results The EP of a switch time of l s to 25 s for13 h and l s to10 s for 6 h produced the highest D value and was declared to be optimal for Mlul and 5mal PFGE of B. burgdorferi. Mlul and Smal were selected as the first and second restriction enzymes for PFGE subtyping of B. burgdorferi according to discrimination and consistency with epidemiological data. Conclusion PFGE can be used as a valuable test for routine genospecies identification of B burgdorferi.
文摘We show that by scanning the frequency of a single mode infrared （IR） optical parametric oscillator （IR- OPO） laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet （VUV） laser to photoionize the IR excited species, high-resolution IR spectra of polyatomic neutrals can be obtained with high sensitivity. The fact that this IR-VUV-photoion （IR-VUV-PI） method is based on VUV photoionization probe, and thus, allows the identification of the neutral IR absorber, makes it applicable for IR spectroscopy measurements of isotopemers, radicals, and clusters, which usually exist as impure samples. The highly resolved IR-VUV-PI measurements achieved using the single mode IR-OPO laser have made possible the selection of single rovibrational states of CH3X （X=Br and I）, C2H4, and C3H4 for VUV-pulsed field ionization-photoelectron （VUV-PFI-PE） measurements, resulting in rovibrationally resolved photoelectron spectra for these polyatomic molecules. These experiments show that the signal- to-noise ratios of the IR-VUV-PI and IR-VUV-PFI-PE spectra obtained by employing the high-resolution IR-OPO laser are significantly higher than those observed in previous IR-VUV-PI and IR-VUV-PFI-PE studies using a low-resolution IR-OPO laser. Further improvement in sensitivity of IR-VUV-PI and IR- VUV-PFI-PE measurements by using the collinear arrangement of IR-VUV lasers and molecular beam is discussed.
文摘Background: We aimed at determining whether the pathogenic bacteria at the onset of disease are genetically different and whether this affects future choice of the therapeutic methods against group A β-hemolytic streptococcal acute pharyngitis/tonsillitis. Methods: A pharynx swab was collected from pediatric patients who visited our hospital. The swab was cultured, and hemolytic streptococcus was detected 230 times. We isolated pathogenic bacteria of patients infected more than once and examined the bacteria using pulse-field gel electrophoresis. Results: Based on gene search results, we found that if the period of developing relapse was within 1 month from the first infection, all patients had the same gene. However, all patients in whom reinfection occurred after 6 months or later had different pertinent genes. Conclusions: The number of relapse/reinfection is significant for this disease, and considerably caution is essential for its treatment. No changes to antibacterial drug administration may be necessary for the second administration unless more than 6 months have passed since the first infection.
