1.Clinical distribution and drug resistance trend of Acinetobacter baumannii and analysis on its drug resistance in comprehensive hospital
Rongfeng YAO ; Juying SHEN ; Guoxiang XU ; Zhendong TAO ; Hui FANG ; Long XU
International Journal of Laboratory Medicine 2017;38(2):194-197
Objective This work was to study the distribution of Acinetobacter baumannii and analyze the change in the trend of its resistance,so as to provide experimental basis for clinical rational drug usage.Methods The identification of isolates were car-ried out by using VITEK-2 compact automatic identification system,and drug susceptibility testing was performed by disc diffusion method,the results were carried out according to the Standard of CLSI 2014 version for interpretation,and data analysis was per-formed with WHONET5.6.Results A total of 981 strains of Acinetobacter baumannii had been isolated from the samples in 2013 to 2015,most of them were isolated from respiratory samples accounted for 80.4%,followed by the urines and other body secre-tion.The distribution of this kind of bacteria mostly was 30.1% in ICU,departments of Emergency observation(16.0%),respirato-ry diseases(15.7%)and senior cadres(10.8%).The drug resistance of this kind of bacteria to polymyxin B and cefoperazone/sul-bactam was to a minimum of lower than 5.0%,and has relatively high sensitivity to amikacin and minocycline(<30.0%).And the resistance to other antimicrobials were higher than 30.0%,and the resistance to Nitrofurantoin and cefotaxime were higher than 94.0%.The most drug resistance of Acinetobacter baumannii in 2014 were lower than those in 2013,but the most drug resistance of Acinetobacter baumannii in 2015 were increased significantly as well as strains had been isolated from the samples.Conclusion The main source for isolation of Acinetobacter baumannii in this hospital mainly comes from sputum specimens of patients in ICU, departments of emergency observation,respiratory diseases and senior cadres.The high prevalence of antimicrobial resistance of this kind of bacteria should be prevented and controlled in nosocomial infection,and rational application of antimicrobial agents in order to reduce the spread of drug-resistant strains.
2.Self-microemulsifying drug delivery system for improving the bioavailability of huperzine A by lymphatic uptake.
Fang LI ; Rongfeng HU ; Bin WANG ; Yun GUI ; Gang CHENG ; Song GAO ; Lei YE ; Jihui TANG
Acta Pharmaceutica Sinica B 2017;7(3):353-360
Huperzine A (Hup-A) is a poorly water-soluble drug with low oral bioavailability. A self-microemulsifying drug delivery system (SMEDDS) was used to enhance the oral bioavailability and lymphatic uptake and transport of Hup-A. A single-pass intestinal perfusion (SPIP) technique and a chylomicron flow-blocking approach were used to study its intestinal absorption, mesenteric lymph node distribution and intestinal lymphatic uptake. The value of the area under the plasma concentration-time curve (AUC) of Hup-A SMEDDS was significantly higher than that of a Hup-A suspension (<0.01). The absorption rate constant () and the apparent permeability coefficient () for Hup-A in different parts of the intestine suggested a passive transport mechanism, and the values ofandof Hup-A SMEDDS in the ileum were much higher than those in other intestinal segments. The determination of Hup-A concentration in mesenteric lymph nodes can be used to explain the intestinal lymphatic absorption of Hup-A SMEDDS. For Hup-A SMEDDS, the values of AUC and maximum plasma concentration () of the blocking model were significantly lower than those of the control model (<0.05). The proportion of lymphatic transport of Hup-A SMEDDS and Hup-A suspension were about 40% and 5%, respectively, suggesting that SMEDDS can significantly improve the intestinal lymphatic uptake and transport of Hup-A.
3.Identification and characterization of a taxol-producing endophytic fungus from Taxus media.
Rongfeng FANG ; Haohao LI ; Peiji ZHANG ; Rang CAO ; Shushen YANG
Chinese Journal of Biotechnology 2017;33(12):1945-1954
To enrich the resource pool of endophytic fungi from plants which produce taxol, a taxol-producing endophytic fungus TMS-26 was isolated from the stem of Taxus Media. The result of high performance liquid chromatography (HPLC) showed that TMS-26 extract exhibited similar chromatographic peaks and retention time (4.545 min) with authentic taxol. Then mass spectrometry (MS) analysis further confirmed that TMS-26 extracts contained the same mass peaks with authentic taxol ((M+Na)+=876). These indicated that the isolated endophytic fungus TMS-26 can produce taxol. According to the morphological characteristics, the molecular analysis of 18S rDNA and internal transcribed spacer nuclear rDNA gene sequence, the fungus was identified as Aspergillus fumigatus TMS-26.